Near Drowning

Near drowning is severe oxygen deprivation (suffocation) caused by submersion in water but not resulting in death; when death occurs, the event is called drowning.

When a person is submerged under water, water enters the lungs. The vocal cords may go into severe spasm, temporarily preventing water from reaching the lungs. When filled with water, the lungs cannot efficiently transfer oxygen to the blood. The decrease in the level of oxygen in the blood that results may lead to brain damage and death. Water in the lungs, particularly water that is contaminated by bacteria, algae, sand, dirt, chemicals, or a person's vomit, can cause lung injury.

Children younger than 4 years are at greatest risk of near drowning because their energy and curiosity can easily lead them to fall into water, including bathtubs and large buckets, from which they cannot escape. In teenagers and adults, near drowning is common in those who are intoxicated, who have taken sedatives, who have had a seizure, or who are physically impaired because of a medical condition. Spinal injuries and paralysis caused by diving accidents, which are likely to occur when diving into shallow water, increase the chances of near drowning. People who intentionally hold their breath under water for extended periods may pass out and be unable to surface, thus increasing the risk of near drowning as well.

Submersion in cold water has both good and bad effects. Cooling of the muscles makes swimming difficult, and dangerously low body temperature (hypothermia) can impair judgment. Cold, however, protects tissues from the ill effects of oxygen deprivation. In addition, cold water may stimulate the mammalian diving reflex, which may prolong survival in cold water. The diving reflex slows the heartbeat and redirects the flow of blood from the hands, feet, and intestine to the heart and brain, thus helping to preserve these vital organs. The diving reflex is more pronounced in children than in adults; thus children have a greater chance of surviving prolonged submersion in cold water than adults.

Symptoms and Diagnosis

People who are drowning and struggling to breathe are usually unable to call for help. Children who are unable to swim may become submerged in less than 1 minute compared with adults, who may struggle longer.

People who are rescued may have symptoms ranging from anxiety to near death. They may be alert, drowsy, or comatose. Some may not be breathing. People who are breathing may gasp for breath or vomit, cough, or wheeze. The skin may appear blue (cyanosis), indicating insufficient oxygen in the blood. In some cases, respiratory problems may not become evident for several hours after near drowning.

A doctor diagnoses near drowning based on the events and the person's symptoms. Measurement of the level of oxygen in the blood and chest x-rays help reveal the extent of lung damage.

Prevention

Swimming pools should be adequately fenced, because they are one of the most common sites of near-drowning accidents. In addition, all doors and gates leading to the pool area should be locked. Children in or near any body of water, including pools and bathtubs, need constant supervision, regardless of whether flotation devices are used. Because a child can drown in only a few inches of water, even water-filled containers, such as buckets or ice chests, can be hazardous.

A person should not engage in swimming or boating when under the influence of alcohol or sedatives. Swimming should be curtailed if a person feels or looks very cold. People who have seizures that are well controlled need not avoid swimming but should be careful near water, whether boating, showering, or bathing.

To decrease the risk of drowning, a person should not swim alone and should swim only in areas patrolled by lifeguards. Ocean swimmers should learn to escape rip currents (strong currents that pull away from the shore) by swimming parallel to the beach rather than by swimming toward the beach. Wearing life jackets when in boats is encouraged for everyone and is required for nonswimmers and for small children, who should also wear a life jacket when playing near bodies of water. Spinal injuries can be prevented by not diving into shallow water.

Treatment

Immediate on-site resuscitation is the key to increasing the chance of survival without brain damage. Attempts should be made to revive the person even when the time under water is prolonged. Artificial respiration and CPR should be provided as necessary (see First Aid: First-Aid Treatment). The neck should be moved as little as possible if there is a chance of spinal injury. Anyone who nearly drowns must be transported to a hospital, by ambulance if possible.

In the hospital, most people need supplemental oxygen, in some cases given with the help of a ventilator. A ventilator can deliver oxygen using high pressures to reinflate collapsed sections of the lungs. If wheezing develops, bronchodilator drugs can help. In some cases, treatment with oxygen in a high-pressure (hyperbaric) chamber may be tried.

If the water was cold, the person may have a dangerously low body temperature (hypothermia) and may need warming (see Cold Injuries: Hypothermia). Spinal injury requires special treatment (see Spinal Cord Disorders: Treatment).

If a person who was submerged has only mild symptoms, discharge home may be possible, but only after several hours of observation in the emergency department. If symptoms persist for a few hours, or if the level of oxygen in the blood is low, the person needs to be admitted to the hospital.

Prognosis

The factors that most influence the chances of survival without permanent brain and lung damage are the duration of submersion, the water temperature (cold water accidents can have a better outcome), the person's age (children are more likely to have a better outcome), and how soon resuscitation begins. People who have consumed alcoholic beverages before submersion are especially likely to die or develop brain or lung damage. Survival is possible after submersion for as long as 40 minutes. Almost all people who are alert and conscious upon their arrival at the hospital recover fully. Many people who need CPR can also recover fully.

Munchausen syndrome by proxy and sudden infant death

Everyone can empathise with the grief of parents who have lost a baby and even more so with the nightmare scenario of being wrongly held responsible for the child's death. It is therefore not surprising that the media showed intense interest in three recent cases in which mothers were accused of murdering their babies.¹ Nothing in this article should be construed as personal opinion on any individual case, but we are concerned that everything we have learnt over the past 40 years about sudden infant death syndrome and the spectrum of child abuse seems to have been forgotten.

Attacks on paediatricians who give evidence in child protection cases^w1 and journalists' use of phrases like "Meadow's discredited theory of Munchausen syndrome by proxy" have left the public and the health professions anxious and bewildered. In this paper we outline the evolving understanding of the relation between unexplained death in infancy and child abuse, draw lessons from recent events, and offer proposals for the future.

History

Caffey described what was undoubtedly child abuse in 1946^w2 but was reluctant to draw the obvious conclusions. Another 16 years passed before Kempe and colleagues published their seminal paper on the battered child syndrome in 1962.^w3 At about the same time, the problem of "cot death" began to attract interest. The phenomenon of unexplained death in previously well babies had been known for centuries and was blamed on overlying, "status thymolymphaticus," witchcraft, and many other causes, including infanticide.

The first major conference on cot death was held in Seattle in 1963, and the possibility that some such deaths might be due to foul play was raised but not pursued.² A second conference in 1969 adopted the term sudden infant death syndrome. The hypothesis that episodes of prolonged apnoeic pauses, possibly of genetic origin, might be the basis for sudden infant death syndrome was investigated by Steinschneider^w4 and many others. This resulted in the widespread adoption of apnoea alarms across the United States and subsequently in the United Kingdom.

Over the next decade doubts emerged about the apnoea hypothesis.² At the Baltimore conference in 1982 Southall et al reported, firstly, that after monitoring almost 10 000 babies they were unable to show any relation between apnoeic pauses and sudden infant death^w5-7 and, secondly, that they had found no case of a second cot death in the same family after following the siblings of over 200 babies who had died from sudden infant death syndrome.^w8

It is now known that sudden infant deaths do not follow a random pattern.^{w9 w10} Substantial relations exist between unexplained death and social background, social chaos, poverty, parental mental illness, prematurity, parental smoking and substance misuse, and pre-existing symptoms of illness in the baby.^w11 The relation with prone sleeping position is still not fully explained, but the United Kingdom's Back to Sleep campaign was associated with a large reduction in incidence.³ However, a completely satisfactory explanation is still elusive in many infant deaths.

Link between child abuse and sudden infant death

The evolving interest in unexplained death and child abuse converged when several families who had apparently lost several babies from sudden infant death syndrome were subsequently found to have murdered their children.^{2 w12} In 1982, Taylor and Emery introduced the concept of gentle battering to describe cases in which suffocation by an object or a hand led to the infant's death.^w13 Several strands of evidence support this. Some parents of babies thought to have died from sudden infant death syndrome have subsequently admitted suffocating their infant. Other unequivocal evidence of physical abuse is sometimes found. The siblings of suspected cases (sometimes including genetically unrelated adopted siblings) are more likely to have died than would occur by chance.

Such scenes have left many paediatricians reluctant to take on child protection cases Credit: CHRIS YOUNG/AP

Southall et al used covert video surveillance to investigate apparent life threatening events and showed that parents do indeed cause suffocation by deliberate airway obstruction. They emphasised that the aim of covert video surveillance was to protect the child rather than to secure convictions.^{4 w14} Covert video surveillance is now an accepted procedure when there is no other way of confirming a diagnosis of suffocation.

Meanwhile, other more subtle forms of abuse were identified.⁵ In 1976, Money and Werlwas described a case of dwarfism caused by starvation in which the parents presented misleading accounts of the child's illness, suggesting an analogy with Munchausen's syndrome.^{w15 w16} The term Munchausen syndrome by proxy received wider publicity when in 1977 Meadow reported a case with deliberate fabrication of bizarre symptoms.⁶ Many manifestations of Munchausen syndrome by proxy are now recognised—for example, intentional poisoning by salt or medicines and fictitious accounts of seizures.⁷

It gradually became clear that parentally induced apnoeic attacks^w17 and cases of deliberate suffocation should be regarded as a form of Munchausen syndrome by proxy. Contrary to the impression created by the recently announced review of 5000 child protection cases, non-accidental suffocation is not a common paediatric diagnosis. A UK-wide survey of Munchausen syndrome by proxy in 1992-4 identified just 128 cases in two years, of which only 32 were related to suffocation.⁸ However, a growing number of case reports suggest that many manifestations of Munchausen syndrome by proxy are underidentified because of lack of professional expertise and public awareness.

The most recent estimate is that around 10% of all otherwise unexplained sudden infant deaths may be caused by deliberate suffocation, though this probably varies over time and between populations.^9-11 Bleeding from the nose and mouth suggests deliberate suffocation,¹¹ and the presence of haemosiderin laden macrophages in the lungs might signify previous episodes of suffocation.^{w18 w19} However, in a single case neither the autopsy findings nor other background information are likely to provide unequivocal evidence.¹²

Recurrent sudden infant death syndrome

Since the Back to Sleep campaign, sudden infant death syndrome has become less common in the United Kingdom and the social class gradient has become steeper. In low risk families, sudden infant death affects just over 1 in 8500 babies. The probability of any two randomly selected low risk babies dying of sudden infant death syndrome is that number squared (about 1 in 73 million), but this does not apply in an individual family that has already had one baby die from sudden infant death syndrome. Chance has no memory, so a low risk family would have a 1 in 8500 risk of a second death.

There is little evidence of familial clustering of sudden infant death syndrome, and more than one unexplained infant death in the same family suggests two other possibilities^w20: homicide or inherited conditions such as metabolic disorders (for example, medium chain acyl coenzyme A dehydrogenase deficiency), cardiac arrhythmias (including prolonged QT syndrome), immune deficits predisposing to infection, and abnormalities of ventilatory control.² These conditions probably account for a small fraction of cases,^w21-23 but their existence and the possibility that some may remain to be discovered add a dimension of uncertainty in any death where autopsy findings are negative or equivocal.

Is Munchausen's the best label?

Only a minority of parents who deliberately harm their children have exhibited features of Munchausen's syndrome themselves,^{13 14} and little is known about the psychopathology underlying the fabrication of illness in older children. It probably differs from that described in parents who induce illness in infants by suffocation or other means. Some parents who induce illness in infants have a personality disorder^w24 or (rarely) a psychotic illness.¹¹ In the postnatal period women have reported a variety of fantasies, obsessions, and anxieties regarding their babies,^{w25 w26} including concerns about their ability to care for the child and worries that they might cause them harm.^w27 An association seems to exist between postnatal depression and sudden infant death.^w28-30

As there is no single psychological profile in Munchausen syndrome by proxy,^{10 w31-34} and the label makes unwarranted assumptions about the parent's mental state and motivation, many UK paediatricians feel that the term should be abandoned. The preferred term is now fabricated and induced illness.¹⁵ Fabricated and induced illness is seen as part of a spectrum of child abuse, and death caused by suffocation is at the severe end of that spectrum. The term keeps the focus on the presenting features of the child who needs to be protected, rather than on the supposed psychopathology of the parent.

Learning the lessons

Recent events have prompted some soul searching about the ways professionals respond to the unexpected death of an infant. We agree with Meadow's comment in his first paper on Munchausen syndrome by proxy: "doctors, although (occasionally) deceived, will rightly continue to believe what most parents say, most of the time."⁶ Stanton and Simpson reported a tragic case in which a mother who clearly loved her baby nevertheless smothered her. They commented on the "difficult cognitive processes involved for a paediatrician to shift from being the parent's ally in attempting to alleviate a child's suffering, to suspecting the parent of being the agent responsible for the child's suffering."^w26 This may explain why some professionals offer conflicting and sometimes improbable explanations for injuries to children, leading to difficulties for the judiciary and increased risks for children.

We need to rethink our approach to cases of unexplained infant death, particularly with families who have had more than one such tragedy. We stress the importance of being alert to inconsistencies in the history, scene of death inquiries,¹⁶ collection of background data,^w35 and an autopsy by a paediatric or forensic pathologist with appropriate training, working to a standard protocol. In future this may sometimes need to include a search for genes that might be associated with conditions predisposing to sudden death. Parents have a right to expect that their baby's tragic unexplained death will be investigated as thoroughly as would be the case for any other citizen.

There are important lessons for the judiciary as well. In a criminal trial the standard of proof is "beyond reasonable doubt." In the United States, a Court of Appeals judgment stated that there might be insufficient evidence in any one child death to prove murder or infanticide, but evidence of repeated incidents was admissible as evidence of non-accidental deaths.^w12 We agree, but at the same time feel that securing a conviction for murder is rarely the priority in cases where evidence rests on epidemiological data, probabilities, and clinical findings whose interpretation is subject to several opinions.^{17 18 w36}

What is the alternative?

We believe that complex child deaths and child protection cases should normally be handled by civil proceedings, following the procedures introduced by the Wolff reforms. There should be a non-adversarial meeting of experts from each of the key agencies and disciplines to share and review all the evidence. More than one opinion should be obtained on difficult issues. The emphasis must be first on assessing and minimising the risk to any other children cared for by the parents and secondly on management of the parents' needs.^{7 14} Although the reasons why parents kill their babies are poorly understood, perhaps many deserve sympathy and treatment rather than imprisonment.

Some cases will nevertheless result in criminal proceedings. Professionals who offer expert evidence must not promote ideas that are unsupported by research but should present the facts as they currently see them. In an adversarial legal system, it is for the lawyers and the judge to make sure that experts explain to them, and to the jury, the limits of knowledge and the extent of uncertainty.

Expert evidence

Professionals expect to be accountable for, and challenged about, the reliability of their research, evidence, and interpretation. Nevertheless, they must be able to undertake their duties without fear of ill informed attacks on their competence and integrity by the media or parental organisations. Orchestrated campaigns intended to discredit expert opinion¹⁹ have made professionals increasingly reluctant to participate in child protection cases. A recent survey undertaken by the Royal College of Paediatrics and Child Health found that 14% of paediatricians have had an official complaint made against them in respect of child protection issues arising in general paediatric practice. The often vexatious and malicious nature of these complaints is illustrated by the fact that although many resulted in unpleasant local or national publicity, only a tiny proportion were upheld.²⁰ Of 87 paediatricians referred to the General Medical Council whose cases have been completed, none was found guilty of serious professional misconduct.

Summary points Recent court cases regarding unexplained infant deaths have raised questions about the diagnosis of Munchausen syndrome by proxy and professional judgment Many paediatricians are now reluctant to take part in child protection cases A non-adversarial approach needs to be introduced to deal with sudden infant deaths The public needs to be better informed of research on sudden infant death and child abuse

Conclusions

We must restore the faith of the public and the professions in the child protection systems that are vital for a civilised society. Munchausen syndrome by proxy has captured the public imagination, but there is still much that we do not know about other aspects of child abuse. For example, questions remain unanswered about subdural bleeding and the interpretation of physical signs in child sexual abuse. We need urgently to review procedures and to fund more research into the causes, mechanisms, and diagnosis of child abuse. And we call on journalists, lawyers, and the judiciary to ensure that they are well informed about the mass of evidence and data gathered over the past 40 years in child protection.
Source: B M J

Angioedema

Angioedema and urticaria should be viewed as varying manifestations of the same pathologic process. Postcapillary venule inflammation results in fluid leakage and edema in both conditions. However, angioedema involves vessels in the layers of the skin below the dermis, while urticaria is localized superficial to the dermis. This results in varying clinical presentations.

The subdermal source of angioedema results in well-demarcated, localized, nonpitting edema. Urticaria is localized to the superficial portion of the dermis and is characterized by well-circumscribed wheals with raised erythematous borders and central blanching. These often coalesce to become giant wheals.

These conditions can occur together or separately. Recurrent episodes of one or both conditions for less than a 6-week duration are considered acute, whereas longer-lasting attacks are considered chronic.

Angioedema, with or without urticaria, is classified as allergic, hereditary, or idiopathic. Complications range from dysphonia or dysphagia to respiratory distress, complete airway obstruction, and death.

Pathophysiology

Angioedema involves vascular leakage beneath the dermis and subcutis. This response is mediated by vasoactive mediators, such as histamine, serotonin, and kinins (eg, bradykinins), which cause the arterioles to dilate while inducing a brief episode of vascular leakage in the venules, where the junction between the endothelial cells appears looser than in the capillaries and arterioles.

Frequency

United States

Approximately 15% of the general population is affected by recurrent idiopathic episodes. The most common kind does not have a discoverable cause.

Mortality/Morbidity

Morbidity and mortality are directly related to the severity of airway obstruction.

Race

No specific racial predilection exists.

Sex

Women tend to have more occurrences than men.

Age

Persons who are predisposed have an increase in frequency of attacks after adolescence, with the peak incidence occurring in the third decade of life.

Clinical

History

• General history
  • Urticarial eruptions usually appear at intervals and are intensely pruritic.
  • Patients with angioedema or urticaria should be questioned in detail to identify the offending antigen (in cases of allergic angioedema).
  • Any family history or history of recurrent episodes with the use of particular agents must be sought.
• Drugs associated with urticaria and angioedema include the following:
  • Radiocontrast agents
  • Opiates
  • Dextran
  • Angiotensin-converting enzyme (ACE) inhibitors
  • Aspirin
  • Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Common sources of antigens that cause urticaria and angioedema include the following:
  • Hymenoptera envenomations
  • Food allergies such as fresh berries, shellfish, fish, nuts, tomatoes, eggs, milk, chocolate, food additives, and preservatives
  • Local trauma (eg, dental procedure, tonsillectomy)
  • Exposure to water, sunlight, cold, or heat
  • Animal dander (from scales of shed skin)
  • Emotional stress
  • Post infection or illness, including autoimmune disorders such as thyroid autoimmunity and leukemia
• Chronic urticaria (increasingly associated with Helicobacter pylori bacteria)

Physical

• General examinations
  • Patients usually present with the acute onset of well-demarcated cutaneous edema of distensible tissues (eg, lips, eyes, earlobes, tongue, uvula).
  • The face, extremities, and genitalia are most commonly affected.
• Airway assessment
  • First, determine airway patency.
  • Severe attacks can herald the onset of systemic anaphylaxis, characterized initially by dyspnea.
• Gastrointestinal (GI): Massive edema of the subcutaneous tissue in the abdominal region may present with abdominal distention and signs consistent with bowel obstruction.

Causes

• Immunoglobulin E (IgE)-mediated angioedema/urticaria may result from antigen ingestion (eg, food, drug) or from parenteral exposure (eg, medications, Hymenoptera).
• Complement-mediated angioedema/urticaria:
  • This angioedema involves immune complex–mediated necrotizing cutaneous venulitis manifested as serum sickness.
  • It is characterized by fever, angioedema, arthralgias, urticaria, and palpable purpura.
• Hereditary angioedema
  • This type of angioedema is characterized by recurrent self-limited attacks involving the skin, subcutaneous tissue, upper respiratory tract, or GI tract. Attacks may last from several hours to 2-3 days.
  • GI or upper respiratory tract attacks may be precipitated by local trauma (eg, dental procedures, tonsillectomy).
• Idiopathic angioedema appears to manifest due to direct mast cell–releasing agents in certain compounds (eg, radiocontrast media, opiates, dextran).
  • Other drugs may precipitate attacks by effects on arachidonic acid metabolism (eg, aspirin, NSAIDs, any compounds that are cyclooxygenase inhibitors).
  • ACE inhibitors precipitate attacks by directly interfering with the degradation of bradykinin, thereby potentiating its biological effect.

Preoperative Testing

Medical consultants are generally asked to assess preoperative risk in most patients who are to undergo surgery. The focus of discussion in this article applies to healthy people who are to undergo an elective surgical procedure.

Despite a low risk of perioperative complications, the use of laboratory tests before surgery became ingrained in clinical practice not only across the United States but also across the world in the latter half of the 20th century. At that time, clinicians thought it logical to order tests to detect abnormalities that might lead to increased morbidity or mortality in the perioperative period. Despite its widespread use, however, systematic evaluations of the clinical effectiveness and cost-effectiveness of routine laboratory testing were often lacking.

In the early and mid 1980s, several investigators published a number of papers demonstrating that routine preoperative testing was not cost-effective and did not benefit the patient. For example, in the mid 1980s, Kaplan and colleagues, in a retrospective review of the charts of 2000 patients who underwent elective surgery, demonstrated that 60% of these patients had laboratory tests ordered for no apparent reason, and that only 0.22% of the abnormal results influenced preoperative management. In another study, Turnbull and colleagues reviewed the charts of 2570 patients undergoing elective surgery, finding that only 104 of 5003 laboratory test results were abnormal and significant, and that only 4 patients would have benefited from "routine" laboratory testing.

To compound the problem, it appears that physicians are poor at evaluating the tests ordered. For example, in a study in which the records of 3782 elective surgery patients were reviewed, only 10 of 160 patients with abnormal test results were treated for such abnormalities. The lack of treatment of identified abnormalities therefore raises the issue of increased legal liability.

In the last 20 years, a progressive challenge to the use of gratuitous routine laboratory testing has developed, especially within the environment of cost-containment and managed care. What, then, should physicians do? A good history and physical examination followed by a review of a patient's chart are undoubtedly the most important routine tests needed.

For example, Narr and colleagues reviewed the charts of 1044 healthy patients who did not undergo any preoperative laboratory testing before their elective surgeries. These patients did not experience any significant perioperative morbidity or mortality. The use of previous laboratory results, performed within 4 months before elective surgery, was supported by a study in which 7549 laboratory results of 1109 patients were reviewed. This study showed that 47% of the laboratory test results duplicated those obtained within 1 year. Of the 3096 normal laboratory test results, only 13 (0.4%) repeated values were abnormal, most of which could have been predicted on the basis of patient history and physical findings.

Furthermore, 5% of healthy people have abnormal test results. This is due to arbitrary cut points that define the range of normal laboratory values to include 2 standard deviations with a 95% confidence interval. For example, the chance that the results of 1 of the 6 tests included in a basic metabolic profile will be abnormal is 26%; hence, the predictive value of the test will be low, especially if the prevalence of the disease is low. For example, based on the Bayes theorem, the positive predictive value of an abnormal hemoglobin test finding is 16.1%, since the prevalence of anemia in healthy individuals is approximately 1%. Accordingly, such abnormal laboratory values, with very low predictive values, may result in further unnecessary workup and delays in surgery.

In a review of studies of routine preoperative testing by Smetana et al (2003), the positive likelihood ratio was modest (>3) for hemoglobin, electrolytes, and renal dysfunction but had a low impact for change on preoperative management. Normal test results did not reduce the likelihood of postoperative complications. In a recent single center study, the incidence of unindicated preoperative screening tests was found to be more than 50%, but it did not add to any benefit to support this persistence of unwarranted testing.

Advancing age, especially older than 70 years, is associated with increased hospital stay and perioperative morbidity and mortality. However, most people in this age group have comorbid conditions, and it remains unclear if complications are secondary to comorbid conditions or age itself.

Contrary to the common belief, obesity does not increase postoperative complications. In a prospective cohort of 6336 patients undergoing general elective surgery, Dindo et al (2003) did not find obesity to be a risk factor for the development of postoperative complications.

For excellent patient education resources, visit eMedicine's Procedures Center. Also, see eMedicine's patient education article Understanding X-rays.

Selective Workup

Laboratory studies:

• CBC count
  • Several studies reported a wide range of hemoglobin abnormality among elective surgery patients, based on different study populations. In healthy individuals undergoing elective surgery, the variation is estimated to be less than 1%. A mild hemoglobin abnormality was not associated with an increase of perioperative morbidity or mortality. Recent guidelines recommend preoperative hemoglobin testing if the history is suggestive of underlying anemia or if a significant blood loss is anticipated during the operation.
  • The prevalence of severe leukopenia or leukocytosis is extremely low and rarely leads to a change in patient management. Similarly, thrombocytopenia is found in fewer than 1% of healthy elective surgery patients; thus, routine preoperative WBC or platelet count is not recommended unless the cost of a CBC count is not substantially higher than that of hemoglobin. The cost of falsely pursuing an abnormal WBC or platelet count may not be substantial, although no studies in that regard are available except for platelets.
• Electrolytes
  • Unanticipated electrolyte abnormality (sodium, potassium, bicarbonate, chloride) ranges from 0.2-8.0% among surgery patients. A recent systemic literature review reported that unsuspected electrolyte abnormality is 1.4% among healthy elective surgery patients.
  • Although hypokalemia is considered a minor risk factor for perioperative cardiac complications based on the Goldman risk index, no study showed a relation between hypokalemia and perioperative morbidity and mortality.
  • Postoperative hyponatremia is common in certain types of surgeries, such as transurethral resection of prostate and neurosurgical procedures; however, it is still unclear how baseline electrolyte abnormality may affect physicians' decisions in postoperative management. Accordingly, electrolyte determination is not routinely recommended for elective surgery in healthy individuals.
• Creatinine
  • The prevalence of elevated creatinine levels in asymptomatic patients ranges from 0.2-2.4% and increases with age. Approximately 9.8% of patients aged 46-60 years have elevated creatinine levels.
  • Patients with mild-to-moderate renal insufficiency are usually asymptomatic but have an increased risk of perioperative morbidity and mortality. Accordingly, testing renal function with serum creatinine level is recommended for all patients older than 40 years, especially if hypotension or use of nephrotoxic medications is anticipated.
• Blood sugar
  • The frequency of abnormal glucose laboratory results in asymptomatic patients ranges from 1.8-5.5%. The frequency increases with age, so that nearly 25% of patients older than 60 years have a fasting blood sugar level above 120 mg/dL.
  • Only in certain operations, such as vascular surgery and coronary artery bypass grafting, was diabetes associated with higher perioperative risks; hence, routine blood sugar determination is not recommended unless the patient has high risk for diabetes (eg, obesity, steroids, strong family history) or will be undergoing vascular or bypass surgery.
• Liver enzymes
  • The frequency of a hepatic aminotransferase enzyme (aspartate aminotransferase [AST], alanine aminotransferase [ALT]) abnormality is estimated to be approximately 0.3%. Although Powell-Jackson and colleagues showed that severe liver test abnormalities may lead to an increase in surgical morbidity and mortality risk, no evidence confirms that mild elevation in liver enzymes is associated with such an increased risk.
  • Because most patients with severe aminotransferase enzyme elevation are likely to be symptomatic, and jaundice may be detected by physical examination, routine preoperative screening is not recommended for healthy individuals.
• Hemostasis
  • In the absence of a history of bleeding diathesis in elective surgery patients, abnormal bleeding time, prothrombin time (PT), and activated partial thromboplastin time (aPTT) results are estimated to be less than 1%.
  • Suchman and colleagues showed that in low-risk patients, per history and physical examination, aPTT does not predict the risk of perioperative bleeding. Similarly, the bleeding time has no predictive value on the incidence of perioperative bleeding in healthy elective surgery patients. Accordingly, PT, aPTT, and bleeding time are not recommended for routine screening.
• Urinalysis
  • The primary rationale for ordering urinalysis (UA) preoperatively is to detect either asymptomatic renal disease or underlying urinary tract infection (UTI). To detect unsuspected renal insufficiency, serum creatinine measurement is recommended for any elective surgery patient older than 40 years, although it is unclear if any correlation exists between asymptomatic UTI and surgical wound infection.
  • One study that included 200 patients undergoing orthopedic procedures showed that physicians addressed only 5 of 27 abnormal urine test results. A further economic analysis showed that in order to prevent a single wound infection, approximately $1.5 million must be spent on UA; therefore, UA is not recommended routinely for asymptomatic patients.
• Fecal occult blood
  • The prevalence of positive fecal occult blood findings among healthy individuals undergoing elective surgery is unknown. In addition, the benefits of routine screening are unclear.
  • A decision-analysis study showed no benefit of routine screening; therefore, insufficient evidence exists to support routine screening for fecal occult blood.

Imaging studies:

• ECG
  • The prevalence of abnormal ECG findings among healthy elective surgery patients ranges from 14-53% and increases with age in a continuous fashion.
  • The rationale for obtaining ECG preoperatively is to identify high-risk patients with prior myocardial infarction or arrhythmia. Detecting a silent myocardial infarction is of main clinical benefit because numerous investigators showed an association between preoperative myocardial infarction and surgical mortality. One study showed that 25% of 708 myocardial infarctions in the Framingham study were detected by ECG. In addition, any rhythm other than sinus, including frequent premature ventricular contraction, is associated with an increase in surgical risk. Accordingly, routine ECG is recommended for all patients older than 40 years undergoing elective surgery.
  • In a recent retrospective study of 23,036 patients who underwent 28,457 surgical procedures, multivariate logistic regression was used to evaluate the relationship between ECG abnormalities and cardiovascular death. A total of 199 in-hospital cardiovascular deaths (0.7%) occurred. A higher incidence of cardiovascular death was observed in patients with an abnormal ECG than in those with normal ECG results (1.8% vs 0.3%; adjusted odds ratio 4.5, 95% confidence interval 3.3-6.0). However, there was no significant difference (0.5%) in the incidence of cardiovascular death in patients, with or without ECG abnormality, who underwent low-risk or low- to intermediate-risk surgery.
  • Noordzij et al (2006) concluded that preoperative ECG provides prognostic information in addition to clinical characteristics and the type of surgery. However, the usefulness of routine ECG testing in lower risk surgery is questionable.
• Chest radiograph
  • The frequency of abnormal chest radiograph (CXR) findings increases with age. One study showed that 0.3% of patients younger than 60 years had unsuspected abnormal CXR results or clinical findings suggestive of underlying cardiac or pulmonary disease compared to 22% of patients older than 60 years.
  • In addition, Goldman reported that CXR in patients with congestive heart failure does not independently add to the risk of perioperative mortality and morbidity. A meta-analysis of 21 studies that included 14,390 routine CXR showed that only 140 of 1444 abnormal results were not clinically expected and that only 14 affected physicians' decisions in managing their patients. Accordingly, routine CXR is recommended only for patients older than 60 years unless underlying heart or lung disease is a possibility.

Summary

Routine preoperative screening of healthy people undergoing elective surgery is not recommended. Instead, a selective strategy, as outlined above, is safe and cost-effective as long as a complete history and physical examination are obtained. Based on the available evidence, the authors recommend the following preoperative tests:

1. Hemoglobin level for major surgery with significant expected blood loss or CBC count if the cost is not substantially increased
2. Serum creatinine level for people older than 40 years
3. ECG in patients older than 40 years
4. CXR in patients older than 60 years

No laboratory test must be repeated if results were normal within 4 months of the surgery and no change in the patient's clinical status occurred. Finally, this strategy applies only to healthy, asymptomatic patients undergoing elective surgery. Patients with suspected pulmonary or cardiac disease or those undergoing urgent operation require additional evaluation that is beyond the scope of this article.

Burns, Thermal Injuries

Initial evaluation and management of small and moderate burns is a routine part of general plastic surgery practice. An ability to accurately evaluate and provide proper initial care for these injuries is essential.

Outcomes for patients with burns have improved dramatically over the past 20 years, but burns still cause substantial morbidity and mortality.¹ Proper evaluation and management, coupled with appropriate early specialty referral, greatly help in minimizing suffering and optimizing results.²

For excellent patient education resources, visit eMedicine's Burns Center. Also, see eMedicine's patient education article Thermal (Heat or Fire) Burns.

Evaluation of the Burn Patient

Before management of the burn wound can begin, properly and completely evaluate the burn patient. Often this is a brief effort, particularly in patients with small, uncomplicated wounds. In those with larger burns, evaluation of the wound often is of secondary importance. As described by the American College of Surgeons Committee on Trauma, evaluation of the burn patient is organized into a primary and secondary survey.

Primary survey

Burn patients should be systematically evaluated using the methodology of the American College of Surgeons Advanced Trauma Life Support Course. This evaluation is described by the primary survey, with its emphasis on support of the airway, gas exchange, and circulatory stability. First evaluate the airway; this is an area of particular importance in burn patients. Early recognition of impending airway compromise, followed by prompt intubation, can be life saving. Obtain appropriate vascular access and place monitoring devices, then complete a systematic trauma survey, including indicated radiographs and laboratory studies.

Secondary survey

Burn patients should then undergo a burn-specific secondary survey, which should include determination of the mechanism of injury, evaluation for the presence or absence of inhalation injury and carbon monoxide intoxication, examination for corneal burns, consideration of the possibility of abuse, and a detailed assessment of the burn wound. (Click here to complete a Medscape CME activity on carbon monoxide screening.)

A detailed history must be elicited upon first evaluation and transmitted with the patient to the next level of care. Inhalation injury is diagnosed by a history of a closed-space exposure and soot in the nares and mouth. Carbon monoxide intoxication is suspected in those injured in structural fires, particularly if they are obtunded; carboxyhemoglobin levels can be misleading in those ventilated with oxygen. Those with facial burns should undergo a careful examination of the cornea prior to the development of lid swelling that can compromise examination. After evaluation of the burn wound, begin fluid resuscitation and make decisions concerning outpatient or inpatient management or transfer to a burn center (see Image 1).

Evaluation of the Burn Wound

After the patient has been fully evaluated and stable hemodynamics and gas exchange ensured, evaluate the burn wound in detail. Evaluate burn wounds initially for extent, depth, and circumferential components. Decisions regarding type of monitoring, wound care, hospitalization, or transfer are made based on this information.

Extent of burn

An accurate estimate of burn size is important for treatment and transfer decisions. Burn size or extent can be estimated in numerous ways. Perhaps most accurate is the age-specific chart based on the Lund-Browder diagram that compensates for the changes in body proportions with growth (see Image 2). A burn is drawn on a cartoon figure and an associated age-specific table is used to calculate the body surface area involved.

An alternative in adults is the Rule of Nines. This is less accurate in children because their body proportions are different than those of adults. For areas of irregular or nonconfluent area burns, the palmar surface of the patient's hand can be used. For a wide age range, the area of the palm without the fingers represents 0.5% of the body surface.

Burn depth

Burns are routinely underestimated in depth on initial examination. Devitalized tissue may appear viable for some time after injury, and often, some degree of progressive microvascular thrombosis around the periphery of wounds is seen. Consequently, the wound appearance changes over the days following injury. Serial examination of burn wounds can be very useful.

Burn depth is classified as first, second, third, or fourth degree.

1. First-degree burns usually are red, dry, and painful. Burns initially termed first degree often are actually superficial second degree, sloughing the next day.
2. Second-degree burns often are red, wet, and very painful. Their depth, ability to heal, and propensity to form hypertrophic scars varies enormously (see Image 3).
3. Third-degree burns generally are leathery in consistency, dry, insensate, and waxy. These wounds will not heal, except by contraction and limited epithelial migration with resulting hypertrophic and unstable cover (see Image 4). Burn blisters (see Image 5) can overlie both second-degree and third-degree burns. The management of burn blisters remains controversial, yet intact blisters help greatly with pain control. Debride blisters if infection occurs.
4. Fourth-degree burns involve underlying subcutaneous tissue, tendon, or bone. Accurately determining burn depth on early examination is usually very difficult, even for an experienced examiner. As a general rule, burn depth is underestimated on initial examination.

Please also see eMedicine article Burns, Thermal for further information on the depth of burn injury and its effect on the skin.

Note circumferential, or near circumferential, burn wounds because they may cause progressive extremity ischemia or interfere with ventilation as burn wound swelling increases. In such situations, timely escharotomy is essential. Perform extremity escharotomies as soon as peripheral perfusion is threatened. Do not wait until the extremity is overtly ischemic. Perform torso escharotomies as soon as ventilation appears compromised.

Burn Wound Infection

An ability to make the diagnosis of burn wound infection is important. A clinically focused set of burn wound infection definitions recently has been published (see Image 6). Two of these, burn wound cellulitis and invasive burn wound infection, are seen with some regularity by clinicians outside a burn center environment.

Burn wound cellulitis (see Image 7) usually manifests as progressive erythema, swelling, and pain in the uninjured skin around a wound. Usually, this is seen in the first few days after burning and typically is caused by Streptococcus pyogenes. Infection can progress rapidly but is generally sensitive to penicillin. Excision of associated deep eschar can be essential to the successful treatment of cellulitis. Elevation to reduce edema is an important adjunct.

Invasive burn wound infection (see Image 8) is a rapid proliferation of bacteria in burn eschar that proceeds to invade underlying viable tissues. A change in color, new drainage, and, occasionally, a foul or sickly sweet odor are clinical findings. Pseudomonas and other gram-negative species are common causes. This infection can be life-threatening and usually requires combined treatment with surgery and antibiotics.

Fever and systemic toxicity commonly accompany both infections. Inspect burn wounds frequently to identify infection early. This is an important consideration in outpatient burn care. Someone must inspect the wounds managed in the outpatient environment to promptly detect infections. Errors in initial depth assessment are routine. Infections occur and must be treated in a timely way. A wound-monitoring plan is an essential part of burn care.

Burn Wound Management

Most burns are small; patients with small burns are appropriately managed as outpatients if their burns do not involve critical areas such as the face, hands, genitals, or feet. The outpatient setting is the primary focus of this section. Outpatient burn management can be taxing and, when poorly performed, can cause unnecessary suffering and compromise long-term results. In some situations, coordinating outpatient management with the burn unit's team of doctors, nurses, and therapists is helpful, as their expertise may facilitate attaining optimal outpatient results; however, most small burns are well managed by community based providers with burn center consultation as needed.

Selection for outpatient care

Several factors are relevant to a decision regarding the location of burn care. The patient's airway must not be potentially compromised. The wound must be small enough so that fluid resuscitation is unnecessary (this generally precludes outpatient care of burns over 10-15% of body surface). Patient must be able to take in adequate fluid orally. Typically, serious burns of the face, ears, hands, genitals, or feet should be initially managed on an inpatient basis.

The patient and his or her family must be able to support an outpatient care plan. A child managed as an outpatient must have an adult caregiver available. A family member or visiting nurse must be available who can perform the necessary wound cleansing, inspection, and dressing applications, as most patients cannot do this themselves. Family must have adequate transportation to return for clinic visits and unexpected emergency visits. If abuse is suspected, outpatient management is contraindicated. Finally, if, on initial examination, surgery is clearly needed for a full-thickness wound area, the patient should be admitted for surgery promptly. Despite all of these qualifications, most patients with smaller burns can be successfully managed as outpatients.

Outpatient wound care strategies

Components of outpatient burn care include the following:

• Patient and family education
• Wound cleansing
• Choice of topical or membrane dressing
• Pain control
• Early return instructions
• Follow-up clinic visits
• Long-term follow-up care

Wound cleansing and dressing techniques must be taught to the person who changes the dressings. Documenting this teaching is ideal.

Which of many medications or membranes to place on burn wounds remains unclear, but certain basic principles apply to all situations. Gently clean the wound of debris and exudate on a regular basis. This usually requires daily removal of accumulated exudate and topical medications. Small superficial burns managed in this setting present a low risk of infection, thus a clean rather than sterile technique is reasonable. Patients may clean the burn with lukewarm tap water and mild soap.

Soaking dressings in lukewarm tap water may decrease the pain associated with their removal. Gently cleanse the wound with a gauze or clean washcloth, inspect for signs of infection, pat dry with a clean towel, and re-dress the patient. To manage infections promptly, it is important to teach the patient and family to return promptly if they notice erythema, swelling, increased tenderness, odor, or drainage. Frequency of wound cleansing and dressing change is debated, but most small burns are managed adequately with daily cleansing and dressing.

Wound dressing, whether one is using topical medication or a wound membrane, should provide 4 benefits: (1) prevention of wound desiccation, (2) control of pain, (3) reduction of wound colonization and infection, and (4) prevention of added trauma to the wound. Most topicals in outpatient use have a viscous carrier that prevents wound desiccation and a broader antibacterial spectrum that reduces wound colonization. Addition of a gauze wrap minimizes soiling of both clothing and unburned skin and protects the wound from the external environment. A large number of excellent agents are available.

Superficial facial burns are commonly treated with a clear, viscous antibacterial ointment. Wounds around the eyes can be treated with heavy topical ophthalmic antibiotic ointments. For more information, see eMedicine article Burns, Ocular. Treat deep burns of the external ear with mafenide acetate, as it penetrates the eschar and prevents purulent infection of the cartilage. Appropriate wound care strategies address these principles.

Control of pain in the outpatient setting can be difficult, and if pain and anxiety cannot be adequately managed at home, then hospitalization is appropriate. In most patients, an oral narcotic medication administered 30-60 minutes prior to a planned dressing change provides adequate pain control. As most dressings are occlusive, pain control between dressing changes tends to be managed adequately without narcotics in most patients.

Elaborate specific conditions mandating an early return. Particularly important are (1) pain and anxiety associated with wound care to the degree that wound care is compromised, (2) signs of infection, or (3) a wound that appears deeper than appreciated at initial examination. Review wound care instructions with caregivers.

Inpatient management

The plan of management of patients with large burns that require inpatient care usually is determined by the physiology of burn injury. Management strategies for these patients are beyond the scope of this article but generally require a coordinated approach that involves a specialized team. Hospitalization is divided into 4 general phases: (1) initial evaluation and resuscitation, (2) initial wound excision and biologic closure, (3) definitive wound closure, and (4) rehabilitation and reconstruction.

Medications and Membranes

The choice of which medication or membrane to place on a wound is a neverending source of discussion and argument. Fortunately, most medications and membranes perform well if physicians carefully monitor wounds, keep them clean, prevent desiccation, and properly manage secondary infection.

A wide range of topical medications is available, including simple petrolatum, various antibiotic-containing ointments and aqueous solutions, and debriding enzymes. Some of the available topical medications and their characteristics are listed in Image 9. All of them can be effectively employed when properly used by experienced providers in a program of burn care that includes wound evaluation, regular cleansing, and monitoring.

Wound membranes are different from medications and dressings in that they provide transient physiologic wound closure. This implies a degree of protection from mechanical trauma, vapor transmission characteristics similar to skin, and a physical barrier to bacteria. These membranes facilitate a moist wound environment with low bacterial density. They are commonly placed on clean superficial wounds while awaiting epithelialization. These membranes are mostly occlusive; therefore, they must be used with caution if wounds are not clearly clean and superficial. If an occlusive membrane is placed over devitalized tissue, submembrane purulence can occur with subsequent local and systemic sepsis. A large number of these membranes are available (see Image 9).

Wounds in Special Areas

Face, ears, hands, genitals, and feet have functional and cosmetic significance that far exceeds their size and physiologic importance. The surface area involved is such that burn sepsis from these sources rarely is life-threatening, and a studied approach to these wounds usually is possible.

Face

Especially in adolescents and adults, the deep sweat and sebaceous glands of the central face make it likely that most second-degree burns will heal well with adequate topical wound care. Many reasonable management options are available, including topical silver sulfadiazine or bland antibiotic ointments. Burns around the eyes can be dressed with topical ophthalmic antibiotic ointments. If grafting is a possibility, reserve thick donor skin with optimal color match for facial resurfacing. Often, the "blush" areas, such as the upper back and shoulders, make good facial donor sites.

The most important point of early management of deeply burned ears is prevention of auricular chondritis. This is a serious complication in which the cartilage becomes infected and quickly liquefies. Twice daily cleansing and application of topical mafenide acetate, which penetrates the eschar, can minimize the condition. Subsequent management of the ear is based on depth of injury.

Deep corneal burns are obvious on physical examination. The cornea has a clouded appearance. More subtle injuries can be detected only with topical fluorescein application. After facial edema resolves, lid retraction may occur with variable degrees of exposure of the globe or ectropion. When this is relatively mild, no intervention is required beyond ocular lubricants. Should keratitis occur, early lid release is advised.

Hand burns

Hand burns assume a high priority from the onset of care. During the first 24-48 hours, adequate blood flow must be ensured. Regularly monitor consistency, temperature, and the presence of pulsatile flow detectable by Doppler in the digital pulp. If blood flow is questionable, perform escharotomy or fasciotomy.

Splint hands in a position of function: the metatarsophalangeal joints at 70-90 º, interphalangeal joints in extension, first web space open, and wrist at 20 º of extension. Elevate hands to minimize edema and have the patient perform range-of-motion exercises with a therapist twice daily. Deep dermal and full-thickness burns should undergo early excision and sheet autograft closure. Perform hand therapy throughout the healing period, halting only in the few days immediately after grafting. If this is not done, suboptimal long-term function results (see Image 10).

Conclusions

After making a careful initial evaluation, refer patients with complex, deeper, or larger wounds for specialty care. In others, application of basic principles of management combined with regular monitoring constitutes adequate therapy and leads to routinely good results.

Multimedia

(Enlarge Image)

Media file 1: American Burn Association has developed a set of criteria for burn center transfer. These have been adopted by most emergency medical services.

[ CLOSE WINDOW ]

American Burn Association has developed a set of criteria for burn center transfer. These have been adopted by most emergency medical services.

(Enlarge Image)

Media file 2: Burn size is best estimated using a chart that corrects for changes in body proportion with aging.

[ CLOSE WINDOW ]

Burn size is best estimated using a chart that corrects for changes in body proportion with aging.

(Enlarge Image)

Media file 3: Second-degree burns often are red, wet, and very painful. Their depth, ability to heal, and tendency to result in hypertrophic scar formation vary enormously.

[ CLOSE WINDOW ]

Second-degree burns often are red, wet, and very painful. Their depth, ability to heal, and tendency to result in hypertrophic scar formation vary enormously.

(Enlarge Image)

Media file 4: Third-degree burns usually are leathery in consistency, dry, and insensate. These wounds will not heal.

[ CLOSE WINDOW ]

Third-degree burns usually are leathery in consistency, dry, and insensate. These wounds will not heal.

(Enlarge Image)

Media file 5: Management of burn blisters is controversial. Burn blisters occasionally obscure the presence of full-thickness wounds.

[ CLOSE WINDOW ]

Management of burn blisters is controversial. Burn blisters occasionally obscure the presence of full-thickness wounds.

(Enlarge Image)

Media file 6: This clinically focused definition set describes burn wound infections.

[ CLOSE WINDOW ]

This clinically focused definition set describes burn wound infections.

(Enlarge Image)

Media file 7: Burn wound cellulitis presents with increasing erythema, swelling, and pain in uninjured skin around the periphery of a wound.

[ CLOSE WINDOW ]

Burn wound cellulitis presents with increasing erythema, swelling, and pain in uninjured skin around the periphery of a wound.

(Enlarge Image)

Media file 8: Invasive burn wound infection implies that bacteria or fungi are proliferating in eschar and invading underlying viable tissues. These wounds display a change in color, new drainage, and often a foul odor. These infections are life-threatening.

[ CLOSE WINDOW ]

Invasive burn wound infection implies that bacteria or fungi are proliferating in eschar and invading underlying viable tissues. These wounds display a change in color, new drainage, and often a foul odor. These infections are life-threatening.

(Enlarge Image)

Media file 9: Numerous topical medications and membranes have a place in burn care.

[ CLOSE WINDOW ]

Numerous topical medications and membranes have a place in burn care.

(Enlarge Image)

Media file 10: If hand positioning and therapy are ignored while overlying burns heal, poor long-term function may result.

[ CLOSE WINDOW ]

If hand positioning and therapy are ignored while overlying burns heal, poor long-term function may result.

(Enlarge Image)

Media file 11:

[ CLOSE WINDOW ]

(Enlarge Image)

Media file 12:

[ CLOSE WINDOW ]

(Enlarge Image)