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Biomedical subjects

D M Heimbach

Publications and source records attributed to D M Heimbach.

At least 37 records · Page 2Linked to original sources

Outcome and treatment of electrical injury with immediate median and ulnar nerve palsy at the wrist: a retrospective review and a survey of members of the American Burn Association.

Electrical injury to the upper extremity with immediate median and ulnar nerve palsy at the wrist is uncommon but devastating. When it does occur, the immediate clinical questions are (1) will the nerves recover, and (2) should the carpal tunnel and Guyon's canal be released? Our review of the literature did not answer these two questions. Therefore, we reviewed our experience with such patients and surveyed approximately 10% of the physician members of the American Burn Association. We reviewed approximately 80 patients with electrical injuries treated between January 1983 and September 1988, and found 5 patients (8 extremities) who did not require amputation and who manifested immediate palsy of the median and ulnar nerves at the wrist. The questionnaire was returned by 83% of those contacted. We concluded that such nerve palsies can recover to a significant degree and that a majority of surgeons would release the carpal tunnel and Guyon's canal, expecting improved recovery. Although it is still not proven whether decompression is beneficial, we will continue to decompress the carpal tunnel and Guyon's canal in such circumstances.

Adult↗

Neurologic consequences of electrical burns.

Permanent neurologic damage following major electric injury is a dreaded and often discussed complication. The incidence, severity, and sequelae are not clear from the literature. Therefore we reviewed the charts of 90 consecutive patients admitted to the University of Washington Burn Center between 1980 and 1986 looking at neurologic consequences. Electric injuries accounted for 4% of 2,305 admissions. The mean age was 31 +/- 13 years, total body surface area involved (TBSA), 6 +/- 11%, and length of stay, 13 +/- 20 days. There were 82 males and eight females. There were four deaths, for a mortality rate of 4%. Fourteen patients had 18 amputations. Twenty-two patients sustained low-voltage injury; 50% had immediate neurologic symptoms which resolved in nine of 11 patients. Eleven patients (50%) were asymptomatic. Sixty-four patients sustained high-voltage injury and 33% were asymptomatic. Forty-three patients (67%) had immediate central and/or peripheral neurologic symptoms. Loss of consciousness accounted for the largest fraction of CNS sequelae in the high-voltage group (45%). Twenty-three patients (79%) recovered consciousness before arrival at the hospital. Six patients remained comatose, three died, and three awoke but had neurologic sequelae. Twenty-two patients in the high-voltage group had one or more acute peripheral neuropathies. Sixty-four per cent of these neuropathies resolved or improved. Five patients had transient initial paralysis, but there were no delayed spinal cord symptoms. Eleven patients developed one or more delayed peripheral neuropathies. Half of these delayed neuropathies resolved or improved.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

Effect of thermal injury on the pharmacokinetics and pharmacodynamics of atracurium in humans.

Thermal injury causes resistance to many nondepolarizing muscle relaxants including d-tubocurarine, metocurine, pancuronium, and atracurium. To evaluate the role of pharmacokinetics and pharmacodynamics in this phenomenon, the disposition and effect of atracurium (0.5 mg/kg iv) were studied in thermally injured patients (5 males, 16-43 yr) in comparison with that in nonburned control patients (3 males, 1 female, 24-53 yr). The decline of plasma atracurium concentration with time was biexponential in both groups of patients. There were no significant differences in the mean value of any pharmacokinetic parameter (clearance, V1, V beta, alpha and beta half-lives). The time course of effect was also similar, although the maximum twitch depression was significantly smaller (66.1% vs. 100% maximal twitch depression) and time to recover to 50% of maximal twitch depression was significantly shorter (14.2 vs. 52 min) in thermally injured patients. Patients with thermal injury had an EC50 (plasma concentration of atracurium required for 50% of the maximum possible response) 3.4 times that of control patients. Plasma-free fraction of atracurium in the thermally injured patients was 75% that in controls, and free EC50 (the product of free fraction and EC50) of the thermally injured group was 2.7 times that of controls. The results of this study confirm a pharmacodynamic mechanism for the majority of resistance to atracurium, with a diminished free fraction in plasma also contributing to this effect.

Adolescent↗

The "sponge deformity" after tangential excision and grafting of burns.

Sequential excision and grafting of burns have resulted in several new problems. We have termed one of these the "sponge deformity," i.e., a grafted area where, in multiple small areas, the bed heals underneath the graft with or without slough of the overlying graft. If the graft sloughs, a pockmark forms. If the graft does not slough, an overlying bridge forms. In our experience, this deformity is very troublesome to patients because it is difficult to wash, catches on objects, bleeds, and looks quite unsightly. Between February of 1981 and June of 1986, we treated 16 patients with this deformity. All 16 patients were treated by simple excision of the bridges and pockmark edges with a curved iris scissors. In all patients, the wounds healed well and the resultant surfaces were considerably smoother. This retrospective review of the patients suggests that the deformity usually occurs around the periphery of the excised area where the excision was shallower and when thicker grafts are used. Perhaps the bed underneath the graft epithelializes from residual epithelial elements prior to vascularization of the autograft. If this is true, it might be possible to prevent the deformity by excising the wound deeper, by applying thinner grafts, or by applying allograft or xenograft, expecting that the area will heal promptly and not require autografting.

Adolescent↗

Toxic epidermal necrolysis. A comprehensive approach. Multidisciplinary management in a burn center.

Toxic Epidermal Necrolysis (TEN) is a life-threatening disorder with reported mortality rates of 25-60 percent in pediatric patients. The authors report on their experience in managing six children using a standardized treatment protocol in the intensive care unit of a regional burn center. Areas of sloughed skin were covered with porcine xenograft (pig skin) until reepithelialization was complete. There was one death in the series, and one child had ophthalmologic complications. Treatment in a multidisciplinary burn center is recommended for children with TEN.

Burn Units↗

Candida. A decreasing problem for the burned patient?

Multiple recent reports have suggested that Candida wound infection and sepsis are major complications of severe burn injury. Our current burn treatment plans include aggressive early burn excision and grafting, avoidance of invasive monitoring and central hyperalimentation lines, enteral nystatin, and judicious use of antibiotics. A retrospective review of 168 severely burned patients admitted to the Intensive Care Unit of the University of Washington Burn Center, Seattle, during the 18-month period from June 1984 through December 1985 was undertaken. Thirteen percent of these patients had one or more cultures positive for Candida from any site. Three patients (1.8%) developed Candida sepsis, which was diagnosed on the basis of clinical signs of sepsis, a positive blood culture for Candida, and at least two additional culture sites positive for Candida. All three patients were treated with amphotericin B. One of these patients died of Candida sepsis, for an overall mortality of 0.6%. Therefore, Candida septicemia was not a major cause of morbidity or mortality in our burn patients in the Intensive Care Unit during this 18-month period under the current management regimen.

Adult↗

Inhalation injuries.

Inhalation injuries occur in approximately one-third of all major burns and account for a significant number of deaths in those burn patients each year. Victims die as a result of carbon monoxide poisoning, hypoxia, and smoke inhalation. These deaths can occur without thermal wounds as well as with burn injuries. There are three distinct problems with inhalation injuries: thermal burns of the upper airway, carbon monoxide poisoning, and smoke inhalation. Each has different symptoms and signs, different treatment, and different prognosis. Thermal burns occurring in the upper airway are usually manifested within 48 hours of injury. Diagnosis is made by direct visualization of the upper airway, looking for signs of thermal injury. Admission for observation with humidified oxygen, attentive pulmonary toilet, bronchodilators as needed, and prophylactic endotracheal intubation as indicated are the mainstays of treatment. Resolution of the injury usually occurs within days. Carbon monoxide poisoning, the most common cause of death in inhalation injury, is a result of combustion. Symptoms and signs correlate with blood levels, but arterial blood gases are used to determine the degree of carbon monoxide intoxication. Treatment is based on the principle that carbon monoxide dissociation occurs much faster if the patient is placed on 100% oxygen. Occasionally the patient's symptoms may persist or get worse despite adequate treatment. Smoke inhalation significantly damages normal respiratory physiology, resulting in injury progressing from acute pulmonary insufficiency to pulmonary edema to bronchopneumonia, depending on the severity of exposure. Diagnosis is based on history, but clinical findings, arterial blood gases, and fiberoptic bronchoscopy are helpful. Treatment is supportive with careful attention paid to fluid resuscitation in the patient with burns.(ABSTRACT TRUNCATED AT 250 WORDS)

Burns, Inhalation↗

Cardiopulmonary responses after spontaneous inhalation of Douglas fir smoke in goats.

In the majority of clinical cases, smoke inhalation results in a self-limited lung injury mostly confined to the airways. In this study, an animal model of inhalation injury was developed that reflected similar pathophysiology. Cardiopulmonary parameters were studied in awake, instrumented goats following spontaneous inhalation of characterized Douglas fir smoke. Peak carboxyhemoglobin levels averaged 37% during a mean exposure time of 33 minutes. All animals survived the 24-hour study period, and showed only transient abnormalities in lung fluid balance and gas exchange, with no change in lung mechanics or plasma eicosanoid (TxB2 and 6-keto-PGF1 alpha) levels. However, extravascular lung water at 24 hours was increased 33%, suggesting the presence of some airway edema and retained secretions. We feel this model fairly represents the majority of clinical smoke inhalation cases. This model is compared to other large animal inhalation injury models producing more severe lung injury.

6-Ketoprostaglandin F1 alpha↗

A comparison of intramarginal and extramarginal excision of hypertrophic burn scars.

Hypertrophic scarring is common in burn patients. The treatment of such scarring is difficult, and recurrence of the hypertrophic changes after scar revision is not uncommon. It has been suggested that intramarginal excision diminishes the chances of recurrent hypertrophic scarring, but we could not find any papers in the literature actually comparing intramarginal and extramarginal excisions. We therefore reviewed our experience with intramarginal and extramarginal excision of hypertrophic scars. Between October 30, 1979, and March 26, 1986, we excised 50 hypertrophic scars in 23 burn patients. Thirty-one (62 percent) of the excisions were intramarginal and 19 (38 percent) were extramarginal. We compared the results and observed that the intramarginal excisions yielded better results than the extramarginal excisions.

Adolescent↗

Toxic epidermal necrolysis. A step forward in treatment.

Toxic epidermal necrolysis is an uncommon but severe form of epidermal sloughing with associated mucositis. Treated in a general hospital, it carries a high mortality (25% to 70%) and substantial long-term morbidity. If the patient is referred early to a burn center, where it can be treated with biologic dressings and intensive support care, the mortality can be reduced below 20% and there may be negligible long-term morbidity. We describe 19 patients so treated, with three deaths and no long-term complications.

Adolescent↗

Clostridium difficile diarrhea in critically ill burned patients.

We followed up 112 patients in the University of Washington Burn Center, Seattle, for the development of Clostridium difficile diarrhea. Diarrhea developed in 20 patients with a mean burn size of 42%, mean age of 38 years, and 49 mean total antibiotic days, for an incidence of 17%. Eleven patients had 16 episodes of nonspecific diarrhea. Nine patients had 11 episodes of C difficile-positive diarrhea and 15 episodes of nonspecific diarrhea for an incidence of 45% of all patients with diarrhea. There were no differences in patient age, burn size, or length of stay between the groups. When the 31 episodes of nonspecific diarrhea were compared with the 11 episodes of C difficile diarrhea, there were no differences between the groups in temperature, albumin levels, or total number of antibiotic days preceding the episodes of diarrhea. The only significant finding that differed between the two types of diarrhea was the white blood cell count on the day of diagnosis. The nonspecific diarrhea was self-limited, requiring antimotility agents in 45% of the episodes. The C difficile diarrhea responded promptly to vancomycin hydrochloride, with resolution of symptoms in an average of 3.3 days. There were two recurrences, and both responded to a second course of vancomycin.

Adolescent↗

Early burn excision and grafting.

The current state of knowledge and experience with early burn wound closure leads to some conclusions that are proved and others that are suggested. The issues that are proved include the following: Small (less than 20 per cent TBSA) full-thickness burns and indeterminate (deep partial-thickness versus full-thickness) burns, if treated by an experienced surgeon, can be excised safely and grafted with a decrease in hospital stay, cost to the patient, and time away from work or school. Early excision and grafting dramatically decreases the number of painful ward debridements required by all patients. Patients with burns between 20 and 40 per cent TBSA appear to have fewer infectious wound complications and a shortened hospital stay if treated with early excision and grafting. In addition to the above conclusions, about which there is little disagreement, there are other suggestive data and clinical impressions that do not yet have "hard data" to support them. These issues include the following: Scarring is less in wounds closed early, leading to better appearance and the need for fewer reconstructive procedures. There presently is not a good measure of "cosmetic appearance," and comparative studies await an acceptable scale to measure results. Mortality from wound infection is less in patients with major burns. Because wounds exceeding the donor sites cannot be closed permanently and completely until donor sites can be reharvested, proof will come only when a durable permanent cover can be applied in a timely fashion. Data now suggest that mortality has decreased, but none of the studies has been conclusive. Mortality from other complications of major burns may decrease with early excision and grafting. Decreasing stress, hypermetabolism, and decreasing the overall bacterial load of such patients enables them to resist other complications better. The only present data supporting this conclusion, however, come from animal studies. The current state of the art suggests that small, deep burns can be excised and grafted by general or plastic surgeons in community hospitals as long as they are interested in the procedure and the hospital has the proper support facilities. Burns of cosmetically or functionally important areas (face, hands, feet, and joints) should be excised by someone with a special interest in burns, and burns in excess of 10 per cent TBSA should be excised only in facilities with excellent support facilities, including an experienced anesthesiologist, trained nursing personnel, good critical-care facilities, and a safe blood bank.

Burns↗

Fever as a predictor of infection in burned children.

Although children with burns often develop fevers, we have found no reports characterizing the course and duration of these fevers. To evaluate the predictive value of fever as an indicator of infection in burned children, we reviewed the hospital charts of all 223 children admitted to a regional burn center in the years 1979 through 1982. The highest temperature reading for each 8-hour period of the child's hospitalization was recorded. The highest mean temperature in burned children occurred at 38 to 96 hours after the burn injury; the peak temperatures appeared at the same time, regardless of whether the child had an infection. All of the 23 children with infections (100%) and 145 of the 200 without infections (73%) had a recorded temperature reading of 38.2 degrees C or higher within 2 weeks after their burn injury. When children less than 4 years, or children with more than 20% total body surface area burns were considered alone, the presence of a temperature greater than 38.2 degrees C was not significant in differentiating those with infections. Fever is not a specific predictor of infection in burned children; in children less than 4 years of age and in children with more than 20% burns, fever has no predictive value for the presence of infection. The physical examination is a reliable source of information about wound infection, sepsis, or other childhood infections, and should be the primary tool used in making the diagnosis of infection in burned children.

Burns↗

Impairment, time out of school, and time off from work after burns.

Objective measurement of impairment after burns is important to patients, physicians, lawyers, and insurance companies. Even so, we could not find any references in the English literature describing how to objectively rate the physical impairment of burn survivors. The American Medical Association (AMA) has published the book Guides to Evaluation of Permanent Impairment, which is commonly used by surgeons to rate injuries. We decided to use this document to rate the impairment of burn patients. We studied patients who were treated at the University of Washington Burn Center during the years 1981, 1982, and 1983; survived the injury; were hospitalized 5 or more days or were skin grafted; and were followed until their condition was fixed (usually 12 months). This group included 325 patients. The mean age was 28.2 years and the mean total body surface area burned (TBSA) was 11.6 percent. We measured whole-man impairment (WMI) as described by the Guides to the Evaluation of Permanent Impairment. The mean whole-man impairment was 7.7 percent. In addition, we recorded time off from work and out of school after burns. The average time off from work was 12.7 weeks, and the average time out of school was 8.5 weeks. We conclude that the AMA publication can be used to rate burn patients and that the whole-man impairment of burn survivors is quite low if amputation, loss of range of motion, and nerve damage can be prevented.

Absenteeism↗

Clotting factor levels and the risk of diffuse microvascular bleeding in the massively transfused patient.

Clotting factor activities and coagulation screening tests in 36 massively transfused patients were measured after every 12 units of blood and whenever diffuse microvascular bleeding (MVB) developed. Moderate deficiencies in clotting factors were common, but they were not associated with MVB. MVB was associated with severe abnormalities of coagulation, i.e. a fibrinogen level less than 0.5 g/l or clotting factor levels less than 20%. The quantitative relationship between the prothrombin (PT) and partial thromboplastin (PTT) times and underlying clotting factor levels was explored by multiple linear regression. Clotting factor levels accounted for only 65-85% of the variability in these tests. However, clotting factor activities less than 20% were reliably reflected by marked prolongations of the PT and PTT (values greater than 1.8 times control). Our data suggest that commonly used replacement formulas are not likely to prevent MVB, since consumption of platelets and/or clotting factors, rather than simple dilution, is a major cause of the deficiencies leading to MVB. Modified whole blood alone was sufficient replacement therapy for most patients. Guidelines for transfusion of supplemental components during massive transfusion are given.

Blood Coagulation Factors↗