Biomedical subjects
Publications and source records attributed to J L Hunt.
Early identification of soft tissue injury is a major problem in the patient with frostbite injury. A patient is presented with a method for early (less than 2 days) identification of nonviable tissue. This is a noninvasive method employing technetium 99m stannous pyrophosphate which was used to accurately predict the level of ultimate amputation.
The objectives of surgery for generalized peritonitis are to eliminate the source of continual bacterial contamination and to prevent septicemia and intra-abdominal abscess formation. A prospective randomized study of three different operative approaches of treating residual peritoneal contamination was undertaken: group 1, no peritoneal irrigation (14 patients); group 2, intraoperative peritoneal irrigation (15 patients); group 3, both intraoperative and postoperative peritoneal irrigation (15 patients). The mortality in groups 1, 2, and 3 was 28.5%, 26.6%, and 33%, respectively. The overall incidence of septicemia and intra-abdominal abscesses in groups 1, 2, and 3 was 23%, 22%, and 17%, respectively. In those patients who survived, the incidence of intra-abdominal abscesses, wound infection, and septicemia was 6%, 23%, and 13%, respectively. In this series, there was no detectable difference in the mortality and infectious complications between the three treatment groups. The only clinical factors that adversely affected mortality and morbidity were peritonitis originating from the colon and age greater than 60 years. Early surgical intervention with removal of the source of peritonitis, debridement of all necrotic tissue, and drainage of abscesses remain the cornerstones of successful therapy in generalized peritonitis.
Full-thickness dorsal hand and digit burns result in serious acute and chronic functional disability. Early wound closure is paramount to minimize functional impairment and improve ultimate cosmetic appearance. Fifty patients were followed for 2 to 6 years after excision and immediate autografting of full-thickness hand and digit burns. Based on the depth of injury distal to the metacarpal phalangeal joints, two groups of hand burns emerged in this series. Group I: Patients had uninjured and intact extensor mechanisms. Near normal range of motion was obtained by the end of the second postoperative week. Local wound sepsis and/or inadequate depth of excision resulted in autograft loss and additional surgical procedures in 10% of the hands. Group II: Patients with thermal damage to some portion of the extensor mechanism of the digit. Seventy-five per cent of these hands had thermal damage to bone. An average of three operative procedures was required on each hand for ultimate wound closure. Prolonged immobilization, persistent edema, and local wound sepsis were common to all Group II hands. Reconstructive surgery was necessary within 1 year in 43% of all hands. Hands in Groups I and II required surgery 12% and 75% of cases, respectively. Early surgical excision coupled with aggressive physical and occupational therapy has decreased but not eliminated many of the acute and chronic sequelae of full-thickness hand and digit burns.
Traumatic arteriovenous fistula (AVF) is an uncommon form of vascular disruption. We reviewed 70 AVFs in 69 patients. Nearly one in ten acute arterial injuries is an AVF. Only half of these lesions, however, are clinically demonstrable. Iatrogenic lesions were present in 13% of patients. Eighty-one percent of lesions were treated surgically. Extracranial-intracranial (EC-IC) vascular bypass was used in over one third of head and high neck AVFs. Embolization was used as an adjunct to surgery in about one fourth of patients, and fewer than one in ten were treated with embolization alone. Since half of these lesions are not clinically detectable, liberal use of angiography is necessary for all traumatic wounds in proximity to a major vascular structure. Embolization was useful both as a primary treatment of AVF and as an adjunct to surgery; EC-IC bypass facilitates treatment of inaccessible fistulae in the head and neck.
A review of 102 cases of high-voltage electric injuries was performed. The average total body surface area was 15.2%. The average age was 32 years. The mortality was 2.1%. Advances in fluid therapy have virtually eliminated renal failure. Devitalized muscle was accurately identified preoperatively with the use of the technetium Tc 99m pyrophosphate muscle scan. Septic complications were reduced substantially by using the following therapeutic modalities: early excision of the burn eschar and necrotic muscle; quantitative wound biopsies to monitor the bacterial flora; allograft as a temporary coverage of open wounds; and early creation of local and distant flaps. Early institution of physical and occupational therapy are mandatory if the patient is to be restored to his or her maximum postinjury potential.
Povidone-iodine ointment is a widely used topical antimicrobial agent in thermally injured patients. In 17 patients with burns ranging from 4 to 85% TBSA this agent was applied to both partial- and full-thickness burns. Peak serum iodine levels in patients treated within 24 hours of injury ranged from 595 to 4,900 micrograms per dL. The amount of iodine absorbed was directly related to the size of the burn. Serum iodine levels continued to rise until the drug was discontinued and remained elevated for as long as 7 days after discontinuance. Iodine excretion was directly related to renal function. The highest serum and lowest urinary iodine levels were present in patients who developed renal failure. Thyroid function was not affected by drug usage. A proven cause-and-effect relationship between the elevated serum iodine attributed to the absorption of povidone-iodine and metabolic acidosis, hypernatremia, and hyperosmolarity was not established. Close monitoring of the patient's fluid and electrolyte balance is imperative during drug usage. The drug is contraindicated in any patient with impaired renal function. The high serum levels of this inorganic ion imply potential toxicity, but clinical evidence of cell or organ toxicity is as yet undetermined.
Of the several tests which measure leukocyte bactericidal competency only one, chemotaxis, has been reported to reflect both leukocyte dysfunction and patient mortality in major thermal injury. To validate the reliability that chemotaxis reflects mortality functional chemotactic index (FCI) was measured in leukocytes from 33 patients with 30% or greater total body surface area burns. Additionally, nitroblue tetrazolium (NBT) reduction and O2 consumption were compared to FCI. Significant decreases were seen in FCI values compared to normals. No differences, however, were seen in FCI values between surviving and nonsurviving patients. NBT reduction and O2 consumption also showed decreases with a significant difference between the mean decrease in surviving and nonsurviving patients. While the data show all these laboratory tests to be reflective of significant impairments in host defense, they do not appear to be reliable as predictive indices of patient survival and therefore should not be interpreted as such.
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Thermal injuries to the hand constitute not only one of the most common burns, but one of the most difficult for the burn surgeon to treat. Early wound closure is mandatory if maximum functional return is to be attained and scarring minimized. Over the last three and one-half years, 60 patients with deep dermal dorsal hand and finger burns were treated by tangential excision and immediate mesh autografting. All patients were admitted to the hospital within 24 hours of injury and excision was performed between the third to the tenth post burn day. Operative technique consisted of sequential eschar excision using the Humby knife or Goulian-Weck dermatome until viable dermis was visible. Mesh autograft, ratio 1 to 1(1/2) without expansion, was applied. There was 100% graft take in all but four hands. Hand function with full range of motion returned by the tenth postoperative day. Complications were minor. Patient follow-up ranged from six months to three and one-half years. No patient has required subsequent surgery for scar revision or contracture release. Range of motion in all patients has been excellent and all patients have continued to maintain normal hand function. The cosmetic appearance has been good except for the early "mesh" appearance of the graft which has become less apparent with time. In summary, early tangential excision and immediate mesh autografting of deep dermal dorsal hand burns has fulfilled the following burn principles-preservation of tissue, prevention of wound infection, maintenance of function and early wound closure.
A patient with a rapidly enlarging symptomatic false aneurysm of the internal carotid artery 30 years after nonoperative treatment of a penetrating neck injury is presented. Preoperative compression of the aneurysm precipitated transient cerebral ischemic attacks. Complete interruption of the right internal carotid artery inflow during aneurysmectomy was considered to be fraught with great danger. An extra-intracranial arterial bypass was therefore performed, and then aneurysmorrhaphy was easily performed and saphenous vein graft interposition accomplished. The importance of early definitive treatment of arterial injuries is emphasized. The bypass used allowed additional cerebral blood flow when complete occlusion of the carotid artery was contraindicated.
A case of liquid propane cold injury is described. This injury was produced by evaporative heat loss, without ignition, from skin and underlying tissues. The cutaneous appearance was that of a flame burn but underlying deep tissue damage was present. Acute vascular compromise and progressive wound sepsis were complications which required surgical intervention. A liquid propane animal model was created which defined the pathophysiology of the clinical injury. The potential for this injury exists wherever volatile liquified gases are used.
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Eleven patients with bronchogenic carcinoma underwent surgical treatment of metastatic abdominal visceral lesions. Successful surgical palliation was achieved in nine. In eight patients intraabdominal metastasis marked the first clinical sign of spread of the primary tumor outside the chest. The longest interval following diagnosis of the primary lung lesion and the appearance of the abdominal symptoms due to metastatic disease was three and one-half years.
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133Xenon lung scanning post-thermal injury was used to detect inhalation injury in 86 patients admitted to the United States Army Institute of Surgical Research during 1974. Inhalation injury was indicated by the 37 (43%) positive scans. Based on all available clinicopathologic evidence, 11 (13%) of the scans were erroneous with seven (8%) falsely positive and four (5%) falsely negative. Eighty-six per cent of the scans were "appropriate." Addition of bronchoscopy and/or pulmonary function testing appeared to improve diagnostic accuracy. By using any pair of tests, falsely negative diagnoses were virtually eliminated. Inhalation injury, as expected, had an adverse effect on survival rates. The group of patients whose expected mortality lay between 40 and 59% were most notably affected. One hundred per cent (five of five) of those with inhalation injury died; only one of eight without inhalation injury died.
Results of the present investigation indicate that an electric burn is simply a thermal injury. The tissue damage associated with an electric injury occurs when electric energy is converted to thermal energy or heat. An electric burn is self limiting: once the current arcs, no further skin and muscle damage is possible because amperage falls to zero. Tissue temperature is the critical factor in determining the magnitude of tissue injury before the current arcs. With the exception of skin resistance, resistances of individual tissues seem not relevant to amount of tissue damage in electric injuries. Living tissue acts as a volume conductor; once skin resistance has been overcome all internal tissue resistance, with the exception of bone, is negligible to current flow. In the present study the volume of tissue traversed by the electric current was more closely related to the extent of tissue injury than the internal resistance of the individual tissues. Muscle injury occurred at the time of initial thermal insult and progressive or de novo muscle necrosis was not seen in this model.
Although electrical burns of the upper extremity comprise a small percentage of all thermal injuries, they present formidable clinical problems. The physician must not be lulled into a false sense of security because the visible cutaneous burn is not great. Sound surgical principles, such as the control of bacterial proliferation with topical chemotherapy, débridement of dead tissue, and timely wound closure, in conjunction with the expertise necessary in caring for thermally injured patients, are necessary for a maximally rehabilitated patient.
Fiberoptic bronchoscopy proved to be a simple, safe, and accurate method of diagnosing acute inhalation injury. Both the anatomic level and the severity of large airway injury were easily identified. The identification of a supraglottic and infraglottic component to inhalation injury was not only helpful in determining the appropriate therapy but also in predicting ultimate pulmonary complications. When bronchoscopy was used in conjunction with the 133Xenon scintiphotoscan, both large and small airway injuries could be identified. The only clinical situation where bronchoscopy failed to identify an inhalation injury was in the immediate postburn period if the patient wasin hypovolemic shock. In this particular clinical circumstance the characteristic mucosal alterations may be absent; yet if bronchoscopy is performed after hypovolemic shock has been corrected, mucosal changes characteristic of inhalation injury will be seen.