Analysis of regional hemodynamic regulation in response to scald injury.

Ultrasonic probes were placed around dog femoral arteries to record blood flow. Hind paw scalding with boiling water (5 s) caused a marked increase in ipsilateral femoral blood flow that persisted for the 2-h observation period. Contralateral femoral blood flow and systemic and pulmonary vascular resistances were unchanged. Compared to scald only animals, methysergide pretreatment diminished and shortened the femoral vasodilator response to scald (109 +/- 14 vs 243 +/- 27 ml/min at 5 min; 59 +/- 14 vs 191 +/- 31 ml/min at 2 h). Pretreatment with ritanserin, BW A1433U83, atropine, ICI 118551, diphenhydramine, ranitidine, meclofenamate, L-nitro-arginine methyl ester, 3-amino-1,2,4-triazine, and U 37883A had no effect on the increased femoral blood flow response to scald, suggesting this vasodilator response is not dependent upon activation of serotonergic2, adenosineA1, muscarinic, beta 2-adrenergic, histaminergic1 or histaminergic2 receptors, on cyclooxygenase products, endothelium-derived relaxing factor derived from nitric oxide (NO) synthase III, NO derived from NO synthase II, or KATP channels, respectively. Methysergide given after burn immediately reduced the augmented femoral blood flow to preburn levels, suggesting the vasodilator response to scald is mediated through continual activation of local serotonergic1-like receptors, which may be target site(s) for therapeutic interventions to influence burn-induced hemodynamic alterations.

Management of necrotizing tracheostomy infections.

Management of three patients with necrotizing tracheostomy infections resulting in tracheal dissolution was reviewed with respect to presentation, cause, and management. Loss of tracheal substance led to difficulty in ventilation because of a large air leak. The stomal area cavitated in two patients, denuding the right common carotid artery in one. Purulent peristomal drainage was present in all three patients. Common factors of possible etiologic significance included necrotizing polymicrobial gram-negative tracheobronchial infections caused by Pseudomonas, Enterobacter, and Klebsiella species. Also of possible importance were suture fixation of the appliance, history of neurologic injury, and closure of the incision. Immediate therapy consisted of oral intubation for ventilatory purposes and a regimen of hourly application of 1% neomycin dressings. Seven to 21 days were necessary to allow formation of sufficient granulation tissue to support replacement of the tracheostomy appliance for continued mechanical ventilation. Once spontaneous ventilation was possible, a Montgomery T-tube was inserted for long-term tracheal stenting prior to reconstruction. The two patients treated by tracheal stenting are long-term survivors. Avoidance of suture fixation of the appliance, aggressive treatment of bronchopulmonary infection, and adequate stomal toilet may help to avoid this devastating complication.

Preventive antibiotic usage in traumatic thoracic injuries requiring closed tube thoracostomy.

OBJECTIVE: To evaluate the safety and effectiveness of antibiotics in reducing the infectious complications following closed tube thoracostomy for isolated chest trauma. DESIGN: Double-blind, randomized clinical trial. SETTING: Medical school affiliated large urban teaching hospital and trauma center. PATIENTS: One hundred nineteen of 159 patients over 18 years old presenting to the emergency department requiring closed tube thoracostomy for isolated chest injuries (113 penetrating, 6 blunt). INTERVENTION: Patients received either placebo or 1 g cefonicid daily intravenously started at chest tube insertion and stopped within 24 h of removal. MEASUREMENTS AND RESULTS: The development of wound infections, pneumonia (CDC criteria), or empyema; the incidence of adverse events; length of hospitalization. One nonspecific infection was seen in the cefonicid group (1.6 percent) and six respiratory tract infections (10.7 percent) in the placebo group (three empyema, one empyema with pneumonia, two pneumonia) (p = 0.0505; p = 0.0094 [excluding nonspecific infection]). No significant differences with antibiotic use were seen in the duration of chest tube use (p = 0.766), peak WBC counts (p = 0.108), lower peak temperatures (p = 0.063), or length of hospitalization (p = 0.165). Patients who developed infectious complications averaged approximately 8 days longer hospitalization than those without (p < 0.0001). CONCLUSION: This study showed that patients receiving antibiotics had a significantly reduced rate of infection than did patients administered placebo. No significant adverse events were seen in either group.

Arterial injuries with lower extremity fracture.

Review of the records of 41 patients with lower extremity fractures associated with major arterial injuries disclosed that femoral artery injuries were consistently repaired with excellent results and no amputations. Diagnostic delay contributed to an 18% amputation rate following popliteal artery disruption. When arteries distal to the popliteal trifurcation were completely disrupted, a 25% rate of long-term good results was obtained.

Peritoneal lavage: a useful diagnostic adjunct for peritonitis.

Diagnostic peritoneal lavage (DPL) was used to aid in the rapid diagnosis of peritonitis in 138 patients for whom standard diagnostic criteria were not applicable because the patients had altered sensorium, were elderly, or had multiple medical problems. There were abnormal results in 77 patients, and all but one patient had peritonitis. Sixty-five patients had lesions that could be cured only by operative means; 54% of this group of extremely ill patients survived. Of 61 patients with negative results of DPL, only one had intraperitoneal inflammation (acute cholecystitis), which occurred 4 days after DPL. We believe DPL is a useful procedure for the detection of peritonitis in a critically ill subset of patients for whom the standard diagnostic criteria were not available.

Occult splenic abscess: an unrecognized complication of heroin abuse.

Despite increased recognition of surgical problems related to narcotic addiction, splenic abscess has not been commonly recognized as such a complication. Seven male patients with splenic abscess secondary to heroin abuse have been treated. Six had bacterial endocarditis. Symptoms were nonspecific. Splenomegaly in two patients was the only useful physical finding. Five patients had left pleural effusion, of which three were proven to be empyemas. Staphylococcus aureus was the predominant pathogen of of bacterial endocarditis and splenic abscess. The splenic scan was diagnostic. All patients recovered following curative splenectomy.

Intimal disruption of major cerebral vasculature following blunt trauma.

A child with blunt traumatic intimal disruption involving the major vessels responsible for cerebral circulation was treated by operation. The injured vessels included both common carotid arteries, both vertebral arteries, and the left subclavian artery. The carotid injuries were treated by saphenous vein interposition grafts, whereas the left subclavian and vertebral arteries were ligated. The patient sustained no neurological deficit and is now completely well 2 years after treatment. The case reported herein is unique in that total intimal disruption of the four major vessels responsible for cerebral flow was treated by operation, resulting in complete recovery. The successful outcome underscores the importance of complete angiographic evaluation and adequate operative exposure in such cases.

Evaluation of a novel synthetic material for closure of large abdominal wall defects.

BACKGROUND: This study was undertaken to compare the efficacy of a novel synthetic material (TMS-1) with polytetrafluoroethylene, polypropylene, and primary closure of experimentally fashioned clean and contaminated abdominal wounds. METHODS: One square centimeter full-thickness abdominal wall defects were created in each of the four abdominal quadrants of anesthetized rats (n = 6). Patches of polytetrafluoroethylene, polypropylene, and a polyurethane-polypropylene composite material (TMS-1) were used to repair three of these defects; the fourth was primarily closed. A second group of rats (n = 9) underwent the same operative protocol; however, peritonitis was induced at the time of operation by using the fecal inoculation technique. Animals were killed 2 to 3 weeks later, and surface area and severity of formed adhesions were assessed. RESULTS: By all methods of assessment, primary closure proved significantly superior to all other methods of closure in clean and contaminated conditions. The three synthetic materials were equally matched for surface area involved in adhesion formation. When compared with the other synthetic materials, TMS-1 was associated with significantly milder adhesions in uninfected (p < 0.002) and in infected (p < 0.002) conditions. CONCLUSIONS: The clear superiority of TMS-1 over other nonabsorbable synthetic materials shown in this pilot study warrants further investigation relative to its use to close large abdominal wall defects.

Bleeding vascular malformations of the intestine.

Thirty-nine patients with bleeding vascular malformations were evaluated. The age range was from 3 to 78 years, with a bimodal age distribution. The younger patients had no associated diseases, while those in the older category invariably had an associated cardiac lesion (aortic stenosis in 12 patients and severe atherosclerotic disease in 11 patients). With experience, colonoscopy has become a valuable adjunct to arteriography with the lesion visualized in 12 patients. Arteriography is the most useful study being diagnostic in 35 of 38 cases. Exploration alone was diagnostic in only one of 39 patients. The most common site of bleeding was the cecum (21 patients) followed by the proximal small intestine (eight patients), terminal ileum (seven patients), and ascending colon (five patients). The lesions in the proximal small bowel were much more common in the younger patients and were believed to be congenital. Resection controlled the bleeding in the majority of patients, although four recurrences have been noted. All have been documented angiographically to have been from a new lesion and two were controlled with reoperation. The key elements to control of these patient's bleeding include: (1) systematic work-up with a team approach emphasizing careful visceral angiography, and (2) the avoidance of a premature laparotomy prior to complete evaluation.

Hepatic cellular hypoxia in murine peritonitis.

Reduced oxygen consumption and lactic acidosis were observed frequently in patients with peritonitis. This study was designed to evaluate whether reduced oxygen consumption is secondary to deficient oxygen delivery or is a function of primary injury to mitochondria. Peritonitis was produced in rats by cecal ligation and perforation. Animals were killed at 2, 4, and 6 hours and agonally. Oxygen utilization was studied polarographically in isolated hepatic mitochondria with glutamate, pyruvate, and succinate substrates. State 3, state 4, respiratory control index (RCI), and ADP:O ratios were determined. Whole tissue and isolated mitochondrial ultrastructure were examined by electron microscopy. Systemic blood pressure and oxygenation were monitored. Hepatic tissue oxygenation was examined using a surface oxygen electrode. Peritonitis resulted in acceleration of state 3 respiratory rates and increased respiratory control indices at all time intervals. Maximal respiratory control was observed at 4 hours with all substrates. Whole tissue mitochondria demonstrated mild swelling and thinning of membranes and matrix. Experimental and control isolates showed similar orthodox-to-condensed conformational changes. Hepatic tissue oxygenation declined to less than 10% of control by 6 hours, while arterial Po2 was unchanged. The conclusions of this study are that lethal peritonitis results in (1) no primary injury to the hepatic mitochondria, (2) increased efficiency of hepatic mitochondrial oxygen utilization, and (3) reduced hepatic tissue oxygenation. The exact mechanisms of defective oxygen delivery require further study.

Management of transmediastinal gunshot wounds.

Gunshot wounds that transverse the mediastinum are major management problems for two primary reasons: (1) multiple injuries to vital structures are common and (2) the operative approach to control hemorrhage may not afford the optimum exposure to repair the various injuries encountered. We devised a management plan whereby patients in hemodynamically unstable condition underwent immediate operation and patients in stable condition underwent a rapid work-up to evaluate the organs at risk for injury including angiography, esophagoscopy, esophagography, bronchoscopy, and pericardial exploratory surgery while under local anesthesia. A total of 76 patients were treated. Thirty-three patients in unstable condition underwent immediate thoracotomy for hemorrhage or shock or median sternotomy for cardiac tamponade. Multiple organs were injured (average 2.7) and the mortality rate was high (12 of 33) because of the severity of the injuries. Twenty-seven of 43 patients in stable condition required operation after the systematic evaluation disclosed injuries to the great vessels (11), esophagus (9), trachea and bronchi (6), and heart (6). Three patients died of delayed complications (6.9%). The 16 patients who were in stable conditions and had no demonstrable injury were closely followed without operation with one complication and one death from an associated abdominal injury. A management plan for this difficult subset of patients with penetrating thoracic trauma is detailed.

Microcirculatory norepinephrine constrictor response in hemorrhagic shock.

Hemorrhagic shock is characterized by a phase of compensation that preserves central blood flow and intravascular pressure through an integrated vasoconstrictor response mediated by catecholamines, particularly norepinephrine (NE). The skeletal muscle microcirculation is important in this response. Decompensation occurs when arteriolar vasodilation occurs despite continued hypovolemia and high circulatory levels of NE. Using an isolated decerebrate rat cremaster muscle, we measured constrictor response to NE (10(-7)M tissue concentration) in compensated and decompensated shock. Our data indicate that larger arterioles (143 to 152 microns) show persistent constrictor response with lowered sensitivity to NE. Smaller arterioles (11 to 22 microns) and all venules dilate late in shock but retain constrictor responses to NE. Dilator responses contribute to decompensation in small arterioles and venules but not because of altered NE constrictor response.

Effects of pentafraction administration on microvascular permeability alterations induced by graded thermal injury.

BACKGROUND: Pentafraction is a pentastarch derivative hypothesized to limit burn edema by "sealing" damaged capillaries, restoring a barrier to fluid translocation and macromolecular (protein) flux. METHODS: Canine hind paw lymph flow (QL) and lymph (CL) and plasma (CP) protein concentrations were measured before and for 6 hours after (1) 5-second 100 degrees C (n = 6) or 80 degrees C (n = 6) foot paw scald, (2) 100 degrees C (n = 5) or 80 degrees C (n = 5) foot paw scald followed 30 minutes later by a 4 cc/kg bolus of 6% pentafraction, or (3) pentafraction infusion without scald (n = 5). Before scald or pentafraction infusion, hind paw venous pressure was elevated and maintained by outflow restriction until a steady state, minimal CL/CP was reached. The reflection coefficient, sigma d, was determined as 1-CL/CP, and the (fluid) filtration coefficient (Kf) was calculated. RESULTS: Scalding uniformly produced statistical (p < 0.05, ANOVA) increases in QL, CL/CP, sigma d, Kf, and paw weight gain. Postburn pentafraction infusion produced no enduring alterations in any measured parameter as compared with those of animals who received a matched severity scald without pentafraction. CONCLUSIONS: Pentafraction does not appreciably ameliorate the adverse microcirculatory consequences observed at the site of burn injury.

Alpha-trinositol reduces edema formation at the site of scald injury.

BACKGROUND: The effects of alpha-trinositol (1D-myo-inositol-1,2,6-triphosphate, IP3) on burn-induced edema formation were investigated. METHODS: Lymph flow (QL; microliter/min) and lymph-to-plasma protein ratio (CL/CP) were monitored in groups of five to six dogs before and 4 hours after (1) a 5-second 100 degrees C or 90 degrees C foot paw scald; (2) IP3 (45 mg/kg intravenous bolus, then a 20 mg/kg/hr infusion) 30 minutes before or after 100 degrees C scald, or 30 minutes after 90 degrees C scald. Hind paw venous pressure was elevated and maintained by outflow restriction until reaching steady state QL and (CL/CP)min. Macromolecular reflection coefficient (1-CL/CP) was measured. Fluid filtration coefficient (Kf; ml/min/mm Hg/100 gm) was calculated. Relative paw weight gain (%) was measured. RESULTS: Compared with preburn values, scald uniformly produced significant increases in QL, CL/CP, and Kf, IP3 significantly (p < 0.02, ANOVA) reduced paw weight gain when given before, but not after, 100 degrees C burn (41% +/- 5% versus 18% +/- 7% preburn IP3 and 31% +/- 3% postburn IP3). Compared with 90 degrees C burn animals, postburn treatment significantly (p < 0.017) attenuated 4-hour increases in QL (550 +/- 87 versus 252 +/- 29 microliters/min), Kf (0.016 +/- 00 versus 0.007 +/- 00 microliter/min/mm/Hg/100 gm), and relative paw weight gain (28% +/- 3% versus 12% +/- 5%). CONCLUSIONS: alpha-Trinositol given after a 90 degrees C scald blunted edema formation at the site of scald, likely through reduced transmembrane fluid flux.

Age-related differences in response to neutrophil-mediated reperfusion injury in the neonatal piglet heart.

BACKGROUND: Neonatal hearts have altered adhesion molecule interactions in response to ischemia-reperfusion. How this affects myocardial function is unknown. METHODS: Isolated, buffer perfused 0- to 2-day (newborn) and 2-week piglet hearts were first subjected to 20-minute global, normothermic ischemia, followed by 45 minutes of reperfusion during which 150 x 10(6) newborn or 2-week neutrophils were infused. In some hearts, an antibody to SLe(x) (CSLEX-1) was infused with neutrophils during reperfusion. Hemodynamic variables, including left ventricular developed pressure (LVDP), were recorded at timed intervals. Neutrophil CD-18, L-selectin, and SLe(x) contents were measured by flow cytometry. RESULTS: Full recovery of LVDP was observed in newborn hearts receiving newborn or 2-week-old neutrophils. Recovery of LVDP was depressed (p < 0.01, ANOVA) in 2-week-old hearts receiving 2-week old, not newborn, neutrophils. Infusion of CSLEX-1 in 2-week-old hearts restored LVDP to baseline. Whereas flow cytometry showed higher (p < 0.01, Student's t test) CD-18 and L-selectin expression on newborn versus 2-week-old neutrophils, newborn neutrophils expressed lower (p < 0.01) SLe(x) levels. CONCLUSIONS: Initial "loose" neutrophil-endothelial selectin interactions are a necessary prelude to "firm" adhesion and reperfusion injury. Operations performed soon after birth may be better tolerated than when surgery is delayed; anti-SLe(x) preparations may prove beneficial when performing cardiac procedures on older infants.

Early tracheostomy for primary airway management in the surgical critical care setting.

During a 12-month period, 264 patients with multiple injuries who required mechanical ventilation were admitted to the surgical intensive care unit. One hundred twenty patients (46%) were disengaged from the ventilator, and 38 patients (14%) died. Of the remaining 106 patients (40%) 51 patients (group I) were to receive tracheostomy within 1 to 7 days, and 55 patients (group II) underwent late (8 or more days after admission) tracheostomy. Multiple variables in four categories (admission, operative, ventilatory, and outcome) were analyzed prospectively to define the impact that early tracheostomy had on duration of mechanical ventilation, intensive care stay, and hospital stay. Morbidity and mortality rates of the procedures were assessed. Early tracheostomy, in a homogeneous group of critically ill patients, is associated with a significant decrease in duration of mechanical ventilation, as well as shorter intensive care unit and hospital stays, compared with translaryngeal endotracheal intubation. There were no deaths attributable to tracheostomy, and overall morbidity of the procedures was 4%. We conclude that early tracheostomy has an overall risk equivalent to that of endotracheal intubation. Furthermore, early tracheostomy shortens days on the ventilator and intensive care unit and hospital days and should be considered for patients in the intensive care unit at risk for more than 7 days of intubation.

Epithelial lining methods in esophageal repair: a comparative study using pedicle flaps in cats.

Methods of restoring luminal lining in repair of partial-circumferential esophageal defects were evaluated to compare incidences of strictures and fistulas and quality of surface lining. In cats 50% and 67% circumferential esophageal defects were repaired by direct closure or pedicle flaps (latissimus dorsi) that were unlined (lining restored by epithelialization from wound margins) or that carried lining of normal skin (myocutaneous flaps), skin grafts, or mucosal grafts. Repairs were evaluated for esophagocutaneous fistulas, luminal stricture, flap luminal surface area, and quality of epithelial surface 6 weeks after surgery. Direct closure of 50% circumferential defects was as satisfactory as any flap repair method. Direct closure of 67% circumferential defects caused high incidences of fistulas and strictures, which were lessened by flap reconstructions. Among flap lining methods, normal skin (myocutaneous flaps) gave the lowest incidence of fistulas and strictures and the highest surface quality, but a high incidence of skin paddle loss occurred in this model. Split-thickness epithelial grafts were nearly as satisfactory as myocutaneous flaps, and less lining loss occurred. Epithelialization of unlined flaps gave the poorest results since lining was thin and often incomplete, and wound contraction produced loss of surface area and strictures. The findings are discussed from a perspective of wound healing physiology, and implications for clinical application are presented.

Effects of methysergide administration on edema formation at the site of scald.

Femoral blood flow (Qa), hind paw lymph flow (Qlym), and lymph-to-plasma protein concentration ratio (Clym/Cp) were monitored before and 4 h after 1) 5-s 100 degrees C paw scald, 2) methysergide (1 mg/kg iv) 20 min before scald, 3) methysergide 30 min after scald, and 4) methysergide only. Before experimentation, hind paw venous pressure was elevated and maintained until steady-state Qa, Qlym, and minimal Clym/Cp levels were reached. The reflection coefficient (sigma d) was determined as 1 - minimal Clym/Cp; the filtration coefficient (Kf) was calculated. Methysergide alone caused no changes. Increases in Qa, Qlym, Clym/Cp, and Kf were identified in all scald groups. Compared with scald only animals, pre- and postscald methysergide blunted the increases in Qa, Qlym, Kf, and paw weight gain without an effect on sigma d. These data demonstrate that methysergide reduces edema formation at the site of scald, perhaps by modulating the burn-induced vasodilator response and/or by limiting the burn-induced increase in microvascular surface area.

Pancreaticoduodenectomy. University experience and resident education.

A radical pancreaticoduodenectomy offers the best chance for survival in patients with periampullary and pancreatic malignant neoplasms. A pancreaticoduodenectomy has educational value since complex pancreatic operations are demanding and important to the training of surgical residents. Increased pancreaticoduodenectomy experience (per surgeon) has been associated with improved outcomes. We examined the hypothesis that residents who are supervised by faculty surgeons can perform pancreaticoduodenectomies with acceptable outcomes. From 1976 to 1987, 127 pancreatic resections were performed by 81 residents who were supervised by 15 faculty surgeons in four teaching hospitals. A pancreaticoduodenectomy was performed on 61 patients. All residents served as an operating surgeon on a pancreatic resection, and 58 (82%) performed pancreaticoduodenectomies. The mortality for the pancreaticoduodenectomies was 8%, with a 36% major complication rate. A pancreaticoduodenectomy can be performed safely by residents under supervision. A review of the results identifies the means of improving outcomes. These results justify the preservation of a pancreaticoduodenectomy as an important experience for residents.

Penetrating arterial trauma. Analysis of missed vascular injuries.

From 1976 to 1981, 677 patients with potential vascular injuries from penetrating wounds to the upper and lower extremities and the neck were treated. Surgical exploration was used to evaluate 237 patients; 440 patients were evaluated by arteriography alone, with negative results. In the group that underwent surgery, there were 137 arterial injuries detected. Follow-up studies were performed to assess the rate of missed vascular injuries using each diagnostic modality. Short-term follow-up was obtained in 81% of all patients. Long-term follow-up, averaging 5.1 years, was obtained in 33% of the patients. Vascular injuries, which went undetected at the time of initial evaluation, were present in both the group evaluated by vascular exploration and the arteriography group. The combination of arteriography and exploration detected no missed injuries on follow-up.