Charles Sheaff

Toxicology screening in urban trauma patients: drug prevalence and its relationship to trauma severity and management

Although toxicology screening is often used when treating trauma patients, its utility and significance remain controversial. Data from 623 toxicology screens performed in urban trauma center patients with mental status alterations are reported. The study patients were predominantly black and male, with a mean age of 32 (+/- 22) years. Overall, 86% of screens were positive. Substances of abuse, including ethanol, were noted in 525 (84%) of urine toxicology screens. Ethanol, cannabinoids, and cocaine were the drugs most commonly found in urine, with positivity noted in 53%, 37%, and 34% of screens. Serum analysis was 44% positive, with ethanol noted in 41% of patients. In blacks, the odds ratio of illicit drug use before trauma ranged from 1.9 to 4.2 (p less than 0.005), and in those aged 17 to 40 years, the odds ratio for illicit urine drugs ranged from 4.7 to 16.8 (p less than 0.001). In patients older than 40 years, the odds of a positive serum ethanol level were 1.7 times greater than in younger patients, and a level above 300 mg% was 3.8 times more likely in this age group (p less than 0.001). When serum ethanol was detected, the odds ratio of a head injury was 1.4 relative to patients without serum ethanol (p less than 0.06), and the odds ratio for abdominal injury was 1.6 for patients with serum ethanol (p less than 0.03). The odds of a TS less than 12 were 1.8 (p less than 0.05), and the odds of a GCS less than 12 were 3.3 (p less than 0.001) with ethanol levels greater than 100 mg%.(ABSTRACT TRUNCATED AT 250 WORDS)

Splenic preservation in adults after blunt and penetrating trauma

This study was carried out to evaluate the possibility and safety of splenic preservation in adults subjected to both blunt and penetrating. In an 18 month period there were a total of 36 splenic injuries studied (in 36 patients): 18 due to blunt trauma, 11 due to gunshot wounds, and 7 due to stab wounds. A total of 18 spleens were repaired: 8 (45 percent) in the blunt trauma group, 4 (36 percent) in the gunshot group, and 6 (85 percent) in the stab wound group. There were no deaths in the entire group nor were there any complications associated with splenic salvage. Splenic preservation after both blunt and penetrating trauma is both safe and feasible in the adult population, except in those instances specified herein.

The use of absorbable mesh in splenic trauma

Previous reports from this hospital documented a splenic preservation rate of 50% (18/36) in adults after blunt and penetrating trauma. Recently (January through December 1984), use of an absorbable mesh helped to attain a 67% (22/33) salvage rate. The mesh is applied in such a fashion that it acts by tamponade. It proved useful in patients with bleeding from a large surface area or from deep parenchymal injuries, even those extending into the hilum. No deaths occurred in the splenic salvage patients. There was no difference in postoperative complications among the splenectomy, conventional splenorraphy, or mesh wrap splenorraphy groups. However, workup of persistent postoperative fevers in two splenic wrap patients revealed perisplenic fluid collections on CT scan. Aspiration yielded sterile fluid. Possible cause and effect relationship is being studied in the dog lab. We conclude that splenic wrapping is both a safe and efficacious method of splenic preservation.

Use of peritoneal lavage to evaluate abdominal penetration

A retrospective study was undertaken to evaluate peritoneal lavage in detecting abdominal penetration. Two hundred thirty-five patients with thoracoabdominal, flank, or tangential abdominal gunshot wounds were lavaged. Of these patients, 44 (18.7%) had positive lavages, defined as red blood cell counts greater than 10,000 cells/mm3, white blood cell counts greater than 500 cells/mm3, or the presence of bile, feces, or vegetable matter. There were 13.6% false positives and 1.0% false negatives, with an overall accuracy of 96.6%. The results were unaffected by mechanism or site of injury. If the criteria were changed to include red blood cell counts greater than 100,000 cells/mm3, there would have been no false positives, but an unacceptably high 11.1% false negative rate. Therefore we conclude that peritoneal lavage can be a reliable indicator of abdominal penetration provided sufficiently sensitive criteria are used. These criteria should include red blood cell counts greater than 10,000 cells/mm3 instead of 100,000 cells/mm3.

The effect of urban trauma system hospital bypass on prehospital transport times and level 1 trauma patient survival

We studied the influence of hospital bypass on prehospital times and Level 1 trauma patient survival. During the nine-month study period, 251 Level 1 trauma patients were transported to the Cook County Hospital trauma unit by Chicago Fire Department (CFD) paramedics. The prehospital times and survival rates in the 203 (81%) patients who arrived with vital signs were analyzed. In this group, 64 (32%) had a hospital Trauma Score (TS) of 12 or less, 74 (39%) had at least one Abbreviated Injury Score (AIS) of 4 or more, and 58 (30%) had an Injury Severity Score (ISS) of more than 20. There were 66 (32%) directly transported patients and 137 (68%) patients who required hospital bypass. The time from CFD contact (by 911) to trauma center arrival (total run time) was on the average three minutes longer in the bypass group than in the direct group (36 +/- 11 vs 33 +/- 10 minutes, P less than .05). The travel time from the scene to the hospital (transport time) also was three minutes longer in the bypass group (7 +/- 3 vs 4 +/- 2 minutes, P less than .005). The need for bypass did not significantly influence survival. Survival was 86% in the bypass group and 85% in the direct group. The elapsed time between the injury and CFD contact (delay time) averaged 27 +/- 26 minutes and contributed 43% to the 63-minute mean overall time from the injury event to arrival at the trauma center. Total run time in directly transported patients accounted for 52% of the mean overall prehospital time.(ABSTRACT TRUNCATED AT 250 WORDS)

Very hot intravenous fluid in the treatment of hypothermia.

The efficacy and safety of very hot (65 degrees C/149 degrees F) intravenous fluid (IVF) were compared with those of conventional warm (38 degrees C/100.4 degrees F) IVF in the treatment of hypothermia. Eight anesthetized beagles (11-20 kg) were studied. Blood pressure (BP), pulse (P), and core temperature (cT degrees) were recorded at baseline, during hypothermia, and during rewarming. The plasma free hemoglobin (PFHg) was measured to assess hemolysis. Each subject was cooled to 32 degrees C/89.6 degrees F and assigned to receive either 65 degrees C or 38 degrees C IVF via a specially designed multiport balloon-tipped catheter in the superior vena cava (SVC). The IV fluid rate was 80% of the blood volume per hour. Conventional rewarming methods were used in all subjects. After 2 hours the subjects were killed and the SVC was examined for injury. The rate of rewarming was 2.9 degrees C/hour in the 65 degrees C IVF group and 1.25 degrees C/hour in the 38 degrees C IVF group. The cT degrees was significantly different in all subjects after 1 (35.2 degrees +/- 1.03 degrees C vs. 33.2 degrees +/- 0.5 degrees C; p < 0.006) and 2 (37.6 degrees +/- 1.17 degrees C vs. 34.3 degrees +/- 0.9 degrees C; p < 0.004) hours of rewarming. The BP, P, and PFHg were not different. Visual examination of the SVC revealed two lesions in the 65 degrees C IVF group and one in the 38 degrees C group. Mechanical or thermal injury could not be differentiated.(ABSTRACT TRUNCATED AT 250 WORDS)

Safety of 65 °C intravenous fluid for the treatment of hypothermia

Background To demonstrate the safety and efficacy of 65°C (149°F) centrally administered intravenous fluid (CIVF) compared to conventional 40°C (104°F) CIVF in the treatment of hypothermia. Method Ten beagles (9–13 kg) were prospectively randomized to receive 65°C or 40°C CIVF. They were anesthetized and data were collected at baseline, during hypothermia, and after 1 and 2 hours of rewarming. The plasma free/total hemoglobin (PFHb/THb) was measured to detect hemolysis. Each subject was cooled to 30°C (86°F) and then received either 65 C or 40°C CIVF through a specialized catheter in the superior vena cava for 2 hours in addition to conventional rewarming techniques. All subjects survived 7 days, after which they were sacrificed and a complete autopsy was performed. Results The rewarming rate was 3.7°C/hr in the 65°C CIVF group and 1.75°C/hr in the 40°C CIVF group. Core temperatures were significantly different after 1 hour (33.4° ± 0.77° versus 31.7° ±0.57°, P Conclusion CIVF at 65°C is a safe and effective means of treating hypothermia.

Effects of Short Heat Exposure on Human Red and White Blood Cells

BACKGROUND The infusion of warm intravenous fluid (IVF) is a simple and effective method used to maintain or restore core body temperature. At present, 40 degrees C is believed to be the highest temperature that can be safely administered. There is concern that temperatures greater than 40 degrees C may harm blood cells. The mixing time of IVF infused into a high-flow vein such as the superior vena cava is very short, however, approximately 300 milliseconds. We will determine the maximum temperature and exposure time tolerated by human red and white blood cells without producing injury. METHODS Whole blood and isolated neutrophils were exposed to temperatures (40-80 degrees C) for short time intervals (150-1,200 milliseconds). Lethal injury to red and white blood cells was measured by the plasma free hemoglobin and percent viability, respectively. Neutrophil viability was measured by trypan blue staining. Sublethal injury to red and white cells was measured by osmotic fragility and oxidative burst, respectively. Neutrophil oxidative burst was measured by chemiluminescence. Control values were compared with postexposure values using analysis of variance with p < 0.05 indicating significance. RESULTS Lethal injury to red blood cells did not occur until exposure at 70 degrees C for 300 milliseconds (plasma free hemoglobin, 116.3 +/- 34.7 mg%; p < 0.05). Lethal injury to neutrophils did not occur, even at exposure at 80 degrees C for 1,200 milliseconds. Sublethal injury to red blood cells did not occur until exposure at 60 degrees C for 1,200 milliseconds. Sublethal injury to neutrophils did not occur until exposure at 60 degrees C for 600 milliseconds (percent change in oxidative burst = 28.9 +/- 0.96%; p < 0.05). CONCLUSIONS The exposure of human red blood cells and neutrophils to temperatures up to 60 degrees C for up to 600 milliseconds does not cause lethal or sublethal injury. These findings contribute to the body of evidence supporting the use of centrally infused IVF at temperatures greater than 40 degrees C for active core rewarming.

CORRELATION OF SPONTANEOUS MICROAGGREGATE FORMATION WITH THE SEVERITY OF TRAUMA IN MAN

Blood samples were obtained from 237 consecutive injured patients before any resuscitation. Microaggregate (MA) formation was measured by the screen filtration pressure (SFP) technique. Arterial blood gases were analyzed concomitantly and the respiratory index (RI) calculated. An Injury Severity Score (ISS) was calculated for each patient. The results show a significantly larger amount of trauma in the patients with the higher SFP results (p less than 0.001). Associated with the increase in the amount of MA formation was a significant decrease in arterial pO2 (p less than 0.05) and a significant rise in the RI (p less than 0.005), suggesting a correlation between MA formation and pulmonary impairment. Attempts to prevent or resolve MA formation may result in a decrease in the incidence or severity of post-traumatic pulmonary insufficiency.

Fibronectin Depletion and Microaggregate Clearance following Trauma

Ninety-seven traumatized patients had blood samples taken immediately upon admission before any resuscitation. Microaggregate (MA) formation was measured by the screen filtration pressure (SFP) technique. Plasma fibronectin levels (Fn) were measured by immunoturbimetric assay. An Injury Severity Score (ISS) was calculated for each patient. The results show a highly significant correlation between severity of trauma, amount of MA formation, and amount of Fn depletion. We conclude that the highly significant correlation between MA formation and Fn depletion following trauma suggests a role for the reticuloendothelial system (RES) in the clearance of MA that form following trauma. Further, enhancement of RES clearance of MA may be possible by purified Fn or cryoprecipitate administration early in the treatment of trauma patients, thereby preventing the adverse sequelae of end organ MA deposition.