An update on the surgeons scope and depth of practice to all hazards emergency response.

This article outlines the position of The Eastern Association of the Surgery of Trauma (EAST) in defining the role of surgeons, and specifically trauma/critical care surgeons, in the development of public health initiatives that are designed to react to and deal effectively with acts of terrorism. All aspects of the surgeon's role in response to mass casualty incidents are considered, from prehospital response teams to the postevent debriefing. The role of the surgeon in response to mass casualty incidents (MCIs) is substantial in response to threats and injury from natural, unintentional, and intentional disasters. The surgeon must take an active role in pre-event community preparation in training, planning, and executing the response to MCI. The marriage of initiatives among Departments of Public Health, the Department of Homeland Security, and existing trauma systems will provide a template for successful responses to terrorist acts.

Calibration of dosemeters used in mammography with different X ray qualities: EUROMET project no. 526.

The effect of different X ray radiation qualities on the calibration of mammographic dosemeters was investigated within the framework of a EUROMET (European Collaboration in Measurement Standards) project. The calibration coefficients for two ionization chambers and two semiconductor detectors were established in 13 dosimetry calibration laboratories for radiation qualities used in mammography. They were compared with coefficients for other radiation qualities, including those defined in ISO 4037-1, with first half value layers in the mammographic range. The results indicate that the choice of the radiation quality is not crucial for instruments with a small energy dependence of the response. However, the radiation quality has to be chosen carefully if instruments with a marked dependence of their response to the radiation energy are calibrated.

Reliability of physical examination as a predictor of vascular injury after penetrating neck trauma.

The policy of routine angiography (ANG) for all penetrating neck wounds results in a high rate of negative studies. The medical records of all patients who presented to Wishard Memorial Hospital and Methodist Hospital of Indiana with penetrating injuries to the neck from January 1992 to April 2001 were reviewed. All patients who were hemodynamically stable underwent four-vessel ANG to evaluate for vascular injury irrespective of findings on physical examination (PE). A total of 216 patients sustained penetrating neck injuries. Patients were divided according to positive or negative PE findings and the results of ANG. Of the 63 patients with a positive PE, 40 (68%) also had a positive ANG finding. Of the 89 patients with negative PE, only 3 had a positive ANG and none of these injuries required operative repair. PE therefore had a 93 per cent sensitivity (SEN) and a 97 per cent negative predictive value (NPV) for predicting the results of ANG. The SEN and NPV of PE for detecting vascular injuries requiring operative repair were both 100 per cent. In this series, no patient with a negative PE had a vascular injury that required operative repair, irrespective of zone of injury. Routine ANG may therefore be unnecessary for patients with penetrating neck injuries and a negative PE.

An assessment of the potential for reducing future combat deaths through medical technologies and training.

BACKGROUND: We examined clinical records of combat casualties that died subsequent to reaching a medical treatment facility in an effort to determine whether new medical technologies or enhanced training might contribute to a reduction in combat deaths. METHODS: Hospital records of 210 fatal combat casualties were independently reviewed by four surgeons. The surgeons assessed each fatality to determine whether it would be preventable if the trauma were sustained today and treated with currently available technology and training. RESULTS: In 8% of the cases, the four surgeons independently agreed that the deaths would be possibly preventable if the same traumas were incurred today. In an additional 17% of the cases, three of the four surgeons judged the deaths to be possibly preventable today. Causes of death viewed as most likely to be salvageable today included hemorrhage, severe burns, pulmonary edema, and sepsis. The medical technologies most often mentioned to have a potentially lifesaving effect were ventilators/respirators, computed tomographic scanners, ultrasound, and antibiotics. Areas of training most often mentioned to have a potential impact on the salvageability of the trauma cases reviewed were damage control, ventilator management, liver packing, respiratory distress management, and burn management. CONCLUSION: Surgeons reviewing records of past combat deaths indicated that reductions in the incidence of combat deaths through deployment of improved medical technologies and training is possible. Deployment of the noted technologies and proficiency in the cited training has the potential for reducing deaths by 8% to 25% when compared with the died-in-hospital incidence among casualties in the last sustained conflict.

Comparison of two methods of therapy level calibration at 60Co gamma beams.

The accuracy and traceability of the calibration of radiotherapy dosimeters is of great concern to those involved in the delivery of radiotherapy. It has been proposed that calibration should be carried out directly in terms of absorbed dose to water, instead of using the conventional and widely applied quantity of air kerma. In this study, the faithfulness in disseminating standards of both air kerma and absorbed dose to water were evaluated, through comparison of both types of calibration for three types of commonly used radiotherapy dosimeters at 60Co gamma beams at a few secondary and primary standard dosimetry laboratories (SSDLs and PSDLs). A supplementary aim was to demonstrate the impact which the change in the method of calibration would have on clinical dose measurements at the reference point. Within the estimated uncertainties, both the air kerma and absorbed dose to water calibration factors obtained at different laboratories were regarded as consistent. As might be expected, between the SSDLs traceable to the same PSDL the observed differences were smaller (less than 0.5%) than between PSDLs or SSDLs traceable to different PSDLs (up to 1.5%). This can mainly be attributed to the reported differences between the primary standards. The calibration factors obtained by the two methods differed by up to about 1.5% depending on the primary standards involved and on the parameters of calculation used for 60Co gamma radiation. It is concluded that this discrepancy should be settled before the new method of calibration at 60Co gamma beams in terms of absorbed dose to water is taken into routine use.

Problem orientation is a new approach to surgical education.

BACKGROUND: There is increasing interest in educational methods that are loosely aggregated under the title of problem-based learning (PBL), but it remains unclear whether PBL is as successful as its conventional predecessor in transmitting factual information. MATERIALS AND METHODS: The authors designed and implemented a PBL curriculum for a third-year surgical clerkship, then prospectively compared that technique with the conventional format. Each student's subject-related knowledge was assessed with a specifically tailored 195-question written exam and correlated with National Board of Medical Examiners shelf exams. Student and faculty responses to the technique were also sought and tabulated. RESULTS: Student and faculty responses to PBL were uniformly positive. We were unable, however, to demonstrate effects on our evaluation instruments. Neither individual student performance nor grouped scores differed based on the mode of presentation. CONCLUSION: A PBL curriculum generates both student and faculty enthusiasm. Unfortunately, this does not translate into more efficient transmission of knowledge.

Penetrating and blunt injuries of the esophagus.

Though uncommon, the incidence of esophageal injury from external trauma is increasing in frequency and requires a thorough knowledge of the principles of esophageal surgery in general and familiarity with the options for repair of both the different anatomic locations of injury and the various types of injuring agents. Such knowledge and experience will avoid the potential for complications such as those described centuries ago by Richard Wiseman in the young man who impaled himself on his toy sword.

Boerhaave's syndrome and barogenic injuries of the esophagus.

Herman Boerhaave clearly elucidated the pathology of barogenic esophageal perforation during the 18th century by describing the sad and fatal case of Baron John von Wassenauer. Although the science of the time had no treatment and surgery was considered a fool's venture, Boerhaave's description has stood the test of time and set the stage for modern surgical repair and treatment. The expeditious diagnosis, aggressive early repair, and vigilant attention to drainage of esophageal perforations in the 20th century all reduce the morbidity and are essential steps to obtaining the best outcome. Today, survival of barogenic esophageal perforation requires the surgeon to have the clarity of Boerhaave's observation of symptoms and to make use of modern surgical techniques to assure the patient's recovery from Boerhaave's syndrome.

Bradycardia following carotid endarterectomy.

This study was performed to determine whether bradycardia complicates the postoperative course of patients undergoing carotid endarterectomy (CEA). The records of 216 patients undergoing 233 CEAs over a 2-year period were reviewed. Patients were divided into two groups based on their lowest Surgical Intensive Care Unit (SICU) heart rate (HR). Those with HR < 60 were in the Bradycardic (BRADY) group and those with HR > or = 60 were in the Non-Bradycardic (NON-BRADY) group. One hundred and sixteen patients developed bradycardia, with a mean (+/- SEM) HR of 51.1 +/- 0.5, compared with 117 NON-BRADY patients with a mean HR of 70.6 +/- 0.9 (P < 0.0005). There were no significant differences between the groups in age, use of cardioactive drugs, SICU severity of illness, or length of SICU stay. The systolic blood pressure for BRADY patients averaged 144 +/- 2.2 on admission and 144 +/- 2.2 (P = NS) in the SICU, while that of NON-BRADY patients rose from 143 +/- 2.3 on admission to 156 +/- 2.5 (P = 0.001). Fifty-four patients receiving a second CEA had a SICU HR not significantly different from those patients undergoing a first CEA. Of 17 patients who underwent bilateral CEAs during the study period, SICU HRs averaged 65.1 +/- 3.7 after the first procedure and 64.7 +/- 3.6 after the second (P = NS). The authors conclude that bradycardia following CEA is a frequent but benign postoperative finding that does not affect outcome, cause significant hypotension, or prolong the SICU stay.

Surgical intensive care in the nonagenarian. No basis for age discrimination.

OBJECTIVE: To investigate the effect of extreme age on outcome from surgical intensive care. DESIGN: Prospective data collection. SETTING: A 20-bed noncardiac surgical intensive care unit (SICU) that admits 2200 patients per year from a 1201-bed tertiary medical center. PATIENTS: Nonagenarians were compared with patients under 90 years of age over a 33-month period. Seven patients over age 100 years and 77 nonsurgical patients were excluded. MAIN OUTCOME MEASURES: Mortality and length of stay were determined for both the SICU and the entire hospitalization. The nonagenarian and younger groups were stratified by severity of illness using the first-day Simplified Acute Physiology Score (SAPS). RESULTS: One hundred forty nonagenarian patients (mean +/- SE age, 92.1 +/- 0.2 years) were compared with 5652 younger patients (mean age, 60.1 +/- 0.3 years). The mean SAPS of 11.1 for nonagenarian patients was significantly higher than the SAPS of 8.6 for younger patients (P < .001). Mortality in the SICU was 4.3% for nonagenarian patients vs 2.3% for younger patients (P = .13). SICU mortality rose with increasing SAPS in both groups, but there was no significant difference between nonagenarian and younger patients for any SAPS group. Hospital mortality differed significantly, with 17.1% for nonagenarian patients and 5.3% for younger patients (P < .001). Hospital and SICU length of stay did not differ significantly between the groups. CONCLUSIONS: Nonagenarians do not differ from younger SICU patients in survival from SICU care, although hospital mortality is greater in nonagenarians. Age alone should not be used to make decisions about the utility of SICU care for the elderly. Outcome correlates better with severity of illness, and the measure is valid in young and old alike.

Neonatal survival during a 2,500-mile flight.

Neonatal respiratory failure, no matter what the cause, may not always respond to standard mechanical ventilation techniques. Extracorporeal membrane oxygenation has emerged over the last 15 years as an adjunct to the treatment of these babies with a greater than 80% survival nationwide. Limited resources and personnel costs can be prohibitive, forcing regionalization of extracorporeal membrane oxygenation (ECMO) centers. Geographic distance from a center should not limit its potential application, however. Familiarity with the technique, early application of the modality and the availability of medical air transport, allows for referral and transfer of neonates over great distances with excellent results and outcomes. We present a case of respiratory failure in a neonate transported 2,500 miles for ECMO therapy with an excellent outcome and a rapid return home.

Glucose intolerance in critically ill surgical patients: relationship to total parenteral nutrition and severity of illness.

The authors evaluated the relative influence of severity of illness and total parenteral nutrition (TPN) on glucose intolerance in critically ill surgical patients. Records of TPN administration, serum glucose measurements, and the simplified acute physiology score (SAPS) were extracted from the surgical intensive care unit (SICU) and hospital clinical information systems (CIS) for all patients admitted to the SICU from October 1, 1989 through March 31, 1990. Critical hyperglycemia was defined as glucose > 400 mg/dL and critical hypoglycemia as < 40 mg/dL. During the study period, 1,129 patients received 3,054 days of care, including 88 patients who received 705 days of TPN. Of 4,985 glucose determinations performed during the study period, 48 (0.96%) were critically abnormal. Critical hyperglycemia occurred in 1.7 per cent of blood samples from TPN patients, compared to 0.7 per cent in non-TPN patients (P < 0.005). However, the mean admission and daily and maximum severity of illness scores were significantly higher in TPN patients compared to non-TPN patients (all P < 0.0005). Mean glucose levels rose with increasing SAPS in both TPN and non-TPN patients. When stratified by severity of illness, TPN patients did not have significantly higher glucose levels than non-TPN patients except for the SAPS = 15 category. The authors conclude that the glucose intolerance noted in critically ill TPN patients reflects their underlying severity of illness rather than TPN administration per se.

Decreasing transfusion exposure risk during extracorporeal membrane oxygenation (ECMO).

Extracorporeal membrane oxygenation (ECMO) is a lifesaving therapy for neonatal pulmonary hypertension but carries a significant risk for transfusion-related complications. Packed red blood cell (PRBC) and platelet exposure were quantified and reviewed in 17 ECMO survivors prior (Group I, n = 9) and subsequent to (Group II, n = 8) changes in transfusion protocols. Blood product requirements included ECMO circuit priming, maintenance of haematocrit > 0.40 or platelet count > 50 x 10(9)/l, and colloid volume expansion. Group I was exposed to 13.8 +/- 10.2 (x +/- SD) different PRBC units. In Group II, multiple transfusions from single donor units decreased exposure 71% to 3.9 +/- 0.7 units (P < 0.05). Decreases in blood withdrawn (11%) and transfusion volume (7%) were coincident with a 15% reduction in mean bypass time. Platelet volume transfusion decreased from 159 +/- 213 to 93 +/- 64 ml using volume-reduced platelet packs. Total transfusion exposure decreased 59% from 20.8 +/- 17.8 units to 8.6 +/- 2.4 donor units. No transfusion complications occurred during the aggregate 1,926 h on bypass. We conclude that neonates on ECMO have a significant transfusion exposure risk increasing with prolonged duration of ECMO therapy. In addition we noted that concentrated platelet packs decreased transfusion volume by 41%, and multiple PRBC transfusions from single donor units decreased donor exposure by 71% while both strategies decreased the overall transfusion exposure risk by 59%.

Impact of ICU nosocomial infections on outcome from surgical care.

The authors studied the impact of intensive care unit (ICU) acquired nosocomial infections on surgical patients stratified by severity of illness before acquisition of the infection. Data were analyzed from 2,122 consecutive patients admitted to a 20 bed surgical intensive care unit (SICU) from January 1, 1988 to December 31, 1988. The simplified acute physiology score (SAPS), a measure of illness severity that correlates with mortality, was calculated for all patients on their first SICU day. Ninety-seven nosocomial infections from various sites were documented in 54 patients. Patients who acquired a nosocomial infection were significantly more ill upon admission to the SICU than patients who did not acquire such an infection (control patients). Stratified by admission severity of illness, patients acquiring one or more nosocomial infections had a significantly longer SICU stay, averaging 25.3 days compared to 2.3 days in control patients (P less than 0.001). Hospital stay was also significantly increased at 59.9 days, compared to 15.0 days in control patients (P less than 0.001). However, the overall mortality rate for patients developing nosocomial infections was significantly higher than control patients only in the middle range of admission SAPS measurements. The authors found that the monthly incidence of isolates of Xanthomatous maltophilia, a multiply-resistant nosocomial organism, reflected the overall incidence of nosocomial infections in the SICU. They observed a decline in the number of new X. maltophilia isolates and nosocomial infections concomitant with the introduction of gown and glove contact isolation procedures. The authors conclude that nosocomial infections in the SICU setting are directly related to increased patient morbidity and mortality depending, in part, on severity of illness upon admission.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulmonary edema and fluid mobilization as determinants of the duration of ECMO support.

The physiological variables that govern recovery of pulmonary function during neonatal extracorporeal membrane oxygenation (ECMO) remain poorly understood. We hypothesized that pulmonary hypertension (PHN) resolves soon after starting ECMO and that neonatal weight gain, pulmonary edema, and fluid mobilization are major determinants of recovery of pulmonary function and the ability to decrease ECMO support. To evaluate this, 17 consecutive neonates requiring ECMO for severe respiratory failure were reviewed. PHN was studied by daily echocardiography to assess the direction of ductal shunting. To evaluate fluid flux, pulmonary function, and edema during ECMO, we measured body weight, urine output, and ECMO flow every 12 hours. To evaluate pulmonary edema, serial chest radiographs obtained every 12 hours were randomly reviewed and scored by two radiologists with a semiquantitative chest radiograph index score (CRIS). By 25% of bypass time, PHN had resolved in all patients. However, at that time, weight had increased to 9.16% +/- 1.78% above birth weight, and the CRIS was 44% worse than the value just prior to ECMO. From 25% time on bypass, as urine output increased, patient weight and CRIS progressively decreased, allowing ECMO support to be weaned. At the time of discontinuation of ECMO support, weight had decreased to 2.0% +/- 1.3% above birth weight, and urine output remained steady at 3.0 +/- 0.3 mL/kg/h. Within 24 hours of stopping ECMO, the CRIS showed a 58% improvement compared to maximal scores during ECMO. We conclude that PHN decreases early in ECMO and that edema and its mobilization are important determinants of the improvement in pulmonary function and duration of ECMO.(ABSTRACT TRUNCATED AT 250 WORDS)

Surgical correction of hydrothorax from diaphragmatic eventration in children on peritoneal dialysis.

Continuous ambulatory peritoneal dialysis (CAPD) is frequently used in the pediatric age group for reversible and end-stage renal failure. Most pediatric patients tolerate this therapy with few complications. Approximately 2% of children, however, develop massive unilateral hydrothorax. This major complication usually results in the discontinuation of peritoneal dialysis in all forms and the institution of hemodialysis. Occult diaphragmatic defects account for most adult and pediatric patients who develop this complication. Three pediatric patients receiving CAPD complicated by massive hydrothorax are described. All patients were successfully treated by thoracotomy and repair of the diaphragmatic eventration with an immediate return to CAPD. This is the first report of successful therapy of this kind in children. A review of the cause, diagnosis, and treatment of massive hydrothorax developing during CAPD therapy is presented.

Quality assurance and utilization assessment: the major by-products of an ICU clinical information system.

In 1985 we developed a method of automatically extracting indices of severity of illness and intensity of interventions from CIS charts daily. These indices, when combined with outcome measures such as length of stay and mortality, provide a powerful new tool for quality management in the ICU. In this paper we describe our ICU's severity adjusted survival rates as compared to internationally publish norms. In addition we provide a detailed analysis of glucose levels in our ICU, which suggests that glucose control in surgical ICU patients is more closely related to measured severity of illness than administration of intravenous alimentation per se. CIS extracted indices provide a new basis for continuous quality measurement and improvement in the ICU.

Deleterious effects of testicular venous occlusion in young rats.

To determine the differences between testicular arterial and venous obstruction, the spermatic artery or vein, or both, were occluded for varying periods of time in young rats. Two months later, at the conclusion of the study, the testes were examined. Histologic degeneration after vascular obstruction was graded by a modified Johnsen's tubular biopsy score (TBS). The testicular concentrations of enzymes (lactic dehydrogenase and sorbitol dehydrogenase), known to decrease with testicular injury, were measured. TBS and seminiferous tubule diameter (STD) were found to decrease significantly after two hours of vascular occlusion and were similar regardless of whether the obstruction was produced by occlusion of arterial inflow or venous drainage, or both. Testicular concentration of enzymes decreased significantly after permanent ligation of the spermatic artery and vein, but decreased minimally when the vascular obstruction lasted less than 120 minutes. Testicular injury produced by venous occlusion was equally severe and occurred as rapidly as injury produced by arterial or combined arteriovenous occlusion. No significant injury was noted in the contralateral testes in any group.