Eva Fischer

Hypothermia during elective abdominal aortic aneurysm repair: The high price of avoidable morbidity

PURPOSE Adverse outcomes apparently associated with hypothermia led us to examine patients undergoing elective abdominal aortic aneurysm (AAA) repairs to test the hypothesis that hypothermia (temperature less than 34.5 degrees C) is associated with increased morbidity and excess mortality rates. METHODS Two hundred sixty-two elective AAA repairs were retrospectively reviewed for preoperative and intraoperative risk factors. Core temperature, age, Acute Physiology and Chronic Health Evaluation (APACHE) II and APACHE III scores (raw and temperature-adjusted), fluid resuscitation, and perioperative organ dysfunction were recorded prospectively. Outcome measures included lengths of stay in the intensive care unit and in the hospital, and hospital mortality rates. RESULTS Except for a higher risk of hypothermia in women (p < 0.05), by univariate analysis, preoperative risk factors were similar in patients in the hypothermic and normothermic groups. After operation, patients with hypothermia had significantly greater APACHE scores (p < 0.0001), and patients in the hypothermic nonsurvivor group took significantly longer to rewarm (p < 0.05), suggesting marked hypoperfusion. Patients with hypothermia had significantly greater fluid (p < 0.05), transfusion (p < 0.01), vasopressor (p < 0.05), and inotrope (p < 0.05) requirements, resulting in significantly higher incidences of organ dysfunction (53.0% vs 28.7%, p < 0.01) and death (12.1% vs 1.5%, p < 0.01) and markedly prolonged lengths of stay in the unit (9.2 +/- 2.0 vs 5.3 +/- 0.6, p < 0.05) and in the hospital (24.3 +/- 2.9 vs 15.0 +/- 0.08, p < 0.01). By multivariate analysis, female gender (p = 0.004) was the only predictor of intraoperative hypothermia, whereas initial hypothermia was significantly predictive of both prolonged hypothermia and development of organ failure (p < 0.05). Organ failure (p < 0.05) and acute myocardial infarction (p < 0.01) were independent predictors of death. CONCLUSIONS After AAA repair, patients with hypothermia have multiple physiologic derangements associated with adverse outcomes. Although multiple etiologic factors are interacting, body temperature is one variable that should be controlled during aortic surgery.

Utility of illness severity scoring for prediction of prolonged surgical critical care.

OBJECTIVE To determine whether APACHE III and multiple organ dysfunction syndrome scores can predict a prolonged length of stay for critically ill surgical patients in the intensive care unit. DESIGN Prospective, inception-cohort study. SETTING Surgical intensive care unit (SICU) of an urban, tertiary care hospital. PATIENTS 2,295 consecutive admissions for critical surgical illness, postoperative complications, or postoperative monitoring in 2,058 patients. INTERVENTIONS Calculation of Acute Physiology and Chronic Health Evaluation (APACHE) II and APACHE III scores 24 hours after admission to the SICU. Serial quantitation of organ dysfunction for the duration of hospitalization according to the multiple organ dysfunction score. Patients were stratified by survival and time intervals for the duration of critical care, and followed until discharge or death. MAIN OUTCOME MEASURES Hospital mortality and length of stay in the SICU. RESULTS The mean APACHE II and APACHE III scores were 14.0 +/- 0.2 and 45.2 +/- 0.6 points, respectively (mean +/- SEM). The incidence of organ dysfunction was 43%, and the hospital mortality was 9.7%. The mean ICU length of stay was 6.1 +/- 0.2 days, but decreased progressively from 6.8 +/- 0.5 days in 1991 to 5.3 +/- 0.6 days in 1995 (p < 0.01) with no change in either illness severity or the number of admissions. By univariate analysis, increased length of stay in the ICU was associated with increasing APACHE scores, an increased incidence of emergency admissions, and the incidence and magnitude of organ dysfunction (all p < 0.01). Severity indices appeared to plateau in magnitude in patients whose ICU stay ultimately exceeded 21 days. By multivariate analysis of variance (MANOVA), independent predictors of a prolonged stay in the SICU were APACHE III (p = 0.0023), emergency admission (p = 0.0007), and the magnitude of organ dysfunction (p < 0.00001), but not APACHE II. Only an emergency admission (p = 0.0005) and the magnitude of organ dysfunction (p < 0.00001) predicted a prolonged stay independently in survivors. In contrast, only the admission APACHE III score(p = < 0.0001) and the magnitude of organ dysfunction (p = 0.0001) were independently predictive of mortality by MANOVA. CONCLUSIONS The development of multiple organ dysfunction syndrome is a powerful predictor of a prolonged ICU course in critical surgical illness, even in survivors. Increased risk of a prolonged stay in the ICU plateaued at 21 days, making 21 days an appropriate definition of prolonged care for future studies. Predictive models should account for organ dysfunction and very long stays in future estimations. The combined use of APACHE III and the multiple organ dysfunction score may provide improved prediction of a prolonged stay in the ICU, but further enhancements are needed before prediction of outcome in individual patients is reliable.

A PROSPECTIVE COMPARISON OF TWO MULTIPLE ORGAN DYSFUNCTION/FAILURE SCORING SYSTEMS FOR PREDICTION OF MORTALITY IN CRITICAL SURGICAL ILLNESS

Multiple organ failure (MOF) is the primary cause of death in surgical intensive care units (SICU). Mortality increases with an increasing number of failed organs, but it has been recognized that lesser degrees of organ dysfunction occur commonly. Such gradations of the multiple organ dysfunction syndrome (MODS) are postulated to provide more descriptive and predictive power. We analyzed and compared two different MODS/MOF scoring systems and determined the utility of gradations of organ dysfunction for prediction of mortality in MODS/MOF. One of the scoring systems defines organ failure as an all-or-nothing phenomenon for each organ, whereas the other scoring system describes increasing organ dysfunction on a 24-point scale. Each scoring system assesses the same six organs. Admission APACHE II (AII) and AIII scores were calculated as independent estimates of mortality. In 867 consecutive SICU admissions, 261 patients (30%) had some degree of organ dysfunction, of whom 142 patients (54%) met criteria for single or multiple organ failure. The mean admission AII score was 19 (25 for nonsurvivors), and the AIII score was 62 (91 for nonsurvivors). Overall mortality was 5.8%, but among those patients with organ dysfunction, mortality was 19%. Death was equally likely for comparable degrees of organ dysfunction and failure. Mortality increased (p < 0.01, ANOVA) with higher scores in both systems. In patients with 9-12 organ dysfunction points, the number of failed organs was 1.5 +/- 0.2 in 34 survivors, versus 2.9 +/- 0.3 in the 14 nonsurvivors (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnosis and management of acute aortic valvular disruption secondary to rapid-deceleration trauma

Acute aortic valve rupture with resultant aortic insufficiency is a rare complication of blunt trauma. We describe a case in which a patient fell 70 feet, sustaining avulsion of two leaflets of the aortic valve along with multiple other injuries, primarily orthopedic. Our case demonstrates that patients with acute aortic regurgitation can be managed nonoperatively if necessary in the acute setting, enabling management of other significant trauma. Subsequent semielective valvular replacement may be undertaken if other injuries must take precedence.

Alterations of preliminary readings on radiographic examinations minimally affect outcomes of trauma patients discharged from the emergency department.

BACKGROUND We hypothesized that trauma patients could be discharged safely from the emergency department (ED) before the availability of official readings for their radiologic examinations. We also sought to determine whether trauma patients were more prone to alterations of preliminary interpretations than other ED patients. METHODS Alterations of preliminary readings (PR) for patients discharged from the ED were reviewed. If the official readings conflicted with the PR used for the patients disposition, attempts were made to contact the patient and provide the appropriate follow-up. Data recorded included the type of radiographic examination, the presence of a missed injury, and the follow-up. By using institutional data, the incidence of inaccurate PR were compared for trauma patients and other ED patients (chi2 test, Fisher exact test, p < 0.05). RESULTS Between January of 1998 and December of 1998, 102 of 38,260 discharged ED patients had official readings differing from PR. Forty-three of the changed readings involved 42 of the 1,073 discharged trauma patients, who were more likely to harbor inaccurate PR (<0.0001) than other discharged ED patients. Twenty-eight altered readings involved plain films and 15 involved computed tomographic scans. The most common altered readings involved computed tomographic scans of the head and face (n = 13). Twelve missed injuries were detected, most commonly related to a missed injury of the extremity (7 cases). Nine other cases involved the detection of incidental pathologic conditions. Eight patients required repeat ED visits for clinical and radiographic evaluation, and one patient required subsequent hospital admission. CONCLUSION Discharged trauma patients are more likely to harbor alterations of preliminary interpretations than other ED patients. Although the official readings for these trauma patients will occasionally reveal previously undetected pathologic conditions, the majority of such cases can be managed with outpatient follow-up.

COMPARISON OF APACHE II AND III SCORING SYSTEMS FOR MORTALITY PREDICTION IN CRITICAL SURGICAL ILLNESS (CSI)

OBJECTIVE To determine whether the Acute Physiology and Chronic Health Evaluation III (APACHE III), an updated version of APACHE II that contains a larger number of postoperative patients in the normative database, offers better prediction in critical surgical illness. DESIGN Prospective cohort study. SETTING Surgical intensive care unit of an urban, tertiary-care university hospital. PARTICIPANTS Eight hundred forty-four consecutive patients in the surgical intensive care unit. Overall scores were determined, as well as scores for survivor, nonsurvivor, trauma, nontrauma, postoperative, and nonoperative patient subgroups. MAIN OUTCOME MEASURES Survival to hospital discharge, and survival compared with published normative APACHE II and III databases. RESULTS Mean age was 65.1 +/- 0.5 years. Overall mortality was 7.0% in the surgical intensive care unit and 9.1% in the hospital. The relationship between APACHE II and APACHE III scores for individual patients was linear and correlated significantly (P < .0001) (range of correlation coefficients, .72 to .86) overall and in all subgroups. Both scoring systems overestimated our mortality, but estimations made by APACHE III were significantly (P < .01) higher overall and in all subgroups. CONCLUSIONS In institutions or groups of patients where APACHE II underestimates mortality, APACHE III may be corrective. However, the differences are subtle and may be difficult to detect in smaller studies.