Elisheva Simchen

Survival of critically ill patients hospitalized in and out of intensive care units under paucity of intensive care unit beds

Objective:The demand for intensive care beds far exceeds their availability in many European countries. Consequently, many critically ill patients occupy hospital beds outside intensive care units, throughout the hospital. The outcome of patients who fit intensive care unit admission criteria but are hospitalized in regular wards needs to be assessed for policy implications. The object was to screen entire hospital patient populations for critically ill patients and compare their 30-day survival in and out of the intensive care unit. Design:Screening teams visited every hospital ward on four selected days in five acute care Israeli hospitals. The teams listed all patients fitting a priori developed study criteria. One-month data for each patient were abstracted from the medical records. Setting:Five acute care Israeli hospitals. Patients:All patients fitting a priori developed study criteria. Interventions:None. Measurements and Main Results:Survival in and out of the intensive care unit was compared for screened patients from the day a patient first met study criteria. Cox multivariate models were constructed to adjust survival comparisons for various confounding factors. The effect of intensive care unit vs. other departments was estimated separately for the first 3 days after deterioration and for the remaining follow-up time. Results showed that 5.5% of adult hospitalized patients were critically ill (736 of 13,415). Of these, 27% were admitted to intensive care units, 24% to specialized care units, and 49% to regular departments. Admission to an intensive care unit was associated with better survival during the first 3 days of deterioration, after we adjusted for age and severity of illness (p = .018). There was no additional survival advantage for intensive care unit patients (p = .9) during the remaining follow-up time. Conclusions:The early survival advantage in the intensive care unit suggests a window of critical opportunity for these patients. Under economic constraints and dearth of intensive care unit beds, increasing the turnover of patients in the intensive care unit, thus exposing more needy patients to the early benefit of treatment in the intensive care unit, may be advantageous.

A Multivariate Analysis of Risk Factors for Acquiring Bacteriuria in Patients With Indwelling Urinary Catheters for Longer Than 24 Hours

Data related to risk factors for catheter-acquired bacteriuria were collected prospectively on 112 patients consecutively catheterized for greater than 24 hours at the Hadassah University Hospital. Logistic regression analysis indicated that factors independently associated (p less than or equal to 0.05) with a higher risk of catheter-acquired bacteriuria were as follows: hospitalization in orthopedics or urology, ethnic origin (Arabs greater than Jews), insertion of a catheter after the sixth day of hospitalization, catheterization outside the operating theatres, lack of administration of systemic antibiotics, unsatisfactory catheter care, and prolonged duration (greater than or equal to 7 days) of catheterization before infection occurred. The risk associated with catheterization outside the operating theater could be explained by its correlate, that is, catheterization for incontinence/obstruction as opposed to output measurement. Life-table analyses demonstrated that the daily risk for acquiring bacteriuria during the first six days of catheterization was higher among patients ultimately catheterized for greater than or equal to 7 days than among those ultimately catheterized for less than 7 days (P less than 0.05).

Survival of critically ill patients hospitalized in and out of intensive care

Objective:A lack of intensive care units beds in Israel results in critically ill patients being treated outside of the intensive care unit. The survival of such patients is largely unknown. The present studys objective was to screen entire hospitals for newly deteriorated patients and compare their survival in and out of the intensive care unit. Design:A priori developed intensive care unit admission criteria were used to screen, during 2 wks, the patient population for eligible incident patients. A screening team visited every hospital ward of five acute care hospitals daily. Eligible patients were identified among new admissions in the emergency department and among hospitalized patients who acutely deteriorated. Patients were followed for 30 days for mortality regardless of discharge. Setting:Five acute care hospitals. Patients:A total of 749 newly deteriorated patients. Interventions:None. Measurements and Main Results:Crude survival of patients in and out of the intensive care unit was compared by Kaplan-Meier curves, and Cox models were constructed to adjust the survival comparisons for residual case-mix differences. A total of 749 newly deteriorated patients were identified among 44,000 patients screened (1.7%). Of these, 13% were admitted to intensive care unit, 32% to special care units, and 55% to regular departments. Intensive care unit patients had better early survival (0–3 days) relative to regular departments (p = .0001) in a Cox multivariate model. Early advantage of intensive care was most pronounced among patients who acutely deteriorated while on hospital wards rather than among newly admitted patients. Conclusions:Only a small proportion of eligible patients reach the intensive care unit, and early admission is imperative for their survival advantage. As intensive care unit benefit was most pronounced among those deteriorating on hospital wards, intensive care unit triage decisions should be targeted at maximizing intensive care unit benefit by early admitting patients deteriorating on hospital wards.

Multivariate analysis of determinants of postoperative wound infection in orthopaedic patients.

In a prospective study of 376 orthopaedic patients, the relative contribution of host factors and patient-care variables to the risk of postoperative wound infection was evaluated. Host factors studied were age, sex, ethnic origin and diagnosis. The number of operations, the insertion of an open drain, the use of prophylactic antibiotics and the length of the operation were the patient-care variables studied. Of the risk factors identified, the performance of more than one operation during an admission had the highest risk coefficient, followed by the presence of an open drain, internal fixation of a fracture, and spine fusion. Within the group of operations for internal fixation, those for fractures of the femur had the highest risk of infection. In spine fusions those operations lasting 5 or more hours were associated with a high risk of infection. The length of stay of infected patients was on average 17.9 days longer than that of their individually-matched non-infected controls.

Use of Antibiotic Exposure to Detect Postoperative Infections

OBJECTIVE To assess the utility of postoperative antibiotic exposure as an indicator of postoperative infection after coronary artery bypass graft surgery. DESIGN We determined an optimal antibiotic exposure threshold by creating receiver operating characteristic curves. SETTING Tertiary healthcare institution (United States); national sample (Israel). PATIENTS 5,887 patients undergoing coronary artery bypass graft surgery. RESULTS Postoperative antibiotic exposure with at least 9 days between the first and last dates of antibiotic administration, excluding the first postoperative day, had a sensitivity of 95% (261/276) and specificity of 85% (3,944/4,628) for identifying surgical-site infection, using as a gold standard surgical-site infections identified by conventional prospective surveillance or extrapolated from review of a sample of medical records. In contrast, using the same gold standard for surgical-site infections, the sensitivity of routine prospective surveillance alone was only 60%. The predictive value positive of the defined antibiotic exposure was 28% (261/945) for surgical-site infection and 60% (563/945) for any nosocomial infection. In the Israeli cohort, the sensitivity was 87% (74/85) and the specificity was 82% (735/898). CONCLUSION Antibiotic exposure of sufficient duration and timing was more sensitive than conventional methods in detecting nosocomial infection and required substantially less effort to collect. Although the predictive value positive for surgical-site infection was only moderate, the majority of individuals identified this way had a nosocomial infection.

A national study of postoperative mortality associated with coronary artery bypass grafting in Israel

BACKGROUND Investigation of observed differences in outcomes among medical centers is of major interest to the medical community and the public and has a substantial impact on efforts to improve the quality of medical care. METHODS This study analyzed data from consecutive patients who underwent isolated coronary artery bypass grafting at 14 medical centers. Data included demographic and clinical information, comorbidity, cardiac catheterization results, and 30-day postoperative vitality status. Logistic regression analysis was used to identify variables associated with mortality. An outlier hospital was defined as one having an observed mortality outside the 95% confidence interval boundaries around the expected mortality rate calculated, given the patient risk factors. RESULTS The overall crude 30-day mortality rate for isolated coronary artery bypass grafting among the 4,835 patients in this study was 3.1%. The rate varied among centers, ranging from 0.85% to 7.05%. Predictors of 30-day mortality included advanced age, female sex, diabetes mellitus, poor left ventricular function, high creatinine level, high priority of operation, and three-vessel disease (with or without left main coronary artery disease). After adjustment for risk factors, two hospitals were defined as outliers. CONCLUSIONS The observed disparity in early mortality among patients undergoing coronary artery bypass grafting is not due solely to differences in case mix.

The Israeli Study of Surgical Infections (ISSI): II. Initial comparisons among hospitals with special focus on hernia operations.

In a study of 5,571 patients from the general surgery departments of 11 Israeli hospitals, the crude overall wound infection rates showed interhospital heterogeneity. The rates ranged from 6.3% to 12.4% (P(chi 2) = 0.039). Controlling for the different distributions of procedures performed in the various institutions did not reduce this variability. None of the hospitals had either consistently high or consistently low infection rates. A hospital could have low rates for one procedure and high rates for another. Therefore, the decision was made to proceed with procedure-specific analyses. This article details results of the analysis of 1,487 hernia operations. Four variables (old age, infection at another site, incarceration, and introduction of drains) accounted for almost all the differences in infection rates among the institutions. Of the four, presence of drains had the strongest association with infection (P derived from the logistic model less than 0.001). The risk was consistent in all hospitals and was unconfounded by other measurable factors. In contrast, the pattern of using drains seemed arbitrary and inconsistent, ranging from 9% of patients in one hospital to 41% in another. These findings were used as a basis for discussion with the surgical teams and for the initiation of a randomized clinical trial on the use of drains in hernia operations.

Determinants of wound infection after colon surgery.

Over a period of 54 months, every patient undergoing colon surgery at the Hadassah University Hospital in Jerusalem was followed up prospectively by the same nurse epidemiologist. A total of 403 patients completed the analysis. Risk factors for postoperative wound infection were explored in an epidemiological study, using both single and multivariate analysis. Of the 13 potential risk factors investigated, the four showing the highest association with wound infection were: the performance of more than one operation during a single admission; Arab ethnicity; the use of open drains; and the performance of a colostomy. In patients undergoing more than one operation, the risk for infection was greater if the second operation followed a surgical complication than if it was performed as an elective second procedure; whether the first operation was elective or not did not affect the infection rate. Second operations performed within 7 days of the first carried a higher risk for infection than those performed later. The different prophylactic protocols used during the period of investigation did not have an independently significant contribution to the risk of infection.

Determinants of wound infection in gastrointestinal operations: The Israeli study of surgical infections

Risk factors for wound infection in operations involving the opening of the gastrointestinal (GI) tract, were explored in a prospective study. There were 813 consecutive operations performed during a period of 9-14 months in 11 Israeli hospitals. The total crude infection rate was 21.6%, and the respective rates for operations on the stomach, small bowel and colon were 14.8, 21.4 and 25.4%. Of 17 putative risk factors, the strongest predictor was the performance of 2 or more operations during the same admission. Other significant risk factors were: a diagnosis of intestinal obstruction or perforation, introduction of an open drain, emergency admission, age over 40, hospital stay prior to surgery 7 or more days, urinary catheter and infection on admission. Adjustment for these factors in a logistic regression model reduced the effect of the anatomical site of the operation (i.e. large bowel vs stomach) to a non-significant level.

Effect of infections on 30-day mortality among critically ill patients hospitalized in and out of the intensive care unit.

Background:This analysis is part of a multicenter study conducted in Israel to evaluate survival of critically ill patients treated in and out of intensive care units (ICUs). Objective:To assess the role of infection on 30-day survival among critically ill patients hospitalized in ICUs and regular wards. Design:All adult inpatients were screened on four rounds for patients meeting ICU admission criteria. Retrospective chart review was used to detect presence and type of infection. Mortality was ascertained from day of meeting study criteria to 30 days thereafter. Analysis:The effect of infection on mortality among patients, treated in and out of the ICU, was compared using Kaplan Meier survival curves. Multivariate Cox models were constructed to adjust interdepartmental comparisons for case-mix differences. Results:Of 641 critically ill patients identified, 36.8% already had an infection on day 0. An additional 40.2% subsequently developed a new infection during the follow-up period, ranging from 64.6% in the ICU to 31.5% in regular wards (p < .001). Resistant infections were more prevalent in ICUs. Infection was independently associated with an increase in mortality, regardless of whether the patient was admitted to the ICU. There was no difference in the adjusted risk of mortality associated with an infection diagnosed on day 0 vs. an infection diagnosed later. Risk of dying was similar in resistant and nonresistant infections. Adjusting for infections, survival of ICU patients was better relative to patients in regular wards (adjusted hazard ratio = 0.7). Among the different types of infection, risk of mortality from pneumonia was significantly lower in ICUs relative to regular wards. There was a protective effect in ICUs among noninfected patients. Conclusion:The risk of acquiring a new infection is greater in the ICU. However, risk of mortality among ICU patients was lower for the most serious infections and for those without any infection.