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Biomedical subjects

M H Kollef

Publications and source records attributed to M H Kollef.

At least 73 records · Page 4Linked to original sources
PubMed1997

Mechanical ventilation with or without daily changes of in-line suction catheters.

The purpose of this study was to determine the safety and cost-effectiveness of not routinely changing in-line suction catheters for patients requiring mechanical ventilation. Patients were randomly assigned to receive either no routine in-line suction catheter changes (n = 258) or in-line suction catheter changes every 24 h (n = 263). The main outcome measure was the incidence of ventilator-associated pneumonia. Other outcomes evaluated included hospital mortality, acquired organ system derangements, duration of mechanical ventilation, lengths of intensive care and hospital stay, and the cost for in-line suction catheters. Ventilator-associated pneumonia was seen in 38 patients (14.7%) receiving no routine in-line suction catheter changes and in 39 patients (14.8%) receiving in-line suction catheter changes every 24 h (relative risk, 0.99; 95% CI, 0.66 to 1.50). No statistically significant differences for hospital mortality, lengths of stay, the number of acquired organ system derangements, death in patients with ventilator-associated pneumonia, or mortality directly attributed to ventilator-associated pneumonia were found between the two treatment groups. Patients receiving in-line suction catheter changes every 24 h had 1,224 catheter changes costing a total of $11,016; patients receiving no routine in-line suction catheter changes had a total of 93 catheter changes costing $837. Our findings suggest that the elimination of routine in-line suction catheter changes is safe and can reduce the costs associated with providing mechanical ventilation.

Adult↗
PubMed1997

Scheduled change of antibiotic classes: a strategy to decrease the incidence of ventilator-associated pneumonia.

The purpose of this study was to determine the impact of a scheduled change of antibiotic classes, used for the empiric treatment of suspected gram-negative bacterial infections, on the incidence of ventilator-associated pneumonia and nosocomial bacteremia. Six hundred eighty patients undergoing cardiac surgery were evaluated. During a 6-mo period (i.e., the before-period), our traditional practice of prescribing a third generation cephalosporin (ceftazidime) for the empiric treatment of suspected gram-negative bacterial infections was continued. This was followed by a 6-mo period (i.e., the after-period) during which a quinolone (ciprofloxacin) was used in place of the third-generation cephalosporin. The incidence of ventilator-associated pneumonia was significantly decreased in the after-period (n = 327) compared with the before-period (n = 353) (6.7 versus 11.6%; p = 0.028). This was primarily due to a significant reduction in the incidence of ventilator-associated pneumonia attributed to antibiotic-resistant gram-negative bacteria (0.9 versus 4.0%; p = 0.013). Similarly, we observed a lower incidence of bacteremia attributed to antibiotic-resistant gram-negative bacteria in the after-period compared with the before-period (0.3 versus 1.7%; p = 0.125). These data suggest that a scheduled change of antibiotic classes can reduce the incidence of ventilator-associated pneumonia attributed to antibiotic-resistant gram-negative bacteria.

Adolescent↗
PubMed1997

Enoxaparin-associated dermal necrosis: a consequence of cross-reactivity with heparin-mediated antibodies.

OBJECTIVE: To describe a patient with enoxaparin-induced dermal necrosis and to review previously reported cases of skin manifestations associated with low-molecular-weight heparins. CASE SUMMARY: A 43-year-old white woman with adult respiratory distress syndrome developed localized dermal necrosis and thrombocytopenia secondary to subcutaneous administration of unfractionated heparin. Upper extremity thrombi that had developed after administration of subcutaneous heparin at an outside hospital were treated with subcutaneous enoxaparin. Although platelet counts remained stable during enoxaparin therapy, dermal necrosis developed at the injection site. Parenteral anticoagulant therapy was discontinued and the necrotic lesions secondary to enoxaparin resolved with minimal local care. DISCUSSION: Numerous cases of dermal necrosis secondary to heparin administration have been reported while this reaction secondary to enoxaparin use has been reported only briefly. It has been postulated that dermal necrosis secondary to heparin is associated with heparin-induced thrombocytopenia and is a result of heparin-mediated thrombosis in the microvasculature. Antibodies to heparin have cross-reactivity with enoxaparin; therefore, dermal necrosis secondary to enoxaparin may occur by a similar mechanism. CONCLUSIONS: Although enoxaparin-associated dermal necrosis appears to be a rare occurrence, we advise against the use of enoxaparin or other low-molecular-weight heparins in patients with a previous history of heparin-associated thrombocytopenia or heparin-induced dermal necrosis.

Adult↗
PubMed1997

The impact of gender on outcome from mechanical ventilation.

OBJECTIVE: To determine the relation of gender to outcome for patients requiring mechanical ventilation. DESIGN: A prospective cohort study. SETTING: Medical and surgical ICUs in two university-affiliated teaching hospitals. PATIENTS: Three hundred fifty-seven patients requiring mechanical ventilation. INTERVENTIONS: Prospective patient surveillance and data collection. MEASUREMENTS AND RESULTS: The primary outcome measure was hospital mortality. Secondary outcome measures included need for reintubation, hospital and ICU length of stay, duration of mechanical ventilation, and hospital charges. The hospital mortality rate for women (n = 189) was significantly greater than the hospital mortality rate for men (n = 168) (28.0% vs 17.3%; p = 0.016). This difference in hospital mortality was observed despite similar baseline demographic characteristics, severity of illness, indications for mechanical ventilation, and number of dysfunctional organ systems in these two groups of patients. The duration of mechanical ventilation and ICU length of stay was also significantly longer for female patients compared with male patients (p < or = 0.056). In a logistic-regression analysis, female gender was found to be independently associated with hospital mortality (adjusted odds ratio [AOR] = 2.38; 95% confidence interval [CI] = 1.70 to 3.35; p = 0.010). The presence of ARDS (AOR = 10.69; 95% CI = 5.86 to 19.51; p < 0.001), the number of dysfunctional organ systems (AOR = 2.07; 95% CI = 1.78 to 2.41; p < 0.001), Acute Physiology and Chronic Health Evaluation (APACHE) II predicted mortality (AOR = 1.15; 95% CI = 1.11 to 1.19; p < 0.001), and patient age (AOR = 1.04; 95% CI = 1.03 to 1.06; p < 0.001) were also found to be independently associated with hospital mortality. The number of dysfunctional organ systems present at the start of mechanical ventilation was the major independent predictor of hospital mortality (54% of total explanatory power). Patient gender was the least important independent predictor of hospital mortality (5% of total explanatory power). CONCLUSIONS: In this patient cohort, women requiring mechanical ventilation were at greater risk for hospital mortality than men. Physicians should be aware that outcome differences according to gender can occur when evaluating or designing clinical trials involving mechanically ventilated patients. Future studies are necessary to determine the general applicability of these findings and to identify explanations for such observed gender-specific differences in outcome.

APACHE↗
PubMed1997

Clinically recognized cardiac dysfunction: an independent determinant of mortality among critically ill patients. Is there a role for serial measurement of cardiac troponin I?

OBJECTIVE: To determine the relative importance of clinically recognized cardiac dysfunction and unrecognized cardiac injury to hospital mortality. DESIGN: Prospective, blinded, single-center study. SETTING: Medical ICU of Barnes-Jewish Hospital, St. Louis, a university-affiliated teaching hospital. PATIENTS: Two hundred sixty adult patients requiring admission to the medical ICU. INTERVENTIONS: Daily blood collection. MAIN OUTCOME MEASURES: The presence of cardiac dysfunction (myocardial infarction, unstable angina, cardiac arrest, or congestive heart failure) as determined by the physicians responsible for the care of the patient. Daily measurement of levels of cardiac troponin I, a sensitive, highly specific, and long-lived marker of myocardial injury. RESULTS: Fifty-five (21.2%) patients had clinical evidence of cardiac dysfunction, among whom 22 (40%) had an elevated level of cardiac troponin I. A total of 41 (15.8%) patients had evidence of acute myocardial injury based on elevated levels of cardiac troponin I. Patients with clinically recognized cardiac dysfunction had a significantly greater hospital mortality rate compared to patients without clinically recognized cardiac dysfunction (45.5% vs 10.2%; p < 0.001). Similarly, patients with elevated blood levels of cardiac troponin I had a greater hospital mortality rate compared to patients without elevated blood levels of cardiac troponin I (26.8% vs 16.0%; p = 0.095). Multiple logistic-regression analysis controlling for potential confounding variables demonstrated that the presence of clinically recognized cardiac dysfunction was independently associated with hospital mortality (adjusted odds ratio = 3.0; 95% confidence interval = 1.9 to 4.8; p = 0.016). However, having an elevated blood level of cardiac troponin I was not found to be an independent determinant of hospital mortality. CONCLUSION: Among critically ill medical patients, clinically recognized cardiac dysfunction is an independent determinant of hospital mortality. The identification of unrecognized cardiac injury, using serial measurements of cardiac troponin I, did not independently contribute to the prediction of hospital mortality.

Adult↗
PubMed1997

A rapid qualitative assay to detect circulating endotoxin can predict the development of multiorgan dysfunction.

OBJECTIVE: To determine whether a rapid qualitative assay for the detection of circulating endotoxin (SimpliRED Endotoxin Test [SRE]; AGEN, Inc; Brisbane, Australia) can predict the occurrence of multiorgan dysfunction and hospital mortality. To compare the SRE to the limulus amebocyte lysate (LAL) assay as a predictor of clinical outcomes. DESIGN: Prospective, blinded, single-center study. SETTING: Medical ICU of Barnes-Jewish Hospital, St. Louis, a university-affiliated teaching hospital. PATIENTS: Included in the study were 265 adult patients requiring medical ICU admission. INTERVENTIONS: Daily collection of blood samples. MEASUREMENTS AND RESULTS: Daily detection for the presence of endotoxin in blood during intensive care and assessment for the development of multiorgan dysfunction (ie, an organ system failure index >2) or death. On ICU day 1, 55 (20.8%) patients had circulating endotoxin detected by the SRE. On ICU day 2, 29 of the 143 (20.3%) patients remaining in the ICU had a positive SRE. The development of multiorgan dysfunction was significantly greater among SRE-positive patients (44.8%) compared to SRE-negative patients (21.9%) on ICU day 2 (p=0.013). Multiple logistic regression analysis identified a positive SRE on ICU day 2 (adjusted odds ratio, 4.1; 95% confidence interval, 2.5 to 6.8; p=0.006) as being independently associated with the development of multiorgan dysfunction. A positive SRE test was not predictive of hospital mortality. Direct quantitative measurement of the concentration of circulating endotoxin using the LAL assay was not associated with either the development of multiorgan dysfunction or hospital mortality (p>0.1). CONCLUSIONS: Our preliminary data suggest that a bedside assay to qualitatively detect circulating endotoxin is predictive of the development of multiorgan dysfunction among patients admitted to a medical ICU. The rapid detection of circulating endotoxin could be useful for stratifying patients into various risk categories for the development of multiorgan dysfunction.

Agglutination Tests↗
PubMed1997

The impact of nosocomial infections on patient outcomes following cardiac surgery.

STUDY OBJECTIVE: To evaluate the relationship between nosocomial infections and clinical outcomes following cardiac surgery, and to identify risk factors for the development of nosocomial infections in this patient population. DESIGN: Prospective cohort study. SETTING: Barnes-Jewish Hospital, St. Louis, a university-affiliated teaching hospital. PATIENTS: Six hundred five consecutive patients undergoing cardiac surgery. INTERVENTIONS: Prospective patient surveillance and data collection. MAIN OUTCOME MEASURES: Occurrence of nosocomial infections, multiorgan dysfunction, hospital mortality, and risk factors for the acquisition of nosocomial infections. RESULTS: One hundred thirty-one (21.7%) patients acquired at least one nosocomial infection following cardiac surgery. Four independent risk factors for the development of a nosocomial infection were identified: the duration of mechanical ventilation, postoperative empiric antibiotic administration, the duration of urinary tract catheterization, and female gender. Thirty (5.0%) patients died during their hospitalization. The mortality rate of patients acquiring a nosocomial infection (11.5%) was significantly greater than the mortality rate of patients without a nosocomial infection (3.2%) (odds ratio [OR]=4.0; 95% confidence interval [CI]=2.7 to 5.8; p<0.001). Multiorgan dysfunction was found to be the most important independent determinant of hospital mortality (adjusted OR=23.8; 95% CI=13.5 to 42.1; p<0.001) along with the aortic cross-clamp time (adjusted OR=2.3; 95% CI=1.7 to 3.0; p=0.002) and severity of illness as measured by APACHE II (acute physiology and chronic health evaluation) (adjusted OR=1.1; 95% CI=1.1 to 1.2; p=0.019). Ventilator-associated pneumonia, clinical sepsis, female gender, the cardiopulmonary bypass time, and severity of illness were identified as independent risk factors for the development of multiorgan dysfunction. Among hospital survivors, patients acquiring a nosocomial infection had longer hospital lengths of stay compared to patients without a nosocomial infection (20.1+/-13.0 days vs 9.7+/-4.5 days; p<0.001). CONCLUSIONS: Nosocomial infections, which are common following cardiac surgery, are associated with prolonged lengths of hospitalization, the development of multiorgan dysfunction, and increased hospital mortality. These data suggest potential interventions for the prevention of nosocomial infections following cardiac surgery that could substantially improve patient outcomes and decrease medical care costs.

APACHE↗
PubMed1997

Patient transport from intensive care increases the risk of developing ventilator-associated pneumonia.

STUDY OBJECTIVE: To determine whether patient transport out of the ICU is associated with an increased risk of developing ventilator-associated pneumonia. DESIGN: Prospective cohort study. SETTING: ICUs of Barnes-Jewish Hospital, a university-affiliated teaching hospital. PATIENTS: Five hundred twenty-one ICU patients requiring mechanical ventilation for > 12 h. INTERVENTION: Prospective patient surveillance and data collection. MEASUREMENTS AND RESULTS: The primary outcome measure was the development of ventilator-associated pneumonia. A total of 273 (52.4%) mechanically ventilated patients required at least one transport out of the ICU while 248 (47.6%) patients did not undergo transport. Sixty-six (24.2%) of the transported patients developed ventilator-associated pneumonia compared with 11 (4.4%) patients in the group not undergoing transport (relative risk=5.5; 95% confidence interval [CI]=2.9 to 10.1; p<0.001). Multiple logistic regression analysis demonstrated that a preceding episode of transport out of the ICU was independently associated with the development of ventilator-associated pneumonia (adjusted odds ratio=3.8; 95% CI=2.6 to 5.5; p<0.001). Other variables independently associated with the development of ventilator-associated pneumonia included reintubation, presence of a tracheostomy, administration of aerosols, and male gender. CONCLUSIONS: We conclude that patient transport out of the ICU is associated with an increased risk for the development of ventilator-associated pneumonia.

APACHE↗
PubMed1996

Acute respiratory distress syndrome.

The acute respiratory distress syndrome (ARDS) is a serious and complex clinical problem that often threatens the lives of patients. Emerging clinical data suggest that the survival of patients with this disorder may have improved during the last two decades, presumably because of advances in supportive medical care. Among the supportive therapies used to treat patients with ARDS, none is more complex than mechanical ventilation. New strategies for administering mechanical ventilation to patients with ARDS may reduce the occurrence of iatrogenic volotrauma and oxygen toxicity, accounting in part for the recently observed improvements in patient survival. Prevention and cure of ARDS have remained elusive goals because of the lack of specific therapies directed against the known pathogenic factors. Ongoing investigations are aimed at identifying specific therapies to interrupt the mechanisms of inflammation and lung injury responsible for this syndrome. Until such therapies become available, clinicians caring for patients with ARDS should attempt to minimize additional morbidity and mortality resulting from nosocomial infections and iatrogenic injuries.

Humans↗
PubMed1996

Private attending physician status and the withdrawal of life-sustaining interventions in a medical intensive care unit population.

OBJECTIVE: To assess the influence of private attending physician status on the withdrawal of life-sustaining interventions among patients dying within a medical intensive care unit (ICU). DESIGN: Retrospective cohort analysis. SETTING: An academic tertiary care center. PATIENTS: One hundred fifty-nine consecutive patient deaths occurring in the medical ICU during a 12-month period. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Withdrawal of life-sustaining interventions (i.e., mechanical ventilation, dialysis, and/or vasopressors), duration of mechanical ventilation, length of intensive care unit stay, medical care costs, and patient charges were recorded. Life sustaining interventions were actively withdrawn from 69 (43.4%) patients prior to death. Patients without a private attending physician were significantly more likely to undergo the withdrawal of life-sustaining interventions compared with patients having a private attending physician (odds ratio = 2.5; 95% confidence interval = 1.8, 3.6, respectively; p = .005). A correlation was found between the possession of private health insurance and private attending physician status (r2 = .39, p < .001). Multiple logistic regression analysis was subsequently used to control for demographic factors and severity of illness. Three independent predictors for the withdrawal of life-sustaining interventions were identified in this patient cohort (p < .05) having a planned therapeutic trial of life-sustaining interventions outlined in the medical record (adjusted odds ratio 9.4; 95% confidence interval = 5.6 to 15.6; p < .001); lack of a private attending physician (adjusted odds ratio = 4.4; 95% confidence interval = 2.9 to 6.5; p < .001); and the presence of clearly defined advance directives regarding patient preferences for medical care (adjusted odds ratio = 3.6; 95% confidence interval = 2.3 to 5.7; p. = .005). Patients with private attending physicians had significantly greater medical care costs and medical care charges compared with patients without a private attending physician. CONCLUSION: Among patients dying within a medical ICU, those patients without a private attending physician are more likely to undergo the active withdrawal of life-sustaining interventions.

APACHE↗
PubMed1996

The accuracy of elevated concentrations of endotoxin in bronchoalveolar lavage fluid for the rapid diagnosis of gram-negative pneumonia.

The purpose of this study was to determine the accuracy of elevated concentrations of endotoxin in bronchoalveolar lavage (BAL) fluid for the diagnosis of gram-negative pneumonia. Sixty-three hospitalized adults underwent 71 evaluations with BAL using quantitative cultures for suspected lung infection. A cutoff value of > 5 EU/ml for the concentration of endotoxin in BAL fluid yielded the best operating characteristics for the diagnosis of gram-negative pneumonia (sensitivity, 100%; specificity, 75.0%; area under receiver operating characteristic [ROC] curve, 0.88). Good diagnostic agreement was found between elevated concentrations of endotoxin in BAL fluid and microbiologically confirmed gram-negative pneumonia (kappa statistic, 0.64; concordance 83.1%). Gram stain examination of BAL fluid for the presence of gram-negative bacteria yielded inferior operating characteristics (sensitivity, 63.2%; specificity, 75.0%; area under ROC curve, 0.69). Poor diagnostic agreement was observed between BAL fluid Gram stain results and microbiologically confirmed gram-negative pneumonia (kappa statistic, 0.35; concordance, 71.8%). These findings suggest that a concentration of endotoxin in BAL fluid > 5 EU/ml is superior to Gram stain examination for the rapid identification of patients with gram-negative pneumonia.

Adult↗
PubMed1995

Mechanical ventilation with or without 7-day circuit changes. A randomized controlled trial.

OBJECTIVE: To determine whether a practice of not routinely changing ventilator circuits in patients who require prolonged mechanical ventilation is associated with an increased incidence of nosocomial pneumonia. DESIGN: Randomized controlled trial. SETTING: Intensive care units in two university-affiliated teaching hospitals. PATIENTS: 300 patients admitted to an intensive care unit who required mechanical ventilation for more than 5 days. INTERVENTION: Patients were randomly assigned to receive either no routine ventilator circuit changes or circuit changes every 7 days. MEASUREMENTS: The primary outcome measure was the incidence of ventilator-associated pneumonia. Other outcome measures included duration of mechanical ventilation, length of hospital stay, and hospital mortality. RESULTS: 147 patients were randomly assigned to receive no routine ventilator circuit changes, and 153 patients were randomly assigned to receive circuit changes every 7 days. The two groups were similar at the time of randomization with regard to demographic characteristics, intensive care unit admission diagnoses, and severity of illness. Ventilator-associated pneumonia was seen in 36 patients (24.5%) receiving no routine changes and in 44 patients (28.8%) receiving changes every 7 days (relative risk, 0.85 [95% CI, 0.55 to 1.17]). No statistically significant differences for hospital mortality, intensive care unit mortality, death during mechanical ventilation, death in patients with ventilator-associated pneumonia, or mortality directly attributed to ventilator-associated pneumonia were found between the two treatment groups (P > or = 0.11). Patients receiving changes every 7 days had 247 circuit changes costing a total of $7410; patients receiving no routine changes had a total of 11 circuit changes costing $330. CONCLUSION: The elimination of routine ventilator circuit changes can reduce medical care costs without increasing the incidence of nosocomial pneumonia in patients who require prolonged mechanical ventilation.

Adult↗
PubMed1995

The safety and diagnostic accuracy of minibronchoalveolar lavage in patients with suspected ventilator-associated pneumonia.

OBJECTIVES: To assess the safety of minibronchoalveolar lavage done by respiratory therapists for the evaluation of suspected ventilator-associated pneumonia and to determine the diagnostic agreement between quantitative lower airway cultures obtained by the minibronchoalveolar lavage and protected specimen brush techniques. DESIGN: A prospective direct comparison of two diagnostic techniques. SETTING: An academic tertiary care center in St. Louis, Missouri. PATIENTS: 72 consecutive patients suspected of having ventilator-associated pneumonia on the basis of clinical evidence. INTERVENTIONS: Sampling of lower airway secretions using the protected specimen brush and minibronchoalveolar lavage techniques. MAIN OUTCOME MEASURES: Clinical complications and quantitative cultures of respiratory secretions. RESULTS: 72 patients suspected of having ventilator-associated pneumonia (first episode) were evaluated using minibronchoalveolar lavage. In 42 patients, lower airway secretions were also obtained using the protected specimen brush technique. No change in arterial blood oxygen saturation or heart rate occurred after minibronchoalveolar lavage (P > 0.2). Mean arterial pressure slightly increased with minibronchoalveolar lavage (baseline mean pressure, 90.1 mm Hg [CI, 88.4 to 91.7 mm Hg]; average within-person change, 2.6 mm Hg; P = 0.024). Good diagnostic agreement was shown for quantitative cultures obtained with the protected specimen brush and minibronchoalveolar lavage techniques (kappa statistic, 0.63; concordance, 83.3%); 10(3) colony forming units/mL was used as the threshold for a clinically significant culture result. CONCLUSIONS: Minibronchoalveolar lavage is a safe and technically simple procedure for obtaining quantitative lower airway cultures in patients requiring mechanical ventilation. Quantitative culture results obtained by minibronchoalveolar lavage are similar to those obtained by the protected specimen brush technique.

Adult↗