Murat Yilmaz

Early Identification of Patients at Risk of Acute Lung Injury: Evaluation of Lung Injury Prediction Score in a Multicenter Cohort Study

RATIONALE Accurate, early identification of patients at risk for developing acute lung injury (ALI) provides the opportunity to test and implement secondary prevention strategies. OBJECTIVES To determine the frequency and outcome of ALI development in patients at risk and validate a lung injury prediction score (LIPS). METHODS In this prospective multicenter observational cohort study, predisposing conditions and risk modifiers predictive of ALI development were identified from routine clinical data available during initial evaluation. The discrimination of the model was assessed with area under receiver operating curve (AUC). The risk of death from ALI was determined after adjustment for severity of illness and predisposing conditions. MEASUREMENTS AND MAIN RESULTS Twenty-two hospitals enrolled 5,584 patients at risk. ALI developed a median of 2 (interquartile range 1-4) days after initial evaluation in 377 (6.8%; 148 ALI-only, 229 adult respiratory distress syndrome) patients. The frequency of ALI varied according to predisposing conditions (from 3% in pancreatitis to 26% after smoke inhalation). LIPS discriminated patients who developed ALI from those who did not with an AUC of 0.80 (95% confidence interval, 0.78-0.82). When adjusted for severity of illness and predisposing conditions, development of ALI increased the risk of in-hospital death (odds ratio, 4.1; 95% confidence interval, 2.9-5.7). CONCLUSIONS ALI occurrence varies according to predisposing conditions and carries an independently poor prognosis. Using routinely available clinical data, LIPS identifies patients at high risk for ALI early in the course of their illness. This model will alert clinicians about the risk of ALI and facilitate testing and implementation of ALI prevention strategies. Clinical trial registered with www.clinicaltrials.gov (NCT00889772).

Effect of 24-hour mandatory versus on-demand critical care specialist presence on quality of care and family and provider satisfaction in the intensive care unit of a teaching hospital*

Objective:The benefit of continuous on-site presence by a staff academic critical care specialist in the intensive care unit of a teaching hospital is not known. We compared the quality of care and patient/family and provider satisfaction before and after changing the staffing model from on-demand to continuous 24-hr critical care specialist presence in the intensive care unit. Design:Two-year prospective cohort study of patient outcomes, processes of care, and family and provider survey of satisfaction, organization, and culture in the intensive care unit. Setting:Intensive care unit of a teaching hospital. Patients:Consecutive critically ill patients, their families, and their caregivers. Interventions:Introduction of night-shift coverage to provide continuous 24-hr on-site, as opposed to on-demand, critical care specialist presence. Measurements and Main Results:Of 2,622 patients included in the study, 1,301 were admitted before and 1,321 after the staffing model change. Baseline characteristics and adjusted intensive care unit and hospital mortality were similar between the two groups. The nonadherence to evidence-based care processes improved from 24% to 16% per patient-day after the staffing change (p = .002). The rate of intensive care unit complications decreased from 11% to 7% per patient-day (p = .023). When adjusted for predicted hospital length of stay, admission source, and do-not-resuscitate status, hospital length of stay significantly decreased during the second period (adjusted mean difference −1.4, 95% confidence interval −0.3 to −2.5 days, p = .017). The new model was considered optimal for patient care by the majority of the providers (78% vs. 38% before the intervention, p < .001). Family satisfaction was excellent during both study periods (mean score 5.87 ± 1.7 vs. 5.95 ± 2.0, p = .777). Conclusions:The introduction of continuous (24-hr) on-site presence by a staff academic critical care specialist was associated with improved processes of care and staff satisfaction and decreased intensive care unit complication rate and hospital length of stay.

Toward the prevention of acute lung injury: Protocol-guided limitation of large tidal volume ventilation and inappropriate transfusion

Objective:We evaluated the effect of two quality improvement interventions (low tidal volume ventilation and restrictive transfusion) on the development of acute lung injury in mechanically ventilated patients. Design:Observational cohort study. Setting:Three intensive care units in a tertiary academic center. Patients:We included patients who were mechanically ventilated for ≥48 hrs excluding those who refused research authorization or had preexisting acute lung injury or pneumonectomy. Interventions:Multifaceted interdisciplinary intervention consisting of Web-based teaching, respiratory therapy protocol, and decision support within computerized order entry. Measurements and Main Results:Of 375 patients who met the inclusion and exclusion criteria, 212 were ventilated before and 163 after the interventions. Baseline characteristics were similar between the two groups except for a lower frequency of sepsis (27% vs. 17%, p = .030), trend toward lower median glucose level (140 mg/dL, interquartile range 118–168 vs. 132 mg/dL, interquartile range 113–156, p = .096), and lower frequency of pneumonia (27% vs. 20%, p = .130) during the second period. We observed a large decrease in tidal volume (10.6–7.7 mL/kg predicted body weight, p < .001), in peak airway pressure (31–25 cm H2O, p < .001), and in the percentage of transfused patients (63% to 38%, p < .001) after the intervention. The frequency of acute lung injury decreased from 28% to 10% (p < .001). The duration of mechanical ventilation decreased from a median of 5 (interquartile range 4–9) to 4 (interquartile range 4–8) days (p = .030). When adjusted for baseline characteristics in a multivariate logistic regression analysis, protocol intervention was associated with a reduction in the frequency of new acute lung injury (odds ratio 0.21, 95% confidence interval 0.10–0.40). Conclusions:Interdisciplinary intervention effectively decreased large tidal volumes and unnecessary transfusion in mechanically ventilated patients and was associated with a decreased frequency of new acute lung injury.

Risk factors for the development of acute lung injury in patients with septic shock : An observational cohort study

Objective:Almost half of the patients with septic shock develop acute lung injury (ALI). The understanding why some patients do and others do not develop ALI is limited. The objective of this study was to test the hypothesis that delayed treatment of septic shock is associated with the development of ALI. Design:Observational cohort study. Setting:Medical intensive care unit in a tertiary medical center. Patients:Prospectively identified patients with septic shock who did not have ALI at the outset, excluding those who denied research authorization. Measurements and Main Results:High frequency cardio-respiratory monitoring, arterial gas analysis, and portable chest radiographs were reviewed to identify the timing of ALI development. Risk factors present before ALI development were identified by review of electronic medical records and analyzed in univariate and multivariate analyses. Seventy-one of 160 patients (44%) developed ALI at a median of 5 (range 2–94) hours after the onset of septic shock. Multivariate logistic regression analysis identified the following predictors of ALI development: delayed goal-directed resuscitation (odds ratio [OR] 3.55, 95% confidence interval [CI] 1.52–8.63, p = .004), delayed antibiotics (OR 2.39, 95% CI 1.06 −5.59, p = .039), transfusion (OR 2.75, 95% CI 1.22–6.37, p = .016), alcohol abuse (OR 2.09, 95% CI .88−5.10, p = 0.098), recent chemotherapy (OR 6.47, 95% CI 1.99−24.9, p = 0.003), diabetes mellitus (OR .44, 95% CI .17−1.07, p = .076), and baseline respiratory rate (OR 2.03 per sd, 95% CI 1.38−3.08, p < .001). Conclusion:When adjusted for known modifiers of ALI expression, delayed treatment of shock and infection were associated with development of ALI.

The Stability and Workload Index for Transfer score predicts unplanned intensive care unit patient readmission: initial development and validation.

Objective:Unplanned readmission of hospitalized patients to an intensive care unit (ICU) is associated with a worse outcome, but our ability to identify who is likely to deteriorate after ICU dismissal is limited. The objective of this study is to develop and validate a numerical index, named the Stability and Workload Index for Transfer, to predict ICU readmission. Design:In this prospective cohort study, risk factors for ICU readmission were identified from a broad range of patients’ admission and discharge characteristics, specific ICU interventions, and in-patient workload measurements. The prediction score was validated in two independent ICUs. Setting:One medical and one mixed medical-surgical ICU in two tertiary centers. Patients:Consecutive patients requiring >24 hrs of ICU care. Interventions:None. Measurements:Unplanned ICU readmission or unexpected death following ICU dismissal. Results:In a derivation cohort of 1,131 medical ICU patients, 100 patients had unplanned readmissions, and five died unexpectedly in the hospital following ICU discharge. Predictors of readmission/unexpected death identified in a logistic regression analysis were ICU admission source, ICU length of stay, and day of discharge neurologic (Glasgow Coma Scale) and respiratory (hypoxemia, hypercapnia, or nursing requirements for complex respiratory care) impairment. The Stability and Workload Index for Transfer score predicted readmission more precisely (area under the curve [AUC], 0.75; 95% confidence interval [CI], 0.70–0.80) than the day of discharge Acute Physiology and Chronic Health Evaluation III score (AUC, 0.62; 95% CI, 0.56–0.68). In the two validation cohorts, the Stability and Workload Index for Transfer score predicted readmission similarly in a North American medical ICU (AUC, 0.74; 95% CI, 0.67–0.80) and a European medical-surgical ICU (AUC, 0.70; 95% CI, 0.64–0.76), but was less well calibrated in the medical-surgical ICU. Conclusion:The Stability and Workload Index for Transfer score is derived from information readily available at the time of ICU dismissal and acceptably predicts ICU readmission. It is not known if discharge decisions based on this prediction score will decrease the number of ICU readmissions and/or improve outcome.

Preliminary results of the first human uterus transplantation from a multiorgan donor

OBJECTIVE To describe the first-year results of the first human uterus transplantation case from a multiorgan donor. DESIGN Case study. SETTING University hospital. PATIENT(S) A 21-year-old woman with complete müllerian agenesis who had been previously operated on for vaginal reconstruction. INTERVENTION(S) Uterus transplantation procedure consisting of orthotopic replacement and fixation of the retrieved uterus, revascularization, end to site anastomoses of bilateral hypogastric arteries and veins to bilateral external iliac arteries and veins was performed. MAIN OUTCOME MEASURE(S) Resumption of menstrual cycles. RESULT(S) The patient had menarche 20 days after transplant surgery. She has had 12 menstrual cycles since the operation. CONCLUSION(S) We have described the longest-lived transplanted human uterus to date with acquirement of menstrual cycles.

Transfusion from male-only versus female donors in critically ill recipients of high plasma volume components

Objective:To reduce the incidence of transfusion-related acute lung injury (ALI), the American Association of Blood Banks recently recommended rapid implementation of strategies to minimize transfusion of high plasma volume components, fresh frozen plasma and apheresis platelets, from potentially alloimmunized donors, especially females. The objective of this study was to evaluate the effect of transfusing components from male-only vs. female donors on development of ALI, gas exchange, and outcome in critically ill patients. Design:In this retrospective case-control study, we identified patients who received high plasma volume components from male-only donors and compared them with patients matched by severity of illness, postoperative state, and number of transfusions but who received high plasma volume components from female donors. Setting:Four intensive care units at a tertiary medical center. Patients:Critically ill patients who received >2 units of fresh frozen plasma or apheresis platelets. Interventions:None. Measurements and Main Results:From a database of 3,567 patients who received a total of 46,101 units of fresh frozen plasma and 6,251 units of apheresis platelets, we identified 112 patients who received three or more male-only donor components and 112 matched controls. Baseline characteristics, ALI risk factors, and development of ALI were similar between the two groups. Arterial oxygenation (Pao2/Fio2) worsened after the female (mean difference −52, 95% confidence interval −14 to −91, p = .008) but not after male-only donor product transfusion (mean difference 22, 95% confidence interval −23 to 67, p = .325). Male-only component recipients had more ventilator-free days (median 28 vs. 27, p = .006) and a trend toward lower hospital mortality rates (14% vs. 24%, p = .054). Conclusions:In critically ill recipients of high plasma volume components, gas exchange worsened significantly after transfusion of female but not male donor components. Prospective studies are needed to evaluate the effect of recommendations by the American Association of Blood Banks on outcome of transfused critically ill patients.

Utility of transcranial doppler ultrasonography for confirmatory diagnosis of brain death: two sides of the coin.

Background. Although the clinical examination and documentation of the clinical signs of brain death are very uniform, there are significant differences in the guidelines for using technical confirmatory tests to corroborate the clinical signs. The current study examined the utility of transcranial Doppler ultrasonography (TCD) for confirmation of brain death. Methods. After 19 patients were excluded from the study because of lack of bone window or because an apnea test could not be performed because of desaturation, 100 patients (61 patients with clinical brain death, and 39 control patients with Glasgow Coma Score<5) were included in the study. The following TCD findings were accepted as confirmatory of brain death when they were found bilaterally or in at least three different arteries for at least 3 minutes within the same examination: (1) brief systolic forward flow or systolic spikes and diastolic reverse flow, (2) brief systolic forward flow or systolic spikes and no diastolic flow, or (3) no demonstrable flow in a patient in whom flow had been clearly documented in a previous TCD examination. Results. The sensitivity and specificity of the first TCD examination for confirmation of brain death were 70.5% and 97.4%, respectively. Eighteen patients with clinical brain death required repeat TCD examinations because of detection of forward systolo-diastolic flow or a diastolic to-and-fro flow pattern, which were not confirmatory for the diagnosis of brain death. Brain death was confirmed ultrasonographically in 12 of 18 patients in a second examination after 12.6±8.3 hours of clinical brain death, in 2 patients in a third TCD examination, and in 1 patient in a fourth examination. Three clinically brain-dead patients had died before the diagnosis was confirmed by repeat TCD examinations. The sensitivity of TCD reached 100% in our study population after the fourth examination. Conclusion. The sensitivity of TCD is increased with repeat examinations and should be repeated in cases in which systolo-diastolic forward flow is demonstrated after the first TCD. TCD may prolong or shorten the time to declaration of brain death. The necessity of demonstrating cerebral circulatory arrest in patients with clinical brain death is debatable.

The routine use of pediatric airway exchange catheter after extubation of adult patients who have undergone maxillofacial or major neck surgery: a clinical observational study

IntroductionWe conducted the present study to determine the usefulness of routinely inserting a pediatric airway exchange catheter (PAEC) before tracheal extubation of adult patients who had undergone maxillofacial or major neck surgery and have risk factors for difficult reintubation.MethodsA prospective, observational and clinical study was performed in the 25-bed general intensive care unit of a university hospital. Thirty-six adult patients who underwent maxillofacial or major neck surgery and had risk factors for difficult reintubation were extubated after insertion of the PAEC.ResultsFour of 36 (11.1%) patients required emergency reintubation after 2, 4, 6 and 18 hours after tracheal extubation, respectively. Reintubation of these patients, which was thought to be nearly impossible by direct laryngoscopy, was easily achieved over the PAEC.ConclusionThe PAEC can be a life-saving device during reintubation of patients with risk factors for difficult reintubation such as laryngeo-pharyngeal oedema due to surgical manipulation or airway obstruction resulting from haematoma and anatomic changes. We therefore suggest the routine use of the PAEC in patients undergoing major maxillofacial or major neck surgery.

Bedside quantification of dead-space fraction using routine clinical data in patients with acute lung injury: secondary analysis of two prospective trials

IntroductionDead-space fraction (Vd/Vt) has been shown to be a powerful predictor of mortality in acute lung injury (ALI) patients. The measurement of Vd/Vt is based on the analysis of expired CO2 which is not a part of standard practice thus limiting widespread clinical application of this method. The objective of this study was to determine prognostic value of Vd/Vt estimated from routinely collected pulmonary variables.MethodsSecondary analysis of the original data from two prospective studies of ALI patients. Estimated Vd/Vt was calculated using the rearranged alveolar gas equation: Vd/Vt=1−[(0.86×V˙CO2est)/(VE×PaCO2)] where V˙CO2est is the estimated CO2 production calculated from the Harris Benedict equation, minute ventilation (VE) is obtained from the ventilator rate and expired tidal volume and PaCO2 from arterial gas analysis. Logistic regression models were created to determine the prognostic value of estimated Vd/Vt.ResultsOne hundred and nine patients in Mayo Clinic validation cohort and 1896 patients in ARDS-net cohort demonstrated an increase in percent mortality for every 10% increase in Vd/Vt in a dose response fashion. After adjustment for non-pulmonary and pulmonary prognostic variables, both day 1 (adjusted odds ratio-OR = 1.07, 95%CI 1.03 to 1.13) and day 3 (OR = 1.12, 95% CI 1.06 to 1.18) estimated dead-space fraction predicted hospital mortality.ConclusionsElevated estimated Vd/Vt predicts mortality in ALI patients in a dose response manner. A modified alveolar gas equation may be of clinical value for a rapid bedside estimation of Vd/Vt, utilizing routinely collected clinical data.