BACKGROUND: An increasing number of patients require prolonged mechanical ventilation (PMV), which is associated with high morbidity and poor long-term survival, but there are few data regarding the incidence and outcome of PMV patients from a community perspective. METHODS: We retrospectively reviewed the electronic medical records of adult Olmsted county, Minnesota, residents admitted to the intensive care units at the 2 Mayo Clinic Rochester hospitals from January 1, 2003, to December 31, 2007, who underwent tracheostomy for PMV. RESULTS: Sixty-five patients, median age 68 years (interquartile range [IQR] 49–80 y), 39 male, underwent tracheostomy for PMV, resulting in an age-adjusted incidence of 13 (95% CI 10–17) per 100,000 patient-years at risk. The median number of days on mechanical ventilation was 24 days (IQR 18–37 d). Forty-six patients (71%) survived to hospital discharge, and 36 (55%) were alive at 1-year follow-up. After adjusting for age and baseline severity of illness, the presence of COPD was independently associated with 1-year mortality (hazard ratio 3.4, 95% CI 1.4–8.2%). CONCLUSIONS: There was a considerable incidence of tracheostomy for PMV. The presence of COPD was an independent predictor of 1-year mortality.
Derivation and Diagnostic Accuracy of the Surgical Lung Injury Prediction Model
Background Acute lung injury (ALI) is a serious postoperative complication with limited treatment options. A preoperative risk-prediction model would assist clinicians and scientists interested in ALI. The objective of this investigation was to develop a surgical lung injury prediction (SLIP) model to predict risk of postoperative ALI based on readily available preoperative risk factors. Methods Secondary analysis of a prospective cohort investigation including adult patients undergoing high-risk surgery. Preoperative risk factors for postoperative ALI were identified and evaluated for inclusion in the SLIP model. Multivariate logistic regression was used to develop the model. Model performance was assessed with the area under the receiver operating characteristic curve and the Hosmer-Lemeshow goodness-of-fit test. Results Out of 4,366 patients, 113 (2.6%) developed early postoperative ALI. Predictors of postoperative ALI in multivariate analysis that were maintained in the final SLIP model included high-risk cardiac, vascular, or thoracic surgery, diabetes mellitus, chronic obstructive pulmonary disease, gastroesophageal reflux disease, and alcohol abuse. The SLIP score distinguished patients who developed early postoperative ALI from those who did not with an area under the receiver operating characteristic curve (95% CI) of 0.82 (0.78-0.86). The model was well calibrated (Hosmer-Lemeshow, P = 0.55). Internal validation using 10-fold cross-validation noted minimal loss of diagnostic accuracy with a mean ± SD area under the receiver operating characteristic curve of 0.79 ± 0.08. Conclusions Using readily available preoperative risk factors, we developed the SLIP scoring system to predict risk of early postoperative ALI.
Timing of the Onset of Acute Respiratory Distress Syndrome: A Population-Based Study
Respiratory Care | May 2, 2011 | Volume: 56 | Issue: 5 | Pages: 576-582
BACKGROUND: Many patients with acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) have had recent healthcare interventions prior to developing ALI/ARDS. OBJECTIVE: To determine the timing of ALI/ARDS onset in relation to hospital admission and other healthcare interventions. METHODS: We conducted a population-based observational cohort study with a validated electronic surveillance tool, and identified patients with possible ALI/ARDS among critically ill adults at Mayo Clinic hospitals that provide critical care services for Olmsted County, Minnesota, in 2006. Trained investigators independently reviewed electronic medical records and confirmed the presence and timing of ALI/ARDS based on the American-European consensus definition. RESULTS: Of 124 episodes of ALI in 118 patients, only 5 did not fulfill the ARDS criteria. The syndrome developed a median 30 hours (IQR 10–82 h) after hospital admission in 79 patients (67%). ARDS was present on admission in 39 patients (33%), of whom 14 had recent hospitalization, 6 were transferred from nursing homes, and 3 had recent out-patient contact (1 antibiotic prescription, 1 surgical intervention, and 1 chemotherapy). Only 16 ARDS patients (14%) did not have known recent contact with a healthcare system. Compared to ARDS on admission, hospital-acquired ARDS was more likely to occur in surgery patients (54% vs 15%, P < .001), and had longer adjusted hospital stay (mean difference 8.9 d, 95% CI 0.3–17.4, P = .04). CONCLUSIONS: ARDS in the community most often develops either during hospitalization or in patients who recently had contact with a healthcare system. These findings have important implications for potential preventive strategies.
Eight-Year Trend of Acute Respiratory Distress Syndrome: A Population-based Study in Olmsted County, Minnesota
American Journal of Respiratory and Critical Care Medicine | August 6, 2010 | Volume: 183 | Issue: 1 | Pages: 59-66
Abstract Rationale Significant progress has been made in understanding the pathogenesis of acute respiratory distress syndrome (ARDS). Recent advances in hospital practice may have reduced the incidence of this lethal syndrome. Objectives To observe incidence trends and associated outcomes of ARDS. Methods This population-based cohort study was conducted in Olmsted County, Minnesota. Using a validated screening protocol, investigators identified intensive care patients with acute hypoxemia and bilateral pulmonary infiltrates. The presence of ARDS was independently confirmed according to American-European Consensus Conference criteria. The incidence of ARDS and associated outcomes were compared over the 8-year study period (2001–2008). Measurements and Main Results Over the 8-year period, critically ill Olmsted County residents presented with increasing severity of acute illness, a greater number of comorbidities, and a higher prevalence of major predisposing conditions for ARDS. The ARDS incidence decreased significantly from 82.4 to 38.9 per 100,000 person-years during the study period (P < 0.001). A decline in hospital-acquired ARDS (P < 0.001) was responsible for the fall in the incidence density with no change on admission (P = 0.877). Overall, mortality and hospital and intensive care unit lengths of stay decreased over time (P < 0.001), whereas the ARDS case-fatality did not change significantly. Conclusions Despite an increase in patients' severity of illness, number of comorbidities, and prevalence of major ARDS risk factors, the incidence of ARDS in this suburban community decreased by more than half. Correlation of the observed findings with changes in health care delivery may have important implications for the planning of acute care services in other regions.