Acetyl salicylic acid usage and mortality in critically ill patients with the systemic inflammatory response syndrome and sepsis.

Crit Care Med. 2012 Jun;40(6):1761-7

Authors: Eisen DP, Reid D, McBryde ES

Abstract

OBJECTIVE: Low doses of acetyl salicylic acid, acting through 15-epi-lipoxin A4, have been shown to be anti-inflammatory in human studies. The manifold effects of acetyl salicylic acid on human physiology potentially may benefit patients with the systemic inflammatory response syndrome after sepsis or tissue trauma. We sought to determine whether acetyl salicylic acid administration at the time of development of systemic inflammatory response syndrome is associated with reduced mortality.

DESIGN: Retrospective cohort study of consecutive intensive care unit admissions between April 2000 and November 2009.

SETTING: Australian tertiary referral center.

PATIENTS: Seven-thousand nine-hundred forty-five intensive care unit admissions examined.

MEASUREMENTS AND MAIN RESULTS: The probability of in-hospital death during admissions in which individuals were identified as having systemic inflammatory response syndrome or sepsis was analyzed according to whether they were administered acetyl salicylic acid. Propensity analysis that matched all patients for their probability of being prescribed acetyl salicylic acid was undertaken. Among 5523 patients with a first episode of systemic inflammatory response syndrome, 2082 were administered acetyl salicylic acid in a 24-hr period around the time of systemic inflammatory response syndrome recognition. Propensity analysis showed a 10.9% mortality for acetyl salicylic acid users and 17.2% mortality in the propensity-matched nonusers (absolute risk difference -6.2%; 95% confidence interval -9.5% to -3.5%). Propensity matching also found that acetyl salicylic acid administration was associated with increased risk of renal injury (6.2% vs. 2.9%; absolute risk difference 13.3%; 95% confidence interval 2.5% to 5.0%). In the 970 patients with proven sepsis, acetyl salicylic acid administration was associated with a lower mortality (27.4% vs. 42.2%; absolute risk difference -14.8%; 95% confidence interval -18.9% to -8.6%) after propensity matching. This quasi-experimental study cannot establish a causal association between acetyl salicylic acid and death from systemic inflammatory response syndrome or sepsis. Unrecognized confounders may remain but numerous covariates are included in the analyses.

CONCLUSIONS: Our study shows a strong association between acetyl salicylic acid and survival in intensive care unit systemic inflammatory response syndrome and sepsis patients. The effect of acetyl salicylic acid treatment on mortality of patients with systemic inflammatory response syndrome and sepsis needs to be evaluated with prospective randomized intervention studies.

PMID: 22610182 [PubMed - indexed for MEDLINE]

Delirium screening in critically ill patients: a systematic review and meta-analysis.

Crit Care Med. 2012 Jun;40(6):1946-51

Authors: Neto AS, Nassar AP, Cardoso SO, Manetta JA, Pereira VG, Espósito DC, Damasceno MC, Slooter AJ

Abstract

OBJECTIVE: Despite its frequency and impact, delirium in critically ill patients is poorly recognized. Our aim was to systematically review the accuracy of delirium screening instruments in critically ill patients.

DATA SOURCE: Systematic review and meta-analysis of publications between 1966 and 2011. The Medline and Embase databases were searched for studies on delirium in critically ill patients.

STUDY SELECTION: The meta-analysis was limited to studies in critically ill patients in intensive care units, surgical wards, or emergency rooms. The delirium screening tool had to be feasible in a clinical setting for use by a nonexpert. As the gold standard, delirium had to be diagnosed based on appropriate criteria by a delirium expert.

DATA EXTRACTION: The outcomes assessed were sensitivity, specificity, likelihood ratios, and summary receiver operating characteristics curves.

DATA SYNTHESIS: Sixteen studies covering 1,523 participants and five screening tools were included in the systematic review. The pooled sensitivities and specificities of Confusion Assessment Method for the Intensive Care Unit for detection of delirium in critically ill patients were 75.5% and 95.8%, and for Intensive Care Delirium Screening Checklist 80.1% and 74.6%, respectively. All but one study was performed in a research setting, and that one study suggested that with routine use of the Confusion Assessment Method for the Intensive Care Unit, half of the patients with delirium were not detected.

CONCLUSIONS: The Confusion Assessment Method for the Intensive Care Unit was the most specific bedside tool for the assessment of delirium in critically ill patients. However, there was significant heterogeneity of the results. These findings were largely obtained in research settings, and the low sensitivity of the Confusion Assessment Method for the Intensive Care Unit in routine, daily practice may limit its use as a screening test.

PMID: 22610196 [PubMed - indexed for MEDLINE]

Continuous negative abdominal distension augments recruitment of atelectatic lung.

Crit Care Med. 2012 Jun;40(6):1864-72

Authors: Chierichetti M, Engelberts D, El-Khuffash A, Babyn P, Post M, Kavanagh BP

Abstract

RATIONALE: In acute lung injury, atelectasis is common and frequently develops in the dependent and diaphragmatic regions. Attempts to recruit lung with positive pressure constitute a major aim in the management of acute respiratory distress syndrome but are associated with overdistension and injury in nonatelectatic regions.

OBJECTIVE: To test the hypothesis that continuous negative abdominal pressure using an iron lung would augment positive end-expiratory pressure in recruiting atelectatic lung.

METHODS AND MAIN RESULTS: An in vivo rabbit model of ventilator-induced lung injury was used in which a recruitment maneuver followed by positive end-expiratory pressure (110 cm H2O) had no effect on oxygenation. Addition of sustained continuous negative abdominal pressure (-5 cm H2O) to the positive end-expiratory pressure significantly increased the end-expired lung volume and PaO2 but impaired ventricular preload and cardiac output (suggested by echocardiography). Addition of transient (15 mins) continuous negative abdominal pressure resulted in comparable and lasting (60 mins) increases in PaO2. Sustained, but not transient, continuous negative abdominal pressure was associated with hemodynamic depression and lactic acidosis, which appeared (illustrative echocardiography, n = 2) to be caused by decreased cardiac preload. Computerized tomography (n = 2) suggested that continuous negative abdominal pressure was an effective adjunct to positive end-expiratory pressure for recruiting atelectasis in dependent and diaphragmatic regions. In surfactant-depleted but noninjured lungs, sustained continuous negative abdominal pressure augmented lung recruitment and oxygenation in the setting of higher (but not lower) levels of positive end-expiratory pressure and reduced central venous oxygenation.

CONCLUSIONS: Continuous negative abdominal pressure may be a potential adjunct to positive end-expiratory pressure in the recruitment of diaphragmatic atelectasis. The approach ultimately might be useful when ceilings exist on the level of desired positive end-expiratory pressure.

PMID: 22610189 [PubMed - indexed for MEDLINE]