Hospital Mortality and Effect of Adjusting PaO2/FiO2 According to Altitude Above the Sea Level in Acclimatized Patients Undergoing Invasive Mechanical Ventilation. A Multicenter Study.

OBJECTIVE: (i) Analyze the effect of altitude above the sea level on the mortality rate in patients undergoing invasive mechanical ventilation. (ii) Validate the traditional equation for adjusting PaO2/FiO2 according to the altitude. DESIGN: A prospective, observational, multicenter and international study conducted during August 2016. PATIENTS: Inclusion criteria: (i) age between 18 and 90 years old, (ii) admitted to intensive care unit (ICU) situated at the same altitude above the sea level (AASL) in which the patients has stayed, at least, during the previous 40 days and (iii) received invasive MV for at least 12h. MATERIAL AND METHODS: All variables were registered the day of intubation (day 0). Patients were followed until death, ICU discharge or day 28. PaO2/FiO2 ratio was adjusted by the AASL according to: PaO2/FiO2*(barometric pressure/760). Categorical variables were compared with χ2 and Cochran-Mantel-Haenszel test. Continuous variables with Mann-Whitney. Correlation between continuous variables was analyzed graphically and analytically. Logistic regression model was constructed to identify factors associated to mortality. Kapplan-Meier method was used to estimate the probability of survival according to the altitude. A 2-side p value <0.05 was consider significant. RESULTS: 249 patients (<1500m n=55; 1500 to <2500m n=20; 2500 to <3500m n=155 and ≥3500m n=19) were included. Adjusted and non-adjusted PaO2/FiO2 were correlated with several respiratory and non respiratory variables. None discordances between non adjusted and adjusted PaO2/FiO2 were identified. However, several correlations were appreciated only in patients situated <1500m or in >1500m. Seventy-nine patients died during the ICU stayed (32%). The mortality curve was not affected by the altitude above the sea level. Variables independently associated to mortality are: PEEP, age, systolic arterial blood pressure, and platelet count. AUROC: 0.72. CONCLUSION: In acclimatized patients undergoing invasive mechanical ventilation, the traditional equation for adjusting PaO2/FiO2 according the elevation above the sea level seems to be inaccurate and the altitude above the sea level does not affect the mortality risk.

Variability in triage practices for critically ill cancer patients: A randomized controlled trial.

PURPOSE: Intensive care triage practices and end-user interpretation of triage guidelines have rarely been assessed. We evaluated agreement between providers on the prioritization of patients for ICU admission using different triage guidelines. MATERIALS AND METHODS: A multi-centered randomized study on providers from 18 different countries was conducted using clinical vignettes of oncological patients. The level of agreement between providers was measured using two different guidelines, with one being cancer specific. RESULTS: Amongst 257 providers, 52.5% randomly received the Society of Critical Care Prioritization Model, and 47.5% received a cancer specific flowchart as a guide. In the Prioritization Model arm the average entropy was 1.193, versus 1.153 in the flowchart arm (P = .095) indicating similarly poor agreement. The Fleiss' kappa coefficients were estimated to be 0.2136 for the SCCMPM arm and 0.2457 for the flowchart arm, also similarly implying poor agreement. CONCLUSIONS: The low agreement amongst practitioners on the prioritization of cancer patient cases for ICU admission existed using both general triage guidelines and guidelines tailored only to cancer patients. The lack of consensus on intensive care unit triage practices in the oncological population exposes a potential barrier to appropriate resource allocation that needs to be addressed.