Epidemiological Characteristics, Ventilator Management, and Clinical Outcome in Patients Receiving Invasive Ventilation in Intensive Care Units from 10 Asian Middle-Income Countries (PRoVENT-iMiC): An International, Multicenter, Prospective Study

Abstract

Epidemiology, ventilator management, and outcome in patients receiving invasive ventilation in intensive care units (ICUs) in middle-income countries are largely unknown. PRactice of VENTilation in Middle-income Countries is an international multicenter 4-week observational study of invasively ventilated adult patients in 54 ICUs from 10 Asian countries conducted in 2017/18. Study outcomes included major ventilator settings (including tidal volume [V T ] and positive end-expiratory pressure [PEEP]); the proportion of patients at risk for acute respiratory distress syndrome (ARDS), according to the lung injury prediction score (LIPS), or with ARDS; the incidence of pulmonary complications; and ICU mortality. In 1,315 patients included, median V T was similar in patients with LIPS < 4 and patients with LIPS ≥ 4, but lower in patients with ARDS (7.90 [6.8-8.9], 8.0 [6.8-9.2], and 7.0 [5.8-8.4] mL/kg Predicted body weight; P = 0.0001). Median PEEP was similar in patients with LIPS < 4 and LIPS ≥ 4, but higher in patients with ARDS (five [5-7], five [5-8], and 10 [5-12] cmH2O; P < 0.0001). The proportions of patients with LIPS ≥ 4 or with ARDS were 68% (95% CI: 66-71) and 7% (95% CI: 6-8), respectively. Pulmonary complications increased stepwise from patients with LIPS < 4 to patients with LIPS ≥ 4 and patients with ARDS (19%, 21%, and 38% respectively; P = 0.0002), with a similar trend in ICU mortality (17%, 34%, and 45% respectively; P < 0.0001). The capacity of the LIPS to predict development of ARDS was poor (receiver operating characteristic [ROC] area under the curve [AUC] of 0.62, 95% CI: 0.54-0.70). In Asian middle-income countries, where two-thirds of ventilated patients are at risk for ARDS according to the LIPS and pulmonary complications are frequent, setting of V T is globally in line with current recommendations.

Figure 1.

Screening and enrolment. ARDS = acute respiratory distress syndrome; IRB = institutional review board; LIPS = lung injury prediction score; MV = mechanical ventilation.

Figure 2.

Ventilation parameters at admission in patients with LIPS < 4 vs. patients with LIPS ≥ 4 and those with ARDS cumulative frequency distribution of (A) V_T, (B) PEEP, (C) plateau pressure, and (D) driving pressure. Vertical dotted lines represent the cutoff for each variable, and horizontal dotted lines represent the respective proportion of patients reaching each cutoff. Cutoffs for ventilator parameters were like those used in previous published reports on invasive ventilation practices, that is, 8 mL/kg PBW for V_T, 5 cmH₂O for PEEP, 30 cmH₂O for Pplat, and 15 cmH₂O for driving pressure. ARDS = acute respiratory distress syndrome; PBW = predicted body weight; PEEP = positive end-expiratory pressure; V_T = tidal volume. This figure appears in color at www.ajtmh.org.

Figure 3.

Ventilatory parameters in the first 4 days of mechanical ventilation. Lines are means and 95% CIs. FiO₂ = fraction of inspired oxygen; PBW = predicted body weight; PEEP = positive end-expiratory pressure; Ppeak = peak pressure; Pplat = plateau pressure; V_T = tidal volume. P-value is for group and time–group interaction. This figure appears in color at www.ajtmh.org.

Figure 4.

Probability of discontinuing mechanical ventilation when accounting for the competing risk of death before extubation in patients with LIPS < 4 vs. patients with LIPS ≥ 4 and those with ARDS estimates is shown as hazard ratio (95% CIs). The cumulative incidence function curves estimate the instantaneous probability over time of extubation (shown in continuous lines) when accounting for the risk set attrition due to the occurrence of the competing risk (death before extubation, shown in survival curves as dotted lines). The “Fine and Gray” proportional sub-distribution hazards analysis was used to model the sub-distribution hazard and derive P-values. ARDS = acute respiratory distress syndrome. This figure appears in color at www.ajtmh.org.