Abstract and Introduction
Objectives: Microaspiration of subglottic secretions is the main pathogenic mechanism for ventilator-associated pneumonia (VAP). Adequate inflation of the endotracheal cuff is pivotal to providing an optimal seal of the extraluminal airway. However, cuff pressure substantially fluctuates due to patient or tube movements, which can induce microaspiration. Therefore, devices for continuous cuff pressure control (CCPC) have been developed in recent years. The purpose of this systematic review and meta-analysis is to assess the effectiveness of CCPC in VAP prevention.
Data Sources: A systematic search of Embase, the Cochrane Central Register of Controlled Trials, and the International Clinical Trials Registry Platform was conducted up to February 2022.
Study Selection: Eligible studies were randomized controlled trials (RCTs) and quasi-RCTs comparing the impact of CCPC versus intermittent cuff pressure control on the occurrence of VAP.
Data Extraction: Random-effects meta-analysis was used to calculate odds ratio (OR) and 95% CI for VAP incidence between groups. Secondary outcome measures included mortality and duration of mechanical ventilation (MV) and ICU stay. The certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation approach.
Data Synthesis: Eleven RCTs with 2,092 adult intubated patients were included. The use of CCPC was associated with a reduced risk of VAP (OR, 0.51). Meta-analyses of secondary endpoints showed no significant difference in mortality but significant differences in durations of MV (mean difference, −1.07 d) and ICU stay (mean difference, −3.41 d) in favor of CCPC. However, the risk of both reporting and individual study bias was considered important. The main issues were the lack of blinding, potential commercial conflicts of interest of study authors and high heterogeneity due to methodological differences between studies, differences in devices used for CCPC and in applied baseline preventive measures. Certainty of the evidence was considered "very low."
Conclusions: The use of CCPC was associated with a reduction in VAP incidence; however, this was based on very low certainty of evidence due to concerns related to risk of bias and inconsistency.
Critically ill patients admitted to ICUs often require invasive ventilation support. This inevitably requires tracheal intubation to guarantee free air entry whilst an endotracheal cuff wrapped around the tip of the tube seals the extraluminal airway to allow positive pressure ventilation. However, inappropriate cuff pressure (Pcuff) control could contribute to ventilator-associated complications.[1–4] About 10–20% of long-term (≥ 48 hr) ventilated ICU patients will develop an episode of ventilator-associated pneumonia (VAP).[1–4] This has important clinical and economic consequences in terms of associated morbidity and mortality.[1–3]
In recent years, VAP prevention has become an important field of research. Preventive strategies such as decontamination of the oral cavity and subglottic secretion drainage (SSD) have shown to be effective in VAP prevention.[5–8] The first step in VAP pathogenesis is microaspiration of colonized oropharyngeal secretions that pool above the endotracheal cuff. Disbalance between host immune response and bacterial inoculum can lead to colonization and subsequent infection.[9–11] The cuff needs to be adequately inflated to provide an optimal seal of the extraluminal airway. Guidelines recommend keeping Pcuff greater than or equal to 20 cm H2O.[12,13] Currently, most centers regulate Pcuff manually every 4–12 hours.[14,15] However, in between two measurements, Pcuff substantially fluctuates due to patient or tube movements.[16–19] Therefore, devices for continuous Pcuff control (CCPC) have been developed to prevent cuff underinflation, microaspiration and possibly VAP.[20–24]
Although some of these devices have been shown to be effective in the prevention of underinflation,[20–27] the effects on microaspiration are inconsistent.[21,28] A 2015 systematic review with meta-analysis reported a significant difference in VAP incidence in favor of CCPC. However, the three included trials had a small sample size, an open-label design and were heterogeneous concerning the devices used for CCPC.[28,30,31] Recently, several randomized controlled trials (RCTs) have been published on this topic. Therefore, we performed this systematic review and meta-analysis to assess the effect of CCPC compared with intermittent Pcuff control (ICPC) on VAP incidence.
Crit Care Med. 2022;50(10):1430-1439. © 2022 Lippincott Williams & Wilkins