Association of Patient Care with Ventilator-Associated Conditions in Critically Ill Patients: Risk Factor Analysis

Abstract

BackgroundVentilator-associated conditions (VACs), for which new surveillance definitions and methods were issued by the Center for Disease Control and Prevention (CDC), are respiratory complications occurring in conjunction with the use of invasive mechanical ventilation and are related to adverse outcomes in critically ill patients. However, to date, risk factors for VACs have not been adequately established, leading to a need for developing a better understanding of the risks. The objective of this study was to explore care-related risk factors as a process indicator and provide valuable information pertaining to VAC preventive measures.MethodsThis retrospective, single-center, cohort study was conducted in the intensive-care unit (ICU) of a university hospital in Japan. Patient data were automatically sampled using a computerized medical records system and retrospectively analyzed. Management and care-related, but not host-related, factors were exhaustively analyzed using multivariate analysis for risks of VACs. VAC correlation to mortality was also investigated.ResultsOf the 3122 patients admitted in the ICU, 303 ventilated patients meeting CDC-specified eligibility criteria were included in the analysis. Thirty-seven VACs (12.2%) were found with a corresponding rate of 12.1 per 1000 ventilator days. Multivariate analysis revealed four variables related to patient care as risk factors for VACs: absence of intensivist participation in management of ventilated patients [adjusted HR (AHR): 7.325, P < 0.001)], using relatively higher driving pressure (AHR: 1.216, P < 0.001), development of edema (AHR: 2.145, P = 0.037), and a larger body weight increase (AHR: 0.058, P = 0.005). Furthermore, this research confirmed mortality differences in patients with VACs and statistically derived risks compared with those without VACs (HR: 2.623, P = 0.008).ConclusionFour risk factors related to patient care were clearly identified to be the key factors for VAC preventive measures.

Using Objective Fluid Balance Data to Identify Pulmonary Edema in Subjects With Ventilator-Associated Events

“…Lewis et al, 17 in a case-control study involving 110 subjects with VAC and 110 subjects without VAC, reported that a positive fluid balance was associated with a risk of VAC (OR 1.2 per L increase, 95% CI 1.0 -1.4). Nakahashi et al 18 also found that the development of edema was positively associated with the occurrence of VAC in a retrospective cohort study enrolling 303 mechanically ventilated subjects (adjusted hazard ratio 2.145, P ϭ .037). Additionally, in line with our data, Kobayashi et al 19 reported that receiving renal replacement therapy was an independent risk factor for IVACs and VAC, and is reflected in our data, which showed that receiving renal replacement therapy was associated with pulmonary edema-associated VAEs (Table 4).…”

Ventilator-associated events: prevalence and mortality in Japan

“…However, information on VAEs in non-Western countries is scarce, with there being no literature on them, except for a few reports (19)(20)(21). The value of VAEs as QIs is uncertain.…”

Shifting the Paradigm: Preventing More Than Infection

“…Therefore, many other noninfectious conditions associated with mechanical ventilation may trigger a VAE: atelectasis, acute respiratory distress syndrome (ARDS), fluid overload resulting in pulmonary edema or pleural effusions, transfusion-related lung injury, traumatic injury to the chest, barotrauma or volume-related trauma from the ventilator, pneumothorax and pulmonary emboli, among others. [1][2][3][4][5][6][7]9,11,12,15,[17][18][19][20] The inclusion of the noninfectious causes has resulted in much scrutiny of the new definitions. Ventilator-associated events are associated with increased costs, duration of mechanical ventilation, ICU length of stay and mortality; however, there are discrepancies between the new and old definitions in the detection of VAP.…”

“…Thus, there is clearly opportunity to prevent some, albeit likely not all, VAEs. [3][4][5]10,14,[18][19][20] In the study "Ventilator Bundle Compliance and Risk of Ventilator-Associated Events," Harris et al 1 addressed whether or not decreased VAP bundle compliance increased the risk of VAEs in a matched, single-center, case-control study of adults. Ventilator bundle success with decreased VAP and overall compliance was previously established via an electronic dashboard in the medical record and consisted of the following elements: elevation of the head of the bed, daily assessment for spontaneous breathing trials with completion if appropriate, assessment of agitation via the Richmond agitation sedation scale, oral care (brushing teeth, oral chlorhexidine swabs, and hypopharyngeal suctioning), and prophylaxis against both stress ulcers and deep vein thrombosis.…”

“…6,7,12,13,16,17 Notably, management by intensivists has also been associated with improvement in VAP rates. 20 For decades, research has focused on refining the definition of ARDS and treating ARDS; however, pharmacologic options have failed to result in significant improvement in ARDS. Improved ventilator management with low tidal volumes, optimized PEEP for each individual patient (decreasing atelectasis and thereby optimizing oxygenation capacity through pressure), and decreased overall driving pressure of each breath from the ventilator, decrease ARDS via prevention or limitation of iatrogenic lung injury.…”