RESPIRATORY CARE Paper in Press. Published on January 30, 2018 as DOI: 10.4187/respcare.05926 Frequent Versus Infrequent Monitoring of Endotracheal Tube Cuff Pressures Adam Letvin MD, Pamala Kremer RN CIC, Patty C Silver RRT MEd, Nizama Samih RRT-ACCS, Peggy Reed-Watts RRT MSc, and Marin H Kollef MD BACKGROUND: Currently there is no accepted standard of practice for the optimal frequency of endotracheal tube cuff pressure monitoring in mechanically ventilated patients. Therefore, we conducted a study to compare infrequent endotracheal tube cuff pressure monitoring (immediately after intubation and when clinically indicated for an observed air leak or due to tube migration) with frequent endotracheal tube cuff pressure monitoring (immediately after intubation, every 8 h, and when clinically indicated). METHODS: We performed a prospective clinical trial with subjects assigned to study groups based on room assignment. The primary outcome was the occurrence of a ventilator-associated event (VAE) and was adjudicated by individuals blinded to the conduct of this study. RESULTS: We enrolled 305 subjects, with 166 (54.4%) assigned to frequent monitoring and 139 (45.6%) assigned to infrequent monitoring. The total number of endotracheal tube cuff pressure monitoring events for both groups was 1,531 versus 336, respectively. The occurrence of Witnessed aspiration .(37. ؍ VAEs was infrequent and similar for both groups (3.6% vs 5.8%, P d-30 ,(27. ؍ ventilator-associated pneumonia (0% vs 0.7%, P ,(36. ؍ events (0.6% vs 0%, P and hospital length of stay (10 d [6 d, 21 d] vs 11 d [6 d, 21 ,(83. ؍ mortality (31.3% vs 30.2%, P were also similar for both study groups. The 30-d hospital readmission rate was (34. ؍ d], P .(02. ؍ statistically lower for the group that received infrequent monitoring (15.1% vs 6.5%, P CONCLUSIONS: More frequent cuff pressure monitoring was not associated with any identifiable clinical outcome benefit. Key words: endotracheal tube; mechanical ventilation; ventilator-associated event. [Respir Care 0;0(0):1–•. © 0 Daedalus Enterprises] Introduction different strategies are reported to include continuous mon- itoring.1 The implied goal of endotracheal tube cuff pres- Currently there is no accepted standard for the frequency sure monitoring is to maintain the cuff pressures between of monitoring endotracheal tube cuff pressure, and widely 20–30 cm H2O to minimize air leaks and loss of tidal volume due to underfilling the cuff and to prevent injury to the tracheal mucosa due to overfilling the cuff. It is known Dr Letvin and Kollef are affiliatd with the Division of Pulmonary and that 20–30% of cuff pressure measurements may deviate Critical Care Medicine, Washington University School of Medicine, St above or below this threshold.1 However, the impact of Louis, Missouri; Ms Kremer is affiliated with the Hospital Epidemiology such deviation on clinical outcomes is not well described and Infection Prevention Department, Barnes-Jewish Hospital, St Louis, 2 Missouri; Ms Silver, Ms Samih, and Ms Reed-Watts are affiliated with in the medical literature. The 2 most common methods Respiratory Care Services, Barnes-Jewish Hospital, St Louis, Missouri. for assessing cuff pressures are using a manometer for direct measurement and performing a minimal leak, with Dr Kollef has disclosed a relationship with the Barnes-Jewish Hospital the former being the most accepted method.3 However, the Foundation. The other authors have reported no conflicts of interests. optimal frequency for conducting cuff pressure assessments Correspondence: Marin H Kollef MD, Division of Pulmonary and Crit- is unknown. One study suggests that the act of measuring ical Care Medicine, Washington University School of Medicine, 4523 cuff pressures results in the removal of air from the cuff Clayton Ave, Campus Box 8052, St Louis, MO 63110. E-mail: 4 [email protected]. and can inadvertently result in underinflation of the cuff. Moreover, a recent animal study suggests that the material DOI: 10.4187/respcare.05926 used to manufacture the endotracheal tube cuff may play a RESPIRATORY CARE • ●●VOL ● NO ● 1 Copyright (C) 2018 Daedalus Enterprises ePub ahead of print papers have been peer-reviewed, accepted for publication, copy edited and proofread. However, this version may differ from the final published version in the online and print editions of RESPIRATORY CARE RESPIRATORY CARE Paper in Press. Published on January 30, 2018 as DOI: 10.4187/respcare.05926 ETT CUFF PRESSURE MONITORING more important role in determining the presence or ab- sence of mucosal injury, with polyurethane being tolerated QUICK LOOK 5 better than polyvinylchloride. Current knowledge An important limitation of the current literature pertain- ing to the frequency of cuff pressure monitoring is the lack There is limited available research to guide clinicians of clinical outcome assessment for various frequencies of on the optimal frequency of performing endotracheal monitoring. Given the lack of a consensus on the optimal tube cuff pressure measurements. Current practices vary frequency for monitoring cuff pressure, we performed a throughout the world, from very infrequent cuff pres- prospective trial to address this issue. The main goal of sure measurements to continuous assessments of cuff this study was to compare frequent cuff pressure monitor- pressure. ing to infrequent monitoring so that we could determine What this paper contributes to our knowledge whether these 2 strategies resulted in identifiable differ- ences in clinical outcomes, including respiratory-related Despite an almost 5-fold difference in cuff pressure complications. assessments, we found no difference in the primary outcome of ventilator-associated events between the Methods study groups. There were also no differences in the secondary outcomes, which included length of stay, Study Population and Data Source mortality, and ventilator-associated pneumonia. Our study suggests that infrequent cuff pressure monitoring This study was conducted within the 2 medical ICUs is safe and can be performed only as clinically indi- (34 beds) at Barnes-Jewish Hospital, an academic referral cated, thus allowing respiratory care resources to be center of 1,250 beds in St. Louis, Missouri. The medical directed to other potentially more crucial issues. ICUs are geographically co-located closed units with shared physician, nursing, pharmacy, and respiratory therapy staffs. The medical ICUs are staffed at all times by these teams, including intensivists who are board- ried out by the infection prevention department as part of certified in critical care. The Washington University their surveillance and quality improvement mandate, as School of Medicine Human Studies Committee approved well as for public reporting. This method of assessing this investigation, and the need for informed consent VAEs has been used previously for clinical studies carried was waived (Institutional Review Board Number: out at Barnes-Jewish Hospital.6,7 Moreover, the medical 201605155; ClinicalTrials.gov Identifier: NCT02950519). ICUs have a long history of routinely using protocols for All patients admitted to the medical ICUs from October the weaning of mechanical ventilation, sedation manage- 10, 2016, through February 28, 2017, who required endotra- ment, and prevention of VAP and VAEs developed in cheal intubation and mechanical ventilation were eligible for conjunction with the infection prevention department and inclusion. Subjects could only be enrolled once in this inves- the Barnes-Jewish Hospital Departments of Respiratory tigation. Patients with a tracheostomy were excluded. Data Care and Nursing.6,8-10 We also recorded the exact number were prospectively collected from the electronic health re- of endotracheal tube cuff pressure assessments performed cord and from subjects’ ICU teams. in both groups. Study Outcomes/Objectives Definitions and Study Design The primary outcome of this study was to determine All subjects admitted to the medical ICUs were assigned whether and how frequently ventilator-associated events to receive either frequent or infrequent monitoring of their (VAEs) occurred. Secondary outcomes included 30-d and cuff pressures according to their room assignment. Sub- 100-d mortality, length of stay, witnessed aspiration events, jects assigned by the hospital admitting office to an odd- ventilator-associated pneumonia (VAP), tracheal compli- numbered room received infrequent cuff pressure moni- cations, and 30-d hospital readmission. The primary out- toring, which was defined as after tracheal intubation (if come (VAEs) and the occurrence of VAP were directly performed in the medical ICU) or upon ICU admission if assessed by the Hospital Epidemiology and Infection Pre- endotracheal intubation occurred in the emergency depart- vention Department of Barnes-Jewish Hospital in a pro- ment or on a hospital ward, and if there was a clinical spective manner. The infection prevention department was indication to assess the cuff pressure, such as an audible blinded to the conduct of this study and to the implication cuff leak or loss of tidal volume. Subjects assigned by the of subject room assignments with regard to this investiga- hospital admitting office to an even-numbered room re- tion. Determination of VAEs and VAP are routinely car- ceived frequent cuff pressure monitoring, which was 2RESPIRATORY CARE • ●●VOL ● NO ● Copyright (C) 2018 Daedalus Enterprises ePub ahead of print papers have been peer-reviewed, accepted for publication,