TY - JOUR
T1 - Respiratory volume monitoring reduces hypoventilation and apnea in subjects undergoing procedural sedation
AU - Nichols, Robert H.
AU - Blinn, Justin A.
AU - Ho, Thuan M.
AU - McQuitty, Robert A.
AU - Kinsky, Michael P.
N1 - Funding Information:
This study was conducted as a randomized clinical trial during a clinical evaluation of the RVM as a device for monitoring total intravenous anesthesia cases at University of Texas Medical Branch. Participants undergoing upper and lower gastrointestinal endoscopies were included in July and December of 2015. Inclusion criteria were men and women aged 18 to 99 y, while exclusion criteria were non-English speakers, allergies to adhesive electrodes, and previous pneumonectomy or lobectomy surgery. Because this study was part of a clinical evaluation in which the use of the RVM was part of standard of care, subject data were collected retrospectively. The University of Texas Medical Branch Institutional Review Board approved the study and waived the requirement to obtain informed consent in accordance with 45 CFR 46.116(d). This study was supported in part by U.S. Army grant W81XWH-12-1-0598.
Publisher Copyright:
© 2018, American Association for Respiratory Care. All rights reserved.
PY - 2018/4/1
Y1 - 2018/4/1
N2 - INTRODUCTION: The use of monitored anesthesia care for endoscopic procedures increases the risk of respiratory depression, necessitating careful monitoring of patient ventilation. We examined the effectiveness of an impedance-based respiratory volume monitor (RVM) in improving the safety of patients undergoing upper and lower gastrointestinal endoscopies under total intravenous anesthesia. We hypothesized that feedback from the RVM would allow anesthesiologists to maintain adequate ventilation, which would reduce the duration of respiratory depression (ie, hypoventilation and apnea) compared to a blinded control group. METHODS: Sixty-five subjects were enrolled in a randomized controlled trial and monitored with a noninvasive impedance-based RVM, which displayed respiratory traces and calculated expiratory minute ventilation (VE), tidal volume (VT), and breathing frequency (f) measurements. Prior to induction of anesthesia, a baseline VE measurement (VE-baseline) was taken as a measurement of normal breathing. VE was monitored throughout the procedure for signs of hypoventilation and apnea. Hypoventilation was defined as VE < 40% VE-baseline, and apneas were defined as VE-0 for > 15 s. RESULTS: Sixty-five subjects were randomly assigned to either a control (n-38) or RVM intervention group (n-27). Subjects in the intervention group had a higher VE% for the entire procedure (P-.045), as well as the third and fourth quartile of the procedure compared to the control group (P-.01). Likewise, subjects in the RVM intervention group spent significantly less time below 40% VE-baseline compared to the control group throughout the entire procedure (12 = 15% vs 32 = 24%, respectively) (P < .001). The median number of apneas per subject was greater in the control group (median 2, interquartile range 1–2, maximum 4) compared to the RVM intervention group (median 1, interquartile range 1–2, maximum 3) (P-.037). CONCLUSIONS: The control group had a higher incidence of hypoventilation and apnea compared to the RVM intervention group. Respiratory monitoring using the RVM can potentially be a useful tool for identifying early signs of respiratory depression and for titrating anesthetics to maintain adequate ventilation while minimizing patient risk. Key words: endoscopy; procedural sedation; respiratory volume monitor; ventilation monitoring. [Respir Care 2018;63(4):448 –454.
AB - INTRODUCTION: The use of monitored anesthesia care for endoscopic procedures increases the risk of respiratory depression, necessitating careful monitoring of patient ventilation. We examined the effectiveness of an impedance-based respiratory volume monitor (RVM) in improving the safety of patients undergoing upper and lower gastrointestinal endoscopies under total intravenous anesthesia. We hypothesized that feedback from the RVM would allow anesthesiologists to maintain adequate ventilation, which would reduce the duration of respiratory depression (ie, hypoventilation and apnea) compared to a blinded control group. METHODS: Sixty-five subjects were enrolled in a randomized controlled trial and monitored with a noninvasive impedance-based RVM, which displayed respiratory traces and calculated expiratory minute ventilation (VE), tidal volume (VT), and breathing frequency (f) measurements. Prior to induction of anesthesia, a baseline VE measurement (VE-baseline) was taken as a measurement of normal breathing. VE was monitored throughout the procedure for signs of hypoventilation and apnea. Hypoventilation was defined as VE < 40% VE-baseline, and apneas were defined as VE-0 for > 15 s. RESULTS: Sixty-five subjects were randomly assigned to either a control (n-38) or RVM intervention group (n-27). Subjects in the intervention group had a higher VE% for the entire procedure (P-.045), as well as the third and fourth quartile of the procedure compared to the control group (P-.01). Likewise, subjects in the RVM intervention group spent significantly less time below 40% VE-baseline compared to the control group throughout the entire procedure (12 = 15% vs 32 = 24%, respectively) (P < .001). The median number of apneas per subject was greater in the control group (median 2, interquartile range 1–2, maximum 4) compared to the RVM intervention group (median 1, interquartile range 1–2, maximum 3) (P-.037). CONCLUSIONS: The control group had a higher incidence of hypoventilation and apnea compared to the RVM intervention group. Respiratory monitoring using the RVM can potentially be a useful tool for identifying early signs of respiratory depression and for titrating anesthetics to maintain adequate ventilation while minimizing patient risk. Key words: endoscopy; procedural sedation; respiratory volume monitor; ventilation monitoring. [Respir Care 2018;63(4):448 –454.
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U2 - 10.4187/respcare.05723
DO - 10.4187/respcare.05723
M3 - Article
C2 - 29208758
AN - SCOPUS:85054449336
SN - 0098-9142
VL - 63
SP - 448
EP - 454
JO - Respiratory Care
JF - Respiratory Care
IS - 4
ER -