Outcomes of Implementation of Continuous High-Frequency Oscillation Therapy on Cardiac Surgery Patients Prior to Liberation From Mechanical Ventilation

Abstract

Background:

Hyperinflation is routinely used to recruit lungs and prevent atelectasis in postoperative patients. This study evaluated the effectiveness of Continuous High-Frequency Oscillation Therapy (CHFO) on Cardiac Surgery (CV) patients before liberation from ventilator. We hypothesized that use of a CHFO device postoperatively (postop) would improve CV outcomes, including fewer pulmonary complications requiring antibiotics, reduced oxygen usage, and shorter ICU and hospital length-of-stay (LOS). There have been no previous studies conducted on adult CV subjects using CHFO prior to liberation from a vent.

Methods:

Study sample consisted of CV patients with ASA scores of 3 or greater between Jan 2018 and Jan 2019 at Mayo Clinic-Eau Claire, WI. Prior to intervention, standard of care was to perform 4 hyperinflation treatments/day after patient was extubated. We developed a protocol incorporating CHFO. After ICU admission, and while patient was still intubated, one 10 minute CHFO treatment was performed inline with the vent. Once extubated, patients received CHFO treatments QID for 48 h. After 48 h, patients continued treatment or CHFO was discontinued. Outcomes included postop. hospital and ICU LOS, duration on vent, oxygen usage, and infections needing antibiotics. Postop. outcomes prior to intervention were compared to outcomes post intervention using linear regression for continuous outcomes, and logistic regression for dichotomous outcomes. This study was approved by Mayo Clinic’s IRB.

Results:

104 adult CV patients were studied with an ASA score ≥ 3 between Jan 2018 and Jan 2019, with 54 receiving standard of care and 50 receiving the CHFO Therapy. Standard of care patients tended to be older men (median age 70 yrs vs. 67; P = .009, 74% vs. 62%; P = .19). Compared to standard of care, CHFO Therapy patients had shorter vent days (0.6 days vs 1.1; P = .06), hospital LOS (6.2 days vs. 7.4; P = .04), ICU LOS (2.7 days vs. 3.4; P = .06), and oxygen usage (3.6 days vs. 4.2; P = .34). After multivariable adjustment, ICU LOS remained significant (0.85 fewer days; 95% CI = 0.06 to 1.65; P = .04). The CHFO Therapy group had fewer postop complications (10% vs. 20%; OR = 0.51; P = .26).

Conclusions:

Use of CHFO Therapy for CV patients prior to liberation from MV significantly reduced ICU LOS. Other outcomes of vent days, hospital LOS, and complications were superior although ultimately not different in the protocol group. Larger studies are needed to confirm findings.