Noninvasive Ventilation After Coronary Artery Bypass Grafting in Subjects With Left-Ventricular Dysfunction

Respir Care. 2018 Jul;63(7):879-885. doi: 10.4187/respcare.05851. Epub 2018 Jun 12.

Abstract

Background: The use of noninvasive ventilation in patients with left-ventricular dysfunction may increase cardiac performance by decreasing inspiratory effort and left-ventricular afterload. The aim of the present study was to evaluate the acute effects of noninvasive ventilation on central-venous oxygen saturation (Scv̄O2 ) and blood lactate in subjects with left-ventricular dysfunction during the early postoperative phase of coronary artery bypass grafting.

Methods: This study included 100 subjects during the postoperative phase of elective coronary artery bypass grafting. Blood samples, at 5 time points, were collected to assess tissue perfusion markers (ie, Scv̄O2 and blood lactate) as follows: (1) the intraoperative period (after anesthesia induction); (2) 20 min after ICU arrival, under intermittent mandatory ventilation; (3) 20 min after extubation with spontaneous breathing; (4) after 1 h of noninvasive ventilation; and (5) 20 min after discontinuation of noninvasive ventilation.

Results: A significant increase in the blood lactate and a drop in the Scv̄O2 were observed on arrival to the ICU compared with intraoperative values (P < .001). After extubation, during spontaneous breathing, the Scv̄O2 significantly decreased (P = .02), whereas the blood lactate increased, although not significantly (P = .21) compared with intermittent mandatory ventilation on arrival to the ICU. During the application of noninvasive ventilation, the Scv̄O2 significantly increased (P = .048) and the blood lactate significantly decreased (P = .008) compared with spontaneous breathing values after extubation. After noninvasive ventilation discontinuation, the Scv̄O2 and blood lactate did not change compared with measures taken during noninvasive ventilation; higher values of Scv̄O2 were maintained compared with those obtained after extubation (P < .001).

Conclusions: The acute application of noninvasive ventilation improved Scv̄O2 and decreased the blood lactate in subjects with left-ventricular dysfunction during the early postoperative phase after coronary artery bypass grafting. (ClinicalTrials.gov registration NCT02767687.).

Keywords: arterial lactate; cardiac surgery; central-venous oxygen saturation; coronary artery bypass grafting; left-ventricular dysfunction; noninvasive ventilation; tissue perfusion.

Publication types

  • Evaluation Study

MeSH terms

  • Adult
  • Aged
  • Blood Gas Analysis
  • Coronary Artery Bypass / adverse effects*
  • Female
  • Humans
  • Lactic Acid / blood
  • Male
  • Middle Aged
  • Noninvasive Ventilation*
  • Postoperative Complications / blood
  • Postoperative Complications / etiology
  • Postoperative Complications / therapy*
  • Postoperative Period
  • Pulmonary Gas Exchange
  • Treatment Outcome
  • Ventricular Dysfunction, Left / blood
  • Ventricular Dysfunction, Left / etiology
  • Ventricular Dysfunction, Left / therapy*

Substances

  • Lactic Acid

Associated data

  • ClinicalTrials.gov/NCT02767687