Sigh Ventilation on Postoperative Hypoxemia in Cardiac Surgery

Postoperative Complications Clinical Trial

Official title:

Effect of Perioperative Sigh Ventilation on Postoperative Hypoxemia and Pulmonary Complications After On-pump Cardiac Surgery: A Randomized Controlled Trial

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT06248320
• Other study ID #: SIGHVENT
• Status: Recruiting
• Phase: N/A
• Start date: February 25, 2024
• Est. completion date: November 2024

Study information

• Verified date: February 2024
• Source: Zhongda Hospital
• Contact: Fengmei Guo, PhD, MD
• Phone: +8613813841261
• Email: fmguo2022[@]163.com
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Postoperative pulmonary complications (PPCs) remain a frequent event after pump-on cardiac surgery and are mostly characterized by postoperative hypoxemia.These complications are significant contributors to prolonged intensive care unit admissions and an escalation in in-hospital mortality rates.

The dual impact of general anesthesia with invasive mechanical ventilation results in ventilator-induced lung injury, while cardiac surgery introduces additional pulmonary insults. These include systemic inflammatory responses initiated by cardiopulmonary bypass and ischemic lung damage consequent to aortic cross-clamping. Contributing factors such as blood transfusions and postoperative pain further exacerbate the incidence of PPCs by increasing the permeability of the alveolo-capillary barrier and disrupting mucociliary functions, often culminating in pulmonary atelectasis.

Protective ventilation strategies, inspired by acute respiratory distress syndrome (ARDS) management protocols, involve the utilization of low tidal volumes (6-8mL/kg predicted body weight). However, the uniform application of low tidal volumes, especially when combined with the multifactorial pulmonary insults inherent to cardiac surgery, can precipitate surfactant dysfunction and induce atelectasis.

The role of pulmonary surfactant in maintaining alveolar stability is critical, necessitating continuous synthesis to sustain low surface tension and prevent alveolar collapse. The most potent stimulus for surfactant secretion is identified as the mechanical stretch of type II pneumocytes, typically induced by larger tidal volumes.

This background sets the foundation for a research study aimed at assessing the safety and efficacy of incorporating sighs into perioperative protective ventilation. This approach is hypothesized to mitigate postoperative hypoxemia and reduce the incidence of PPCs in patients undergoing scheduled on-pump cardiac surgery.

Description:

The purpose of this single center, parallel group, randomized controlled study is to evaluate the effect of a perioperative sigh ventilation strategy on postoperative outcomes during the first 7 days following cardiac surgery. The study will include 192 adult patients undergoing scheduled on-pump cardiac surgery. The sigh ventilation approach will combine sigh ventilation and lung protective ventilation (6-8 ml/kg/pbw) from intubation to extubation. It will be compared to a conventional approach without sigh ventilation, with lung protective ventilation and positive end-expiratory pressure (PEEP) setting same as the intervention arm. The primary endpoint is the Spo2/Fio2 ratio during the initial post extubation hour. The secondary endpoints are postoperative pulmonary complications and hospital length of stay .

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 192
• Est. completion date: November 2024
• Est. primary completion date: October 2024
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years to 80 Years

Eligibility

Inclusion Criteria:

• Elective cardiac surgery with general anesthesia

• Conventional cardiopulmonary bypass and aortic cross clamp

• Providing written informed consent by the patient himself/herself or the next of kin

Exclusion Criteria:

• Emergent surgery including aortic dissection, cardiac rupture and active endocarditis surgery

• Left ventricular assist device implantation

• Patients anticipated to require intraoperative support with Extracorporeal Membrane Oxygenation (ECMO) or Intra-Aortic Balloon Pump (IABP)

• Chronic pulmonary disease requiring long-term home oxygen therapy

• Receiving invasive mechanical ventilation within 7 days prior to surgery

• Preoperative shock

• Obstructive Sleep Apnea Syndrome (OSAS) requiring intermittent non-invasive ventilatort support

• Preoperative left ventricular ejection fraction<40%

• Pulmonary arterial systolic pressure>50 mmHg

• Redo surgery

Related Conditions & MeSH terms

• Acute Lung Injury
• Cardiac Disease
• Heart Diseases
• Hypoxemia
• Hypoxia
• Lung Injury
• Postoperative Complications

Intervention

Procedure:
• Sigh ventilation
Sigh breaths were delivered from intubation to extubation. Intervention primarily conducted in the following three stages: 1. From intubation to surgical opening of the chest cavity; 2. From the surgical closure of the chest cavity close and continue unit the operating room exiting; 3. From Intensive Care Unit (ICU) arrival to Spontaneous breathing trial (SBT) start.

Locations

Country	Name	City	State
China	Zhongda Hospital, Southeast University	Nanjing	Jiangsu

Sponsors (1)

Lead Sponsor	Collaborator
Zhongda Hospital

Country where clinical trial is conducted

China, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Time-weighted average pulse oximetry (SpO2/FiO2)	Calculated the SpO2/FiO2 ratio every 15min during the initial postextubation hour, then averaged the SpO2/FiO2 ratios weighted by measurement interval. The comparison between arms was made through T-test.	1 hour after endotracheal extubation
Secondary	Proportion of respiratory failure	Definition of respiratory failure was adapted from previous publications. Mild respiratory failure: SpO2 < 90% or PaO2 < 60 mmHg after breathing ambient air for 10 min (excluding hypoventilation) and corrected with an oxygen supply of 1-3 L/min with a nasal cannula; Moderate respiratory failure: SpO2 < 90% or PaO2 < 60 mmHg despite a 3 L/min oxygen supply with a nasal cannula (excluding hypoventilation) and corrected with an oxygen supply from 4 to 10 L/ min with a face mask; Severe respiratory failure: SpO2 < 90% or PaO2 < 60 mmHg despite a 10 L/min oxygen supply with a face mask (excluding hypoventilation) and corrected with an oxygen supply > 10 L/min with a high-flow face mask or with non-invasive ventilation or with high-flow nasal oxygen therapy or with invasive mechanical ventilation.; Tested between arms through Chi-Square Test.	first 7 days postextubation
Secondary	Severity of postoperative pulmonary complications	Score of pulmonary complications adapted from previous publications, with 5 degrees, where the higher one means death before hospital discharge, degree (4) means the need of mechanical ventilation for more than 48 hours after surgery or after reintubation, degree (3) means pneumonia or intense noninvasive ventilation need, degree (2) means hypoxemia and abnormal lung findings, degree 1 means simple atelectasis and degree (0) means no complication.; Tested between arms through Mann-Whitney U tests and ordinal logistic regression by estimating the common odds ratio for a shift in the direction of a better outcome on the scale of pulmonary complications.	first 7 days after surgery
Secondary	Invasive mechanical ventilation (IMV) days	Durations of invasive mechanical ventilation.	first 7 days after surgery
Secondary	Reintubation rate	Occurrence of endotracheal reintubation.	first 7 days after surgery
Secondary	Proportion of receiving non-invasive ventilation (NIV) or High-flow nasal cannula (HFNC) support	Tested through the Fisher exact test or likelihood ratio tests.	first 7 days after surgery
Secondary	No ventilatory-support days	Days alive and not receive IMV, HFNC and non-invasive ventilatory support.	first 7 days after surgery
Secondary	In-hospital mortality	Deaths occurred during hospital stay, tested with logistic regression.	From the day of surgery up to Hospital discharge or death, maximum censoring at day 28 after surgery
Secondary	Length of ICU stay	Days since surgery until ICU discharge, analyzed through Kaplan-Meyer curves (log-Rank test), where the time to event is the time of discharge from the ICU. The censoring was performed at 28 days. Patients dying before leaving the ICU were censored as not discharged from ICU at day 28.	From the day of surgery up to ICU discharge, maximum censoring at day 28 after surgery
Secondary	Length of hospital stay	Days since surgery until Hospital discharge, analyzed through Kaplan-Meyer curves (log-Rank test), where the time to event is the time of discharge from the Hospital. The censoring was performed at 28 days. Patients dying before leaving the Hospital were censored as not discharged from Hospital at day 28.	From the day of surgery up to Hospital discharge, maximum censoring at day 28 after surgery