Yang

Pre-conditioning with HBO may induce cerebral and cardiac protection in patients undergoing on-pump CABG surgery

• • Clinical Bottom line:
  • 1. Pre-conditioning with HBO resulted in improved clinical outcomes for patients undergoing 'on-pump CABG surgery.
  • 2. There were also potential cerebral and cardiac protective effects as determined by proxy outcomes.
  • 3. No protective effects were noted in off-pump CABG

Citation/s: Yang L, Dong H, Chen M et al. Preconditioning with repeated hyperbaric oxygen induces myocardial and cerebral protection in patients undergoing coronary artery bypass graft surgery: a prospective, randomized, controlled clinical trial. Journal of Cardiothoracic and Vascular Anesthesia 2011;25(6):908-916. Lead author's name and email: Yang Li: lxiong@fmmu.edu.cn Three-part Clinical Question: For patients undergoing CABG, does the addition of hyperbaric oxygen to standard care confer any myocardial and cerebral protection?Search Terms: CABG, preconditioning, cardiopulmonary bypass

The Study: Single-blinded randomised controlled trial without intention-to-treat. The Study Patients: Male patients under 80 years having CAG either on cardiopulmonary bypass or off-pump. Control group (N = 16; 15 analysed): Full orthodox pre-operative care for CABG. No sham treatment. Experimental group (N = 15; 14 analysed): As above, but patients were given 5 daily sessions of HBOT at 2ATA breathing 100% ATA for 70 minutes.

• • The Evidence:

Outcome		Control Group		HBOT Group	Difference	95% CI
^	Mean	SD	Mean	SD	^	^
Length of ICU Stay in on-pump patients (hrs)	85.9	40.3	59.4	20.9	26.5	1.8 to 51.2
Serum S100B concentration of on-pump patients at time of ICU arrival (pg/ml)	89.7	14.6	60.4	26.4	29.3	13.2 to 45.4
Serum NSE concentration of on-pump patients at 24hrs post-op (ng/ml)	38.0	8.4	30.3	6.1	7.7	2.1 to 13.3

Comments: 1. Exclusion of female subjects and small numbers may limit external validity of the study 2. Only 2 biochemical markers were analyzed to measure cerebral injury; it may not be fully representative of actual cerebral damage. 3. Early post-operative outcomes may not be representative of long-term morbidity and mortality 4. Values of mean and standard deviation were not provided for non-significant results in off-pump patients.

Appraised by: Bryan Hui and Michael Bennett, Tuesday, 23 April 2013 Email: bryan.hui@student.unsw.edu.au Kill or Update By: April 2020