Li

Preconditioing with hyperbaric oxygen reduced the ICU length of stay and inotrope requirements for patients having on-pump coronary bypass grafting.

1. ICU time was reduced following preconditioning with HBO for those patients requiring on-pump CABG ** 2. The requirement for inotropes post-operatively was reduced in the same group following preconditioning. ** 3. No differences were note for those having off-pump surgery.

Citation/s: 1. Li Y, Dong H, Chen M, Liu J, Yang L, Chen S, Xiong L. 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 Dec 31;25(6):908-16.

• • Lead author's name and fax: Lize Yiong lxiong@fmmu.edu.cn
  • Three-part Clinical Question: For patients requiring coronary artery bypass grafting (CABG) (on or off-pump), does preconditioning with hyperbaric oxygen result in protective cerebral or myocardial effects?

• • Search Terms: coronary artery bypass grafts; preconditioning, brain injury

• • The Study: Single-blinded concealed randomised controlled trial with intention-to-treat.

The Study Patients: Adult male patients for first time coronary arterial bypass grafting.

• • Control group (N = 16; 15 analysed): Standard surgical procedures for on-pump CABGs. Anaesthesia with propofol infusion and no volatile agents or steroids. ACT maintained at >480 sec with heparin.

Experimental group (N = 15; 14 analysed): As above, plus HBO at 2.0 ATA for 70 minutes daily for five days prior to operation.

• • The Evidence:

Measure		Control Group		HBO Group	Difference	95% CI
^	Mean	SD	Mean	SD	^	^
Length of stay in ICU (hours)	85.9	41.8	59.4	21.7	26.500	0.84 to 52.16
Inotrope scores at 36 hours (microg/kg/min)	9.6	4.3	6.7	3.0	2.900	0.06 to 5.75
Serum S100B after 1 hr crossclamp time (pg/ml)	138.2	37.4	82.2	42.8	56.000	25.43 to 86.57
Serum catalase activity at 24 hours (U/ml)	3.73	1.78	6.1	1.53	2.27	1.00 to 3.54

• • Comments:

• • 1. Results indicate some clinical benefit with preconditioning and these findings are supported by differences in a marker of cerebral injury (S100B) and a number of others in the paper.

• • 2. Any benefit of HBO may reflect a combination of anti-inflammatory and/or antioxidant actions.

3. There were no differences shown on the same analysis of off-pump CABG implying the crucial exposure is to CPB.

4. A small study with wide 95% CIs and no longer-term follow-up means we should interpret cautiously.

• • Appraised by: Mike Bennett, POWH m.bennett@unsw.edu.au; Monday, 13 November 2017

Kill or Update By: November 2022