Xiang2017
Hyperbaric oxygen plus dexamethasone (vs hyperbaric oxygen therapy alone) improved outcomes for patients with delayed encephalopathy after acute carbon monoxide poisoning.
| Clinical bottom line: 1. The addition of dexamethasone improved the outcome of patients with DEACMP and remission rates were higher. 2. No evidence to support the use of hyperbaric oxygen |
Citation/s: 1. Xiang W, Xue H, Wang B, Li Y, Zhang J, Jiang C, Liang F, Pang J, Yu L. Combined application of dexamethasone and hyperbaric oxygen therapy yields better efficacy for patients with delayed encephalopathy after acute carbon monoxide poisoning. Drug design, Development and Therapy. 2017:11 513-519.
Lead author's name: Lehua Yu, Department of Rehabilitation Medicine at the Second Affiliated Hospital of Chongqing Medical University, 76 Linjiang Road, 40010 Chongqing, China.
Three-part Clinical Question:Does the addition of dexamethasone to hyperbaric oxygen therapy improve cognitive function and disability in patients with delayed encephalopathy after acute carbon monoxide poisoning (DEACMP)?
Search Terms: Carbon monoxide poisoning; steroids; brain injury
The Study: Double-blinded concealed randomised controlled trial with intention-to-treat.
The Study Patients: COP patients with DEACMP
Control group (N = 60; 60 analysed): 20 sessions over four weeks breathing 100% oxygen at 2.4ATA for 80 minutes. All patients received standard ancillary care depending on functional state.
Experimental group (N = 60; 60 analysed): As above plus either 5mg dexamethasone daily (n=30) or 10mg daily for four weeks.
The Evidence:
Outcome |
Time to Outcome |
HBOT Group |
Dexameth |
Relative risk Reduction |
Absolute Risk Reduction |
NNT |
Remission |
4 weeks |
0.23 |
0.42 |
83% |
0.19 |
5 |
95% CIs: |
11% to 154% |
0.03 to 0.35 |
3 to 39 |
Outcome |
Time to outcome |
HBOT group |
Dex. groups |
P-value |
Mean MMSE |
4 weeks |
13 |
18 |
0.04 |
Mean NIHSS |
4 weeks |
15 |
12.5 |
0.0 |
Comments:
1. The study is really testing the use of dexamethasone as a treatment for delayed encephalopathy of carbon monoxide poisoning. HBOT is a part of standard treatment.
2. Results of the MMSE and NIHSS scores were given as a dynamite plot with p-values above: very difficult to interpret and difficult to recreate either error or standard deviation as presented. We have retrocalculated NNT and CIs but are cautious about the results.
3. The researcher's definition of DEACMP is any patient who has experienced coma and is then affected by memory impairment, cognitive dysfunction and behavioural disorders 2-60 days after exposure. No data is given for where in this time spectrum their patients were.
Appraised by:Dr Katherine Witheridge The Department of Diving and Hyperbaric Medicine, Prince of Wales Hospital 02 9382 3834; Friday, 20 April 2018
Email: katherine.witheridge@health.nsw.gov.au
Kill or Update By: August 2022
