BLOOD SUGAR LEVEL IN DIABETIC PATIENTS FOLLOWING HYPERBARIC OXYGEN THERAPY
Dr Michael Bennett - Medical Director, The Prince Of Wales Hospital
Introduction:
Previous investigations have suggested that blood sugar level (BSL) may fall in association with exposure to hyperbaric oxygen therapy (HBOT).
Methods:
We have conducted a prospective observational study of BSL before and after treatment in diabetic patients presenting for HBOT in our unit. 27 patients were studied over a total of 237 treatment episodes. BSL was measured immediately before and after HBOT in each individual.
Results:
The mean change in the BSL for an individual subject after HBOT was a statistically significant reduction of 2.04mmol/L, SD 1.38 (P=< 0.0001). 11 treatment sessions were associated with symptomatic hypoglycaemia requiring glucose administration while in the hyperbaric chamber (9 insulin requiring subjects, 2 non-insulin requiring). Using the remaining 226 treatments as the unit of analysis, the mean change in BSL was very similar (a reduction of 2.13mmol/L, SD 2.35 (P=< 0.0001). There was a larger mean reduction of BSL in insulin requiring patients than non-insulin requiring patients (2.48mmol/L (95% CL 2.89 to 2.07) versus 1.65mmol/L (95% CL 2.12 to 1.19), P = 0.009.
The number of treatment sessions where BSL drop was> 4.0mmol/L and/or intervention was required was 44/133 (33%) in the insulin requiring group and 17/104 (16%) in the non-insulin requiring group (Chi2 = 8.6, P = 0.003). In the 17 subjects in whom the HbA1c was estimated, there was a small mean reduction in HbA1c of 0.22 % (SD 0.43) over the course of treatment (P = 0.06).
Conclusions:
HBOT reduces BSL in both non-insulin requiring and insulin requiring diabetics, but overall diabetic control is not improved over a course of 10 sessions of therapy. Problematic hypoglycaemia is more common in insulin requiring patients. We recommend daily monitoring of BSL prior to HBOT and prophylactic administration of glucose if the pre-HBOT BSL is < 8 mmol/L.
Time of Presentation:
- Tuesday 6 May 2003 - 1115-1130
Additional Authors:
- Dr Barbara Trytko
Biography:
- Dr. Bennett is a staff specialist anaesthetist and hyperbaric physician working in Sydney. He has a strong interest in clinical epidemiology and is the author of a searchable database appraising all randomised evidence in the field of diving and hyperbaric medicine. He is a founding member of the ANZCA SIG in this area.
