Related Experiment Videos
Relationship between right-to-left shunts and cutaneous decompression illness.
P T Wilmshurst1, M J Pearson, K P Walsh
1The Royal Shrewsbury Hospital, Shrewsbury SY3 8XQ, UK.
Clinical Science (London, England : 1979)
|April 11, 2001
Summary
A large right-to-left shunt significantly increases the risk of cutaneous decompression illness in divers. This shunt is linked to paradoxical gas embolism, with affected individuals experiencing symptoms even after shallow dives.
Area of Science:
- Cardiovascular physiology
- Diving medicine
- Pathophysiology of decompression illness
Background:
- Neurological decompression illness is linked to right-to-left shunts.
- The role of shunts in cutaneous decompression illness is less understood.
- Paradoxical gas embolism is a proposed mechanism for shunt-related decompression illness.
Purpose of the Study:
- To investigate the association between right-to-left shunts and cutaneous decompression illness.
- To compare shunt prevalence and size in divers with and without cutaneous decompression illness.
- To explore the pathophysiological mechanisms of cutaneous decompression illness.
Main Methods:
- Retrospective case-control study.
- Contrast echocardiography to assess right-to-left shunts in 61 cases and 123 controls.
- Shunt assessment was performed blind to patient history.
Main Results:
- Cutaneous decompression illness cases had a significantly higher prevalence of right-to-left shunts (77.0% vs 27.6%).
- Cases also exhibited significantly larger shunts, with 49.2% having large shunts at rest.
- Individuals with shunts experienced decompression illness after shallower, non-provocative dives.
Conclusions:
- Cutaneous decompression illness has two main mechanisms: paradoxical gas embolism via right-to-left shunts, and alternative pathways in shunt-negative individuals.
- Large right-to-left shunts are a major risk factor for cutaneous decompression illness.
- Divers with shunts are also at increased risk for neurological decompression illness.