by researchers from King’s College London, Royal Melbourne Hospital, Oxford University Hospitals NHS Foundation Trust, Beth Israel Deaconess Medical Center and the University of Limerick.
, which are associated with higher rates of complications and deaths after surgery. Anesthetists are urgently trying to develop more effective means of improving fitness before operations, known as prehabilitation, to reduce this possibility.
Altitude training is known to improve fitness and lead to higher blood levels (hemoglobin, which carries oxygen in the body) in athletes through exposure to reduced oxygen levels (hypoxia), which are similar to the conditions passengers experience during an airline flight. In athletes, a low oxygen environment stimulates an increase in hemoglobin to carry more oxygen throughout the body, enabling them to perform better in low-altitude environments.
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Researchers questioned whether exposure to simulated high altitude could benefit older people who face a risk of complications ahead of surgery, introducing the concept of ‘altitude prehabilitation’. To test this, they recruited eight sedentary volunteers with an average age of 64 to spend two weeks living in the National Altitude Training Centre in Ireland, a ‘hypoxic house’ in which oxygen levels in the air are tightly controlled.
During one week, the house contained normal air, while during the other week the oxygen levels were mildly reduced (similar to conditions during an airline flight, equivalent to approximately 2438 m or 8000 ft). Volunteers underwent cardiopulmonary exercise tests before and after each week-long exposure.
Simulated high altitude boosted hemoglobin significantly in participants but didn’t alter aerobic fitness. This rise in hemoglobin might benefit surgery preparation.
In practice, small scale hypoxic canopies could be provided to patients to use while sleeping for the weeks leading up to their surgery. The use of hypoxic technology is also already widespread, as hypoxic rooms or tents are available at high-end gyms and in professional sports clubs, and similar hypoxic air systems are used to prevent fires on an industrial scale, such as in warehouses and library archives. In healthcare settings, hospitals could create small or large hypoxic spaces for patients ahead of surgery, as the technology is available.
Lead author Professor Thomas Smith, a Consultant Anesthetist and Head of Aerospace Medicine Research at King’s College London, said: “We know that athletes can use hypoxic canopies over their bed to simulate altitude exposure and that altitude can induce performance benefits after two to three weeks even in people who are extremely fit. We were interested in whether this approach could also benefit older patients ahead of major surgery, who due to sedentary lifestyles and low levels of fitness, are more at risk of negative postoperative outcomes.
Source: Eurekalert
