Influence of the diving wetsuit on standard spirometry

INTRODUCTION A well-fitting wetsuit exerts a pressure on the body that may influence spirometry. This pressure is expected to reduce the forced vital capacity (FVC) due to hampered inspiration. Since the shape of the spirometric flow curve should not be changed by the pressure effects of the wetsuits, FVC, the forced expiratory volume during the first second of expiration (FEV₁), the peak expiratory flow (PEF) and the flow between 25 and 75% of FVC (FEF25-75) should change to the same degree. This study investigates the influence of a wetsuit on spirometric variables using age, suit thickness and suit type as the parameters. Spirometry (dry) was performed in 28 volunteers (12 women), aged 27-69 years. The wetsuit (3.8 mm, range 2-7 mm) resulted in a change in FVC of -4.0% (P = 2∙E-08 〈 0.001), in FEV₁ of -3.6% (P = 3∙E-05 〈 0.001) and in PEF of -2.4% (P = 0.03); the FEF25-75 may also diminish. The FEV₁/FVC ratio did not change. The decreases can be regarded as a quasi-ageing effect of about 3.5 years. No influence of age, suit thickness and suit type was found. The wetsuit appears to impair ventilatory mechanics. Both the medical examiner and the diver should be aware that a too-thick or too-tight suit might be a potential pulmonary risk factor in diving