[Vital capacity reduction in postoperative of elective craniotomy]

To assess the vital capacity (VC), tidal volume, minute volume and respiratory rate during the first four postoperative days of elective craniotomy and how they are correlated with smoking, associated diseases and respiratory symptoms.

Ninety-four patients were initially evaluated for elective craniotomy and they were included in this study only if they presented normal consciousness level and spontaneous breathing at the first postoperative. The preoperative and postoperative evaluations comprised physical examination and ventilometry up to the fourth postoperative. The repeated measures analysis of variance was used to the ventilation measurements. The significance level adopted for all the statistical tests was p = 0.05.

Sixty-two patients were included in this study. There was a 20% fall in the VC from the first to the third postoperative (p = 0.001). Patients with systemic arterial hypertension presented in the preoperative period a lower mean VC (2.59 L) than the patients without (3.28 L) (p = 0.045). Smokers presented a lower mean VC (2.65 and 1.95 L) than the nonsmokers (3.13 and 2.43 L), both in the preoperative and in the postoperative, but with no statistic significance (p = 0.090).

After elective craniotomy, there is a significant decrease in VC immediately after surgery, improving gradually thereafter; there was no difference in VC between the smoking and nonsmoking patients in the pre- and postoperative as well.