Alteration in blood gases in tetanus.

Tetanus is an important cause of patient mortality. Hypoxia is an important determinant of poor prognosis in tetanus. Oxygen saturation (Sa02) determines effectiveness of muscle relaxants. We performed arterial blood gas (ABG) studies in 20 patients with tetanus and 20 controls. All patients had hypoxemia and metabolic acidosis at admission. The mortality rate in patients with admission PaO2 < 70mm Hg was higher compared to those with PaO2 > 70mm Hg (P < 0.01). Patient with pH < 7.2 had higher mortality compared to those with pH > 7.2 (p < 0.05). Severe hypoxemia and severe metabolic acidosis connoted poor prognosis.