Postprandial hypotension as a predictor of respiratory failure in patients with foodborne botulinum intoxication - a case-control study in outbreak investigation.

OBJECTIVES: Botulism is a rare syndrome characterized by acute, flaccid paralysis with possible involvement of respiratory muscle-producing pump failure requiring mechanical ventilation. A predominance of autonomic involvement can occur. METHODS: We enrolled patients affected by foodborne botulism during an outbreak. All patients underwent the detection of the toxin in stool specimens, and 24-hour ambulatory blood pressure monitoring (ABPM). A blinded expert operator analyzed ABPM data for the diagnosis of hypertension and postprandial hypotension (PPH). RESULTS: Twenty male patients met the inclusion and exclusion criteria. Thirty-four healthy subjects matched for sex and age were enrolled as a control group. PPH was significantly more frequent in the botulin group than in healthy subjects (40% vs 2.9%, P <0.0001). At the logistic regression, the probability that patients affected by botulinum could require ventilation was increased by 733% (adjusted odds ratio: 8.33) when PPH is encountered. CONCLUSIONS: The likelihood of resorting to ventilation in subjects with botulinum intoxication was seven times greater in patients presenting PPH. These results could allow the prompt identification of patients at high risk for requiring ventilation.