REVIEW QUESTION

Which medical treatments are effective in the treatment of botulism?

TYPE OF REVIEW

A systematic review of one randomized controlled trial (RCT) with 122 participants.

RELEVANCE FOR NURSING

Botulism is an acute paralytic illness caused by a neurotoxin produced by Clostridium botulinum. Botulism is characterized by symmetric cranial nerve palsies, often with blurred vision and dry mouth, followed by paralysis of voluntary muscles. There are four types of botulism: infant intestinal, foodborne (the most common), wound, and adult intestinal, all of which have the same symptoms. The only specific medical treatment for botulism is botulinum antitoxin, which should be given as early as possible and within 24 hours of symptom onset. Timely diagnosis and treatment are critical, as botulinum antitoxin only neutralizes toxin molecules that have not yet bound to nerve endings; existing paralysis cannot be reversed. The mainstay of treatment for botulism is supportive care, which often includes prolonged mechanical ventilation in an ICU and an extended hospital stay. The goal of supportive care strategies is to prevent the sequelae that can result from a prolonged paralytic illness.

CHARACTERISTICS OF THE EVIDENCE

The purpose of this review was to assess the effects of medical treatment of botulism on mortality. The primary outcome was mortality within four weeks of randomization or the beginning of treatment. Secondary outcomes were measured within 12 weeks of randomization or the beginning of treatment and included death from any cause, length of hospitalization, length of mechanical ventilation, duration of tube or parenteral feeding, and the proportion of patients with adverse events or complications of treatment.

The review considered RCTs that examined equine serum botulism antitoxin, human-derived botulism immune globulin intravenous (BIG-IV), plasma exchange, 3,4-diaminopyridine, and guanidine. Only one study was included: a study on infant intestinal botulism that included 59 patients who received BIG-IV and 63 patients who received a control immune globulin with no effect on botulism toxin. The primary outcome of mortality could not be measured, as there were no deaths in either group. Among the secondary outcomes, the treatment group had reductions in length of hospitalization, length of mechanical ventilation, and duration of tube or parenteral feeding. All evidence was of moderate certainty. There were no differences between groups in the number of adverse events or complications.

BEST PRACTICE RECOMMENDATIONS

Although the effect of BIG-IV on mortality rates in infant botulism patients could not be measured, it did improve several secondary outcomes. The use of BIG-IV decreased length of mechanical ventilation, which is important, as a longer length of time on mechanical ventilation can lead to a higher risk of ventilator-associated pneumonia and other sequelae. BIG-IV also decreased length of hospitalization, which decreases the risk of hospital-associated infections; duration of tube or parenteral feeding, which reduces the risk of potential aspiration; and hospital length of stay, which may reduce the financial burden for many families.

RESEARCH RECOMMENDATIONS

Given the low-to-moderate-certainty evidence for using BIG-IV to treat infant intestinal botulism in this one trial, further RCTs of high quality are needed to estimate its effects on mortality. Further clinical trials are also required to investigate the use of BIG-IV, equine-derived antitoxin, and other potential therapies including plasmapheresis in all forms of botulism.

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