BARCELONA, Spain — Botulinum toxin injections are first-line treatment for cervical dystonia, and although the injections can have adverse effects, adequate consent is rarely obtained from patients, a study shows. Formal consent was deficient at the time of an initial injection and even more so at subsequent ones.
"What tends to happen is there's a mention of consent in a clinic letter rather than a specific form that the patient is signing," Stefan Williams, MBBS, a trainee in neurology at Leeds Teaching Hospitals National Health Service (NHS) Trust in the United Kingdom, told Medscape Medical News. "We feel that because the side effects are potentially serious, it's very important to have the patient clearly document consent [and] sign for it in a clear form."
Adverse effects may include excessive weakness in injected muscles or local drug diffusion, causing neck weakness, dysphagia, dry mouth, and sore throat. European Federation of Neurological Societies guidelines call for consent by the patient or a guardian, "understanding the potential benefits and risks," and the Leeds local hospital guidelines state that "consent should be documented in the medical notes."
The study, presented here at the 23rd Meeting of the European Neurological Society (ENS), identified all patients with cervical dystonia seen at the hospital's botulinum toxin clinic for the past year. Investigators performed a chart review for evidence of documentation of consent at each clinic visit and also reviewed medical records for subsequent adverse effects and complications of treatment.
Notes were available for 22 patients, who attended the clinic a total of 284 times (mean, 12.9 per patient). Consent was documented at 77% of the initial visits. Of these, only 2 (12%) were patient-signed notes. The rest were clinic letters only (65%) or clinic letters and notes (24%). None was an NHS consent form. On subsequent visits, consent was obtained from only 11% of patients.
Nine patients (41%) experienced complications, including dysphagia or muscle weakness. There were 2 hospital admissions, 1 of which involved a patient who was admitted for 2 months and required a nasogastric tube, which was still in place for an additional month after discharge. The overall complication rate was 4.9% per visit.
Dr. Williams noted that the complication rate was similar to that in published studies except that in this study the incidence of dysphagia was higher than in the literature. The difference may have resulted from even mild dysphagia being documented in a clinical note in practice, in contrast to some higher threshold being set in clinical trials. Also, trials may have used lower, standardized botulinum toxin doses as compared with higher doses often used in practice because doses are titrated up to an effective level.
Simple Consent Form
Dr. Williams and colleagues have designed a simple consent form specific to botulinum toxin treatment consisting of a line stating the intended benefit and several check boxes of possible adverse effects specific to each condition for which botulinum toxin may be used, followed by lines for consent signatures and the date. "What was done before was a documentation that a conversation had been had without specifics," Dr. Williams said. An additional advantage of the standardized form is that it is quicker than the conversations and notes.
When asked to comment on the study, John O'Dwyer, MD, MB, consultant neurologist and director for dystonia and botulinum at St. George's Hospital Health Care Trust in London, United Kingdom, who was not involved with the study, told Medscape Medical News that formal consent for these treatments is important not only for medico-legal reasons but also for patient care.
"Treatment complications are quoted in the literature as being common, and I suppose if a patient is getting their injection first and they don't have a good effect or if they have a very negative experience because of pain or worsening, then they're very unlikely to come back, and that will be a treatment failure for the patient," he said. "If they were consented properly and told about efficacy and also complications then it might have made a difference to them long term. So, it's disappointing to see such a low rate of consent and even consent on follow-up treatments as well."
Dr. O'Dwyer said he is careful to obtain consent before every botulinum toxin injection and always writes down the product used and the concentration. "I always ask, 'Do you want to have your injection again, and you are aware that you're still going to have that 1 in 20 chance of having a complication and just because you didn't have it before, at least maybe 1 in 20 of the 20 injections that you're going to have over a 4- or 5-year period, you'll probably get something like a droopy eyelid or swallowing trouble depending on what the injection is for.' So I always consent them. You're not immune just because you don't have a complication once."
In fact, he said, patients may be at higher risk for complications on subsequent injections because injecting an atrophic or smaller muscle may lead to more spread of the drug to other muscles in the area.
Unfortunately, Dr. O'Dwyer said the study findings are consistent with what he sees in practice by many physicians. Comparing these injections to other procedures, he said no one would ignore getting consent each time if it were a surgical procedure or laparoscopy that was to be performed. Therefore, "practice needs to change because every single treatment is a risk," he emphasized.
There was no commercial funding for the study. Dr. Williams and Dr. O'Dwyer have disclosed no relevant financial relationships.
23rd Meeting of the European Neurological Society (ENS). Abstract P728. Presented June 10, 2013.
Medscape Medical News © 2013 WebMD, LLC
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