Common Emergency Medicine Myths Debunked
By Doug Brunk
Elsevier Global Medical News
SAN DIEGO -- Is it a myth or a fact that atropine must always be given when using ketamine for procedural sedation in children?
That's a myth, Dr. Peter E. Sokolove said during the annual meeting of the California chapter of the American College of Emergency Physicians. "Hypersalivation with ketamine is infrequent and can be managed with suctioning or atropine," said Dr. Sokolove, vice chair for education and residency program director in the department of emergency medicine at the University of California, Davis Health System. "Atropine is not routinely required when using ketamine for sedation in children."
The weight of the evidence comes from a prospective observational study of 1,090 children who received dissociative sedation at Loma Linda (Calif.) University Medical Center and Children's Hospital (Acad. Emerg. Med. 2008;15:314-8). The researchers used a 100-mm visual analog scale to measure hypersalivation, with zero being the lowest rate, and recorded the frequency of airway complications.
Of the 1,090 sedations, 947 (87%) did not require atropine and the majority of patients (92%) had a score of zero on the visual analog scale. Only 12 (1.3%) had a visual analog score of greater than 50 mm, and 4.2% required some form of intervention, usually suctioning. One patient (0.11%) exhibited brief desaturation from hypersalivation.
Dr. Sokolove went on to dispel several other myths common in emergency medicine:
Myth: Buckle fractures of the distal radius must be treated with a cast for several weeks.
One randomized trial of 39 children (most aged 5-10 years) in the United Kingdom found that buckle fractures of the distal radius are safely treated in a soft bandage (J. Pediatr. Orthop. 2005;25:322-5). The researchers randomized the children to a soft bandage or to a cast for 4 weeks. The soft bandage consisted of orthopedic wool, cotton crepe, and tape.
At 4 weeks, children in the soft-bandage group reported less pain overall, had a shorter recovery from injury, and displayed significantly better range of motion (162 degrees vs. 126 degrees in the cast group).
In a separate study, Canadian researchers randomized 113 children (aged 6-15 years) with wrist buckle fractures to either a cast or a plaster volar splint for 3 weeks (Pediatrics 2006;117:691-7). Children in the volar splint group were instructed to remove the splint as desired for activities of daily living such as bathing, but were asked to refrain from contact sports.
The researchers followed the children via weekly telephone calls for 4 weeks and assessed their physical function using the Activities Scale for Kids, a self-report measure (available at www.activitiesscaleforkids.com).
Children in the splint group had better Activities Scale for Kids scores at 2 weeks, compared with their counterparts in the cast group. They also reported less difficulty bathing, had no increase in pain, and had no visits to the emergency department for splint problems (11% of children in the cast group visited the ED for cast problems).
"Buckle fractures of the distal radius may have a better outcome when treated with a soft bandage instead of a cast," Dr. Sokolove commented. "A removable plaster splint is a reasonable alternative to a cast. From a practical standpoint, it really depends on the patient and his or her level of activity, and the parent's level of anxiety."
Myth: Mist therapy is a useful first-line treatment for children with croup in the ED.
In a trial of 71 children (aged 3 months to 6 years) who presented with moderate croup, researchers randomized the children to receive the mist stick (humidified oxygen) or nothing. All patients received dexamethasone. Racemic epinephrine or budesonide was administered at the physician's discretion (Acad. Emerg. Med. 2002;9:873-9).
Over a period of 2 hours, there were no differences between the two groups in croup score, oxygen saturation, heart rate, or respiratory rate. "The mist made zero difference for these patients," Dr. Sokolove said.
In a separate study, Canadian researchers randomized 142 children (aged 3 months to 10 years) with moderate to severe coup to receive 30 minutes of treatment with blow-by mist, controlled delivery of 40% humidity, or delivery of 100% humidity with 6.2-mcm particles (JAMA 2006;295:1274-80).
No significant differences were observed among the three groups at 30 minutes or 60 minutes in terms of croup score, oxygen saturation, heart rate, respiratory rate, use of steroids, or rate of hospital admission.
"This doesn't tell us about kids with mild croup," Dr. Sokolove noted. "Maybe it does work for those kids; it doesn't hurt to try."
Myth: Pelvic ultrasound will be inadequate unless the patient has a full bladder.
In a 1-month study of 206 consecutive patients, Dr. Beryl R. Benacerraf of the department of obstetrics and gynecology at Massachusetts General Hospital, Boston, and her associates found that transvaginal ultrasound alone was sufficient to detect findings in 172 patients (83.5%), transvaginal and transabdominal scans through an empty bladder were required for 31 patients (15%), and only 3 patients (1.5%) required a full bladder in addition to transvaginal and transabdominal scans (J. Ultrasound Med. 2000;19:237-41).
"Overfilling [the bladder] can give false positives and false negatives," Dr. Sokolove added. "And of course, it's more uncomfortable. Pelvic ultrasounds rarely require a full bladder."
Myth: Response to antacids and nitroglycerin can help with the diagnosis of acute coronary syndromes.
A review of published articles on the topic discussed one small study of 46 patients with acute myocardial infarction (Emerg. Med. J. 2003;20:170-1). Nearly half of the patients (45%) had pain consistent with indigestion, and use of antacids relieved pain in 29% of cases. "That is the same number we see for placebo in all sorts of pain trials," Dr. Sokolove said. "About 30% of patients in pain trials get better with placebo."
In a later prospective study of 664 patients who presented to the ED with chest pain, researchers used an 11-point numeric descriptive scale for pain after the initial dose of nitroglycerin (Ann. Emerg. Med. 2005;45:581-5). They defined cardiac-related pain as chest pain in a patient discharged with a diagnosis of myocardial infarction or with coronary artery disease based on a positive diagnostic test.
Cardiac-related etiology was identified in 122 patients (18%). In the overall patient population, 125 (19%) patients had no change in pain, 206 (31%) patients had minimal reduction, 145 (22%) patients had moderate reduction, and 188 (28%) patients had significant or complete reduction in pain.
The researchers detected no significant difference in any subgroup of numeric descriptive scale response to sublingual nitroglycerin administration in patients with and without a diagnosis of cardiac chest pain.
"Your response to antacids and nitroglycerin does not predict ischemic chest pain," Dr. Sokolove said. "These medications are treatments, not diagnostic tools. That's the key point."
Dr. Sokolove said that he had no relevant financial conflicts of interest to disclose.