the ED tends to intubate based on clinical analysis.
My few asthmatic intubations have been based entirely on clinical assessment, and they all had the telltale "sweat halo" around them on the bed sheet.....In my intern year, I got scolded for doing an ABG on an asthmatic that I was considering intubating (southerndoc: A.W. in case you were wondering).
Sedation w/ Ketamine works well for RSI....There was an article in the ANnals to see if Ketamine in low doses is good to prevent intubation, but it doesn't appear to be the case:
Abstract
Study objective: To evaluate the efficacy of IV ketamine in the management of acute, severe asthma.
Methods: This prospective, randomized, double-blind, placebo-controlled clinical trial at an urban teaching hospital emergency department involved 53 consecutive patients aged 18 to 65 with a clinical diagnosis of acute asthmatic exacerbation and a peak expiratory flow of less than 40% of the predicted value after three albuterol nebulizer treatments. All patients received oxygen, continuous nebulized albuterol, and methylprednisolone sodium succinate (Solu-Medrol). Patients then received either ketamine hydrochloride in a bolus of .2 mg/kg followed by IV infusion of .5 mg/kg per hour for 3 hours or a placebo bolus and infusion for 3 hours. Because of the occurrence of dysphoric reactions, the bolus dose was lowered to .1 mg/kg after the first 9 patients; the infusion dose was kept the same.
Results: The first nine patients were eliminated from analysis. Repeated ANOVA testing on the remaining 44 patients determined significant improvements over time within each treatment group in peak flow (F=3.637, P=.004), Borg score (F=22.959, P=.0001), respiratory rate (F=8.11, P=.0001), and 1-second forced expiratory volume (F=9.076, P=.0001). However, no difference could be detected over time between treatment groups (power, 80%). Patients receiving ketamine gave the treatment a rating of 4.3 on a scale of 1 to 5, whereas those receiving placebo scored their treatment 3.7 (P=.0285). The hospital admission rate was not different between treatment groups (P=.1088).
Conclusion: IV ketamine at a dose low enough to avoid dysphoric reactions demonstrated no increased bronchodilatory effect compared with standard therapy in treating exacerbations of asthma in the ED. Although there was a slight increase in satisfaction in the ketamine group, no clinical benefit in terms of hospital admission rate was noted. [Howton JC, Rose J, Duffy S, Zoltanski T, Levitt MA: Randomized, double-blind, placebo-controlled trial of intravenous ketamine in acute asthma.
Ann Emerg Med February 1996; 27:170-175.]
And another one for kids:
The Efficacy of Ketamine in Pediatric Emergency Department Patients Who Present With Acute Severe Asthma
Joseph Y. Allen, MD, FAAP, Charles G. Macias, MD, FAAP
Received 27 April 2004; received in revised form 15 September 2004 and 21 January 2005; accepted 4 February 2005 published online 31 May 2005.
Study objective
We determine whether a continuous infusion of ketamine can decrease the severity of a moderately severe acute asthma exacerbation by a clinically significant 2 points using a 15-point Pulmonary Index scoring scale.
Methods
A double-blinded, randomized, placebo-controlled trial was performed to evaluate patients aged 2 to 18 years who presented to a pediatric emergency department with an acute asthma exacerbation. Exclusion criteria included temperature greater than 39°C (102°F), focal infiltrate on radiograph, or any glucocorticoid use in the last 72 hours. Eligible patients received 3 treatments with albuterol, ipratropium bromide, and a dose of oral or parenteral glucocorticoids. If the Pulmonary Index score remained 8 to 14, enrollment proceeded. All enrolled patients received continuous nebulized albuterol at 10 mg/hour and were randomized to receive an intravenous bolus of 0.2 mg/kg of ketamine, followed by a 2-hour ketamine infusion at 0.5 mg/kg per hour or an equal-volume regimen with normal-saline placebo. A Pulmonary Index score was performed on patients at 0, 30, 60, 90, and 120 minutes.
Results
Sixty-eight patients were enrolled, with 33 randomized to the ketamine infusion and 35 randomized to placebo. Mean ages of patients enrolled, chronic severity of asthma, and duration of symptoms before presentation were similar between groups. At enrollment, the mean Pulmonary Index score in the placebo group was 10.3±1.1 versus 10.5±1.5 for the ketamine group (difference of means 0.2; 95% confidence interval [CI] −0.5 to 0.8). Sixty-two patients completed the entire 2-hour infusion protocol. No significant difference between groups was seen in rate of improvement in the Pulmonary Index score at completion. The mean decrease in the Pulmonary Index scores at the end of the infusion was 3.6±1.3 in the placebo group versus 3.2±2.0 in the ketamine group (difference of means 0.4; 95% CI −0.4 to 1.3). No short-term adverse effects necessitating discontinuation of the infusion or adverse behavioral impacts at 48 hours after discharge were noted.
Conclusion
We conclude that ketamine given at 0.2 mg/kg followed by an infusion of 0.5 mg/kg per hour for 2 hours provided no incremental benefit to standard therapy in this cohort of children with a moderately severe asthma exacerbation.
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