What data supports the use of nebulized lidocaine for the treatment of asthma in the ED?

Comment by InpharmD Researcher

Limited data suggests that nebulized lidocaine may not be an effective treatment option for asthma in the emergency department (ED). Data investigating the use of nebulized lidocaine for treatment of asthma specifically in the emergency department appears to be limited to a single randomized, double-blinded trial (Table 1), which found no benefit from its addition to standard treatment. Other data, although not specific to the emergency department setting, also appears conflicting, with some small studies finding reduction in glucocorticoid needs for asthma patients after use of nebulized lidocaine, while others finding no significant differences in glucocorticoid doses and pulmonary function. Comparisons against active comparators are lacking, with studies generally limited to placebo controls.

Background

Although not specific to use in the emergency department setting, several studies have investigated the effect of nebulized lidocaine for treatment of cough and asthma. A 2013 literature review identified 17 such studies, focusing on safety and efficacy of nebulized lidocaine in intractable cough and asthma. Doses of lidocaine utilized amongst the studies ranged from 10 mg to 400 mg. Most studies compared lidocaine with placebo, limiting conclusions regarding comparative efficacy against other active treatments. Additionally, sample sizes of many studies were limited, with most ranging from 15 to 50 participants. Of the 17 trials, 5 evaluated nebulized lidocaine for improvement in pulmonary function and glucocorticoid-sparing effects in patients with mild to severe asthma, utilizing doses of 40 to 160 mg for this specific indication. Results of these studies were mixed. Some noted no significant improvement in pulmonary function associated with nebulized lidocaine, while others found reduction in glucocorticoid doses, in turn reducing risk of adverse effects such as cushingoid appearance. Still, in one study placebo was associated with an increased likelihood of reduction in glucocorticoid dose compared to lidocaine, highlighting the uncertainty regarding the efficacy of nebulized lidocaine. Safety data regarding use of lidocaine solution via nebulization has been associated with initial bronchoconstriction in patients with baseline bronchial hyperreactivity. Although this effect may be prevented by pretreatment with a bronchodilator. Most studies included in the current review did not report occurrence of bronchoconstriction as an adverse effect resulting from nebulized lidocaine doses of 10 to 400 mg. Overall, generalizability of these data to support use of nebulized lidocaine in moderate to severe asthma is limited due to conflicting results, heterogeneity in study design, small sample sizes, and other design flaws. While three trials noted improvement in pulmonary function and two found significant reduction in glucocorticoid doses, two other trials found no improvement in pulmonary function and no glucocorticoid-sparing effect. Use of nebulized lidocaine is not supported as a first-line treatment, but may be considered as an alternative in cases of severe asthma in patients with poor tolerability to glucocorticoids. [1]

References:

[1] Slaton RM, Thomas RH, Mbathi JW. Evidence for therapeutic uses of nebulized lidocaine in the treatment of intractable cough and asthma. Ann Pharmacother. 2013;47(4):578-585. doi:10.1345/aph.1R573
Literature Review

A search of the published medical literature revealed 1 study investigating the researchable question:

What data supports the use of nebulized lidocaine for the treatment of asthma in the ED? What is its place in therapy and how does it compare to other alternatives?

Please see Table 1 for your response.

 

Efficacy of adjuvant treatment with nebulized lidocaine in improving clinical and pulmonary function parameters of acute asthma attacks: a randomized double‑blind clinical trial
Design

Prospective, double-blind, randomized clinical trial (Iran)

N= 60
Objective To evaluate the efficacy of nebulized lidocaine as an adjuvant treatment in improving clinical and pulmonary function parameters during acute asthma attacks in emergency department (ED)
Study Groups Lidocaine group (n= 30)  
Control group (n= 30)
Inclusion Criteria Adults aged 18-55 years with an initial diagnosis of asthma compatible with the asthma clinical triad, referred to the emergency department
Exclusion Criteria Consumption of bronchodilators within 6 hours before ED admission, inability to use a peak flow meter, underlying pulmonary disease, heart disease, pregnancy, smoking history, and very severe asthma attacks (forced expiratory volume in 1 s [FEV1] < 25%)
Methods Patients in the intervention group received nebulized lidocaine 200 mg at 0, 20, 40, and 60 minutes, along with standard treatment: oral prednisolone 50 mg at arrival, plus nebulized albuterol 2.5 mg and ipratropium bromide 0.5 mg at 0, 20, 40, and 60 minutes. The control group received the same standard treatment, but with distilled water as a placebo instead of lidocaine. Nebulization was performed using Devilbiss Pulmo-Aide compact compressor nebulizers.
Duration Follow-up: 60 minutes
Outcome Measures

FEV1, peak expiratory flow rate (PEFR), Borg Dyspnea Scale
Baseline Characteristics Characteristic Control (n= 30) Lidocaine (n= 30) p-value
Age, years 40.63 ± 8.47 38.46 ± 6.07 0.26
Male 16 (53.3%) 18 (60%) 0.622
Asthma duration, years 4.36 ± 1.73 4.13 ± 1.9 0.602
Results Variable Timepoint Control (n= 30) Lidocaine (n= 30) p-value
Dyspnea (Borg Dyspnea Scale score)  Before intervention 4.13 ± 0.69 4.03 ± 0.81 0.612
At discharge 0.68 ± 0.56 0.76 ± 0.55 0.566
FEV1, L  0 min 1.31 ± 0.11 1.34 ± 0.12 0.24
60 min 1.81 ± 0.13 1.79 ± 0.13 0.629
PEFR, L/min  0 min 154.96 ± 3.24 154.93 ± 3.21 0.968
60 min 222.13 ± 13.74 226.26 ± 10.91 0.202

FEV1, forced expiratory volume in 1 s; PEFR, peak expiratory flow rate

Other parameters, including heart rate, systolic and diastolic blood pressure, and oxygen saturation, showed no significant differences between the two groups. 
Adverse Events No adverse effects were detected in either treatment group during the trial.
Study Author Conclusions The study found no benefit from adding nebulized lidocaine to standard asthma treatment in improving clinical and pulmonary function parameters during acute asthma attacks. Further research is needed to clarify the detailed clinical effects.
Critique The study is the first to compare nebulized albuterol with and without lidocaine in acute asthma management in ED. However, the small sample size and short follow-up duration limit the findings. Further studies with larger samples and longer follow-up are recommended.

 

References:

Motamed H, Maleki Verki M, Mozafari P. Efficacy of adjuvant treatment with nebulized lidocaine in improving clinical and pulmonary function parameters of acute asthma attacks: a randomized double-blind clinical trial. Drugs Ther Perspect. 2018:34(528-533). doi:10.1007/s40267-018-0550-y