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Serum Lidocaine Concentrations in Asthmatics Undergoing Research Bronchoscopy

2000; Elsevier BV; Volume: 117; Issue: 4 Linguagem: Inglês

10.1378/chest.117.4.1055

1931-3543

Esther L. Langmack, Richard J. Martin, Juno Pak, Monica Kraft,

Airway Management and Intubation Techniques

Study objectives To determine how often serum lidocaine concentrations (SLC) fall into the potentially toxic range (> 5 mg/L) in asthmatics undergoing research bronchoscopy, and to determine whether subject or procedure characteristics are associated with higher SLC. Design Prospective, observational study. Setting Academic research center. Participants Fifty-one volunteers with mild to moderate asthma enrolled in three separate bronchoscopy protocols to study airway inflammation in asthma. Interventions Lidocaine was administered topically to the upper airway and tracheobronchial tree to achieve local anesthesia for bronchoscopy. Venous blood was sampled during bronchoscopy, 30 min after upper airway anesthesia was completed (time 1), and 30 min after bronchoscopy was completed (time 2). Measurements and results The mean total amount of lidocaine administered was 600 ± 122 mg (8.2 ± 2.0 mg/kg). No signs or symptoms of lidocaine toxicity were observed in any of the subjects. SLC ranged between 0.10 and 2.90 mg/L at time 1 and 0.50 and 3.20 mg/L at time 2. SLC was significantly correlated with the total amount of lidocaine (milligrams/kilogram) administered at both points (time 1, r = 0.33, p = 0.021; time 2, r = 0.33, p = 0.023). No statistically significant relationship was observed between SLC and subject age, sex, weight, baseline FEV1, procedure length, or study protocol. No statistically significant relationship was found between subject FEV1 and either total lidocaine dose or procedure length. Conclusions An average total dose of 600 mg (8.2 mg/kg) of lidocaine appears to be safe in mild to moderate asthmatics undergoing research bronchoscopy. To determine how often serum lidocaine concentrations (SLC) fall into the potentially toxic range (> 5 mg/L) in asthmatics undergoing research bronchoscopy, and to determine whether subject or procedure characteristics are associated with higher SLC. Prospective, observational study. Academic research center. Fifty-one volunteers with mild to moderate asthma enrolled in three separate bronchoscopy protocols to study airway inflammation in asthma. Lidocaine was administered topically to the upper airway and tracheobronchial tree to achieve local anesthesia for bronchoscopy. Venous blood was sampled during bronchoscopy, 30 min after upper airway anesthesia was completed (time 1), and 30 min after bronchoscopy was completed (time 2). The mean total amount of lidocaine administered was 600 ± 122 mg (8.2 ± 2.0 mg/kg). No signs or symptoms of lidocaine toxicity were observed in any of the subjects. SLC ranged between 0.10 and 2.90 mg/L at time 1 and 0.50 and 3.20 mg/L at time 2. SLC was significantly correlated with the total amount of lidocaine (milligrams/kilogram) administered at both points (time 1, r = 0.33, p = 0.021; time 2, r = 0.33, p = 0.023). No statistically significant relationship was observed between SLC and subject age, sex, weight, baseline FEV1, procedure length, or study protocol. No statistically significant relationship was found between subject FEV1 and either total lidocaine dose or procedure length. An average total dose of 600 mg (8.2 mg/kg) of lidocaine appears to be safe in mild to moderate asthmatics undergoing research bronchoscopy.