Safety and tolerability of sputum induction in adolescents and adults with suspected pulmonary tuberculosis

Abstract

Sputum induction by the inhalation of hypertonic saline may increase the yield of microbiological diagnosis of pulmonary tuberculosis (TB). This is particularly relevant in paucibacillary TB, such as in children or human immunodeficiency virus (HIV)-infected patients. Sputum induction must be shown to be safe and tolerable in community settings where invasive diagnostic methods are unavailable. The objective of this study was to describe the changes in physiological parameters and adverse events occurring during sputum induction in ambulatory adult and adolescent TB suspects recruited in community clinics. Sputum induction was performed in HIV-infected (n = 35) and HIV-uninfected (n = 67) TB suspects (n = 102). Oxygen saturation (%), blood pressure (mm Hg), heart rate (/minute), respiratory rate (/minute), and adverse events were monitored at baseline, continuously during the salbutamol pre-treatment and saline nebulization phases, and for 30 min afterwards. During nebulization, there was a statistically significant increase in oxygen saturation (1%, p < 0.0001), systolic BP (7 mm Hg, p < 0.0001), and diastolic BP (2 mm Hg, p = 0.008). Post-nebulization decrease in the systolic BP occurred (4 mm Hg, p = 0.016). These changes were not considered to be clinically significant. Eight minor, transitory, self-resolving adverse events occurred (labored breathing, n = 2; chest pain, n = 2; paroxysmal coughing, n = 1; elevated heart rate, n = 1; vomiting, n = 1; hypotension, n = 1), leading to procedure termination in four participants. No serious adverse events occurred. Induced sputum is safe, tolerable, and feasible in adult and adolescent TB suspects in a community healthcare setting.

A controlled trial of sputum induction and routine collection methods for TB diagnosis in a South African community

“…The number of viable MTB organisms in the sputum sample, as shown by shorter time to positive MGIT culture, was higher in samples collected by SI, and also by early morning expectorated sputum collection, compared to spot expectorated sputum. The SI procedure was safe and well tolerated, in keeping with our earlier results in this study population [15]. Although there was no increase in diagnostic yield by sputum induction cumulative yield was increased by taking more than one sample for culture by any collection method.…”

“…The sputum induction procedure was performed by a trained registered nurse in an out-patient procedure room of the regional TB hospital. Resuscitation and monitoring equipment were available and standard infection control measures, including a high flow extractor fan and N95 particulate filter masks, were used [15]. Participants fasted for at least 3 hours before the start of the SI procedure.…”

“…We have shown previously in a community setting that SI is safe and well tolerated in ambulatory patients with suspected TB [15]. We aimed to quantify the potential benefit offered by first-line SI in this study population, compared to spontaneous expectorated sputum collection methods, using a direct, within-subject comparison of microbiological diagnostic yield.…”

Duration of Pulmonary Tuberculosis Infectiousness under Adequate Therapy, as Assessed Using Induced Sputum Samples

“…Each IS comprised three procedural steps: (1) administration of 2 mL of salbutamol via a mouthpiece using an ultrasonic nebulizer (Pari Boy SX, Pari GmbH, Starnberg, Germany), (2) administration of 20 mL of 3% hypertonic saline using a nebulizer over a period of 20 minutes, and (3) sample collection following spontaneous expectoration of 1–20 mL sputum over the next 10–30 minutes14232425. IS was not performed in patients with a history of airway hyperresponsiveness or bronchoconstriction including asthma and chronic obstructive pulmonary disease, or an oxygen saturation level below 90% in ambient air, because of the possibility of deterioration of their condition2324.…”

Sputum induction for the diagnosis of pulmonary tuberculosis: a systematic review and meta-analysis

“…It has been suggested that higher nebulized saline concentrations might have a greater osmotic effect on airway secretions [35], increasing the volume of the induced sputum sample, and, thereby, increasing the diagnostic yield. Our group has shown that nebulized 5% saline is both safe and tolerable, with minimal physiologic changes, when used for SI among adults investigated for PTB in an ambulatory setting [36]. However, others have suggested that higher nebulized saline concentrations might be associated with a greater risk of airway reactivity and higher rates of adverse events during the procedure [37].…”