Effect of Upper Respiratory Tract Infection in Patients with Neuromuscular Disease

Abstract

Respiratory muscle strength during acute upper respiratory tract infection (URI) was assessed in patients with various forms of neuromuscular disease. Vital capacity (VC), oxygen saturation, end-tidal PCO2, maximal inspiratory pressure (MIP), and maximal expiratory pressure (MEP) were determined in 25 stable patients with various forms of neuromuscular disease. Thirteen episodes of URI developed in 10 patients. Respiratory parameters were reassessed within 24-36 h following the onset of symptoms in each patient. In patients with URI, mean baseline VC, MIP, and MEP were 1.16 L +/- 0.14, 49.2 cm H2O +/- 6.8, and 35.5 cm H2O +/- 3.8 and fell to 1.01 L +/- 0.15, 37.1 cm H2O +/- 6.2, and 25.5 cm H2O +/- 3.0 during URI (p < 0.05 for each), respectively. Mean baseline PCO2 and oxygen saturation were 39.1 mm Hg +/- 1.1 and 95.1% +/- 1.0, and during URI, 43.9 mm Hg +/- 2.1 (p < 0.05) and 95.0% +/- 1.0 (NS), respectively. Five episodes of significant hypercapnia were observed in 4 patients. All parameters returned to near baseline values following recovery. We conclude that patients with various forms of neuromuscular disease develop reductions in respiratory muscle strength in association with URI. Unlike normal subjects, however, these decrements in respiratory muscle function may result in symptoms of shortness of breath, reductions in vital capacity, and acute hypercapnia in this patient population.

ChronicPseudomonas aeruginosaInfection and Respiratory Muscle Impairment in Cystic Fibrosis

“…30,31 Infection induces respiratory muscle weakness in animal models, 32 and respiratory muscle weakness is associated with upper-respiratory-tract infections in humans. 33 Induced chronic bronchopulmonary infection by P. aeruginosa significantly decreased diaphragm and limb strength in infected mice, 28 and tumor necrosis factor alpha depressed the diaphragmatic tetanic force in murine diaphragm and limb muscle preparations. 8 Furthermore, in mice, endotoxin caused diaphragm weakness and contractile dysfunction.…”

Practice parameter: The care of the patient with amyotrophic lateral sclerosis (an evidence-based review) [RETIRED]

“…A VC less than 1 L (or less than 25 to 30% of predicted) indicates significant risk of impending respiratory failure or death. 65 Bulbar impairment increases the risk of aspiration, 64 and acute respiratory infection can precipitate sudden respiratory failure. 64 Does noninvasive ventilation improve respiratory function or increase survival?…”

“…65 Bulbar impairment increases the risk of aspiration, 64 and acute respiratory infection can precipitate sudden respiratory failure. 64 Does noninvasive ventilation improve respiratory function or increase survival? Impaired ventilatory function, which is expected late in the course of ALS, occasionally occurs shortly after onset of symptoms.…”

Hot Topics in Noninvasive Ventilation: Report of a Working Group at the International Symposium on Sleep-Disordered Breathing in Leuven, Belgium

“…34,38,39 Patients with ALS should be taught cough augmentation techniques when their unassisted cough peak flow falls below 270 L/min, aiming to prevent secretion retention, 38 respiratory infection, and subsequent respiratory decompensation. 40 The consequence of a respiratory infection in these patients is a further reduction in respiratory strength and likely deterioration to the critical cough peak flow threshold of 160 L/min. 34,38,39 In patients with ALS, a cough peak flow of Ͼ330 L/min indicates a survival of Ͼ 18 months.…”