Measuring Inspiratory Muscle Weakness in Patients with Cancer and Breathlessness

BACKGROUND: Inspiratory muscle weakness is a recognised cause of unexplained dyspnoea. It may be suggested by the finding of a low static inspiratory mouth pressure (MIP), but MIP is a difficult test to perform, with a wide normal range; a low MIP may also occur if the patient has not properly performed the manoeuvre. Further investigation conventionally requires balloon catheters to obtain oesophageal (Poes) and transdiaphragmatic pressure (Pdi) during sniffs or phrenic nerve stimulation. Two non-invasive tests of inspiratory muscle strength have recently been described--nasal pressure during a maximal sniff (Sn Pnas) and mouth pressure during magnetic stimulation of the phrenic nerves (Tw Pmo). The use of these two tests in combination might identify patients without inspiratory muscle weakness who are unable to produce a satisfactory MIP< therefore avoiding the need for investigation with balloon catheters. METHODS: Thirty consecutive patients with clinically suspected inspiratory muscle weakness and a low MIP underwent both conventional (Sn Poes and Tw Pdi) and non-invasive testing (Sn Pnas and Tw Pmo). Weakness was considered to be excluded by a Sn Poes of > or = 80 cm H20 or a Tw Pdi of > or = 20 cm H20. The limit values used to test the hypothesis were Sn Pnas > or = 70 cm H20 or Tw Pmo > or = 12 cm H20. RESULTS: Inspiratory muscle weakness was excluded in 17 of the 30 patients. Fifteen of these would have been identified using Sn Pnas and Tw Pmo, with better results when the two tests were combined. The cut off values selected for Sn Pnas and Tw Pmo were shown by ROC plots to indicate normal strength conservatively, avoiding failure to detect mild degrees of weakness. No patient with global weakness was considered normal by Sn Pnas or Tw Pmo. CONCLUSIONS: In most patients with normal inspiratory strength and a low MIP, Tw Pmo and Sn Pnas used in combination can reliably exclude global inspiratory muscle weakness, reducing the number of patients who need testing with balloon catheters.

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The role of the inspiratory muscle weakness in functional capacity in hemodialysis patients

PLoS ONE ◽

10.1371/journal.pone.0173159 ◽

2017 ◽

Vol 12 (3) ◽

pp. e0173159 ◽

Cited By ~ 5

Author(s):

Pedro Henrique Scheidt Figueiredo ◽

Márcia Maria Oliveira Lima ◽

Henrique Silveira Costa ◽

Rosalina Tossige Gomes ◽

Camila Danielle Cunha Neves ◽

...

Keyword(s):

Muscle Weakness ◽

Functional Capacity ◽

Hemodialysis Patients ◽

Inspiratory Muscle

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A randomized controlled trial of high-intensity interval training and inspiratory muscle training for chronic heart failure patients with inspiratory muscle weakness

Chronic Illness ◽

10.1177/1742395320920700 ◽

2020 ◽

pp. 174239532092070

Author(s):

Zahra Sadek ◽

Ali Salami ◽

Mahmoud Youness ◽

Charifa Awada ◽

Malek Hamade ◽

...

Keyword(s):

Heart Failure ◽

Chronic Heart Failure ◽

Muscle Weakness ◽

Muscle Function ◽

Interval Training ◽

Inspiratory Muscle ◽

Control Group ◽

Muscle Training ◽

Heart Failure Patients

Objectives Chronic heart failure is a major public health problem in which supervised exercise programs are recommended as part of non-pharmacological management. There are various reports of the success of high-intensity aerobic interval training (HI-AIT) and inspiratory muscle training (IMT) in the management of chronic heart failure patients. This study tested the hypothesis that the combination of HI-AIT and IMT could result in additional benefits over the IMT and the HI-AIT alone in terms of inspiratory muscle function, exercise capacity, and quality of life in patients with chronic heart failure and inspiratory muscle weakness. Methods Forty patients with ejection fraction ≤45% and inspiratory muscle weakness described by maximal inspiratory pressure <70% predicted, underwent three exercise training sessions per week for 12 weeks. Patients were randomly allocated to one of four groups: the HI-AIT group, the IMT group, the combined (HI-AIT & IMT) group, and the control group. Before and after completing their training period, all patients underwent different tests that are mentioned above. Results No changes were detected in the control group. However, the combined group, when compared to HI-AIT and IMT groups, respectively, resulted in additional significant improvement in maximal inspiratory training (62%, 24%, 25%), exercise time (62%, 29%, 12%), the 6-minute walk test (23%, 15%, 18%), and the Minnesota Living with Heart Failure Questionnaire (56%, 47%, 36%). Conclusion In patients with chronic heart failure and inspiratory muscle weakness, the combination of the HI-AIT and the IMT resulted in additional benefits in respiratory muscle function, exercise performance, and quality of life compared to that of HI-AIT or IMT alone. Trial Registration number: NCT03538249

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