The American review of respiratory disease
-
Am. Rev. Respir. Dis. · Sep 1990
Thoracoabdominal asynchrony in acute upper airway obstruction in small children.
The assessment of the severity and response to therapy of acute upper airway obstruction (UAO) in small children relies on subjective parameters. Using a noncalibrated respiratory inductance plethysmograph (RIP), we quantitated the rib cage (RC) to abdominal (AB) asynchrony and the lag phase in chest wall expansion by the phase angle from the RC versus AB signal curve. Phase angles were obtained in 17 children aged 1 to 50 months with acute UAO and 30 normal control subjects. ⋯ A high association was observed between the phase angle and the degree of stridor (p less than 0.005 Fisher's exact test), and in 90% (26 of 29) the changes in the phase angle and in the degree of stridor were in agreement. We conclude that the RC-AB asynchrony in acute UAO can be objectively quantitated by phase-angle measurement from a noncalibrated RIP and is thus suitable for use in infants and small children. The phase angle may be used to assess objectively the response of UAO to therapy.
-
Am. Rev. Respir. Dis. · Sep 1990
Maximal inspiratory pressure is not a reliable test of inspiratory muscle strength in mechanically ventilated patients.
Maximal Inspiratory pressure (MIP) is an important clinical method used to assess respiratory muscle strength. The reliability and reproducibility of this measurement in mechanically ventilated patients is not certain. In 14 stable, mechanically ventilated patients, capable of spontaneous inspiratory efforts, we assessed maximal inspiratory efforts using the technique originally described by Marini and associates. ⋯ ANOVA showed that MIP was significantly affected by investigator (p less than 0.0001) as well as by patient (p less than 0.0001). Because "true" MIP must be equal to or greater than the best measured MIP, these data indicate that the MIP is commonly underestimated in patients receiving mechanical ventilation, even when standardized technique is used. Furthermore, our data show that reproducibility of triplicate MIP determination by a single observer does not indicate that the test is reliable.