Impulse oscillometry indices in relation to respiratory symptoms and spirometry in the Swedish Cardiopulmonary Bioimage Study

Background

Impulse oscillometry (IOS) is sensitive in detecting lung function impairment. In small studies, impaired IOS relates better to respiratory symptoms than spirometry. We studied how IOS related to spirometry and respiratory symptoms in a large population of individuals (n=10 360) in a cross-sectional analysis.

Methods

Normal values for IOS and spirometry were defined in healthy, never-smoking individuals, aged 50-64 years, from the Swedish CArdioPulmonary bioImage Study (n=3664 for IOS and 3608 for spirometry). For IOS, abnormal values for resistance at 5 Hz (R5) and at 20 Hz and area of reactance were defined using the 95th percentile. Abnormal reactance at 5 Hz for IOS and abnormal conventional spirometry indices (forced expiratory volume in 1 s (FEV1), forced and slow vital capacity and their ratios) were defined using the 5th percentile.

Results

Abnormal IOS parameters were found in 16% of individuals and were associated with increased odds ratios for nearly all respiratory symptoms when adjusted for age, gender and smoking. In individuals with normal spirometry, abnormal IOS resistance was related to cough and dyspnoea, while abnormal reactance was related to wheeze. In these individuals, the combination of abnormal R5 with abnormal reactance resulted in approximately two-fold higher likelihood for having cough, chronic bronchitis and dyspnoea, even when further adjusting for FEV1, expressed as % predicted.

Conclusions

Abnormal IOS is related to increased respiratory burden in middle-aged individuals with normal spirometry, especially when resistance and reactance parameters are combined. The different relationships between respiratory symptoms and reactance and resistance warrant further research.

Care of infants after major surgery: observation of behavior and analgesic administration

To examine pain management in infants after surgery, 12 infants were observed and audiovisually recorded for 24 hours postoperatively following major surgery. Analgesic administration, sleep-awake states, facial expression-vocalization, and care routines were monitored. A clinical pain scoring system (Attia, Amiel-Tison, Mayer, Shnider, & Barrier, 1987) was used to analyze the video tapes. Only 5 infants showed occasional episodes of quiet sleep and were awake for 50% of the observed episodes. Moaning-crying was observed in 56% of the episodes for 4 infants and in 29% of the episodes for 6 infants. Analysis using the pain scoring system showed 36% of the episodes to have scores below 14 (M = 7.7). Results indicated that pain management was inconsistent, care routines need to be changed and better coordinated, and environmental issues must be addressed.