The correlation between transient blood glucose levels and alterations in cardiorespiratory output among asthma patients treated with nebulised β₂ agonists. (ID 509)
South East Coast Ambulance Service NHS Foundation Trust
Funding: None
Abstract
Background: Although β₂ agonists are effective in treating acute asthma exacerbations, the 'off-target' receptor stimulation that patients often experience can result in a complex interplay of internal and external processes. This may complicate the usual asthma pathway, leading to heightened inflammatory and compensatory responses and consequently more severe and extended exacerbations. This study aimed to ascertain the impact of nebulised salbutamol on blood glucose levels and its correlation with the ventilation/perfusion ratio (V/Q).Method: A pragmatic, single-arm observational study used both prospective and retrospective data to explore the relationship between blood glucose levels and cardiorespiratory output during nebulised salbutamol administration. Inferential and descriptive statistical methods were employed to evaluate the significance of the correlations observed.
Results: In a sample of 100 participants selected based on comparable criteria, statistically significant changes pre and post nebulisation were observed in Heart Rate (HR) [p= 0.0163, 95% CI], Respiratory Rate (RR) [p= <0.0001, 95% CI], and Peripheral Blood Oxygen Saturation (SpO2) [p= <0.0001, 95% CI]. There was a mean decrease in HR [x̅ = -3 bpm] and RR [x̅ = -5 bpm], with an increase in SpO2 [x̅ = +2%]. Additionally, a prospective subset revealed statistically significant differences in Capillary Blood Glucose (CBG) levels pre and post nebulisation [p= 0.0067, 95% CI] with a mean increase of +0.375 mmol/L. A tendency for SpO2 and CBG levels to increase were noted, yet the causal factors remain uncertain.
Conclusions: A strong correlation was observed between pre and post treatment CBG levels alongside proactive V/Q matching, indicating a real time side effect amongst asthma patients treated with nebulised salbutamol. These observations highlight the importance of monitoring CBG in acute asthma patients, as cardiorespiratory and endocrine changes may compound the existing exacerbation. Nonetheless, the complex relationship between HR, RR and CBG warrants further exploration.
Conflicts of interest: None
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