Hyperglycaemia as a predictor of outcome during non-invasive ventilation in decompensated COPD.
BACKGROUND
Hyperglycaemia predicts a poor outcome in Intensive Care Unit (ICU) patients. Whether this is true for respiratory failure necessitating non-invasive ventilation (NIV) is not known.


OBJECTIVE
To determine whether hyperglycaemia within 24 h of admission independently predicts outcome of NIV during acute decompensated ventilatory failure complicating chronic obstructive pulmonary disease (COPD) exacerbations.


METHODS
Patients with COPD presenting with acute hypercapnic respiratory failure at University Hospital Aintree between June 2006 and September 2007 and receiving NIV within 24 h of admission were studied prospectively. Random blood glucose levels were measured before NIV administration.


RESULTS
88 patients (mean baseline pH 7.25, PaCO(2) 10.20 kPa, and PaO(2) 8.19 kPa) met the inclusion criteria, with NIV normalising arterial pH off therapy in 79 (90%). After multivariate logistic regression, the following predicted outcome: baseline respiratory rate (OR 0.91; 95% CI 0.84 to 0.99), random glucose > or = 7 mmol/l (OR 0.07; 95% CI 0.007 to 0.63) and admission APACHE II (Acute Physiology and Chronic Health Evaluation II) score (OR 0.75; 95% CI 0.62 to 0.90). The combination of baseline respiratory rate (RR) <30 breaths/min and random glucose <7 mmol/l increased prediction of NIV success to 97%, whilst use of all three factors was 100% predictive.


CONCLUSIONS
In acute decompensated ventilatory failure complicating COPD, hyperglycaemia upon presentation was associated with a poor outcome. Baseline RR and hyperglycaemia are as good at predicting clinical outcomes as the APACHE II score. Combining these variables increases predictive accuracy, providing a simple method of early risk stratification.
Chakrabarti
B
B
Clinical Sciences Centre, University Hospital Aintree, University of Liverpool, Liverpool L9 7AL, UK. biz@doctors.org.uk
Angus
R M
RM
Agarwal
S
S
Lane
S
S
Calverley
P M A
PM
D000208:Acute Disease; D000368:Aged; D001784:Blood Gas Analysis; D001786:Blood Glucose / Q000378:metabolism*; D003422:Critical Care; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006935:Hypercapnia / Q000209:etiology; D006943:Hyperglycemia / Q000209:etiology*; D008297:Male; D011175:Positive-Pressure Respiration; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood / Q000628:therapy*; D012131:Respiratory Insufficiency / Q000209:etiology; D016896:Treatment Outcome
D001786:Blood Glucose