Treatment and outcome of acute cardiogenic pulmonary oedema presenting to an emergency department in Hong Kong: Retrospective cohort study

Abstract

Objectives: To explore the epidemiology, treatment and outcome of acute cardiogenic pulmonary oedema (ACPO) in a Hong Kong emergency department (ED). Methods: This was a retrospective cohort study in a university hospital ED. Cases were identified from ED records and resuscitation room logbooks. The study extended from 1 September 2004 to 30 April 2005. Parametric tests and logistic regression were used to identify predictors of survival. Results: A total of 140 patients were identified, with a mean age of 75 years and male:female ratio of 1:1.4. Mean values (range) on presentation were as follows: pulse rate 103 beats/minute (36-108); blood pressure (BP) 169/88 mmHg (77-274/20-162) and respiratory rate 31 breaths/minute (12-88). Past medical history included previous ACPO (12.1%), diabetes (45.7%), chronic obstructive pulmonary disease (9.3%), ischaemic heart disease (45.0%), hypertension (72.1%) and congestive heart failure (40.7%). On admission, 47.1% had pH<7.35 and 40.7% had PaCO2>5.5kPa. ED treatments included: sublingual nitrates (n=2), intravenous (IV) nitrates (n=89, median 10 mg/hr), IV frusemide (n=85, median 40 mg), IV morphine (n=25, median 3 mg). There were 21 patients on non-invasive ventilation; 27 intubations and 41 patients were admitted to the intensive care unit. Survival to discharge was 95.7%; and median length of hospital stay was 8 days. The 90-day all-cause hospital readmission rate was 30.0%. The 30-day mortality was 12.9% (n=18) and 90-day mortality was 29.3% (n=41). Logistic regression showed that past history of hypertension (p=0.0061), higher systolic BP on ED discharge (p=0.0102) and lower creatinine following treatment (p=0.035) were predictors of improved survival at 90 days. Conclusion: ACPO commonly presents to the ED in Hong Kong and has a high 90-day mortality. Previous hypertension, higher systolic blood pressure on leaving the ED and lower creatinine following treatment predict improved survival at 90 days.