Association between access block and time to parenteral opioid analgesia in renal colic: a pilot study

To seek an association between access block and time to parenteral opioid analgesia (POA) in ED patients presenting with renal colic.

Renal colic patients given POA were retrospectively identified over 3 months. Time of administration of POA was abstracted from patients' charts. Access block data, time of arrival and demographics were retrieved electronically. A logistic regression was used to seek an association between time to POA (dichotomized into <1 h and >1 h of arrival) with daily access block (proportion of patients requiring hospital admission in a 24 h period who have a total ED time >8 h, dichotomized at its median), time of administration of POA (00.00-07.59 hours [T1], 08.00-15.59 hours [T2], 16.00-23.59 hours [T3] ), age and sex.

Of 69 patients, 42 (60.1%, 95% CI 51-70%) received POA within 1 h. Access block occurred daily (median 28.8%, range 6.8-53.1%). Mean hourly ED attendance rates for all patients during T1, T2 and T3 were 4.0, 11.7 and 7.8 patients/h respectively. As predictors of time to POA (>1 h vsor=29% vs <29%) was 1.0 (95% CI 0.4-2.9), T3 versus T2 was 5.0 (95% CI 1.4-17.7), T1 versus T2 was 1.0 (95% CI 0.3-23.8), age (>or=47 years vs <47 years) was 0.8 (95% CI 0.3-2.3) and for sex (female vs male) was 0.4 (95% CI 0.1-1.6).

Time to POA was related to time of administration, but not to access block. Access block might be too crude a measure to quantify ED overcrowding, and so its influence on time to POA may not be exhibited.