Paracetamol induced skin blood flow and blood pressure changes in febrile intensive care patients: An observational study

Summary 

Objective

To determine the relationship between paracetamol administration and skin blood flow (skBF) and blood pressure (BP) in critically ill patients treated for fever.

Design

Prospective, observational study.

Setting

Intensive care units of university teaching hospital.

Patients

29 adults (17 males and 12 females), aged 58±15 years treated with enteral or intravenous paracetamol for fever. APACHE II score was 17.2±8.3 and admission classifications were 41% medical (n=12), 31% surgical (n=9), and 28% neurological intervention (n=8). Thirty healthy afebrile volunteers were also studied after ingesting 1g paracetamol.

Measurements and main results

Temperature, BP and skBF (laser Doppler flowmetry perfusion units) were recorded 15min prior to administration of paracetamol, at administration (T0) and then for every 15min for 60min. Cutaneous vascular conductance (CVC=skBF/mean arterial pressure) was calculated. Thirty data sets were recorded from 29 patients. Temperature at T0 was 38.7±0.6°C. BP decreased over the study period whilst skBF and CVC increased (repeated measured ANOVA, p<.05). Systolic BP decreased significantly (p<.01) at all post-administration times and was 90±13% of T0 at 60min. CVC was 128±48% of T0 at 60min. Systolic BP fell by a clinically significant amount (≥15%) in 17 patients (59%) and hypotension was treated during 33% (n=10) of the observation periods. BP and skBF did not change significantly in afebrile volunteers.

Conclusions

Paracetamol induced increases in skBF consistent with its antipyretic action and may be associated with significant falls in BP in the critically ill.

Keywords: Laser Doppler flowmetry, Acetaminophen, Paracetamol, Fever, Hypotension, Intensive care