Clinical impact of pharmacists’ interventions in intensive care units in a tertiary institution in Singapore – A retrospective cohort study

Previous studies have deemed pharmacists essential in the intensive care units (ICU) to provide quality healthcare and ensure medication safety. As the impact of pharmacists in ICU varies according to different factors, our study aims to characterise and evaluate the impact of pharmacists’ interventions in ICUs in Singapore, to enable the identification of areas of improvement in our critical care pharmacy practice. We retrospectively evaluated 7 months of pharmacists’ interventions in five ICUs at Singapore General Hospital. Interventions were classified based on the medication-related problems (MRPs) addressed. The impact of pharmacists’ interventions was assessed by rating the severity of error in medication order, the clinical relevance of intervention, and the probability of adverse drug events (pADE) that would have occurred without pharmacists’ interventions. There were 619 interventions addressing 775 MRPs, of which 91.1% were accepted. The main MRP identified was inappropriate drug regimen (49.2%) and the medication class most frequently involved in MRPs was anti-infectives (56.9%). Majority of the interventions were rated as significant for both the severity of error (76.9%) and clinical relevance (72.4%). However, the pADE was deemed to be low (61.2%). The rating of pADE may be affected by the lack of information in patient profiles. This study demonstrated the crucial role of pharmacists in ensuring medication safety in ICUs. Possible areas of service improvement include educating medical residents on common medication errors and empowering pharmacists towards collaborative prescribing.