Screening for impaired liver function as a risk factor for drug safety at hospital admission of surgical patients

Hepatic Impairment as a Risk Factor for Drug Safety: Suitability and Comparison of Four Liver Scores as Screening Tools

Hepatic impairment (HI) influences the pharmacokinetics and pharmacodynamics of drugs and represents an important risk factor for drug safety. A reliable screening tool for HI identification at hospital admission by pharmacists would be desirable but is currently lacking. Therefore, we tested four liver scores as potential screening instruments. We retrospectively recorded liver/bile diagnoses, symptoms and abnormalities (summarized as hepatic findings) of 200 surgical patients followed by an assessment of the relevance of these findings for drug therapy (rating). The agreement between the Model of Endstage Liver Disease (MELD), Non-alcoholic fatty liver disease fibrosis score (NFS), Fibrosis 4 index (FIB-4), and aspartate-aminotransferase to platelet ratio index (APRI) and the rating was quantified by Cohen's Kappa. The performance of the scores in this setting was further evaluated by their sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Of 200 patients, 18 (9%) had hepatic findings relevant for drug therapy. Fair agreement was found for FIB-4 and MELD and slight agreement for APRI and NFS compared to the rating. The highest values for sensitivity, specificity, PPV, and NPV were 41.2% (MELD), 99.3% (APRI), 66.7% (APRI), and 93.6% (MELD), respectively. Due to low performance, none of the scores can be recommended for clinical use as a single screening tool for HI at hospital admission.

Feasibility of the MELD score as a screening tool for pharmacists to identify patients with impaired hepatic function at hospital admission

WHAT IS KNOWN AND OBJECTIVE

Hepatic impairment (HI) is a known risk factor for drug safety. The MELD score (Model-for-endstage-liver-disease), calculated from serum creatinine, bilirubin and International Normalized Ratio (INR), is a promising screening tool corresponding to Child-Pugh Score (CPS) for drug adjustment. We tested the feasibility of MELD as an automatic screening tool accounting for correct calculation, interfering factors (IF) and detection of patients corresponding to CPS-B/C potentially requiring drug adjustment.

METHODS

We retrospectively calculated MELD for a 3-month cohort of surgical patients and assessed need for adjustment of MELD parameters to standard values. IF for INR (oral anticoagulants) and serum creatinine (renal insufficiency (RI; eGFR<60 ml/min/1.73m²); as well as drugs elevating creatinine levels (DECL)) and the number of patients with MELD scores corresponding to CPS-B/C were analysed. For MELD ≥7.5, liver and bile diagnoses were recorded.

RESULTS AND DISCUSSION

Of 1183 patients, MELD was calculable for 761 (64%; median 7.5, range 6.4-36.8). Parameters had to be adjusted for 690 (91%) patients. IF of parameters were RI in 172 (23%), INR-elevating drugs in 105 (14%) and DECL in 33 (4%) patients. Of 335 (44%) patients with MELD ≥7.5, 122 (36%) had documented liver or bile diagnoses. MELD 10-<15 (corresponding to CPS-B) was found for 105 (14%), MELD ≥15 (corresponding to CPS-C) for 66 (9%) of the 761 patients with a calculated MELD. Referred to all patients, drug adjustments due to possible HI were recommendable for 14% of patients with suspected CPS-B/C.

WHAT IS NEW AND CONCLUSION

MELD is a feasible screening tool for HI as a risk factor for drug safety at hospital admission when appropriately considering correct parameter adjustment and RI and INR-elevating drugs as IF. Further evaluation of sensitivity and specificity is needed.