P139
DRUG DOSING OF VENOUS THROMBOEMBOLISM PROPHYLAXIS AND
ANTIBIOTICS IN ELDERLY INPATIENTS WITH RENAL IMPAIRMENT
Basu, S, Khan, H
Watford General Hospital, West Hertfordshire NHS Trust
PROBLEM: Inappropriate dosing in patients with renal impairment can cause toxicity or
ineffective therapy. NCEPOD highlighted medications as the commonest risk factor for acute
kidney injury that was inadequately assessed. Older inpatients are at a higher risk of developing
significant adverse events due to age-related decline in renal function and comorbid conditions.
During admission they may face further acute insults including sepsis, nephrotoxic drugs,
contrast exposure and hypovolaemia that can lead to irreversible loss of renal function and
hasten progression to end stage renal failure.
PURPOSE: During care of the elderly ward rounds it was noted that a high proportion of
medications that had been commenced on admission were incorrectly prescribed for the given
renal function. The aim of this audit was to quantify the prevalence of these errors relating to
venous thromboembolism (VTE) prophylaxis and antibiotic prescriptions and instigate
interventions to reduce incorrect prescribing rates. Baseline clinician knowledge of renal
prescribing from the acute medical admission and care of the elderly teams was also assessed.
DESIGN: 110 elderly inpatients (68-96 years) were included of which 73 patients (66%) had
renal impairment. 18% had acute kidney injury from a normal baseline, 35% acute on chronic
kidney impairment and 13% stable chronic kidney disease (CKD). Data was collected from
drug charts and laboratory results from pertaining to age, sex, weight, VTE and antibiotic doses
and eGFR or CrCl calculated using the MDRD and Cockcroft-Gault formulae. Prescription
accuracy was compared to standards of the Renal Drug Handbook, local trust VTE guidelines
and manufacturer’s guidance.
FINDINGS: 63/73 were prescribed pharmacological VTE prophylaxis. 44% were prescribed
correctly according to trust guidelines compared to 56% being correct when using
manufacturer’s guidance. 77 antibiotic courses were prescribed across the 73 patients. 56% were
prescribed accurately. There was poor baseline clinician knowledge of sources of guidance for
this population.
Interventions included a trust antibiotic mobile app with eGFR &CrCl calculators, novel lecture
on antibiotic renal prescribing in new doctor’s induction as well as renal prescribing teaching
delivered to current acute medical and care of the elderly teams, weighing scales in the acute
admissions unit, a clearer VTE guideline and ongoing publicity of reference sources such as the
Renal Drug Handbook.
CONCLUSION: Re-audit included 64 elderly inpatients with renal impairment. Following
interventions 92% of antibiotics (114/124 antibiotic courses) were correctly prescribed and 75%
of VTE prophylaxis accurately adhered to trust guidance.
RELEVANCE: This demonstrates simple interventions such as increased awareness of sources
of guidance can significantly improve rates of prescribing in comparison to the 15% of
NCEPOD patients with AKI that had medications adjusted to renal doses. Given the high
prevalence of renal impairment amongst elderly inpatients it is imperative to ensure appropriate
medicines management to preserve renal function as long as is possible.