EFFECTS OF SINGLE DOSE PROPHYLACTIC GENTAMICIN AND ‘FAST-TRACK’ PERI-OPERATIVE CARE ON POST-OPERATIVE RENAL FUNCTION IN PRIMARY HIP AND KNEE ARTHROPLASTY

Abstract

Introduction: Prophylactic systemic antibiotics are commonly used peri-operatively in primary hip and knee arthroplasty in the UK. ‘Fast-Track’ (FT) peri-operative care – a multimodal concept aiming to accelerate postoperative rehabilitation and reduce general morbidity – is also becoming more common in arthroplasty surgery. There are no published reports of acute kidney injury (AKI) as a result of a single-dose prophylactic Gentamicin. The renal impact of hypotensive anaesthesia and reduced routine post-operative intravenous fluid therapy, both features of FT protocol, has not yet been reported. Aim: To evaluate the renal impact of prophylactic Gentamicin and FT perioperative care in hip and knee arthroplasty surgery.

Methods: Four hundred and eighty-four total hip/knee arthroplasty patients had their pre-operative, first and third post-operative day serum creatinine concentration measured and recorded. The first 180 patients (group A) received 1.5g Cefuroxime at induction and two further doses of 750mg at 8 hours and 16 hours post-operatively as antibiotic prophylaxis. The next 160 patients (Group B) received 5mg/kg single-dose Gentamicin at induction instead of Cefuroxime. These patients (Group A and B) were not treated as per FT protocol. The final 144 patients (Group C) received the same Gentamicin as Group B and were treated as per FT protocol. Outcome measures were overall change and an increase of > 30 μmol/L, the latter signifying an AKI.

Results: Mean creatinine change at day 1 was −4.63 in Group A, −3.95 in Group B and 4.19 in Group C. Mean creatinine change by day 3 was −5.28 in Group A, −2.53 in Group B and 8.89 in Group C. No patients in Group A, 4 patients (2.56%) in Group B and 9 patients (6.66%) in Group C had a rise of > 30 μmol/L in day 1 creatinine concentrations.

Conclusions: Comparing the groups, there was no statistically significance change in the day 1 creatinine when Gentamicin replaced Cefuroxime (p=0.625,) however this became significant once FT was also introduced (p=0.001.) In terms of an important creatinine rise (AKI,) the change to Gentamicin produced a statistically significant rise in the number of patients with a day 1 creatinine rise > 30 μmol/L (p=0.048.) By day 3 there is no significant difference in the number of patients with a creatinine rise > 30 μmol/L.

Discussion: FT protocol aims to encourage haemostatic surgery and early ambulant patients (free from drip stands) at the expense of mild hypovolaemia. When these patients are also receiving Gentamicin, the kidneys are concentrating urine and Gentamicin in the tubules thus causing and AKI in some cases. It appears that Gentamicin and FT are cumulative in their effect on renal function.