POSTOPERATIVE ANALGESIA IN TOTAL ARTHROPLASTIES OF LOW EXTERMITIE. THE EPIDURAL TECHNIQUE

Abstract

Total arthroplasties are considered as severe and very painful operations, intra- and postoperatively. The operation is usually carried out under epidural anaesthesia via a catheter and it is logical to proceed for postoperative analgesia epidurally.

In this study, two methods of epidural postoperative analgesia are compared: with infusion of a local anaesthetic alone or in combination with a small dose of opioid.

Material-method: Twenty-five patients, scheduled for total hip or knee arthroplastie were studied. They were randomly allocated in two groups: in group LA they received an epidural infusion of 10 ml/h ropivacaine 0,2%, while in group OP they infused epidurally 5 ml/h of a mixture of morphine 3 ug/kg in ropivacaine 0,1%. The infusion was performed using disposable pumps. At 2–6-12–24–48 hour postoperatively, analgesia (at rest and movement, VAS 0–10), sedation (0–3) and motor blockade (Bromage 0–3) were evaluated and recorded. Additionally, side effects (pruritus, nausea-vomiting) as well as the need for rescue analgesic (paracetamol 500mg on patients demand) were recorded.

Results: Demographic data of two groups were comparable. In general, postoperative analgesia was satisfactory in both groups. Pain was reported by: a) at 6 h 10% of patients in LA group (none in OP group) b) at 12 h 30% of patients in LA group and 10% in OP group c) at 24 h 10% of patients in LA group and 30% in OP group and d) at 48 h 10% of patients in LA group and 0% in OP group. The 10% of patients in OP group reported pruritus at 2 h after operation. The 10% of patients in LA group presented intence motor blockade (Bromage 3) at 12 and 24 h. in case of motor blockade the infusion was discontinued and the blockade was completely recovered after 1–2 hours. In 1 patient of LA group and 2 of OP group nausea and vomiting was observed, only at the first 2 h from the end of anaesthesia. The big percentage of patients (LA group: 12 h = 27%, 24 h = 45%• OP group: 24 h = 7%) that needed additional analgesics, is attributed to a discomfort of most patients, even under light pain.

Conclusions: The epidural infusion of ropivacaine alone or in combination with low dose of morphine, can be considered effective and usefull method for postoperative analgesia in total hip or knee arthroplasties.