Aim: To assess and compare effectiveness and side effects of postoperative anesthesia methods, using intrathecal morphine and local infiltration of ropivacaine, a day after knee joint arthroplasty operations with spinal anesthesia.
Introduction: Inadequately chosen postoperative anesthesia method after knee joint arthroplasty surgery might cause prolonged hospitalization period, readmissions due to pain and overall increased cost of care.
Methods: In 2016 a prospective research was conducted in Vilnius University Hospital Santaros Clinics. 25 patients undergoing knee joint arthroplasty surgery with spinal anesthesia were enrolled in the study. Group1 – local soft tissue ropivacaine infiltration anesthesia around the knee (n=13; dose 300mg); Group2 – inthratecal morphine sulfate analgesia (n=12; dose 0.1–0.2mg). Pain intensity (using VAS) at rest and in motion, patient's satisfaction and side effects - nausea, vomiting, itch, urinary retention – were assessed at time intervals – 1, 2, 4, 6, 12, 18, 24h postoperatively.
Results: In the first 12h mean values of VAS were 1.8±2.6/1.4±1.7 in Group1 and Group2 accordingly. After 12h period a downtrend occurred and values were 1.7±1.1/1.1±1.5, respectively (p>0.05). Examining pain in motion 12h after the surgery pain intensity values were 2.5±2.7/3.3±2.7 and after 24h in both groups pain intensity was 3.2±1.5/3.6±2.1, resp. (p>0.05). Zero episodes of nausea/vomiting were registered in Group1, while 58.3% (n=7) of Group2 patients experienced nausea and 5 of them also vomited. Even 66.7% (n=8) patients in Group2 had itch while none patients of Group1 indicated this side effect. It was difficult to assess urinary retention as 30.8% (n=4) Group1 and 66.7% (n=8) Group2 patients were catheterized prior surgery. Finally, satisfaction level of both groups were evaluated very similarly: 8.2±1.7/8.2±1.3 (p>0.05).
Conclusion: VAS values at rest were very similar in both groups, but pain relief efficiency compared to the intensity of pain during movement was better with local ropivacaine infiltration, also patients with ropivacaine analgesia experienced no side effects.