Christina Olofsson

Pain control after total knee arthroplasty: a randomized trial comparing local infiltration anesthesia and continuous femoral block

Background and purpose Pain after total knee arthroplasty (TKA) is usually severe, and epidural analgesia or femoral nerve block has been considered to be an effective pain treatment. Recently, local infiltration analgesia (LIA) has become increasingly popular but the outcome of this method regarding the analgesic effect has not been fully evaluated. We compared local infiltration analgesia and femoral block with regard to analgesia and morphine demand during the first 24 h after TKA. Methods 40 patients undergoing TKA under spinal anesthesia were randomized to receive femoral nerve block (group F) or peri- and intraarticular infiltration analgesia (group LIA) with a mixture containing ropivacaine, ketorolac, and epinephrine. All patients had access to intravenous patient-controlled analgesia (PCA) with morphine postoperatively. Pain intensity at rest and upon movement was assessed on a numeric rating scale (0–10) on an hourly basis over 24 h if the patients were awake. Results The average pain at rest was marginally lower with LIA (1.6) than with femoral block (2.2). Total morphine consumption per kg was similar between the 2 groups. Ancillary analysis revealed that 1 of 20 patients in the LIA group reported a pain intensity of > 7 upon movement, as compared to 7 out of 19 in the femoral block group (p = 0.04). Interpretation Both LIA and femoral block provide good analgesia after TKA. LIA may be considered to be superior to femoral block since it is cheaper and easier to perform.

Analgesic efficacy of diclofenac in combination with morphine and paracetamol after mastectomy and immediate breast reconstruction

Background:  Breast cancer treatment with mastectomy and immediate breast reconstruction (IBR) is associated with intense pain in the primary post‐operative period. The present prospective, placebo‐controlled and double‐blind study aimed to evaluate the analgesic efficacy of diclofenac, a non‐steroid anti‐inflammatory drug (NSAID), in combination with paracetamol and opioids. This was done by 64‐h assessment of post‐operative pain intensity, opioid consumption, blood loss, nausea and tiredness.

Diclofenac in the treatment of pain after caesarean delivery: An opioid-saving strategy

OBJECTIVE Pain relief of good quality after caesarean section (CS) results in early mobilization and good early mother-child interaction. Patient-controlled analgesia (PCA), with systemic opioids, gives a very high level of patient satisfaction. However, opioids have well documented side-effects i.e. sedation, nausea and respiratory depression. To minimize the risk of such negative effects we studied how far the required dose of opioid could be decreased with a multimodal strategy adding diclofenac. STUDY DESIGN In a randomized double-blind study, 50 parturients scheduled for elective CS under spinal anaesthesia, received rectally either diclofenac (Suppositorium diclofenac) 50 mgx3 or placebo 1x3 during the first 24 h postoperatively. All patients had PCA with the possibility of self-administered doses of ketobemidone 1 mg/6 min. RESULTS In the group receiving diclofenac rectally the consumption of ketobemidone was reduced with 39% compared to the placebo group. CONCLUSION A multimodal analgetic strategy with the addition of 150 mg diclofenac during the first 24 h after CS reduces the need for opioids significantly with maintained or improved analgetic effect. This is expected to reduce the risk of negative side-effects of systemic opioids.

Plasma concentration of ketorolac after local infiltration analgesia in hip arthroplasty.

Local infiltration analgesia (LIA) with local anaesthetic (ropivacaine), a nonsteroidal anti‐inflammatory drug (ketorolac) and epinephrine after lower extremity arthroplasty has gained increasing popularity during the last decade. This method has certain advantages, which include minimal systemic side effects, faster post‐operative mobilization, earlier post‐operative discharge from hospital and less opioid consumption. However, information regarding plasma concentrations of ketorolac after LIA mixture is insufficient to predict the risk of renal impairment in patients subjected to arthroplasty.

A randomized study comparing plasma concentration of ropivacaine after local infiltration analgesia and femoral block in primary total knee arthroplasty

Abstract Pain after total knee arthroplasty (TKA) is difficult to control. A recently developed and increasingly popular method for postoperative analgesia following knee and hip arthroplasty is Local Infiltration Analgesia (LIA) with ropivacaine, ketorolac and epinephrine. This method is considered to have certain advantages, which include administration at the site of traumatized tissue, minimal systemic side effects, faster postoperative mobilization, earlier postoperative discharge from hospital and less opioid consumption. One limitation, which may prevent the widespread use of LIA is the lack of information regarding plasma concentrations of ropivacaine and ketorolac. The aim of this academically initiated study was to detect any toxic or near-toxic plasma concentrations of ropivacaine and ketorolac following LIA after TKA. Methods Forty patients scheduled for primary total knee arthroplasty under spinal anaesthesia, were randomized to receive either local infiltration analgesia with a mixture of ropivacaine 300 mg, ketorolac 30mg and epinephrine or repeated femoral nerve block with ropivacaine in combination with three doses of 10mg intravenous ketorolac according to clinical routine. Plasma concentration of ropivacaine and ketorolac were quantified by liquid chromatography–mass spectrometry (LC–MS). Results The maximal detected ropivacaine plasma level in the LIA group was not statistically higher than in the femoral block group using the Mann–Whitney U-test (p = 0.08). However, the median concentration in the LIA group was significantly higher than in the femoral block group (p < 0.0001; Mann–Whitney U-test). The maximal plasma concentrations of ketorolac following administration of 30mg according to the LIA protocol were detected 1 h or 2 h after release of the tourniquet in the LIA group: 152–958 ng/ml (95% CI: 303–512 ng/ml; n = 20). The range of the plasma concentration of ketorolac 2–3 h after injection of a single dose of 10mg was 57–1216 ng/ml (95% CI: 162–420 ng/ml; n = 20). Conclusion During the first 24 h plasma concentration of ropivacaine seems to be lower after repeated femoral block than after LIA. Since the maximal ropivacaine level following LIA is detected around 4–6 h after release of the tourniquet, cardiac monitoring should cover this interval. Regarding ketorolac, our preliminary data indicate that the risk for concentration dependent side effects may be highest during the first hours after release of the tourniquet. Implication Femoral block may be the preferred method for postoperative analgesia in patients with increased risk for cardiac side effects from ropivacaine. Administration of a booster dose of ketorolac shortly after termination of the surgical procedure if LIA was used may result in an increased risk for toxicity.

Placebo-controlled trial of local anaesthesia for treatment of pain after breast reconstruction

Breast reconstruction with submuscular tissue implants is associated with substantial postoperative pain. High pain scores despite large doses of opioids were described in earlier studies, which indicated that opioids alone or together with paracetamol are insufficient. In the present placebo-controlled study we aimed to evaluate the analgesic efficacy of local anaesthesia as a supplement. Forty-three women who had previously been operated on for breast cancer and were listed for unilateral secondary breast reconstruction were assigned at random to one of two groups. The patients received 2.5 mg/ml levobupivacaine (Chirocaine®) 15 ml or placebo in a double-blind manner through an indwelling catheter in the operation site every three hours for 45 hours. All patients were given oral paracetamol 1 g x 4 orally and morphine intravenously as patient-controlled analgesia. A visual analogue scale (VAS) was used to assess the intensity of the postoperative pain. Amount of morphine used was recorded. The women in the levobupivacaine group (n=21) reported significantly less pain at rest during the first 15 hours postoperatively (p<0.05). During mobilisation the intensity of pain was lower for the first six hours (p=0.01) and for the interval 18-24 hours (p=0.045) in the same group. Total mean (SD) consumption of opioids in the levobupivacaine and placebo groups was 24.6 mg (22.88) and 33.8 mg (30.82), respectively (p=0.28). After reconstruction, levobupivacaine injected locally every third hour as a supplement to paracetamol orally and morphine given by PCA resulted in improved pain relief at rest and during mobilisation. Morphine consumption was reduced, but this was not significant (p=0.28).

Single-shot intrathecal sufentanil with bupivacaine in late labour—analgesic quality and obstetric outcome

OBJECTIVES To investigate the analgesic effect and obstetric outcome after single-shot intrathecal sufentanil with bupivacaine in late labour. STUDY DESIGN Forty multiparous women in advanced labour were given a spinal injection of sufentanil 7.5 microg and bupivacaine 2 mg. Pain intensity was recorded by the parturient on a visual analogue scale. The quality of pain relief was also rated with a verbal score directly after delivery. Side effects, such as hypotension, pruritus, sedation, nausea and motor block were noted. Obstetric parameters were followed and recorded. Apgar score and umbilical artery pH were noted. RESULTS Median visual analogue scores after 5, 15, 30, 60, 90, 120 and 150 min were 1.5, 0.5, 0, 1, 1.5, 2 and 3, respectively. Seventy-seven percent of the parturients scored the analgesic quality as excellent. Six parturients had hypotension. Motor block, sedation and nausea were rare. Pruritus was seen in 85% of the cases. No ceasarean section was performed. Vacuum extraction was done in six (15%) cases. Oxytocin augmentation was needed in 26 (65%) of the parturients. Fetal heart rate disturbances following the spinal block were seen in four cases. Apgar scores were high. No neonate had Apgar < 7. CONCLUSIONS Intrathecal block with sufentanil 7.5 microg in combination with bupivacaine 2 mg is a very effective pain relief in late labour. Due to its limited duration it is important to select women in rapid progress of labour, and active obstetric management is necessary. It is also very important that the obstetrician is aware of the risk of non-reassuring fetal heart rate changes after intrathecal block.

Ropivacaine pharmacokinetics after local infiltration analgesia in hip arthroplasty.

In this study, we determined the plasma concentration of ropivacaine by liquid chromatography-mass spectrometry for 30 hours after local infiltration analgesia in 15 patients with elective hip arthroplasty. The 95% upper prediction bound of maximal unbound plasma concentration of ropivacaine was 0.032 mg/L. Side effects sufficient to stop an IV infusion have been reported at arterial concentrations of 0.34 to 0.85 mg/L. Alpha-1-acid glycoprotein did not correlate with the fraction of unbound ropivacaine during the first 24 hours after local infiltration analgesia. No signs or symptoms of systemic local anesthetic toxicity were observed. The Clopper-Pearson 95% upper confidence limit for adverse signs was 0.218.