Perioperative intravenous ketamine for acute postoperative pain in adults.

BACKGROUND: Inadequate pain management after surgery increases the risk of postoperative complications and may predispose for chronic postsurgical pain. Perioperative ketamine may enhance conventional analgesics in the acute postoperative setting. OBJECTIVES: To evaluate the efficacy and safety of perioperative intravenous ketamine in adult patients when used for the treatment or prevention of acute pain following general anaesthesia. SEARCH METHODS: We searched CENTRAL, MEDLINE and Embase to July 2018 and three trials registers (metaRegister of controlled trials, ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP)) together with reference checking, citation searching and contact with study authors to identify additional studies. SELECTION CRITERIA: We sought randomised, double-blind, controlled trials of adults undergoing surgery under general anaesthesia and being treated with perioperative intravenous ketamine. Studies compared ketamine with placebo, or compared ketamine plus a basic analgesic, such as morphine or non-steroidal anti-inflammatory drug (NSAID), with a basic analgesic alone. DATA COLLECTION AND ANALYSIS: Two review authors searched for studies, extracted efficacy and adverse event data, examined issues of study quality and potential bias, and performed analyses. Primary outcomes were opioid consumption and pain intensity at rest and during movement at 24 and 48 hours postoperatively. Secondary outcomes were time to first analgesic request, assessment of postoperative hyperalgesia, central nervous system (CNS) adverse effects, and postoperative nausea and vomiting. We assessed the evidence using GRADE and created a 'Summary of findings' table. MAIN RESULTS: We included 130 studies with 8341 participants. Ketamine was given to 4588 participants and 3753 participants served as controls. Types of surgery included ear, nose or throat surgery, wisdom tooth extraction, thoracotomy, lumbar fusion surgery, microdiscectomy, hip joint replacement surgery, knee joint replacement surgery, anterior cruciate ligament repair, knee arthroscopy, mastectomy, haemorrhoidectomy, abdominal surgery, radical prostatectomy, thyroid surgery, elective caesarean section, and laparoscopic surgery. Racemic ketamine bolus doses were predominantly 0.25 mg to 1 mg, and infusions 2 to 5 µg/kg/minute; 10 studies used only S-ketamine and one only R-ketamine. Risk of bias was generally low or uncertain, except for study size; most had fewer than 50 participants per treatment arm, resulting in high heterogeneity, as expected, for most analyses. We did not stratify the main analysis by type of surgery or any other factor, such as dose or timing of ketamine administration, and used a non-stratified analysis.Perioperative intravenous ketamine reduced postoperative opioid consumption over 24 hours by 8 mg morphine equivalents (95% CI 6 to 9; 19% from 42 mg consumed by participants given placebo, moderate-quality evidence; 65 studies, 4004 participants). Over 48 hours, opioid consumption was 13 mg lower (95% CI 10 to 15; 19% from 67 mg with placebo, moderate-quality evidence; 37 studies, 2449 participants).Perioperative intravenous ketamine reduced pain at rest at 24 hours by 5/100 mm on a visual analogue scale (95% CI 4 to 7; 19% lower from 26/100 mm with placebo, high-quality evidence; 82 studies, 5004 participants), and at 48 hours by 5/100 mm (95% CI 3 to 7; 22% lower from 23/100 mm, high-quality evidence; 49 studies, 2962 participants). Pain during movement was reduced at 24 hours (6/100 mm, 14% lower from 42/100 mm, moderate-quality evidence; 29 studies, 1806 participants), and 48 hours (6/100 mm, 16% lower from 37 mm, low-quality evidence; 23 studies, 1353 participants).Results for primary outcomes were consistent when analysed by pain at rest or on movement, operation type, and timing of administration, or sensitivity to study size and pain intensity. No analysis by dose was possible. There was no difference when nitrous oxide was used. We downgraded the quality of the evidence once if numbers of participants were large but small-study effects were present, or twice if numbers were small and small-study effects likely but testing not possible.Ketamine increased the time for the first postoperative analgesic request by 54 minutes (95% CI 37 to 71 minutes), from a mean of 39 minutes with placebo (moderate-quality evidence; 31 studies, 1678 participants). Ketamine reduced the area of postoperative hyperalgesia by 7 cm² (95% CI -11.9 to -2.2), compared with placebo (very low-quality evidence; 7 studies 333 participants). We downgraded the quality of evidence because of small-study effects or because the number of participants was below 400.CNS adverse events occurred in 52 studies, while 53 studies reported of absence of CNS adverse events. Overall, 187/3614 (5%) participants receiving ketamine and 122/2924 (4%) receiving control treatment experienced an adverse event (RR 1.2, 95% CI 0.95 to 1.4; high-quality evidence; 105 studies, 6538 participants). Ketamine reduced postoperative nausea and vomiting from 27% with placebo to 23% with ketamine (RR 0.88, 95% CI 0.81 to 0.96; the number needed to treat to prevent one episode of postoperative nausea and vomiting with perioperative intravenous ketamine administration was 24 (95% CI 16 to 54; high-quality evidence; 95 studies, 5965 participants). AUTHORS' CONCLUSIONS: Perioperative intravenous ketamine probably reduces postoperative analgesic consumption and pain intensity. Results were consistent in different operation types or timing of ketamine administration, with larger and smaller studies, and by higher and lower pain intensity. CNS adverse events were little different with ketamine or control. Perioperative intravenous ketamine probably reduces postoperative nausea and vomiting by a small extent, of arguable clinical relevance.

[Robotic laparoscopic radical prostatectomy]. / Muutakin kuin lisää leluja kirurgeille? Robottiavusteinen laparoskooppinen radikaaliprostatektomia.

Robotic laparoscopic radical prostatectomy is an established method in the treatment of localized prostatic cancer. The equipment comprises a separate control console that makes ergonomic working possible. The optics creates a three-dimensional view and 10 to 15-fold magnification, thus enabling accurate operation. Recovery from the procedure is quicker and the number of blood transfusions lower than in open radical prostatectomy. The methods do not differ in regard to oncological results. Regardless of technique, radical prostatectomy is a demanding operation, in which the surgeon's skills and experience are decisive for the final result.

Do surgical patients benefit from perioperative gabapentin/pregabalin? A systematic review of efficacy and safety.

BACKGROUND: Gabapentin and pregabalin have antiallodynic and antihyperalgesic properties useful for treating neuropathic pain. These properties may also be beneficial in acute postoperative pain. In this study we evaluated randomized, controlled trials examining the analgesic efficacy, adverse effects, and clinical value of gabapentinoids in postoperative pain. METHODS: A systematic search of Medline, PubMed, and Cochrane Central Register of Controlled Trials (CENTRAL) databases yielded 22 randomized, controlled trials on perioperative administration of gabapentinoids for postoperative pain relief. RESULTS: Pain relief was better in the gabapentin groups compared with the control groups. The opioid-sparing effect during the first 24 h after a single dose of gabapentin 300-1200 mg, administered 1-2 h preoperatively, ranged from 20% to 62%. The combined effect of a single dose of gabapentin was a reduction of opioid consumption equivalent to 30 +/- 4 mg of morphine (mean +/- 95% CI) during the first 24 h after surgery. Metaregression analysis suggested that the gabapentin-induced reduction in the 24-h opioid consumption was not significantly dependent on the gabapentin dose. Gabapentin reduced opioid-related adverse effects, such as nausea, vomiting, and urinary retention (number-needed-to-treat 25, 6, and 7, respectively). The most common adverse effects of the gabapentinoids were sedation and dizziness (number-needed-to-harm 35 and 12, respectively). CONCLUSIONS: Gabapentinoids effectively reduce postoperative pain, opioid consumption, and opioid-related adverse effects after surgery. Conclusions about the optimal dose and duration of the treatment cannot be made because of the heterogeneity of the trials. Studies are needed to determine the long-term benefits, if any, of perioperative gabapentinoids.

New approach for treatment of prolonged postoperative pain: APS Out-Patient Clinic.

BACKGROUND AND AIMS: Persistent postoperative pain (PPP) is a significant clinical problem. Several patient-related risk factors for PPP have been identified, including a previous chronic pain problem, young age, female gender and psychological vulnerability. Intra- and postoperative risk factors include surgical complications such as infections, haematoma, nerve damage and repeated surgery. As the length of hospital stay has been shortened, some patients may be discharged despite ongoing pain and insufficient analgesic medication. The challenge is to identify patients at high risk of developing PPP and to create a targeted care pathway to ensure effective and safe pain treatment especially in the subacute postoperative phase at home. This observational study describes the first two years of the Acute Pain Service Out-Patient Clinic (APS-OPC) at the Helsinki University Hospital. METHODS: Patient characteristics, known risk factors, and details of treatment of PPP for the first 200 patients referred to our APS-OPC were retrospectively collected from the medical records. The APS-OPC clinic functions in close collaboration with the Multidisciplinary Pain Clinic (MPC), and the number of patients in need of physiotherapist, psychologist or psychiatrist counselling was recorded, as well as the number of patients referred to the MPC for further PPP management. RESULTS: Patients were referred to the APS-OPC from different surgical specialities, the two most common being thoracic and orthopaedic surgery. Seventy per cent of the patients (139/200) presented symptoms indicating neuropathic postsurgical pain. The patients had, on average, five risk factors for PPP. The median time from surgery to the first contact to the APS-OPC was two months, and the median duration of follow-up was 2.8 months (0-16 months). The median number of contacts with APS-OPC was 3 (range 1-14). Every fourth patient needed only one contact to the APS-OPC. Nineteen per cent of the patients had an appointment with the physiotherapist and 20% with a psychologist or psychiatrist. At discharge after surgery, 54% of the patients were using weak opioids, 32% strong opioids and 71% gabapentinoids; at discharge from the APS-OPC, these numbers were 20%, 6% and 43%, respectively. Twenty-two per cent of the patients were referred to the MPC for further pain management. CONCLUSIONS: The APS-OPC provides a fluent fast-track method of ensuring effective multimodal analgesia in the subacute recovery phase after surgery. Even strong opioids can be safely used after discharge and then tapered off in close supervision of the APS-OPC anaesthesiologist. As the APS-OPC was implemented in close collaboration with the MPC, the multidisciplinary resources are easily available during the course of the APS-OPC treatment. IMPLICATIONS: The first two years of the APS-OPC have shown that a significant number of surgical patients benefit from continuing active pain management after discharge from hospital. This fast-track service provides physician-supervised titration of analgesics to improve pain relief in the subacute phase. An important task of the APS-OPC is to ensure that strong opioids are not inappropriately continued after recovery. Another goal of the APS-OPC is to identify patients in need of multidisciplinary pain management services to prevent chronification.

Managing post-thoracotomy pain: Epidural or systemic analgesia and extended care - A randomized study with an "as usual" control group.

Background and aims Thoracotomies can cause severe pain, which persists in 21-67% of patients. We investigated whether NSAID + intravenous patient-controlled analgesia (IV-PCA) with morphine is an efficacious alternative to thoracic epidural analgesia (TEA). We also wanted to find out whether an extended controlled pain management protocol within a clinical study can decrease the incidence of persistent post-thoracotomy pain. Methods Thirty thoracotomy patients were randomized into 3 intervention groups with 10 patients in each. G1: preoperative diclofenac 75mg orally+150 mg/24h IV for 44h, then PO; G2: valdecoxib 40mg orally+parecoxib 80mg/24h IV for 44h, then PO. IV-PCA morphine was available in groups 1 and 2 during pleural drainage, and an intercostal nerve block at the end of surgery was performed; G3: parac-etamol+patient controlled epidural analgesia (PCEA) with a background infusion of bupivacaine with fentanyl. After PCA/PCEA oxycodone PO was provided when needed. These patients were contacted one week, 3 and 6 months after discharge. Patients (N = 111) not involved in the study were treated according to hospital practice and served as a control group. The control patients' data from the perioperative period were extracted, and a prospective follow-up questionnaire at 6 months after surgery similar to the intervention group was mailed. Results The intended sample size was not reached in the intervention group because of the global withdrawal of valdecoxib, and the study was terminated prematurely. At 6 months 3% of the intervention patients and 24%ofthe control patients reported persistent pain (p<0.01). Diclofenac and valdecoxib provided similar analgesia, and in the combined NSAID group (diclofenac+valdecoxib) movement-related pain was milder in the PCEA group compared with the NSAID group. The duration of pain after coughing was shorter in the PCEA group compared with the NSAID+IV-PCA group. The only patient with persistent painat6 months postoperatively had a considerably longer duration ofpain after coughing than the other Study patients. The patients with mechanical hyperalgesia had more pain on movement. Conclusions Both PCEA and NSAID+IV-PCA morphine provided sufficient analgesia with little persistent pain compared with the incidence of persistent pain in the control group. High quality acute pain management and follow-up continuing after discharge could be more important than the analgesic method per se in preventing persistent post-thoracotomy pain. In the acute phase the measurement of pain when coughing and the duration of pain after coughing could be easy measures to recognize patients having a higher risk for persistent post-thoracotomy pain. Implications To prevent persistent post-thoracotomy pain, the extended protocol for high quality pain management in hospital covering also the sub-acute phase at home, is important. This study also provides some evidence that safe and effective alternatives to thoracic epidural analgesia do exist. The idea to include the standard "as usual" care patients as a control group and to compare them with the intervention patients provides valuable information of the added value of being a study patient, and deserves further consideration in future studies.

The effect of paracetamol and tropisetron on pain: experimental studies and a review of published data.

Experimental studies suggest that paracetamol-induced analgesia is mediated via central serotonergic pathways and attenuated by 5-HT3-antagonists. However, clinical studies do not support this, and 5-HT3-antagonists are expected to reduce pain by blocking the descending pronociceptive pathway. The current project tested whether tropisetron attenuates analgesia by paracetamol. Two randomized, double-blind, crossover studies with 18 healthy male volunteers in each were performed. Pain stimuli were cold water immersion (cold pressor test), contact heat pain (study 1) and electrical stimulation (study 2). In both studies, tropisetron 5 mg i.v. or saline was administered, followed by paracetamol 2 g i.v. 30 min. later. Individual changes in heat and cold pain intensity, cold pain tolerance and unpleasantness were recorded. The same thresholds were also expressed as scores (% of the individual score at baseline). Additionally, previously published findings on the effects of paracetamol and its interaction with 5HT3-antagonists in human experimental pain models were reviewed. After calculation of the sensory and pain scores (%), tropisetron seemed to amplify the analgesic action of paracetamol. Paracetamol 2 g i.v. did not show any statistically significant analgesia in thermal tests (study 1), or differences in sensory, pain detection or moderate pain thresholds of the electrical stimulus (study 2). As paracetamol did not have a measurable analgesic effect in these tests, no conclusions can be drawn about the interaction between paracetamol and tropisetron. However, tropisetron may have an analgesic effect of its own. Clinicians should not avoid using these drugs together, unless larger clinical studies indicate otherwise.