Postoperative hyperalgesia does not predict persistent post-sternotomy pain; observational study based on clinical examination.

BACKGROUND: Persistent post-sternotomy pain is a common problem, but the risk of developing it varies among patients. We sought to find out whether the risk of persistent post-sternotomy pain could be predicted by measuring the area of acute sensory dysfunction around the sternotomy wound. The secondary aim was to determine risk factors for persistent post-sternotomy pain. PATIENTS AND METHODS: Hundred patients who were scheduled to undergo elective coronary artery bypass surgery were recruited to the study. Patients were excluded if they had undergone previous cardiac surgery or if they lacked co-operation. Preoperative pain scores were determined and the patients filled in questionnaires about depression, anxiety, and pain. The area of sensory dysfunction around the sternotomy wound was assessed by pin prick on postoperative day 4. The presence of persistent post-sternotomy pain was determined at a follow-up evaluation at 4-6 months after surgery. RESULTS: The sizes of the area of hyperalgesia or overall sensory dysfunction were not associated with persistent post-sternotomy pain. Independent risk factors for persistent post-sternotomy pain were found to be smoking and high pain score on postoperative day 1. The prevalence of persistent post-sternotomy pain in our study population was 38% analyzed by only the questionnaire and 15% according to the clinical examination. CONCLUSION: Measuring the area of hyperalgesia in the acute phase does not give any additional information on the risk of developing a persistent post-sternotomy pain. We do thus not recommend measuring the area in this particular group of patients. Evaluation of pain by only a questionnaire risks to overestimate the presence of persistent post-sternotomy pain as compared to clinical examination.

Bedside diagnosis of persistent post-sternotomy pain.

BACKGROUND: The prevalence of persistent post-sternotomy pain (PPSP) varies largely and has been mainly studied using questionnaires. We decided to perform a systematic qualitative and quantitative sensory examination study on a power-calculated sample of patients who had undergone sternotomy for cardiac surgery. Pain was diagnosed as PPSP if the patient complained of sternal pain that had developed after surgery together with corresponding sensory disturbances. PATIENTS AND METHODS: One hundred elective patients undergoing coronary artery bypass via sternotomy were recruited for dynamic sensory mapping 4-6 months after surgery. Sensory testing was performed using thermal rollers, a cotton stick and pinprick. The intensity of sensation was registered as a score on a numeric rating scale. The area of sensory dysfunction on the chest wall was traced onto paper and calculated with the help of a computer-based program. The patient also answered a validated pain questionnaire. RESULTS: Altogether 90 patients took part in the examination. Thirteen (15.4%) of the patients had pain and formed the PPSP group, while the remaining patients formed the non-PPSP group. Both groups had sensory abnormalities over the chest wall (69% of all patients). Sensory disturbances were more common, more profound and extended over a larger skin area in the PPSP group. Furthermore, daily activity performance in the PPSP group was poorer compared to the non-PPSP group. CONCLUSION: PPSP is a clinical diagnosis easily achieved using simple diagnostic tools and a medical history. Severity and extent of sensory abnormalities were found to be greater in the PPSP group.

Etoricoxib pre-medication for post-operative pain after laparoscopic cholecystectomy.

BACKGROUND: Etoricoxib alleviates and prevents acute pain. The hypothesis of our study was that the pre-operative use of etoricoxib would reduce the post-operative need for additional pain treatment. METHODS: In this double-blind, randomized and active placebo-controlled study, 75 patients were pre-medicated 1.5 h before elective laparoscopic cholecystectomy with 120 mg of etoricoxib (E120 group), the same dose of etoricoxib combined with 1 g of paracetamol (E + P group) or placebo (Pla group). To alleviate post-operative pain, a patient-controlled analgesia (PCA) device was programmed to deliver 50 microg of fentanyl intravenously (lockout time, 5 min). The pain intensity and nausea were assessed using a visual analogue scale (VAS). The number of patients with post-operative nausea and vomiting was recorded. Blood loss was compared between the groups. Because the operations are almost blood-less, the operation time was also recorded to compare the possible effect on bleeding time. RESULTS: Pre-medication with etoricoxib or etoricoxib plus paracetamol had a statistically significant fentanyl-sparing effect 2-20 h post-operatively compared with placebo (P = 0.001). No significant differences were demonstrated in fentanyl-sparing effect between the E120 and E + P groups. No significant differences in pain intensity were found between the three study groups. No significant differences were observed between the groups with regard to nausea, blood loss, duration of anaesthesia or duration of surgery. CONCLUSION: Etoricoxib is suitable for pre-medication before laparoscopic cholecystectomy as it reduces the need for post-operative opioids. Opioid-related side-effects, however, were not reduced in the present study, despite the observed opioid-sparing effect of etoricoxib and combined etoricoxib and paracetamol.

Lack of analgesic effect of parecoxib following laparoscopic cholecystectomy.

BACKGROUND: The cyclo-oxygenase-2 inhibitor, parecoxib, can be administered parenterally. The recommended dose for post-operative use is 40 mg twice daily, which may not be the appropriate dose for the treatment of visceral pain. We studied the effect of a single dose of parecoxib of either 40 or 80 mg in laparoscopic cholecystectomy, and its effect on opioid-induced side-effects. METHODS: Seventy-three patients scheduled for elective laparoscopic cholecystectomy were enrolled in this prospective, randomized, double-blind study. Patients were randomized into three groups: a placebo-treated control group, a 40-mg parecoxib-treated group (P40) and an 80-mg parecoxib-treated group (P80). We recorded the cumulative fentanyl consumption during the first 20 h post-operatively by patient-controlled analgesia equipment, the pain scores during rest, coughing and mobilization (visual analogue scale, 0-10), the worst pain during the first 2 h post-operatively and in the following 18 h, and the side-effects by questionnaire. RESULTS: No significant differences in fentanyl consumption between the three groups could be detected. The worst pain experienced between 2 and 20 h post-operatively on the ward was significantly lower in the P80 group than in the control group. CONCLUSION: The recommended dose of parecoxib, 40 mg, is not effective for the treatment of pain during the early post-operative period after laparoscopic cholecystectomy. Doubling the dose to 80 mg seems to improve the results.