Effect of Segmental Epidural Analgesia upon the Uterine Activity with Special Reference to the Use of Different Local Anaesthetic Agents

Segmental epidural block was given to 60 primiparous women during vaginal delivery, and the effect of the block on the uterine activity was studied after the first epidural injection. The women were divided into two main groups, according to whether or not oxytocin was used for stimulating the uterine contractions, and three different local anaesthetics--lidocaine-adrenaline, bupivacaine-adrenaline and plain bupivacaine--were tested. There was a transitory decrease in uterine activity in all women after the block was applied. In women with normal uterine activity before the block, a return to almost pre-analgesic values was noted within 30 min after the block, whereas in women treated with oxytocin there was still a reduction of 15-17% at this time. The reduction was caused by a decreasing intensity and at the same time an increase in the variability of the intensity, manifested as an increase in the coefficient of variation for this variable. There were no significant differences between the local anaesthetic agents tested, but addition of adrenaline to the bupivacaine solution resulted in a more marked decrease in uterine activity in women treated with oxytocin.     

Comparison of Short-Term Versus Long-Term Epidural Analgesia After Limited Thoracotomy with Special Reference to Pain Score, Pulmonary Function, and Respiratory Muscle Strength

To determine the optimal duration of epidural analgesia (EA) after lung cancer surgery, a retrospective analysis was conducted to compare chest pain, pulmonary function, and respiratory muscle strength between patients given EA until postoperative day (POD) 3 and those given EA until POD 8. Each group comprised 25 lung cancer patients who underwent a lobectomy under anterior limited thoracotomy and given continuous thoracic EA using morphine until POD 3 (POD3-EA group) or POD 8 (POD8-EA group). The two groups were matched by sex and age. Postoperative pain from PODs 1 to 12 was evaluated by the pain score and analgesic requirements. The pulmonary function and respiratory muscle strength were measured on POD 7. The POD3-EA group did not experience any increase in pain after withdrawal, but the POD8-EA group did show a significant increase in pain the day after withdrawal (P < 0.05). The pain scores on PODs 8 and 9 in the POD8-EA group were significantly higher than those in the POD3-EA group (P < 0.05). There was no significant difference in pulmonary function and respiratory muscle strength on POD 7 between the two groups. Although the postoperative thoracic EA did not affect pulmonary function and respiratory muscle strength, prolonged thoracic EA after a limited thoracotomy significantly increased the pain after withdrawal, thus negatively affecting postoperative pain control. Received: May 8, 2000 / Accepted: September 6, 2000     

TIBIAL PRESSURE ALGESIMETRY: The Significance of Changes in Pain Threshold with reference to the Assessment of Analgesia

A controlled investigation of tibial pressure algesimetry wasundertaken in 100 patients to determine the significance ofchanges in pain threshold with reference to their use as a methodof measuring analgesia. Pethidine 1.6 mg/kg was used as a standardanalgesic and atropine 0.009 mg/kg aaed as a control. Individualresults were very variable, but provided enough subjects wereinvestigated, the analgesic action of pethidine could be demonstrated.The relationship between analgesic potency, the change in painthreshold and the number of cases required to demonstrate achange of statistical significance is discussed. Pethidine 1.6mg/kg with atropine 0.009 mg/kg produced a mean rise in painthreshold of 16.2 per cent in 50 subjects. Atropine alone produceda rise of 1.1 per cent in 50 subjects. The difference in painthreshold raising effects between the two groups was significant(P=0.0014). A minimum of two groups of about 20 cases is likelyto be required before a rise in pain threshold due to pethidine1.6 mg/kg can be demonstrated to a statistically significantdegree in a hospital patient population.     

Factors Associated with the Development of Chronic Pain after Surgery for Breast Cancer: A Prospective Cohort from a Tertiary Center in the United States

Chronic pain has been shown to affect up to 60% of patients undergoing surgery for breast cancer. Besides younger age, other risk factors for the development of chronic pain have not been consistent in previous studies. The objective of the current investigation was to detect the prevalence and risk factors for the development of chronic pain after breast cancer surgery by examining a patient population from a tertiary cancer center in the United States. The study was a prospective observational cohort study. Subjects were evaluated at least 6 months after the surgical procedure. Subjects responded to the modified short form Brief pain inventory and the short form McGill pain questionnaire to identify and characterize pain. Demographic, surgery, cancer treatment, and perioperative characteristics were recorded. Propensity matching regression analysis were used to examine risk factors associated with the development of chronic pain. 300 patients were included in the study. 110 reported the presence of chronic pain. Subjects with chronic pain reported median (interquartile range [IQR]) rating of worst pain in the last 24 hours of 4 (2–5) and a median (IQR) rating on average pain in the last 24 hours of 3 (1–4) on a 0–10 numeric rating scale. Independent risk factors associated with the development of chronic pain were age, OR (95% CI) of 0.95 (0.93–0.98) and axillary lymph node dissection, 7.7 (4.3–13.9) but not radiation therapy, 1.05(0.56–1.95). After propensity matching for confounding covariates, radiation was still not associated with the development of chronic pain. Chronic pain after mastectomy continues to have a high prevalence in breast cancer patients. Younger age and axillary lymph node dissection but not radiation therapy are risk factors for the development of chronic pain. Preventive strategies to minimize the development of chronic pain are highly desirable.     

Anesthetic duration of lidocaine with 10% dextran is comparable to lidocaine with 1:160 000 epinephrine after intraosseous injection in the rabbit.

OBJECTIVE: To compare the effects of 10% dextran and epinephrine on intraosseous injection with lidocaine in rabbits. STUDY DESIGN: Twenty male Japanese white rabbits were used. The effect of intraosseous injection was evaluated using an electromyogram (EMG) of the digastric muscle after electrical pulp stimulation. Two percent lidocaine alone (L), 2% lidocaine containing 1:80000 epinephrine (LE8), 2% lidocaine containing 1:160 000 epinephrine (LE16), and 2% lidocaine containing 10% dextran (LD) were tested. Electromyogram recordings were repeated before and 30 seconds, 1, 2, 3, 4, 5, 7, 10, 12, 15, and 20 minutes after the intraosseous injection. Thereafter, recordings were repeated every 5 minutes until the EMG recovered to the control value. RESULTS: There was no difference in the onset time between the 4 groups. The order of the duration of maximum effect was LE8 >LE16 = LD >or=L. The order of the duration of anesthesia was LE8 >LE16 = LD >L. CONCLUSION: Ten percent dextran potentiates local anesthetic effects of 2% lidocaine in intraosseous injection. The potency of 10% dextran is comparable to 1:160 000 epinephrine.     

Bilateral PECS II Block is Associated with Decreased Opioid Consumption and Reduced Pain Scores for up to 24 hours After Minimally Invasive Repair of Pectus Excavatum (Nuss Procedure): A Retrospective Analysis

Objective(s)Compared to the open surgical technique, the minimally invasive repair of pectus excavatum (MIRPE; Nuss procedure) is a thoracoscopic technique designed to minimize intraoperative tissue damage. It still causes severe postoperative pain due to the insertion and pressure of the retrosternal bar used to raise the sternum and stabilize the chest. This study aimed to identify associations between ultrasound-guided PECS-II block and postoperative analgesia after the Nuss procedure.DesignA retrospective cohort studySettingSingle-center, training and research hospital affiliated with a universityParticipantsFrom Jan 1, 2018 to Nov 15, 2021, 171 consecutive patients were identified who underwent MIRPE surgery under general anesthesia. All patients received intravenous (I) patient-controlled analgesia (PCA) with or without PECS-II blocks for postoperative analgesia. One hundred twenty-five patients who met the inclusion criteria were evaluated.InterventionsDemand-only morphine intravenous PCA was used for postoperative pain management in the PECS and control groups. Bilateral PECS-II block with 0.25% bupivacaine was performed in to the PECS group.Measurements and main resultsThe primary outcome was postoperative opioid consumption, calculated as mg/kg of IV morphine. Secondary outcomes included Numeric Rating Scale (NRS) pain scores at rest (static) and with movement (dynamic) recorded 1, 4, 8, 12, 24 h after surgery. Postoperative morphine consumption was significantly lower in the PECS group than in the control group over the first 24 hours postoperatively: 0.325 mg/kg vs. 0.425 mg/kg (p<0.001). Static and dynamic NRS values were significantly lower in the PECS group for the first 12 postoperative hours (p <0.05).ConclusionsBilateral PECS-II block is associated with decreased pain scores for up to 12 hours, and with decreased opioid consumption for up to 24 hours, following minimally invasive repair of pectus excavatum (Nuss procedure) in adolescents. PECS-II block in this context has not been previously described.