Yuan-Yi Chia

Gender and pain upon movement are associated with the requirements for postoperative patient-controlled iv analgesia: a prospective survey of 2,298 Chinese patients.

PurposeTo investigate prospectively the influence of patient characteristics upon, and the association of postoperative measurements with, the requirements for postoperative morphine and the assessment of resting pain and pain upon movement in Chinese patients.MethodsFrom January 1998 to December 1999, patients receiving patient-controllediv morphine subsequent to general anesthesia and surgery at our institute (Kaohsiung Veterans General Hospital), were enrolled in the study. Demographic data (such as gender, age, weight, height and education level) and postoperative measurements, including pain scores at rest or during movement, sedation scores and morphine consumption, were recorded.ResultsIn total 2,298 patients were recruited. Females consumed significantly less morphine via patient-controlled analgesia (PCA) in the first three postoperative days than was the case for males (P < 0.05). Gender was the strongest predictor for postoperative morphine requirements. Postoperative pain upon movement was another effective predictor for morphine requirement (P < 0.05). Age, body height, body weight, education and operation sites were not associated with morphine consumption.ConclusionGender and postoperative pain upon movement are the major factors influencing morphine requirement for patientcontrollediv morphine analgesia during the first three postoperative days in Chinese patients.RésuméObjectifExaminer prospectivement si les caractéristiques du patient, et l’association des mesures postopératoires des douleurs, influencent les besoins de morphine postopératoire et l’évaluation de la douleur au repos et lors de mouvement chez des malades chinois.MéthodeDe janvier 1998 à décembre 1999, les patients qui ont reçu de la morphine iv auto-contrôlée, à la suite d’une opération sous anesthésie générale au Kaohsiung Veterans General Hospital, ont participé à l’étude. Les données démographiques (sexe, âge, poids, taille et niveau d’instruction) et les mesures postopératoires, incluant les scores de douleur au repos et pendant le mouvement, les scores de sédation et la consommation de morphine, ont été enregistrées.RésultatsNous avons recruté 2 298 patients. Pendant les trois premiers jours postopératoires, les femmes ont utilisé significativement moins de morphine que les hommes (P < 0,05) au moyen de l’analgésie auto-contrôlée (AAC). La variable prédictive la plus significative de la consommation de morphine postopératoire a été le sexe du patient. La douleur postopératoire pendant le mouvement a été un autre prédicteur efficace (P < 0,05). L’âge, la taille, le poids, l’instruction et le type d’opération n’ont pas été significatifs pour la consommation de morphine.ConclusionLe sexe et la douleur postopératoire pendant le mouvement sont les principaux facteurs d’influence des besoins de morphine pour l’analgésie iv auto-contrôlée pendant les trois premiers jours postopératoires chez des sujets chinois.

Intrathecal bupivacaine with morphine or neostigmine for postoperative analgesia after total knee replacement surgery

PurposeTo compare the postoperative analgesic efficacy and safety of intrathecal (IT) néostigmine and IT morphine in patients undergoing total knee replacement under spinal anesthesia. Methods: Sixty patients scheduled for elective total knee replacement under spinal anesthesia were randomly divided into three equal groups which received IT 0.5% hyperbaric bupivacaine 15 mg with either normal saline 0.5 ml_, néostigmine 50 μg, or morphine 300μg. The maximal level of sensory block, duration of analgesia, time to use of rescue analgesics, the overall 24-hr and four-hour interval visual analogue scale (VAS) pain score, and the incidence of adverse effects were recorded for 24 hr after administration.ResultsThere was no significant difference in maximal level of sensory block among the three groups. The morphine group had a later onset of postsurgical pain and longer time to first rescue analgesics than the néostigmine group (P < 0.05). Overall 24-hr VAS pain scores were significantly higher in the saline groupvs the morphine and néostigmine groups (P < 0.05). Motor block lasted significantly longer in the néostigmine group than in the morphine and saline groups (P < 0.05). The incidence of adverse effects was similar in the néostigmine and morphine groups except for pruritus (70%) occurring more frequently in the morphine group than in the néostigmine and saline groups (0%; P < 0.05). Overall satisfaction rates were better in the néostigmine group than in the morphine and saline groups (P < 0.05).ConclusionsIT néostigmine 50 μg produced postoperative analgesia lasting about seven hours with fewer side effects and better satisfaction ratings than IT morphine 300 μg.RésuméObjectifComparer l’efficacité et l’innocuité analgésique postopératoire de l’administration intrathécale (IT) de néostigmine et de morphine chez des patients devant subir une arthroplastie totale du genou sous rachianesthésie.MéthodeSoixante patients devant recevoir une prothèse totale de genou sous rachianesthésie ont été répartis au hasard en trois groupes égaux. Ils ont reçu 15 mg de bupivacaine hyperbare IT à 0,5 % et, soit 0,5 mL de solution salée, soit 50 μg de néostigmine, soit 300 μg de morphine. Le niveau maximal du bloc sensitif, la durée de l’analgésie, l’heure des premières demandes d’analgésiques de secours, les scores de douleur des 24 h d’observation et de chaque intervalle de quatre heures selon l’échelle visuelle analogique (EVA) et l’incidence d’effets indésirables ont été enregistrés pendant 24 h après l’administration médicamenteuse.RésultatsLe niveau maximal de blocage sensitif n’a pas présenté de différence intergroupe significative. Chez les patients avec morphine, la douleur post-chirurgicale s’est installée plus tard et leur première demande d’analgésie de secours a donc eu lieu plus tard que chez les patients avec néostigmine (P < 0,05). Les scores de douleur à l’EVA ont été, sur 24 h, signifcativement plus élevés avec la solution salée vs la morphine ou la néostigmine (P < 0,05). La durée du blocage moteur a été signifcativement plus longue avec la néostigmine qu’avec la morphine ou la solution salée (P < 0,05). L’incidence d’effets indésirables a été similaire avec la néostigmine et la morphine, sauf pour le prurit (70%) qui a été plus fréquent avec la morphine qu’avec la néostigmine ou la solution salée (0 %; P < 0,05). Le taux de satisfaction générale a été meilleur avec la néostigmine qu’avec la morphine ou la solution salée (P < 0,05).

The preoperative administration of intravenous dextromethorphan reduces postoperative morphine consumption.

UNLABELLED We evaluated the effect of dextromethorphan on postoperative pain management. Sixty ASA physical status I-III female patients undergoing major abdominal surgery underwent standardized general anesthesia. Thirty patients received an i.v. infusion of dextromethorphan 5 mg/kg before anesthetic induction (Pre group), whereas the remaining 30 patients received the same volume of isotonic sodium chloride solution, followed by a postoperative i.v. infusion of dextromethorphan 5 mg/kg (Post group). Patients in the Pre group received the same volume of isotonic sodium chloride solution postoperatively. All patients were then treated with patient-controlled i.v. analgesia, which administered a 0.6-mg bolus of morphine on demand (maximal 4 h dose 20 mg). The mean visual analog pain score during cough or movement and at rest were similar in the two groups in the first 3 days postoperatively. However, Post group patients consumed more morphine than Pre group patients during the first 2 days (P < 0.01). The sedation scores, patient satisfaction, and the incidence of morphine-related side effects were similar between the two groups. We conclude that the preoperative administration of dextromethorphan 5 mg/kg reduces postoperative morphine consumption compared with postoperative administration. IMPLICATIONS In this double-blinded study, we found that the preoperative administration of i.v. dextromethorphan 5 mg/kg, compared with postoperative administration, reduces postoperative morphine consumption, which may provide clinical evidence of preemptive or preventive analgesic effects of dextromethorphan.

The effect of promethazine on postoperative pain: a comparison of preoperative, postoperative, and placebo administration in patients following total abdominal hysterectomy

Background:  Histamine receptors are involved in the development of inflammatory pain and hyperalgesia, and the use of antihistamines is advocated as an alternative for pain therapy and treatment of postoperative nausea and vomiting. We investigated the influence of timing of promethazine administration on postoperative pain outcomes.

The efficacy of thoracic epidural neostigmine infusion after thoracotomy

Few anesthesia studies have explored perioperative continuous epidural infusion of neostigmine. We examined such a regimen in thoracotomy patients. Ninety patients were randomized to one of three groups in this double-blind trial. Before anesthesia induction, an epidural catheter was inserted in all patients at T5-8 levels under local anesthesia. Pre-neo patients received bolus 500-&mgr;g epidural neostigmine before anesthesia induction followed by infusion of 125 &mgr;g/h until the end of surgery. Post-neo patients received epidural saline during the same time periods plus bolus 500-&mgr;g epidural neostigmine at end of surgery. Patients in the control group received saline placebo during all three periods. Patients in the neostigmine groups postoperatively received patient-controlled epidural analgesia with morphine 0.02 mg/mL, bupivacaine 0.08 mg/mL, and neostigmine 7 &mgr;g/mL. Control patient-controlled epidural analgesia excluded neostigmine. Data were recorded for 6 postoperative days. Daily patient-controlled epidural analgesia consumption (mL) for Pre-neo patients was significantly less than that of post-neo and control group patients for postoperative days 1–6 (at least 10% and 16% less, respectively; P < 0.05). There was a modest decrease in pain intensity on postoperative days 3–6 for pre-neo patients versus other groups (P < 0.05). These results suggest that continuous thoracic epidural neostigmine started before anesthesia provided preemptive, preventive analgesia and an analgesic-sparing effect that improved postoperative analgesia for these patients without increasing the incidence of adverse effects.

Optimal Duration of Urinary Catheterization After Thoracotomy in Patients Under Postoperative Patient-controlled Epidural Analgesia

BACKGROUND Epidural analgesia is widely used for efficient pain relief after major surgery. However, it may cause urinary retention, leading to delayed removal of bladder catheters with prolonged patient discomfort. Using a specific regimen in patient controlled epidural analgesia (PCEA), we examined the optimal duration of urinary catheterization in patients undergoing major thoracic surgery. METHODS Seventy-eight patients scheduled for elective thoracotomy were prospectively randomized into two groups: Group 1, removal of the transurethral catheter on the first postoperative day (n = 38); Group 2, removal of the catheter after discontinuation of PCEA (n = 40). The PCEA regimen was a mixture containing low-dose morphine, bupivacaine and neostigmine and was given for 3 days after surgery in all subjects. Micturition problems, pain scores assessed by the visual analog scale (VAS), and side effects were evaluated during and after PCEA treatment. RESULTS The average duration of urinary drainage after surgery was 30.2 + or - 5.1 hours and 78.5 + or - 7.3 hours in Groups 1 and 2, respectively. After removal of the bladder catheter, no patient in either group required re-catheterization for urinary retention or encountered catheter-related infection. VAS scores were significantly lower in Group 1 at rest and at 24, 36 and 48 hours after cessation of PCEA. VAS scores were significantly higher in Group 2 patients, possibly due to catheter-induced pain related to prolonged catheterization. CONCLUSION Routine continuous bladder catheterization may not necessarily be required after thoracotomy in patients with ongoing continuous thoracic epidural analgesia.

Single-injection femoral nerve block lacks preemptive effect on postoperative pain and morphine consumption in total knee arthroplasty

OBJECTIVE Postoperative pain is severe after total knee arthroplasty (TKA). Therefore, femoral nerve block (FNB) is commonly used as an adjuvant to spinal anesthesia for TKA. Some anesthesia providers perform this preoperatively, while others perform it postoperatively. To our knowledge, no study has compared the relative benefits of the timing of performing the procedure. In this study, we investigated whether preoperative FNB would provide better analgesic effects than postoperative FNB in patients undergoing unilateral TKA. METHODS In this double-blind, randomized, controlled trial, we divided 82 patients (ASA physical status I-III) undergoing unilateral TKA into four groups: (1) a pre-treatment group, in which FNB was performed with 0.4 mL/kg 0.375% bupivacaine plus 1:200,000 epinephrine after spinal anesthesia but before the operation; (2) a post-treatment group, in which FNB was performed with the same drugs at similar dosages immediately after the operation; (3) a pre-control group, in which FNB was performed with normal saline in the same volume as the tested drugs before the operation; and (4) a post-control group, in which FNB was performed with normal saline in the same volume as the tested drug after the operation. At 2, 4, 6, 24, 48 and 72 postoperative hours, we recorded cumulative morphine consumption, visual analog pain scales (VAS), the time of first request for morphine and its side effects. We also measured knee maximum flexion range of motion once a day for 3 days. Our primary aim was to obtain cumulative morphine consumption in 24 hours. RESULTS Within the postoperative 24 hours, we found significant differences in cumulative morphine consumption between patients who received true FNB and those who did not (at 24 hours, treatment groups = 45.6 ± 31.7 and 33.5 ± 20.6 mg vs. controls = 70.8 ± 31.2 and 78.8 ± 37.7 mg, p < 0.001). We also found significant differences in VAS (at 24 hours, p < 0.001) and time to first request of morphine (p = 0.005) between the treatment group and the sham group. However, there were no significant differences in these values between the pre-surgical treatment group and the post-surgical treatment group. Beyond 24 hours, there were no significant differences in morphine consumption or maximum flexion range on day 2 and day 3 among the four groups. CONCLUSION Patients who received FNB used for total knee arthroplasty consumed significantly less postoperative morphine and had significant relief of post-TKA pain on postoperative day 1 than those who did not have FNB. However, at follow-up we found no significant differences in these values between those receiving FNB before surgery and those receiving it after surgery.

Gene knockdown of the N-methyl-D-aspartate receptor NR1 subunit with subcutaneous small interfering RNA reduces inflammation-induced nociception in rats.

Background:Spinal N-methyl-d-aspartate receptors have been demonstrated to play an important role in the facilitation and maintenance of nociception. To avoid adverse effects of blocking N-methyl-d-aspartate receptors in the central nervous system, blocking N-methyl-d-aspartate receptor in peripheral nervous system is an ideal alternative. Transfection of small interfering RNAs (siRNAs) into cells has been revealed to provide potent silencing of specific genes. In this study, the authors examined the effect of subcutaneous injection of siRNA targeting the NR1 subunit of the N-methyl-d-aspartate receptor on silencing NR1 gene expression and subsequently abolishing inflammatory nociception in rats. Methods:Male Sprague-Dawley rats received intradermal injection of NR1 siRNA and underwent injection of formalin or complete Freunds adjuvant. The flinch response and mechanical hypersensitivity by von Frey filaments were assessed. Then the messenger RNA and protein of NR1 in skin and dorsal root ganglion were analyzed. Results:The results revealed that subcutaneous injection of 1 nmol NR1 siRNA effectively diminished the nociception induced by formalin and complete Freunds adjuvant stimuli and attenuated the level of NR1 messenger RNA and protein in skin and ipsilateral dorsal root ganglion. The antinociception effect and the inhibition of NR1 expression persisted for about 7 days after administration of NR1 siRNA. Conclusions:The data of this study suggest that NR1 siRNA has potential therapeutic value in the treatment of inflammatory pain induced or maintained by peripheral nociceptor activity and support the potential application of this method to the study of nociceptive processes and target the validation of pain-associated genes.

Effects of postoperative background PCA morphine infusion on pain management and related side effects in patients undergoing abdominal hysterectomy

STUDY OBJECTIVE To examine the effects of background morphine infusion via patient-controlled intravenous analgesia (PCA) device. DESIGN Randomized, controlled, double-blinded study. SETTING University-affiliated hospital. PATIENTS 60 ASA physical status 1 and 2 patients scheduled for abdominal hysterectomy. INTERVENTIONS Patients were randomly allocated to either the PCA group without continuous background morphine infusion (Group 1; n = 30) or the PCA group with continuous background morphine infusion (Group 2; n = 30). MEASUREMENTS Pain intensity during movement and at rest, morphine consumption at indicated time intervals, and related side effects were evaluated and recorded for three postoperative days at 12-hour intervals. The degree of patient satisfaction with PCA pain management was elicited and recorded. MAIN RESULTS Pain intensity during movement (VASC) at 12 and 36 hours postoperatively and pain intensity at rest from 12 to 60 hours were significantly higher in Group 2 than Group 1. PCA morphine consumption for three days postoperatively in Group 2 was significantly higher. The frequency of vomiting, nausea, and dizziness were higher in Group 2. The frequency of pruritus, urinary retention, and allodynia was similar for both groups. The degree of patient satisfaction with pain management was generally equivalent between the groups. CONCLUSION A continuous background morphine infusion of 0.5 mg/hr did not lower pain intensity during movement or at rest, but induced higher pain intensity, higher opioid usage, and more complications such as vomiting, nausea, and dizziness.

Lignocaine plus morphine in bolus patient-controlled intravenous analgesia lacks post-operative morphine-sparing effect

Lignocaine has been used successfully to treat burn pain and neuropathic pain. We have conducted a randomized, double-blind trial to assess the morphine-sparing effect of intravenous lignocaine in patients with acute pain. After major abdominal surgery, patients were treated with post-operative patient-controlled intravenous analgesia in two groups: group M (n = 25, morphine 0.2 mg mL-1) and group ML (n = 25, morphine 0.2 mg mL-1 plus lignocaine 3.2 mg mL-1). The patient-controlled analgesia system was programmed to deliver a 5 mL bolus with a 50 mL per 4 h limit; the lockout time was 10 min. Both groups closely resembled each other in terms of demographic data, pain intensity, cumulative morphine dose and the morphine-associated nausea, vomiting and pruritus. However, the sedation scores in group ML patients during the first post-operative day were significantly greater than those in group M. The incidence of lignocaine-related lightheadedness and dry mouth was also significantly greater in group ML than in group M. It was concluded that the addition of lignocaine 3.2 mg mL-1 to morphine 0.2 mg mL-1 given via patient-controlled analgesia system does not provide a post-operative morphine-sparing analgesic effect.