Postoperative patient-controlled analgesia with tramadol: analgesic efficacy and minimum effective concentrations

Forty patients (ASA status I-III) recovering from major orthopedic or gynecological operations were investigated to evaluate analgesic efficacy and threshold concentrations of tramadol and its main metabolite O-demethyltramadol (M1) in serum during the early postoperative period, using patient-controlled analgesia (PCA) by means of the Abbott Lifecare Infuser. Following an individualized intravenous loading dose of 97.5 +/- 42.3 mg (mean, SD), tramadol demand doses were 20 mg with a limit of 500 mg within 4 h; the lockout time was set to 5 min. The duration of PCA was 20.5 +/- 4.8 h. During this time 8.0 +/- 5.0 demands per patient were recorded, resulting in an average tramadol consumption of 257.5 +/- 102.8 mg (including loading dose). Analgesia was mostly judged good to excellent. Side effects were only of minor intensity and never gave rise to concern. There were no statistically significant differences between the types of surgery. Tramadol proved to be about 1/6 to 1/10 as potent an analgesic as morphine when both intensity and duration of effect were considered. Minimum effective tramadol serum concentration (MEC) varied greatly and could be best described by a log-normal distribution (range 20.2-986.3 ng/ml, median 287.7 ng/ml). Intraindividual MEC variability was lower than intersubject variability (38.2 vs 59.1%). Median M1 concentrations were 36.2 ng/ml.     

Postoperative patient-controlled analgesia in children

Patient-controlled analgesia (PCA) has been found to be an effective method of pain management for adults. Children are now being considered for self-administration of analgesia. With careful patient selection and preparation, nurses and children find patient-controlled analgesia to be an effective way to maintain comfort in the postoperative period.     

Postoperative nausea management and patient-controlled analgesia

Following the establishment of an acute pain service in one UK acute NHS trust, including the introduction of patient-controlled analgesia (PCA), pain scoring, and a rationalization of the use of simple analgesics, attention was drawn to an apparent increase in postoperative nausea and vomiting (PONV) among women given PCA following abdominal hysterectomy. Audits were conducted into clinical practice and patient satisfaction and it was agreed that an evaluation of the evidence should be conducted to ensure that the correct direction for development in the management of PONV could be established. This article discusses the evidence surrounding the issues regarding the management of PONV in patients who have been given PCA. The possibility of adding antiemetics to the analgesic solution, and the choice of antiemetic drugs, are investigated. Other factors that can affect the incidence of PONV in patients with PCA are also discussed, and an auditable framework for the evaluation of clinically effective practice is suggested.     

Postoperative patient-controlled analgesia in the pediatric population: a literature review

An exciting revolution in pediatric pain control has evolved in anesthesia during the past 2 decades. The creative use of systemic analgesic techniques has dramatically improved the quality of postoperative pain management. The postsurgical pediatric population is reaping the benefits of such advancements in acute pain management, as there is an increasing use of patient-controlled analgesia (PCA). The goal of PCA is to provide safe and effective postoperative pain control by achieving a continuous level of analgesia in the body, along with the opportunity for Nursbolus doses as requested by the patient. The aim of this analgesic technique is optimal pain relief and a high level of patient and parent satisfaction. This review of the literature addresses safety issues, indications, contraindications, complications, and dosing regimens related to pediatric PCA. Recommendations for continuous pulse oximetry and sedation monitoring, along with individualized dosage requirements, are presented to decrease the incidence of complications. Overall, the literature shows that PCA provides adequate pain control and high levels of satisfaction for the pediatric postsurgical population and their families.     

Modifiers of patient-controlled analgesia efficacy in acute and chronic pain

Patient-controlled analgesia (PCA) is widely used as an effective tool for the treatment of acute and chronic pain. Its greatest advantage seems to be the easily achieved individualization of therapy, allowing optimum titration of analgesic dose to analgesic needs. This short review summarizes some predictors of PCA efficacy.     

不同浓度罗哌卡因复合芬太尼用于分娩镇痛的临床研究

目的比较不同浓度罗哌卡因复合小剂量芬太尼用于分娩镇痛的效果。方法100例单胎、足月、头住初产妇，ASAⅠ～Ⅱ级，随机分成四组，每组n=25。所用药物：A组：0．075％罗哌卡因；B组：0、125％罗哌卡因；C组：0．2％罗哌卡因，每组均加21ag／ml芬太尼：D组：对照组，未行分娩镇痛，于产程进展宫口开3cm时，行硬膜外腔穿刺置管，首次剂量硬膜外腔给予8—12ml，半小时后，连接PCA泵持续硬膜外腔输注，维持量6～10ml／h至宫口开全停药，PCA剂量4ml，锁定时间30min。所有产妇均行视觉模拟评分WAS）和改良Bromage评分，评估镇痛、运动神经阻滞情况，观察记录各组产妇的生命体征、产程时间、分娩方式及新生儿Apgar评分。结果A、B、C组与D组相比产妇用药后VAS评分均明显降低。且A、B、C组第一产程均较对照组明显缩短（P〈0．01），但A组的镇痛效果欠佳，VAS评分高于B、C组，有显著差异（P〈0．01）。C组的难产率较高，与对照组相比有显著差异（P〈0。01）。B组镇痛效果最满意。宫口扩张速度和胎头下降速度较快，分娩中产妇的BP、HR、RR平稳，对产程和分娩方式及新生儿Agpar评分均无明显影响，联合用药可减少局麻药用量。结论0.125％罗哌卡因复合芬太尼用于硬膜外分娩镇痛（PCEA）对产程影响最小，镇痛效果确切，简便易行。是硬膜外分娩镇痛较为理想的药物浓度。     

Perioperative pharmacology: patient-controlled analgesia

Patient-controlled analgesia (PCA) is an effective treatment option for reducing pain, but PCA errors can be quite serious. Opioid analgesics are among the most effective pain relievers available, but all have contraindications and can have adverse effects, including respiratory depression and other effects on the central nervous system. Practitioners must weigh the potential benefits of PCA use against the risks. Errors associated with the PCA process have been documented in each phase of the medication-use process; therefore, practice improvements in prescribing, transcribing, dispensing, administering, and monitoring PCA may reduce the likelihood of errors. Perioperative nurses can make important contributions to safe PCA use by establishing standardized processes to help ensure positive patient outcomes in pain management.     

Modifiers of patient-controlled analgesia efficacy. II. Chronic pain

Fifty-eight gynecologic surgical patients using patient-controlled analgesia (PCA) were given several psychological questionnaires and their pain was monitored postoperatively. Pain scores were recorded hourly on postoperative day 1. In addition, patients were asked to score retrospectively their overall pain experience while using PCA (Patient Overall Evaluation). Patients having had a history of pain for at least 6 months were considered to have 'chronic pain,' while those who had no history of chronic pain were grouped as 'acute pain' patients. Chronic pain patients spent more time in 'moderate' pain than did acute pain patients. While patients with a history of chronic pain had higher scores on the hourly pain scale compared to acute pain patients, there were no differences between the two groups on the Patient Overall Evaluation. In addition, chronic pain patients reported the same pain levels after completion of PCA as they did during its use, in contrast to acute pain patients whose retrospective pain levels were higher than during PCA use. Compared to acute pain patients, chronic pain patients had higher scores on both the Hypochondriasis and the Hysteria scales of the MMPI. A history of chronic pain may affect the use of patient-controlled analgesia since chronic pain patients may accommodate to a 'moderate' pain level which approximates their preoperative perception of pain. By contrast, acute pain patients who have no 'chronic pain experience' may self-administer pain medication so as to attain a predominately 'mild' level of pain.     

地佐辛与芬太尼患者自控静脉镇痛的比较

目的比较地佐辛与芬太尼自控静脉镇痛(PCIA)的镇痛效果和不良反应。方法将120例胆囊切除术患者随机均分为A、B 2组,每组60例。术后A组PCIA采用地佐辛1 mg/Kg、氟哌利多5 mg,B组PCIA采用芬太尼18μg/Kg、氟哌利多5 mg,分别于术后4、8、12、24 h采用视觉模拟评分法(VAS)评定镇痛效果,并记录不良反应情况。结果 2组患者术后镇痛效果无显著性差异;2组均未见血压心率的波动及呼吸抑制等严重并发症发生;A组镇静评分为Ⅰ~Ⅳ级的比例显著低于B组,其余不良反应发生率与B组均无统计学差异。结论地佐辛PCIA镇痛效果可靠,不失为一种比较好的PCIA方法。     

地佐辛与芬太尼患者自控静脉镇痛的比较

目的比较地佐辛与芬太尼自控静脉镇痛(PCIA)的镇痛效果和不良反应。方法 120例胆囊切除术患者,年龄39~52岁,随机均分为2组,术后A组PCIA采用地佐辛1 mg/kg+氟哌啶5 mg,B组PCIA采用芬太尼18μg/kg+氟哌啶5mg,分别于术后4、8、12、24 h采用视觉模拟评分法(VAS)评定镇痛效果及不良反应。结果 2组患者术后镇痛效果及不良反应均无显著性差异。结论地佐辛PCIA镇痛效果可靠,不失为一种比较好的PCIA方法。     

Postoperative analgesia using a computerised infusion of alfentanil following aortic bifurcation graft surgery

Summary A Psion microcomputer controlled infusion system for alfentanil was assessed for the provision of post-operative analgesia in 14 patients who had undergone aortic bifurcation graft surgery. The system employed a pharmacokinetic model working in real time to deliver any selected target plasma concentration of alfentanil. The alfentanil infusion system was used for a mean time of 39 hours and for 96% of this time, patients were scored as having no pain or only mild pain. Severe pain was recorded for only 0.05% of the study time. The use of a pharmacokinetic delivery system may offer a convenient and simple method of providing postoperative analgesia with alfentanil.Abstract presented at the 6th International Symposium on Computing in Anaesthesia and Intensive Care; Hammamatsu, Japan.     

Controlling postoperative pain with patient-controlled analgesia

Patient-controlled analgesia is an innovative method of pain control that is being used with increasing frequency in postoperative patients. Besides affording patients a sense of control over their pain, the method seems to offer superior pain relief with less sedation compared with traditional methods. Nurses report that valuable patient care time is saved when complicated negotiations among nurses, patients, and physicians regarding pain management are eliminated, and tasks such as signing out and preparing analgesic injections are no longer necessary. A review of the method is presented.     

Modifiers of patient-controlled analgesia efficacy. I. Locus of control

The effectiveness of patient-controlled analgesia (PCA) depends upon the patient's appropriate response to a strong aversive stimulus (i.e., pain) with subsequent reinforcement (i.e., opiate injection). Each patient may have psychological characteristics that modify this response to aversive stimuli. To test for such characteristics, 76 female patients undergoing abdominal gynecologic procedures were given psychological tests (i.e., the Chance External, Powerful Others External, and Internal subscales of the Multidimensional Health Locus of Control; the Activities of Daily Living scale; and the Hypochondriasis, Depression, and Hysteria scales of the Minnesota Multiphasic Personality Inventory). Patients utilized PCA for postoperative analgesia. At the completion of PCA, patients were given a questionnaire assessing both the level of pain and degree of satisfaction with pain relief. Correlational analysis compared the level of pain and degree of satisfaction with results of psychological testing. Results showed that female patients with an external locus of control had higher levels of pain and greater dissatisfaction with PCA. An internal locus of control was predictive of lower pain scores and increased satisfaction. PCA effectiveness, as measured by the level of pain and degree of patient satisfaction, correlated with results of psychological testing. The delineation of these and other possible modifiers of PCA efficacy may define populations that are optimally responsive to PCA.     

Patient-controlled analgesic infusions: alfentanil versus morphine.

Previously, we found that cancer patients using a pharmacokinetically based patient-controlled intravenous infusion system (PKPCA) to regulate their own morphine infusion rates achieved more relief from oral mucositis pain than similar patients using morphine by bolus-dose PCA. In this study, we employed the PKPCA system to compare efficacy and side-effect intensities of 2 mu-selective opioid analgesics, alfentanil and morphine, in bone marrow transplant (BMT) patients self-administering the drugs to relieve pain from oral mucositis. Patients using morphine by PKPCA obtained more pain relief than patients regulating their own alfentanil infusions during the first 4 days of continuous opioid infusion therapy. Side-effect intensities did not differ between the 2 study groups. In contrast to patients using morphine for 4-14 days, those receiving alfentanil by PKPCA required unexpectedly high plasma concentrations of the drug to obtain equivalent pain relief. Our results indicate that either the relative potencies of these 2 mu-selective opioids differ from previous estimates or analgesic tolerance developed to alfentanil but not to morphine. We conclude that alfentanil has similar efficacy in control of prolonged pain in BMT patients, but the utility of alfentanil in long-term pain management may be limited by relatively rapid tolerance onset.     

Side effects of morphine patient-controlled analgesia and meperidine patient-controlled analgesia: a follow-up of 500 patients.

Many physicians, Certified Registered Nurse Anesthetists (CRNAs), and registered nurses have the clinical impression that either morphine sulfate or meperidine hydrochloride is a better drug to control postoperative pain. In this study, we evaluated pain relief and side effects for these two drugs to assess their potential differences. CRNAs conducted a structured interview of 500 female patients 24 hours after major gynecologic, urologic, or breast surgery. Patients' responses on 4-point scales of none, mild, moderate, and severe were collected for pain intensity, degree of nausea, severity of vomiting and itchiness, and degree of sedation experienced since the operation. There were 91 patients who received morphine patient-controlled analgesia (PCA) and 409 patients administered meperidine PCA. No statistically significant differences for pain intensity, degree of nausea, severity and incidence of vomiting, or degree of sedation were found. However, a significant difference was found in the incidence rates of mild itchiness, which occurred more frequently in the morphine PCA group (P less than .001). Patients vomited more often after vaginal hysterectomy than patients having laparotomy, major oncology, or tuboplasty surgeries (P less than .05), and vaginal repair patients reported more vomiting than patients having major oncology or tuboplasty surgeries. Clinical impressions that either morphine or meperidine should be the preferred treatment for patients following gynecologic operations was not found by a 24-hour review of 500 patients for pain relief and side effects. Although mild itchiness occurred more frequently in the morphine PCA group, treatment was rarely necessary.     

Postoperative pain therapy with tilidin and tilidin retard as an oral patient-controlled analgesia after uncomplicated myocardial revascularization

OBJECTIVE: The purpose of this study was to evaluate whether or not the combination of tilidin and tilidin retard as oral patient-controlled analgesia provide a suitable pain management in patients after uncomplicated myocardial revascularization. METHODS: We conducted a randomised phase IV study to evaluate the effectiveness of postoperative analgesia with tilidin and tilidin retard.Patients with a baseline tilidin retard and tilidin liquid demand medication (group B, 42 patients) were compared with a base line paracetamol and tramadol-HCl liquid demand medication (group A, 44 patients). All patients received the first dose of study medication at the second postoperative day after evaluation of the individual pain score using NRS (numeric rating scale). RESULTS: Pain relief in group B was significantly better only at the second postoperative day (NRS 1,8 compared to 3,3 in group A), associated with tolerable side effects and comfortable handling. CONCLUSION: The combination of sustained release with immediate release drugs as a patient controlled analgesia provides suitable and comfortable analgesia after myocardial bypass surgery.     

Postoperative ketamine analgesia in children: efficacy and safety after halothane anesthesia

This study was done to investigate the effectiveness and safety of ketamine analgesia after halothane anesthesia for surgery in children. After completion of a surgical procedure, ten children had ketamine (1 mg/kg) injected intravenously during maintenance of anesthesia with 1% halothane in a 60:40 nitrous oxide-oxygen mixture. Cardiovascular parameters measured with noninvasive oscillometry and transthoracic impedance plethysmography remained unchanged after administration of ketamine. Excellent analgesia and a calm anesthetic recovery were produced, without detectable cardiovascular depression. When ketamine and halothane are administered in combination, careful restriction of dosages of these agents is recommended. Interaction of higher doses of ketamine and halothane has been reported to produce hypotension and bradycardia, which can be avoided with use of subdissociative, analgesic doses of ketamine during light halothane maintenance before emergence. After halothane anesthesia in healthy children, ketamine may be considered a suitable alternative to narcotics for postoperative analgesia.     

胸部手术后硬膜外自控与静脉自控镇痛的效果比较

目的比较经硬膜外和经静脉在胸部手术后病人自控镇痛(PCA)的有效性和安全性。方法将72例在全麻下行胸部手术的患者随机分为经硬膜外镇痛组(PCEA组,36例)和经静脉镇痛组(PC IA组,36例),病人均于手术结束前30m in接PCA泵。PCA泵背景量2m l/h,PCA量0.5m l,锁定时间15m in。自控镇痛期间记录各时间点的疼痛程度(PI)(使用口述描绘5级评分法)和患者的舒适满意度(采用BCS模拟评分法),并记录发生的不良反应。结果PC IA组患者舒适满意度低于PCEA组,PC IA组不良反应高于PCEA组(P<0.05),两组病人并发症、镇痛效果无明显差异。结论胸部手术尤其开胸手术后PCEA镇痛的有效性和安全性高于PC IA,术后镇痛应以PCEA方法为主。     

Pediatric patient-controlled analgesia with morphine versus meperidine.

To assess prospectively any difference in either analgesia or side effect frequency with morphine versus meperidine, 50 patients, ages 8-16 years, were randomly assigned to receive postoperative patient-controlled analgesia (PCA) with either morphine or meperidine. A numerical rating scale pain score was obtained from each patient twice a day, and any nausea, vomiting, pruritis, or urinary retention requiring catheterization was noted. No significant difference in the incidence of side effects was noted between the morphine and meperidine groups; however, pain scores during morphine PCA were significantly less than those during meperidine PCA (P less than 0.001). These results suggest that morphine is the better opioid for pediatric PCA.     

布托啡诺与吗啡用于患者自控硬膜外术后镇痛的比较

目的:比较布托啡诺与吗啡在硬膜外术后镇痛的效果及不良反应。方法:选取80例择期硬膜外麻醉下行下肢手术患者,分成2组,分别予布托啡诺复合布比卡因(B组)和吗啡复合布比卡因(M组)硬膜外术后镇痛,记录术后4、8、24h视觉模拟评分(VAS评分)、呕吐、尿潴留及瘙痒发生率以及满意率。结果:2组患者术后的镇痛效果均满意,VAS评分<3分。呕吐发生率B组为7.5%,M组为22.5%,B组发生率较M组低。尿潴留发生率B组为7.5%,M组为55.0%,B组要低于M组。满意率B组为90.0%,M组为72.5%,B组的满意率要高。结论:布托啡诺复合布比卡因较吗啡复合布比卡因更适合于作为硬膜外术后镇痛配方。