L. Brian Ready

Postoperative epidural morphine is safe on surgical wards.

The use of epidural morphine for postoperative analgesia outside of intensive care units remains controversial. In this report our anesthesiology-based acute pain service documents experience with 1,106 consecutive postoperative patients treated with epidural morphine on regular surgical wards. This

Neurotoxicity of Intrathecal Local Anesthetics in Rabbits

The authors developed a new method of intrathecal local anesthetic injection in rabbits in order to study the relationship between anesthetic concentration and impaired neurologic function. They found that none of the local anesthetics studied produced persistent neurologic damage in concentrations used clinically. However, lidocaine and tetracaine can be prepared in high concentrations (far exceeding those clinically used) that will produce extensive irreversible neurologic injury and histologic changes. This was also true for sodium bisulfite, an antioxidant used in a number of commercially prepared local anesthetic solutions. Pure solutions of relatively insoluble local anesthetics (bupivacaine and 2-chloroprocaine) failed to produce comparable neurologic or neuropathologic changes when tested at concentrations up to their solubility limits. Extensive neurologic impairment was not necessarily accompanied by equally extensive lesions in the spinal cord and nerve roots.

Patient satisfaction with intravenous PCA or epidural morphine.

In many institutions postoperative patients may receive morphine for analgesia administered into the epidural space, epidural opioid analgesia (EOA), or through intravenous self-administered patient-controlled analgesia pumps (PCA). Although a number of studies have compared the two approaches with regard to efficacy and side effects, there is less known with regard to patient satisfaction and its sources. In this study, 711 patients using PCA morphine and 205 patients receiving epidural morphine following a variety of gynaecological, urological, orthopaedic, and general surgical procedures rated their satisfaction with the method they used on a 0–10 verbal analogue satisfaction scale (0 = very dissatisfied; 10 = very satisfied). A consecutive subset of 100 patients (50 from EOA group and 50 from the PCA group) underwent further evaluation to identify advantages and disadvantages of the technique used which contributed to their satisfaction and /or dissatisfaction. Overall satisfaction (mean ± SD) in the two large groups was 8.6 ± 1.8 for PCA and 9.0 ± 1.5 for EOA (P < 0.01). In the subset of 100 patients, there were differences between the EOA and PCA groups with regard to the advantages and disadvantages selected. Patients in the PCA group identified “personal control” and “method worked quickly” as advantages whereas patients receiving EOA selected “clear mind,” “effective relief resting,” and “effective relief while moving or coughing.” The single disadvantage identified more frequently by PCA patients was “pain immediately after surgery before method became effective.” Disadvantages identified more frequently by EOA patients were “side effects” and “poor pain relief.” We conclude that overall patient satisfaction was high whether patients received PCA or EOA. The reasons for satisfaction or dissatisfaction differ depending on the method used.RésuméDans de nombreuses institutions, les patients opérés reçoivent une analgésie à la morphine administrée soit dans l’espace épidural — analgésie épidurale par opiacés: (AEO) soit par une auto-administration intraveineuse — pompe d’analgésie contrôlée par le patient: (PCA). Bien que de nombreuses études aient comparé les deux approches et en ce qui concerne l’efficacité et les effets secondaires, on en sait moins sur la satisfaction des patients et leurs raisons. Dans cette étude, 711 patients sous PCA à la morphine et 205 patients sous épidurale à la morphine évaluent leur satisfaction par une échelle analogue verbale entre 0 et 10 (0 = très insatisfait, 10 = très satisfait). Ils ont subi une variété d’interventions gynécologiques, urologiques, orthopédiques ou générales. Un sous-groupe ultérieur de 100 patients (50 du groupe AEO et 50 du groupe PCA) est soumis à une évaluation secondaire pour identifier quels avantages et désavantages de la technique proposée contribuent ou non à leur satisfaction. La satisfaction globale (moyenne ± DS) dans les deux groupes de départ est de 8,6 ± 1,8 pour le PCA et 9,0 ± 1,5 pour l’AEO (P < 0,01). Dans le sous groupe de 100 patients, il y a eu des différences entre les groupes AEO et PCA en ce qui concerne les avantages et les désavantages proposés. Les patients dans le groupe PCA ont identifié comme avantage le « contrôle personnel » et la « rapidité de la méthode » tandis que les patients du groupe AEO ont souligné la « clarté d’esprit », le « soulagement de repos » et le « soulagement pendant la toux et le mouvement ». L’unique désavantage identifié plus fréquemment par les patients PCA est la présence de « la douleur post-opératoire immédiate avant l’efficacité du PCA »; les désavantages identifiés plus fréquemment par les patients AEO sont les « effets secondaires » et le « faible soulagement ». Nous concluons que la satisfaction globale est élevée, que le patient soit sous PCA ou AEO. Les raisons de satisfaction ou non différent en fonction de la méthode utilisée.

Spinal needle determinants of rate of transdural fluid leak.

Using a new in vitro model and samples of human dura, a number of factors related to spinal needle design and use were examined with respect to their effects on the rate of transdural fluid leak. These included needle size, bevel design, bevel orientation, and angle of approach. Using 25-gauge Quincke needles, a 30 degree approach caused a rate of leak across the dura significantly less than those following 60 degree and 90 degree approaches. A significant increase in leak rate was found with 22-gauge Quincke needles when the bevels were oriented so as to be perpendicular rather than parallel to the long axis of the dura. Also, 22-gauge Whitacre needles caused significantly less leak than did 22-gauge Quincke needles, and 25-gauge Quincke needles produced significantly less leak than 22-gauge Quincke needles. If human dura behaves in vivo as it does in this in vitro model, it would be advantageous to perform lumbar puncture using oblique approaches and small needles with conical tips.

Drug utilization patterns in chronic pain patients

Abstract In the population of chronic pain patients seen at multidisciplinary pain clinics, excessive and/or inappropriate medication use is a frequent problem. This study examined differences between chronic pain patients who used no addicting medication (30% of the sample of 131 patients), those who used narcotic but not sedative medications (33%) and those who used both narcotic and sedative medications (37%). Patients in the narcotic and narcotic‐sedative groups had undergone significantly more pain‐related hospitalizations and surgeries than those in the no addicting drugs group. Narcotic‐sedative patients spent significantly more money on pain medication per month, reported significantly greater physical impairment, and had higher MMPI hypochondriasis and hysteria scores when compared to the other patients. The findings are interpreted in light of the hypothesis that certain patients show greater readiness to complain of and seek help for physical symptoms.

Epidural morphine after anterior cruciate ligament repair: a comparison with patient-controlled intravenous morphine.

To compare the management of postoperative pain using morphine administered by epidural catheter with intravenous patient-controlled analgesia (PCA), we prospectively studied 47 consecutive cases involving repair of the anterior cruciate ligament of the knee. Both the quality of analgesia and the incidence of side effects were documented. Compared with patients receiving PCA morphine, patients given epidural morphine reported significantly lower pain scores both at rest (0.7 ± 1.1 versus 3.4 ± 2.1, P < 0.01) and with mobilization (3.2 ± 2.1 versus 6.1 ± 2.1, P < 0.01). Although patients receiving epidural morphine had a greater incidence of urinary retention, there were no significant differences in the incidence of nausea or pruritis. There was no respiratory depression in either group. We conclude that epidural morphine provides superior analgesia with a clinically inconsequential increase in side effects. Further, epidural morphine may have special advantages when early mobilization is indicated.

Intravenous high-dose methadone administered by patient controlled analgesia and continuous infusion for the treatment of cancer pain refractory to high-dose morphine

The management of severe tumor-related pain in the patient with cancer may be problematic. Systemically administered opioids remain the cornerstone of treatment for moderate to severe cancer pain, while parenteral routes should be considered for patients who require rapid onset of analgesia, and for highly tolerant patients whose dose requirements cannot be conveniently administered. The use of intravenous methadone by patient controlled analgesia (PCA) is attractive for the management of severe, intractable cancer pain and may offer some advantages over morphine. We describe the safe and effective use of high-dose intravenous methadone by PCA and continuous infusion for a patient with intractable tumor-associated cancer pain who experienced inadequate pain control and dose-limiting side-effects with high-dose intravenous morphine.

Epidural block for treatment of renal colic during pregnancy

This report documents for the first time the application of continuous segmental epidural block (Tl1 to L2) to treat renal colic complicating pregnancy. The block was maintained for 16 hours and the pain did not recurr. Advantages for the mother, and possibly for the foetus, are considered. The published experience of others using this technique in nonpregnant patients is reviewed.RésuméCette observation décrit pour la première fois I’application d’un bloquage épidural continu segmentaire (Tl1 à Ll) au traitement de la colique renale pendant la grossesse. On a maintenu le bloquage pendant 16 heures sans réapparition de la douleur. Les avantages pour la mére et possiblement pour le foetus sont discutés. Les auteurs font un tout d’horizon des publications concernant l’utilisation de cette technique chez des patientes chez qui la grossesse n’est pas un problème.

PCA is effective for older patients--but are there limits?

PATIENT-CONTROLLED analgesia (PCA) has proven to be an important concept and therapeutic tool in the quest to improve acute pain management. The pharmacologic and nonpharmacologic benefits of PCA have been studied extensively and discussed widely. Despite these benefits, some acute pain therapists are reluctant to offer PCA to older patients, having seen that some members of this group are unwilling or unable to use PCA effectively. Explanations for this failure of therapy have included lack of understanding of the technique by older patients, different attitudes among older patients with regard to pain relief, and patient roles and fears of complications associated with analgesics or PCA equipment. The possibility of differences in pain perception or pain reporting with advancing age has also been considered. In this issue of ANESTHESIOLOGY, Gagliese et al. have provided further insight into the influence of patient age on PCA therapy. The authors have systematically compared postoperative PCA use in two adult populations with mean ages of 39 and 67 yr. In addition to the anticipated findings related to opioid consumption and pain scores, this work includes evaluation of the effects of age on preoperative psychologic factors, concerns regarding PCA therapy, and treatment satisfaction. Gagliese et al. observed that, on the first postoperative day, PCA morphine consumption averaged 66.6 mg in the younger group, compared with 39.1 mg in the older group (see table 5). These values are remarkably similar to the morphine requirements predicted by Macintyre and Jarvis in 1996. Those authors recommended the following formula for estimating average morphine requirements based on patient age:

Trigger point injections vs. jet injection in the treatment of myofascial pain

Trigger point injections using dilute solutions of local anesthetic agents have proved effective for many patients with myofascial pain. The treatment itself, however, can produce severe pain and may occasionally be associated with complications. It was determined in this study that a local anesthetic solution administered by jet injection in the area of myofascial trigger points was capable of providing short-term pain relief equal to conventional trigger point injections using a hypodermic needle and syringe. The jet injector system produced significantly less pain during treatment than conventional trigger point injections and therefore was preferred by most subjects having the opportunity to compare both forms of treatment.