E. Congedo

New Drugs for Epidural Analgesia

In recent years there has been a wide use of the epidural technique not only during surgery to provide anesthesia and analgesia, but also for obstetric and trauma as well as acute, chronic and cancer pain states. Nowadays there is an increase in the number of the epidural drugs. Local anesthetics and opioids are still the pharmacological agents more widely used epidurally, nevertheless other drugs from different pharmacological classes are administered as adjuvant to local anesthetics and opioids or are in various early stages of investigation. Regarding to local anesthetics, the most recent literature focuses on the new enantiomers, ropivacaine and levobupivacaine, the efficacy of which is similar to that of bupivacaine with a reduced risk of cardiotoxicity. About opioids, the other class of drugs mainly used, the debate, in the last years, concerned the physicochemical properties of morphine and of the more recent lipophilic agents, fentanyl and sufentanil, in order to explain the main differences in efficacy and safety. Other categories of agents have been investigated for epidural administration, such as alpha(2)-adrenergic agonists clonidine and dexmedetomidine. They are being used increasingly as adjuvants to local anesthetics and opioids. Ketamine and neostigmine, the more recent studied drugs for epidural use, are still under investigation and are not part of routine clinical practice.

Ropivacaine vs. levobupivacaine combined with sufentanil for epidural analgesia after lung surgery

Background and objectives: There are no clinical studies that compare epidural infusion of ropivacaine and levobupivacaine in patients undergoing lung surgery. The aim of this prospective, randomized double‐blind study was to evaluate the efficacy and safety of two commercially available solutions of ropivacaine (0.2% w/v) and levobupivacaine (0.125% w/v) when administered by continuous epidural infusion together with sufentanil in patients undergoing lung surgery. Methods: After obtaining informed consent, 54 patients, ASA physical status I‐III undergoing lung resection, were enrolled. Patients were randomly assigned to two groups in which analgesia was performed by continuous thoracic epidural infusion of ropivacaine 0.2% w/v (Group R) or levobupivacaine 0.125% w/v (Group L) with or without sufentanil 1 &mgr;g mL−1. After a test and a loading dose of each drug for the respective group, continuous epidural infusion, set at 5 mL h−1, began. General anaesthesia was standardized. In the recovery room, patients were provided with intravenous morphine patient‐controlled analgesia. Visual analogue scale at rest and when coughing, rescue patient‐controlled analgesia morphine amount, haemodynamics, sensory and motor block, sedation, nausea and vomiting, patient satisfaction score, were evaluated within 48 h. Results: The two groups were similar regarding patient characteristics, quality of analgesia, level of sensory block, morphine consumption and satisfaction score. Postoperative haemodynamic profile was stable in all the patients. Minor side‐effects occurred with a similar incidence. Motor block was not seen. Conclusions: Equivalent volumes of ropivacaine (0.2% w/v) and levobupivacaine (0.125% w/v) provided similar static and dynamic analgesia with similar incidence of minor side‐effects after thoracotomy.

Dreams recall and auditory evoked potentials during propofol anaesthesia

It is unclear whether shorter wave latencies of middle-latency-auditory-evoked-potentials may be associated to cognitive function other than nondeclarative memory. We investigated the presence of declarative, nondeclarative and dreaming memory in propofol-anaesthetized patients and any relationship to intraoperatively registered middle-latency-auditory-evoked-potentials. An audiotape containing one of two stories was presented to patients during anaesthesia. Patients were interviewed on dream recall immediately upon emergence from anaesthesia. Declarative and nondeclarative memories for intraoperative listening were assessed 24 h after awakening without pointing out positive findings. Six patients who reported dream recall showed an intraoperative Pa latency less than that of patients who were unable to remember any dreams (P<0.001). A high responsiveness degree of primary cortex was associated to dream recall formation during anaesthesia.

Epidural infusion of levobupivacaine and sufentanil following thoracotomy

A prospective, randomised, double‐blind study was conducted to compare the efficacy of two doses of levobupivacaine combined with sufentanil for continuous epidural infusion following thoractomy. A total of 72 patients undergoing lobectomy or pneumonectomy were enrolled. An epidural catheter was inserted between the levels of T4 and T6 before induction of anaesthesia and a loading dose of levobupivacaine and sufentanil was administered. At the end of surgery an epidural infusion was commenced at 5 ml.h−1 and continued for 48 h. Patients were randomly allocated to receive either levobupivacaine 0.125% (group A) or 0.0625% (group B) and all patients also received sufentanil (1 μg.ml−1). Visual analogue pain scores after coughing (VASi) were always higher in group B (p < 0.05); VAS pain scores at rest were higher for the first 4 h and at 16 and 28 h in group B (p < 0.05). Total morphine consumption and requests number was lower in group A (p < 0.05). Better pain relief was achieved using epidural 0.125% levobupivacaine.

Effect of remifentanil and fentanyl on postoperative cognitive function and cytokines level in elderly patients undergoing major abdominal surgery.

PURPOSE Postoperative cognitive dysfunction is a frequent complication occurring in geriatric patients. Type of anesthesia and the patients inflammatory response may contribute to postoperative cognitive dysfunction (POCD). In this prospective randomized double-blinded controlled study we hypothesized that intraoperative remifentanil may reduce immediate and early POCD compared to fentanyl and evaluated if there is a correlation between cognitive status and postoperative inflammatory cytokines level. METHODS Six hundred twenty-two patients older than 60 years undergoing major abdominal surgery were randomly assigned to two groups and treated with different opioids during surgery: continuous infusion of remifentanil or fentanyl boluses. Twenty-five patients per group were randomly selected for the quantitative determination of serum interleukin (IL)-1β, IL-6, and IL-10 to return to the ward and to the seventh postoperative day. RESULTS Cognitive status and its correlation with cytokines levels were assessed. The groups were comparable regarding to POCD incidence; however, IL-6 levels were lower the seventh day after surgery for remifentanil group (P= .04). No correlation was found between POCD and cytokine levels. CONCLUSIONS The use of remifentanil does not reduce POCD.

Postoperative Analgesia in Thoracic Surgery: A Comparison between Continuous Paravertebral Nerve Block and Continuous Incisional Infusion with OnQ Pain Relief System

Objectives: Thoracotomy is one of the most painful surgical stimuli and inadequate management of postthoracotomy pain is often associated with pulmonary and cardiac complications. The aim of this prospective, randomized, double-blinded study was to compare continuous paravertebral block versus continuous incisional infusion with OnQ Pain Relief System. Methods: Forty eight patients, undergoing thoracotomy for elective lobectomy, were randomized to receive a continuous paravertebral infusion of bupivacaine 0.25% through an elastomeric pump which delivers 0.1 mL/Kg/h (group A) or a continuous incisional infusion of bupivacaine 0.25% at an infusion rate of 4 mL/h with OnQ Pain Relief System (group B). Both infusions were started before wound closure, and continued for 48 postoperative hours. General anaesthesia was standardized. In the recovery room, patients were provided with intravenous morphine patient-controlled analgesia (PCA). Visual analogue scale at rest (VASr) and when coughing (VASi), rescue patientcontrolled analgesia morphine consumption, hemodynamic, time to ambulation and side-effects were evaluated within 48 h. Results: The two groups were comparable regarding to patients’ number and characteristics, type of surgery, time to ambulation and side-effects; postoperative hemodynamic profile was stable in all the patients. Absolute pain scores were low in both groups; patients in group A reported significant lower VASr and VASi values during the postoperative 48 hours compared with group B (p<0.001). Total morphine consumption and PCA requests number were significantly lower in group A than in group B (p= 0.05 and p< 0.01). Conclusions: Continuous incisional infusion of local anesthetic is not as effective as paravertebral analgesia after thoracotomy.