G. Fanelli

Nerve stimulator and multiple injection technique for upper and lower limb blockade : Failure rate, patient acceptance, and neurologic complications

UNLABELLEDnTo evaluate the failure rate, patient acceptance, effective volumes of local anesthetic solution, and incidence of neurologic complications after peripheral nerve block performed using the multiple injection technique with a nerve stimulator, we prospectively studied 3996 patients undergoing combined sciatic-femoral nerve block (n = 2175), axillary blocks (n = 1650), and interscalene blocks (n = 171). The success rate and mean injected volumes of local anesthetic were: 93% with 22.6 +/- 4.5 mL in the axillary, 94% with 24.5 +/- 5.4 mL in the interscalene, and 93% with 28.1 +/- 4.4 mL in the sciatic-femoral nerve blocks. Patients receiving combined sciatic-femoral nerve block showed more discomfort during block placement and worse acceptance of the anesthetic procedure than patients receiving brachial plexus anesthesia. During the first month after surgery, 69 patients (1.7%) developed neurologic dysfunction on the operated limb. Complete recovery required 4-12 wk in all patients but one, who required 25 wk. The only variable showing significant association with the development of postoperative neurologic dysfunction was the tourniquet inflation pressure (<400 mm Hg compared with >400 mm Hg, odds ratio 2.9, 95% confidence intervals 1.6-5.4; P < 0.001). We conclude that using the multiple injections technique with a nerve stimulator results in a success rate of >90% with a volume of <30 mL of local anesthetic solution and an incidence of transient neurologic complication of <2%.nnnIMPLICATIONSnBased on a prospective evaluation of 3996 consecutive peripheral nerve blocks, the multiple injection technique with nerve stimulator allows for up to 94% successful nerve block with <30 mL of local anesthetic solution. Although the data collection regarding neurologic dysfunction was limited, the withdrawal and redirection of the stimulating needle was not associated with an increased incidence of neurologic complications. Sedation/analgesia should be advocated during block placement to improve patient acceptance.

A new posterior approach to the sciatic nerve block : A prospective, randomized comparison with the classic posterior approach

To evaluate the efficacy and acceptance of a new posterior subgluteus approach to the sciatic nerve, as compared with the classic posterior approach, 128 patients undergoing foot orthopedic procedures were randomly allocated to receive either the classic posterior sciatic nerve block (Group Labat, n = 64) or a modified subgluteus posterior approach (Group subgluteus, n = 64). All blocks were performed with the use of a nerve stimulator (stimulation frequency, 2 Hz; intensity, 1–0.5 mA). In Group subgluteus, a line was drawn from the greater trochanter to the ischial tuberosity; then, from the midpoint of this line, a second line was drawn perpendicularly and extended caudally for 4 cm. The end of this line represented the needle entry. In both groups, a proper sciatic stimulation was elicited at 0.5 mA; then 20 mL of 0.75% ropivacaine was injected. The time from needle insertion to successful sciatic nerve stimulation was 60 s (range, 10–180 s) with the Labat’s approach and 32 s (range, 5–120 s) with the new subgluteus approach (P = 0.0005). The depth of appropriate sciatic stimulation was 45 ± 13 mm (mean ± sd) after 2 (range, 1–7) needle redirections in Group subgluteus and 67 ± 12 mm after 4 (range, 1–10) needle redirections in Group Labat (P = 0.0001 and P = 0.00001, respectively). The failure rate was similar in both groups. Severe discomfort during the procedure was less frequent and acceptance better in Group subgluteus (5 patients [8%] and 60 patients [94%], respectively) than in Group Labat (20 patients [31%] and 49 patients [77%], respectively) (P = 0.0005 and P = 0.005, respectively). We conclude that this new subgluteus posterior approach to the sciatic nerve is an easy and reliable technique and can be considered an effective alternative to the more traditional Labat’s approach.

A double-blinded, randomized comparison of either 0.5% levobupivacaine or 0.5% ropivacaine for sciatic nerve block

To compare intraoperative and postoperative clinical properties of levobupivacaine and ropivacaine for sciatic nerve block, 50 ASA physical status I and II patients undergoing hallux valgus repair received a femoral nerve block with 15 mL of 2% mepivacaine. They were then randomly allocated in a double-blinded fashion to receive a sciatic nerve block with either 0.5% levobupivacaine (n = 25) or 0.5% ropivacaine (n = 25). An independent blinded observer evaluated the onset time of surgical anesthesia as well as the quality of the surgical block and postoperative analgesia. The median (range) onset time of surgical block at the sciatic nerve distribution was 30 min (5–60 min) with levobupivacaine and 15 min (5–60 min) with ropivacaine (P = 0.63). Four patients (two patients in each group) received a supplementary ankle block by the surgeon just before the beginning of surgery. All four patients also received IV fentanyl supplementation, but in three of them, propofol infusion was required to complete surgery (two in the Levobupivacaine group [8%] and one in the Ropivacaine group [4%];P = 0.99). In six patients of the Levobupivacaine group (24%) and five patients of the Ropivacaine group (20%), IV fentanyl supplementation was required to complete surgery (P = 0.99). No differences in the time to recovery of sensory and motor function were observed between the two groups, whereas median (range) duration of postoperative analgesia was 16 h (8–24 h) with levobupivacaine and 16 h (8–24 h) with ropivacaine (P = 0.83). We conclude that 0.5% levobupivacaine and 0.5% ropivacaine provide comparable surgical anesthesia and postoperative analgesia.

Temperature control and recovery of bowel function after laparoscopic or laparotomic colorectal surgery in patients receiving combined epidural/general anesthesia and postoperative epidural analgesia

UNLABELLEDnWe compared the effects of a laparoscopic (n = 23) versus laparotomic (n = 21) technique for major abdominal surgery on temperature control in 44 patients undergoing colorectal surgery during a combined epidural/general anesthesia. A thoracic epidural block up to T4 was induced with 6-10 mL of 0.75% ropivacaine; general anesthesia was induced with thiopental, fentanyl, and atracurium IV and maintained with isoflurane. Core temperature was measured with a bladder probe and recorded every 15 min after the induction. In both groups, core temperature decreased to 35.2 degrees C (range, 34 degrees C-36 degrees C) at the end of surgery. After surgery, normothermia returned after 75 min (60-120 min) in the Laparoscopy group and 60 min (45-180 min) in the Laparotomy group (P = 0.56). No differences in postanesthesia care unit discharge time were reported between the two groups. The degree of pain during coughing was smaller after laparoscopy than laparotomy from the 24th to the 72nd observation times (P < 0.01). Morphine consumption was 22 mg (2-65 mg) in the Laparotomy group and 5 mg (0-45 mg) in the Laparoscopy group (P = 0.02). The time to first flatus was shorter after laparoscopy (24 h [16-72 h]) than laparotomy (72 h [26-96 h]) (P = 0.0005), and the first intake of clear liquid occurred after 48 h (24-72 h) in the Laparoscopy group and after 96 h (90-96 h) in the Laparotomy group (P = 0.0005). Although laparoscopic surgery provides positive effects on the degree of postoperative pain and recovery of bowel function, the reduction in heat loss produced by minimizing bowel exposure with laparoscopic surgery does not compensate for the anesthesia-related effects on temperature control, and active patient warming must also be used with laparoscopic techniques.nnnIMPLICATIONSnThis prospective, randomized, controlled study demonstrates that laparoscopic colorectal surgery results in less postoperative pain and earlier recovery of bowel function than conventional laparotomy but does not reduce the risk for perioperative hypothermia. Accordingly, active warming must be provided to patients also during laparoscopic procedures.

Randomized comparison of remifentanil-propofol with a sciatic-femoral nerve block for out-patient knee arthroscopy.

BACKGROUND AND OBJECTIVEnTo evaluate preparation and discharge times as well as the anaesthesia-related costs of out-patient knee arthroscopy performed with a combined sciatic-femoral nerve block, or a propofol-remifentanil general anaesthetic.nnnMETHODSnWith Ethics Committee approval and written informed consent, 40 healthy patients were pre-medicated with intravenous midazolam (0.05 mg kg(-1)) and ketoprofen (50 mg). They were then randomly allocated to receive either a combined sciatic-femoral nerve block with 25 mL mepivacaine 2% (15 mL for the femoral nerve, 10 mL for the sciatic nerve) (PNB group, n = 20), or a general anaesthetic with a continuous intravenous infusion of remifentanil (0.1-0.3 microgkg(-1) min(-1)) and propofol (target plasma concentration 2-4 microg mL(-1)) with a laryngeal mask airway (GA group, n = 20).nnnRESULTSnThe median (range) preparation time was 16 (10-28)min in the PNB group and 13 (8-22)min in the GA group (P = 0.015). Ten PNB patients were directly discharged to the day-surgery unit after the procedure as compared with one GA patient (P = 0.003). Discharge from the postanaesthesia care unit (PACU) required 5 (5-20) min in the PNB group and 23 (7-95) min in the GA group (P = 0.001). Home discharge criteria were fulfilled after 277 (150-485) min in the PNB group and 170 (100-400) min in the GA group (P = 0.005). Costs related to the time spent in the PACU were lower for the PNB group (1.10 euro, range Euro 0-22 euro) compared with the GA group (30 euro, range 0-176 euro) (P = 0.0005). There were no differences in total costs: PNB group 158 euro (range 105-194 euro) versus GA group 160 euro (range 101-238 euro) (P = 0.61).nnnCONCLUSIONSnIn patients undergoing out-patient knee arthroscopy, the length of stay in the PACU can be shorter after a sciatic-femoral nerve block with a small volume of mepivacaine 2% compared with a propofol-remifentanil anaesthetic, and there is an increased likelihood that they will bypass the first phase of the postoperative recovery.

Fibrinolysis or hypercoagulation during radical prostatectomy? An evaluation of thrombelastographic parameters and standard laboratory tests

Background and objectives Radical prostatectomy is at high risk for intraoperative and postoperative bleeding due to surgical trauma, release of urokinase and tissue type plasminogen activator. We conducted this prospective, observational multi‐centre study to assess the degree of systemic fibrinolysis or hypercoagulation in the perioperative period. We studied serial changes in standard laboratory values and in thrombelastographic (TEG®; Haemoscope Corporation, Skokie, IL, USA) parameters including lysis at 30 and 60 min (LY‐30, LY‐60), alpha‐angle (&agr;) and maximum amplitude. Methods In all, 49 patients undergoing radical retropubic prostatectomy in five Italian University Hospitals were included. Blood samples were taken before surgery (T1), at the removal of the prostate (T2), 4 h after surgery (T3) and then 1 day after surgery (T4). Native blood samples were analysed using a thrombelastograph Haemoscope 5000 (Haemoscope Corporation). Results We did not see any relevant activation of fibrinolysis during any stage. Intraoperatively, we showed even more activated blood coagulation with consumption of fibrinogen and a reduced TEG® percentage clot lysis. Only at the first postoperative sample point we saw a trend towards a more fibrinolytic state indicated by increasing partial thromboplastin time, LY‐30 and LY‐60 values, and a peak of the fibrin degradation product D‐dimers. This is consistent with a normal reaction to the hypercoagulable state before and is unlikely to be due to an intraoperative tissue type plasminogen activator release. We found no evidence of an uncontrolled activation of fibrinolysis on the day after surgery. On the contrary, &agr;‐values which indicate the rate of clot formation and which increase during hypercoagulation showed the tendency to rise slightly compared with the preoperative value. Conclusion Neither standard coagulation parameters nor TEG® values showed any significant activation of fibrinolysis or of hypercoagulation in the preoperative period. Nevertheless, hypercoagulation seems to have a substantial clinical impact as it has been shown that cardiovascular complications and pulmonary embolism were the most common causes of death after retropubic prostatectomy.

Improving postoperative analgesia after axillary brachial plexus anaesthesia with 0.75% ropivacaine:a double-blind evaluation of adding clonidine

BACKGROUNDnThe aim of this prospective, randomized, double-blind study was to evaluate the effects of adding 1 microg/kg clonidine to 20 ml of ropivacaine 0.75% for axillary brachial plexus anesthesia.nnnMETHODSnWith Ethical Committee approval and written consent, 30 ASA physical status I-II in-patients, undergoing upper extremity orthopedic procedures were randomly allocated to receive axillary brachial plexus block with 20 ml of 0.75% ropivacaine alone (group ropivacaine, n = 15) or 0.75% ropivacaine + 1 microg/kg clonidine (group ropivacaine-clonidine, n = 15). Nerve blocks were placed using a nerve stimulator with the multiple injection technique (stimulation frequency was 2 Hz; stimulation intensity was decreased to < or = 0.5 mA after each muscular twitch; the anesthetic volume was equally divided among arm flexion, arm extension, wrist flexion, and thumb adduction). A blinded observer recorded the time required to achieve surgical block [loss of pinprick sensation in the innervation areas of the hand (C6-C8) with concomitant inability to move the wrist and hand] and first analgesic request.nnnRESULTSnNo differences in demography, degree of sedation, peripheral oxygen saturation, and hemodynamic variables were observed between the two groups. Readiness for surgery required 15 min (5-36 min) with 0.75% ropivacaine and 20 min (5-30 min) with the ropivacaine-clonidine mixture. The degree of pain measured at first analgesic request, and consumption of postoperative analgesics were similar in the two groups; while first postoperative analgesic request occurred after 13.8 h (25th-75th percentiles: 9.1-13 h) in the ropivacaine group and 15.2 h (25th-75th percentiles: 10.7-16 h) in the ropivacaine-clonidine group (p = 0.04).nnnCONCLUSIONSnAdding 1 microg/kg clonidine to 20 ml of ropivacaine 0.75% for axillary brachial plexus anesthesia provided a 3 h delay in first analgesic request postoperatively, without clinically relevant effects on the degree of sedation and cardiovascular homeostasis.