Giorgio Danelli

A prospective, randomized comparison between ultrasound and nerve stimulation guidance for multiple injection axillary brachial plexus block.

Background:This prospective, randomized, blinded study tested the hypothesis that ultrasound guidance can shorten the onset time of axillary brachial plexus block as compared with nerve stimulation guidance when using a multiple injection technique. Methods:Sixty American Society of Anesthesiology physical status I–III patients receiving axillary brachial plexus block with 20 ml ropivacaine, 0.75%, using a multiple injection technique, were randomly allocated to receive either nerve stimulation (group NS, n = 30), or ultrasound guidance (group US, n = 30) for nerve location. A blinded observer recorded the onset of sensory and motor blocks, the need for general anesthesia (failed block) or greater than 100 &mgr;g fentanyl (insufficient block) to complete surgery, procedure-related pain, success rate, and patient satisfaction. Results:The median (range) number of needle passes was 4 (3–8) in group US and 8 (5–13) in group NS (P = 0.002). The onset of sensory block was shorter in group US (14 ± 6 min) than in group NS (18 ± 6 min) (P = 0.01), whereas no differences were observed in onset of motor block (24 ± 8 min in group US and 25 ± 8 min in group NS; P = 0.33) and readiness to surgery (26 ± 8 min in group US and 28 ± 9 min in group NS; P = 0.48). No failed block was reported in either group. Insufficient block was observed in 1 patient (3%) of group US and 2 patients (6%) of group NS (P = 0.61). Procedure-related pain was reported in 6 patients (20%) of group US and 14 patients (48%) of group NS (P = 0.028); patient acceptance was similarly good in the two groups. Conclusion:Multiple injection axillary block with ultrasound guidance provided similar success rates and comparable incidence of complication as compared with nerve stimulation guidance.

Continuous monitoring of cerebral oxygen saturation in elderly patients undergoing major abdominal surgery minimizes brain exposure to potential hypoxia.

Elderly patients are more prone than younger patients to develop cerebral desaturation because of the reduced physiologic reserve that accompanies aging. To evaluate whether monitoring cerebral oxygen saturation (rSO2) minimizes intraoperative cerebral desaturation, we prospectively monitored rSO2 in 122 elderly patients undergoing major abdominal surgery with general anesthesia. Patients were randomly allocated to an intervention group (the monitor was visible and rSO2 was maintained at ≥75% of preinduction values; n = 56) or a control group (the monitor was blinded and anesthesia was managed routinely; n = 66). Cerebral desaturation (rSO2 reduction <75% of baseline) was observed in 11 patients of the treatment group (20%) and 15 patients of the control group (23%) (P = 0.82). Mean (95% confidence intervals) values of mean rSO2 were higher (66% [64%–68%]) and the area under the curve below 75% of baseline (AUCrSO22< 75% of baseline) was lower (0.4 min% [0.1–0.8 min%]) in patients of the treatment group than in patients of the control group (61% [59%–63%] and 80 min% [2–144 min%], respectively; P = 0.002 and P = 0.017). When considering only patients developing intraoperative cerebral desaturation, a lower Mini Mental State Elimination (MMSE) score was observed at the seventh postoperative day in the control group (26 [25–30]) than in the treatment group (28 [26–30]) (P = 0.02), with a significant correlation between the AUCrSO2 < 75% of baseline and postoperative decrease in MMSE score from preoperative values (r2= 0.25, P = 0.01). Patients of the control group with intraoperative cerebral desaturation also experienced a longer time to postanesthesia care unit (PACU) discharge (47 min [13–56 min]) and longer hospital stay (24 days [7–53] days) compared with patients of the treatment group (25 min [15–35 min] and 10 days [7–23 days], respectively; P = 0.01 and P = 0.007). Using rSO2 monitoring to manage anesthesia in elderly patients undergoing major abdominal surgery reduces the potential exposure of the brain to hypoxia; this might be associated with decreased effects on cognitive function and shorter PACU and hospital stay.

Spinal anesthesia with lidocaine or preservative-free 2-chlorprocaine for outpatient knee arthroscopy : A prospective, randomized, double-blind comparison

BACKGROUND:In this prospective, randomized, double-blind study we tested the hypothesis that 50 mg of 1% preservative-free 2-chloroprocaine would provide a faster resolution of spinal block than the same dose of 1% plain lidocaine. METHODS:After IV midazolam premedication (0.03 mg/kg), 30 ASA physical status I–II outpatients undergoing knee arthroscopy were randomly allocated to receive 50 mg of either 1% plain lidocaine (n = 15) or 1% preservative-free plain chloroprocaine (n = 15). A blinded observer recorded the evolution of sensory (loss of pinprick sensation) and motor (modified Bromage scale) block until complete regression, as well as times to unassisted ambulation and voiding. A telephone call follow-up was performed 24 h and 7 days after surgery. RESULTS:Two chloroprocaine patients (13%) and one lidocaine patient (7%) required fentanyl supplementation (100 &mgr;g IV) (P = 0.99) intraoperatively, but no patient required general anesthesia to complete surgery. Median (range) times for recovery of sensory and motor function, and unassisted ambulation were faster with 2-chloroprocaine [95 (68–170) min; 60 (45–120) min; and 103 (70–191) min] than lidocaine [120 (80–175) min; 100 (60–140) min; and 152 (100–185) min] (P = 0.019, P = 0.0005, and P = 0.003, respectively). No differences in first voiding were reported between chloroprocaine [180 (100–354) min] and lidocaine patients [190 (148–340) min] (P = 0.191). Transient neurological symptoms were reported in five lidocaine patients (33%) but no chloroprocaine patients (0%) (P = 0.042). CONCLUSION:Intrathecal injection of 50 mg of preservative-free 2-chloroprocaine 1% resulted in quicker recovery of sensory/motor function, and unassisted ambulation, and fewer incidences of transient neurologic symptoms than the same dose of 1% lidocaine.

The effects of ultrasound guidance and neurostimulation on the minimum effective anesthetic volume of mepivacaine 1.5% required to block the sciatic nerve using the subgluteal approach.

BACKGROUND: We tested the hypothesis that ultrasound (US) guidance may reduce the minimum effective anesthetic volume (MEAV50) of 1.5% mepivacaine required to block the sciatic nerve with a subgluteal approach compared with neurostimulation (NS). METHODS: After premedication and single-injection femoral nerve block, 60 patients undergoing knee arthroscopy were randomly allocated to receive a sciatic nerve block with either NS (n = 30) or US (n = 30). In the US group, the sciatic nerve was localized between the ischial tuberosity and the greater trochanter. In the NS group, the appropriate muscular response (foot plantar flexion or inversion) was elicited (1.5 mA, 2 Hz, 0.1 ms) and maintained to ≤0.5 mA. The volume of the injected local anesthetic was varied for consecutive patients based on an up-and-down method, according to the response of the previous patient. The initial volume was 12 mL. An independent observer evaluated the occurrence of complete loss of pinprick sensation and motor block: positive or negative responses within 20 min after the injection determined a 2-mL decrease or increase for the next patient, respectively. RESULTS: The mean MEAV50 for sciatic nerve block was 12 mL (95% confidence interval [CI], 10–23 mL) in Group US and 19 mL (95% CI, 15–23 mL) in Group NS (P < 0.001). The effective dose in 95% of cases was 14 mL (95% CI, 12–17 mL) in Group US and 29 mL (95% CI, 25–40 mL) in Group NS (P = 0.008). CONCLUSIONS: US provided a 37% reduction in the MEAV50 of 1.5% mepivacaine required to block the sciatic nerve compared with NS.

The Efficacy of a Resistive Heating Under-Patient Blanket Versus a Forced-Air Warming System: A Randomized Controlled Trial

BACKGROUND: We compared temperature changes in patients undergoing hip replacement during warming with a resistive heating blanket or air-forced system. METHODS: Fifty-six patients were enrolled. Patients were randomly allocated to the “forced-air group” (forced-air system) or to the “heating-blanket group” (resistive heating under-patient blanket). RESULTS: Baseline tympanic temperatures were 36.0 ± 0.6°C in the forced-air group and 36.1 ± 0.4°C in the heating-blanket group (P > 0.05). At the end of surgery tympanic temperatures were 35.3 ± 0.5°C in the forced-air group and 35.1 ± 0.6°C in the heating-pad group (P > 0.05). CONCLUSIONS: We demonstrated that, using either a resistive heating-blanket or forced-air warming systems, patients ended surgery in mild hypothermia after elective total hip replacement, but without significant differences between these two warming devices.

Intrathecal 2-chloroprocaine for lower limb outpatient surgery: a prospective, randomized, double-blind, clinical evaluation.

We evaluated the dose-response relationship of 2-chloroprocaine for lower limb outpatient procedure in 45 ASA physical status I-II outpatients undergoing elective lower limb surgery under spinal anesthesia, with 30 mg (group Chlor-30, n = 15), 40 mg (group Chlor-40, n = 15), or 50 mg (group Chlor-50, n = 15) of 1% preservative free 2-chloroprocaine. Onset time was similar in the three groups. General anesthesia was never required to complete surgery. Intraoperative analgesic supplementation as a result of insufficient duration of spinal block was required in 5 patients of group Chlor-30 (35%) and 2 patients of group Chlor-40 (13%) (P = 0.014), with a median (range) time for supplementation request of 40 (30–60) min. Spinal block resolution and recovery of ambulation were faster in group Chlor-30 (60 [41–98] min and 85 [45–123] min) than in groups Chlor-40 (85 [46–141] min and 180 [72–281] min) and Chlor-50 (97 [60–169] min and 185 [90–355] min) (P = 0.001 and P = 0.003, respectively), with no differences in home discharge time (182 [120–267] min in group Chlor-30, 198 [123–271] min in group Chlor-40, and 203 [102–394] min in group Chlor-50; P = 0.155). No transient neurologic symptoms were reported at 24-h and 7-day follow-up. We conclude that although 40 and 50 mg of 2-chloroprocaine provide adequate spinal anesthesia for outpatient procedures lasting 45–60 min, 30 mg produces a spinal block of insufficient duration.

A comparison of remifentanil and Sufentanil as adjuvants during sevoflurane anesthesia with epidural analgesia for upper abdominal surgery : Effects on postoperative recovery and respiratory function

UNLABELLED We compared the recovery profile and postoperative SpO(2) after the administration of general anesthesia with either sevoflurane-remifentanil or sevoflurane-sufentanil in 30 healthy patients undergoing upper abdominal surgery. They were randomly allocated to receive general anesthesia with sevoflurane and small doses of either remifentanil (n = 15) or sufentanil (n = 15), followed by postoperative epidural analgesia. The median sevoflurane minimum alveolar anesthetic concentration-hour was 2.3 (1.2-6.3) in group Remifentanil and 2.6 (1.4-5.2) in group Sufentanil (P: = 0.39), while the median consumption of remifentanil was 1.3 mg (0.7-3.4 mg) and sufentanil 0.09 mg (0.05-0.6 mg). Tracheal extubation required 10 min (6-18 min) with remifentanil and 14 min (8-24 min) with sufentanil (P: = 0.05); however, no differences in time to discharge from the recovery area were reported (24 min [12-75 min] with remifentanil and 30 min [12-135 min] with sufentanil; P: = 0. 35). From the first to seventh hour after surgery, SpO(2) was decreased more in the sufentanil than in the remifentanil group (P: = 0.001), and seven patients in the sufentanil group showed at least one episode with SpO(2) < or = 90% for more than 1 min (P: = 0.006) (median: 1 episode; range: 0-17 episodes; P: = 0.003). When added to sevoflurane, remifentanil is as effective as sufentanil during the intraoperative period, but provides shorter time to tracheal extubation and fewer effects on postoperative SpO(2) in the first 7 h after surgery. IMPLICATIONS In this double-blinded study, we evaluated the effects of adding small infusions of either remifentanil or sufentanil to sevoflurane in combination with postoperative epidural analgesia for upper abdominal surgery. We demonstrated that remifentanil is as effective as sufentanil during the intraoperative period, but that it provides shorter time to extubation and fewer effects on postoperative SpO(2) in the first 7 h after surgery.

0.2% ropivacaine with or without Fentanyl for Patient-Controlled Epidural Analgesia after Major abdominal Surgery: a Double-Blind Study

STUDY OBJECTIVE To evaluate the effects of adding low concentration of fentanyl to 0.2% ropivacaine when providing patient-controlled epidural analgesia (PCEA) outside the Post-Anesthesia Care Unit. DESIGN Prospective, randomized, double-blind study. SETTING Inpatients at a University Department of Anesthesia. PATIENTS 32 ASA physical status I, II, and III patients, who were scheduled for elective major abdominal surgery, including bowel resection, hepatic resection, and pancreaticoduodenectomy. INTERVENTIONS Patients received standard general/epidural anesthesia. After surgery patients were randomly allocated in a double-blind fashion to receive PCEA with either 0.2% ropivacaine (n = 16) or 0.2% ropivacaine/2 microg/mL fentanyl (n = 16) [background infusion ranging between 4 and 6 mL/hr, with 1.5-mL incremental doses and a 20-min lock-out time]. Dynamic pain during coughing, sedation, pulse oxymetry, hemodynamic variables, and motor block were evaluated at 1, 6, 12, 24, and 48 hours after the end of surgery by a blinded observer. Occurrence of untoward events, including nausea, vomiting, pruritus, need for supplemental oxygen (for SpO(2) < 90%), and respiratory complications, as well as total consumption of PCEA solution and incremental doses given to the patient were also recorded. MEASUREMENTS AND MAIN RESULTS No differences in pain relief, motor block, degree of sedation, recovery of gastrointestinal motility, and other side effects were observed between the two groups. Patients receiving 0.2% ropivacaine alone requested far more incremental doses (23 doses [0-60] vs. 5 doses [0-25]) (p = 0.006) and needed far more analgesic solution (230 mL [140-282] vs. 204 [130-228]) (p = 0.003) than patients receiving the ropivacaine/fentanyl mixture. Peripheral oxygen saturation was lower at 12, 24, and 48 hours during ropivacaine/fentanyl infusion than in patients receiving ropivacaine alone (12 h: 91% +/- 2% vs. 95% +/- 2%, p < 0.006; 24 h: 93% +/- 1% vs. 96% +/- 2%, p = 0.003; 48 h: 92% +/- 1.8% vs. 96% +/- 1%, p = 0.004). CONCLUSIONS A thoracic epidural infusion of 0.2% ropivacaine, with or without fentanyl, provided effective pain relief in most patients with a very low degree of motor blockade. Adding 2 microg/ml fentanyl to 0.2% ropivacaine reduced total consumption of local anesthetic solution and need for incremental doses, but did not provide clinically relevant advantages in quality of pain relief and incidence of motor block, leading to a significant decrease in peripheral SpO(2), lasting up to 48 hours after surgery.

Spinal block or total intravenous anaesthesia with propofol and remifentanil for gynaecological outpatient procedures

BACKGROUND AND OBJECTIVE The aim of this prospective, randomized study was to compare the preparation and discharge times, the side-effects and patient satisfaction after gynaecological outpatient procedures performed using either spinal block or total intravenous anaesthesia with propofol and remifentanil. METHODS With Ethics Committee approval and written informed consent, 40 healthy females scheduled for hysteroscopic ablation of endometrial neoplasm were randomly allocated to receive either a spinal block with bupivacaine 0.5% hyperbaric solution 10 mg (n = 20) or total intravenous anaesthesia with propofol and remifentanil (n = 20). Preparation and discharge times, as well as occurrence of untoward events and anaesthesia-related costs, were recorded. RESULTS The median (range) preparation time was 7 (7-10) min with general anaesthesia, and 11 (7-21) min with spinal block (P = 0.00005). No differences in discharge time from the postanaesthesia care unit and incidence of hypotension or bradycardia, or both, were reported between the two groups. Hospital discharge times were 156 (101-345) min after general anaesthesia and 296 (195-720) min after spinal anaesthesia (P = 0.0005). Acceptance of the anaesthesia technique was better after general (100%) than after spinal anaesthesia (75%) (P = 0.04). No differences in total costs were reported between spinal block ([symbol: see text] 155 ([symbol: see text] 117-[symbol: see text] 224)) and propofol-remifentanil general anaesthesia ([symbol: see text] 143 ([symbol: see text] 124-[symbol: see text] 203) (P = 0.125)). CONCLUSIONS Accurate titration of short-acting intravenous anaesthetic drugs such as propofol and remifentanil results in shorter preparation times and earlier home discharge after outpatient gynaecological procedures compared with spinal anaesthesia with hyperbaric bupivacaine 10 mg, with better patient acceptance and no increased costs.

Transversus Abdominis Plane Block for Postoperative Analgesia in Patients Undergoing Total Laparoscopic Hysterectomy: A Randomized, Controlled, Observer-Blinded Trial.

BACKGROUND:In this randomized, controlled, observer-blinded study, we evaluated analgesia provided by transversus abdominis plane (TAP) block after elective total laparoscopic hysterectomy in terms of reduced postoperative morphine consumption as the primary end point. METHODS:Fifty-two patients were randomly divided into 2 groups: patients in group T (TAP, n = 26) received an ultrasound-guided bilateral TAP block with 40 mL of 0.375% levobupivacaine and morphine patient-controlled analgesia, whereas patients in group C (control, n = 26) received morphine patient-controlled analgesia. Secondary outcomes included pain measurements (Numeric Rating Scale from 0 to 10) during the first 24 hours postoperatively, times to postanesthesia care unit discharge, times to surgical ward discharge, incidence of postoperative nausea and vomiting, functional capacity measurements in terms of 2-minute walking test, and first oral solid intake. RESULTS:Demographic and anthropometric variables were similar in the 2 groups. The total dose of morphine consumed by patients during postanesthesia care unit stay was 6 (0–8) mg in group T vs 8 (5.5–8.5) mg in group C (P = 0.154). Postoperative morphine consumption during the first 24 hours was 10.55 ± 10.24 mg in group C vs 10.73 ± 13.45 mg in group T (P = 0.950). The 95% confidence interval of the difference between means of 24-hour morphine consumption was −7.45 to +7.09. The 2 groups were comparable. There were no significant differences in secondary outcome variables between groups. CONCLUSIONS:TAP block did not reduce morphine consumption during the first postoperative 24 hours after elective total laparoscopic hysterectomy.