Search PubMed⌕ Search

Biomedical subjects

G Fanelli

Publications and source records attributed to G Fanelli.

At least 73 records · Page 4Linked to original sources
PubMed1999

Nerve stimulator and multiple injection technique for upper and lower limb blockade: failure rate, patient acceptance, and neurologic complications. Study Group on Regional Anesthesia.

UNLABELLED: To 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%. IMPLICATIONS: Based 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.

Adult↗
PubMed1999

The target plasma concentration of propofol required to place laryngeal mask versus cuffed oropharyngeal airway.

UNLABELLED: To determine the target plasma concentration of propofol required to place either a laryngeal mask airway (LMA) or a cuffed oropharyngeal airway (COPA), we started a continuous target-controlled infusion of propofol in 60 ASA physical status I or II unpremedicated patients scheduled for minor orthopedic surgery with peripheral nerve block. The target plasma concentration of propofol was initially set at 2 microg/mL. When the effect-site calculated concentration of propofol was equal to the plasma concentration according to the computer simulation, the target plasma concentration was increased by 0.5-microg/mL steps until successful placement of either the LMA (n = 30) or the COPA (n = 30). The mean target plasma concentration of propofol required to place a LMA was 4.3 +/- 0.8 microg/mL compared with 3.2 +/- 0.6 microg/mL to place a COPA (P < 0.001). To successfully place the airways in 95% of patients, the target plasma concentration of propofol had to be increased up to 4 microg/mL for the COPA and 6 microg/mL for the LMA. We conclude that placing a LMA in healthy, unpremedicated patients requires target plasma concentrations of propofol higher than those required for placing a COPA. IMPLICATIONS: We evaluated the use of target-controlled infusion of propofol to place extratracheal airways in this prospective, randomized study and demonstrated that the target plasma concentration of propofol required to successfully place a laryngeal mask in >95% of healthy, unpremedicated patients is 6 microg/mL, compared with 4 microg/mL to place a cuffed oropharyngeal airway.

Adolescent↗
PubMed1999

Peribulbar anesthesia with either 0.75% ropivacaine or a 2% lidocaine and 0.5% bupivacaine mixture for vitreoretinal surgery: a double-blinded study.

UNLABELLED: No study has evaluated the efficacy of ropivacaine in peribulbar block for ophthalmic surgery. The purpose of this prospective, randomized, double-blinded study was to compare ropivacaine and a lidocaine-bupivacaine mixture in peribulbar anesthesia. Sixty ASA physical status I or II patients scheduled for elective vitreoretinal surgery were randomized to receive a peribulbar block with 8 mL of either 0.75% ropivacaine (ropivacaine group, n = 30) or a 1:1 mixture of 2% plain lidocaine and 0.5% plain bupivacaine (lido-bupivacaine group, n = 30). Time required for onset of surgical anesthesia, quality of postoperative analgesia, incidence of side effects, and analgesic consumption were recorded. Surgical block was achieved after 8 +/- 5 min in the lido-bupivacaine group and after 10 +/- 5 min in the ropivacaine group (P = 0.23). A 3-mL supplemental injection 15 min after block placement was required in 6 patients in the lido-bupivacaine group (20%) and in 10 patients in the ropivacaine group (33%) due to inadequate motor block (P = 0.38). On Postoperative Day 1, 26 patients in the ropivacaine group (87%) reported no pain at the verbal rating score, compared with 18 patients in the lido-bupivacaine group (60%) (P = 0.005). We conclude that 0.75% ropivacaine may be a suitable choice when performing peribulbar anesthesia for vitreoretinal surgery. IMPLICATIONS: Quick onset of block with prolonged postoperative analgesia is an important goal in regional anesthesia for ophthalmic surgery. Evaluating clinical properties of 0.75% ropivacaine and a 1:1 mixture of 2% lidocaine and 0.5% bupivacaine for peribulbar anesthesia, we demonstrated that ropivacaine has an onset similar to that of the lidocaine-bupivacaine mixture and provides a better quality of postoperative analgesia.

Amides↗
PubMed1999

Ropivacaine or 2% mepivacaine for lower limb peripheral nerve blocks. Study Group on Orthopedic Anesthesia of the Italian Society of Anesthesia, Analgesia, and Intensive Care.

BACKGROUND: Intra- and postoperative clinical properties of sciatic-femoral nerve block performed with either ropivacaine at different concentrations or mepivacaine have been evaluated in a multicenter, randomized, blinded study. METHODS: Adult patients scheduled for foot and ankle surgery were randomized to receive combined sciatic-femoral nerve block with 225 mg of either 0.5% (n = 83), 0.75% (n = 87), or 1% (n = 86) ropivacaine, or with 500 mg of 2% mepivacaine (n = 84). A thigh tourniquet was used in all patients. Onset time, adequacy of surgical anesthesia, time to offset of nerve block, and time until first postoperative requirement for pain medication were evaluated by a blinded observer. RESULTS: The adequacy of nerve block was similar in the four treatment groups (the ratios between adequate:inadequate: failed blocks were 74:9:0 with 0.5% ropivacaine, 74:13:0 with 0.75% ropivacaine, 78:8:0 with 1% ropivacaine, and 72:12:0 with 2% mepivacaine). The onset of the block was slower with 0.5% ropivacaine than with other anesthetic solutions (P < 0.001). Regardless of the concentration, ropivacaine produced a longer motor blockade (10.5+/-3.8 h, 10.3+/-4.3 h, and 10.2+/-5.1 h with 0.5%, 0.75%, and 1% ropivacaine, respectively) than with mepivacaine (4.3+/-2.6 h; P < 0.001). The duration of postoperative analgesia was shorter after mepivacaine (5.1+/-2.7 h) than after ropivacaine (12.2+/-4.1 h, 14.3+/-5 h, and 14.5+/-3.4 h, with 0.5%, 0.75%, or 1% ropivacaine, respectively; P < 0.001). Pain relief after 0.5% ropivacaine was 14% shorter than 0.75% or 1% ropivacaine (P < 0.05). During the first 24 h after surgery, 30-37% of patients receiving ropivacaine required no analgesics compared with 10% of those receiving mepivacaine (P < 0.001). CONCLUSIONS: This study suggests that 0.75% ropivacaine is the most suitable choice of local anesthetic for combined sciatic-femoral nerve block, providing an onset similar to mepivacaine and prolonged postoperative analgesia.

Adult↗
PubMed1999

Autotransfusion with predeposit-haemodilution and perioperative blood salvage: 20 years of experience. Rizzoli Study Group on Orthopaedic Anesthesia.

BACKGROUND: Through a prospective study, we evaluated the efficacy of an integrated autotransfusion regimen comprised of predeposit-hemodiluition and intra and post-operative blood salvage in major orthopaedic surgery. METHODS: We examined the records of 2303 consecutive patients (1524 females and 779 males, mean age 62.7, standard deviation 11 years (range 16-90 yrs), pre-operative haemoglobin (Hb) concentration 13.5 (SD 1.4) (range 6.7-19.3) g/dl undergong total hip arthroplasty (THA 1582 patients), THA after the removal of internal fixation devices (RFD+THA, 25 patients), total knee arthroplasty (TKA, 347 patients), revision surgery of the hip (HR, cup+stem revision, 248 patients; cup revision 64 patients; stem revision 23 patients) and total knee revision (TKR 14 patients). We estimated that the number of predonations (MSBOS - maximum surgery blood order schedule) was 2 units for THA, TKA and TKR, and 3 units for partial or total hip revision and for total hip arthroplasty with fixation removal. RESULTS: It was possible to obtain the MSBOS in 2070 patients (89.8%). Homologous red blood cell (HRBC) transfusion were carried out in 184 patients (8%). We found that the need to use HRBC was significantly associated with failure to meet the number of MSBOS, female sex, lower pre-operative Hb concentration, use of calcium heparin for antithrombosis prophylaxis, more extensive surgery, a higher ASA rating and co-existing diseases such as coronary artery disease. CONCLUSIONS: Cooperation among anaesthesis, transfusionists and surgeons in the application of an integrated autotransfusion regimen enabled us to treat 92% of our patients with only autotransfusion.

Adolescent↗
PubMed1999

Do we need new supraglottic devices? Clinical appraisal of the cuffed oropharyngeal airway (COPA)

BACKGROUND: The laryngeal mask airway (LMA) has been widely studied for both conventional and nonconventional uses, while the literature on the cuffed oropharyngeal airway (COPA) is still limited. The purpose of this manuscript was to review the initial appraisal of efficacy, safety, effects on hemodynamics and respiratory function, induction agents and drug requirements of this new supraglottic device. METHODS: We reviewed main results of studies recently published on peer reviewed journals concerning the clinical uses of COPA. RESULTS: When used in healthy adults undergoing general anesthesia for routine minor procedures, the COPA and LMA are substantially equivalent. The LMA is associated with a higher first-time placement rate and fewer manipulations during usage, but the incidence of airway untoward events during COPA anesthesia is equivalent to that reported when using an LMA. The quality of breathing and capnography during COPA ventilation is similar to that provided by the LMA ventilation, with clinically relevant decrease in the physiological deadspace/tidal volume ratio and arterial to end-tidal CO2 tension difference compared with facemask ventilation. In selected patients without risk factors for regurgitation of gastric content, positive-pressure ventilation is similarly successful and safe with the COPA as with the LMA. The COPA seems to be less stimulating than LMA because it has been demonstrated to cause a lower incidence of pharyngeal trauma and sore throat in the immediate postoperative period, requires shorter exposure to an inhalational anesthetic and lower concentrations of propofol to be successfully placed, and is associated with lower effects on the patient's hemodynamic homeostasis than LMA. CONCLUSIONS: More extensive clinical evaluations should be advocated to better understand the risk/benefit ratio of this new supraglottic device; however, it may be concluded that in healthy adults receiving general anesthesia for short procedures the COPA allows for an effective and safe control of the patient's airway and ventilation.

Adult↗
PubMed1998

Low dose hyperbaric bupivacaine for unilateral spinal anaesthesia.

PURPOSE: To evaluate the effects of hyperbaric bupivacaine concentration in producing unilateral spinal anaesthesia. METHODS: With Ethical Committee approval and written consent, 60 patients undergoing lower limb surgery were placed in the lateral position with the side to be operated on dependent. After dural puncture (25-gauge Whitacre spinal needle), the needle hole was turned toward the dependent side and patients were randomly assigned to receive 8 mg of either 0.5% (Group0.5%, n = 30) or 1% (Group1%, n = 30) hyperbaric bupivacaine. The lateral position was maintained for 15 min, while a blinded observer recorded loss of pinprick sensation and degree of motor block on both sides until two segment regression of sensory level on the dependent side. RESULTS: At the end of the 15 min lateral position spinal anaesthesia was more frequently unilateral in Group0.5% (80%) than in Group1% (53%)(P < 0.05). However, 30 min after patients were turned supine, unilateral spinal anaesthesia decreased to 60% of cases in Group0.5% and 40% of cases in Group1% (P = NS). The maximum sensory level on the dependent side [T10(L1-T2) in Group0.5% and T8 (T12-T3) in Group1%], time to reach it [20 (5-30) min in Group0.5% and 25 (10-35) min in Group1%], and time to two segment regression of sensory level [80 (30-135) min in Group0.5% and 75 (20-135) min in Group1%] were similar in both groups. CONCLUSION: Highly concentrated solutions of hyperbaric bupivacaine are not advantageous in obtaining a unilateral spinal anaesthesia, when a small anaesthetic dose is injected slowly through a Whitacre spinal needle.

Adult↗
PubMed1998

Comparison between epidural infusion of fentanyl/bupivacaine and morphine/bupivacaine after orthopaedic surgery.

PURPOSE: To compare epidural infusions of bupivacaine-fentanyl and bupivacaine-morphine mixtures for postoperative pain relief after total hip replacement. METHODS: In a prospective, randomized, double-blind study, 30 ASA physical status I-II patients undergoing total hip replacement were studied. Anaesthesia was provided by combined general/epidural anaesthesia without epidural opioids. Postoperative epidural analgesia was by continuous infusion of bupivacaine 0.125% (4 ml.hr-1) with either 0.05 mg.ml-1 morphine (morphine, n = 15) or 0.005 mg.ml-1 fentanyl (fentanyl, n = 15). Visual analogue pain scale (VAS), sedation (four-point scale), respiratory rate, pulse oximetry, rescue analgesics and supplemental oxygen were recorded by a blind observer at 1, 3, 6, 9, 12 and 24 hr after surgery. RESULTS: No differences in pain relief, sedation, or non-respiratory side effects were observed between the two groups. Rescue analgesics were required in three patients in the fentanyl group (20%) and in two receiving morphine (13.3%) (P:NS). Two patients in the fentanyl group and three in the morphine group required oxygen due to SpO2 < 90% (P:NS). Both opioid/bupivacaine mixtures decreased haemoglobin oxygen saturation compared with preoperative values. The mean +/- SD SpO2 values measured at 3, 6, 12 and 24 hr were 94.4 +/- 1, 92.6 +/- 0.9, 92 +/- 0.8, and 92.8 +/- 1 in the morphine group, 95.3 +/- 0.5, 95 +/- 0.5, 94.6 +/- 1.2, and 95.6 +/- 1 in the fentanyl group (P < 0.05). CONCLUSION: Continuous epidural infusion of bupivacaine-morphine or bupivacaine-fentanyl mixtures provided similar pain relief. Patients receiving morphine showed a more marked decrease in SpO2 than those receiving fentanyl. However, the average SpO2 remained > 90% in both groups.

Analgesia, Epidural↗
PubMed1998

Physiological dead space/tidal volume ratio during face mask, laryngeal mask, and cuffed oropharyngeal airway spontaneous ventilation.

OBJECTIVE: To compare the physiological dead space/tidal volume ratio and arterial to end-tidal carbon dioxide tension (ETCO2) difference during spontaneous ventilation through a face mask, a laryngeal mask (LMA), or a cuffed oropharyngeal airway. DESIGN: Prospective, randomized, cross-over study. SETTING: Inpatient anesthesia at a university department of orthopedic surgery. PATIENTS: 20 ASA physical status I and II patients, without respiratory disease, who underwent ankle and foot surgery. INTERVENTIONS: After a peripheral nerve block was performed, propofol anesthesia was induced and then maintained with a continuous intravenous (i.v.) infusion (4 to 6 mg/kg/h). A face mask, a cuffed oropharyngeal airway, or an LMA were placed in each patient in a random sequence. After 15 minutes of spontaneous breathing through each of the airways, ventilatory variables, as well as arterial, end-tidal, and mixed expired CO2 partial pressure, were measured, and physiological dead space/tidal volume ratio was calculated. MEASUREMENTS AND MAIN RESULTS: Expired minute volume and respiratory rate (RR) were lower with LMA (5.6 +/- 1.2 L/min and 18 +/- 3 breaths/min) and the cuffed oropharyngeal airway (5.7 +/- 1 L/min and 18 +/- 3 breaths/min) than the face mask (7.1 +/- 0.9 L/min and 21 +/- 3 breaths/min) (p = 0.0002 and p = 0.013, respectively). Physiological dead space/tidal volume ratio and arterial to end tidal CO2 tension difference were similar with the cuffed oropharyngeal airway (3 +/- 0.4 mmHg and 4.4 +/- 1.4 mmHg) and LMA (3 +/- 0.6 mmHg and 3.7 +/- 1 mmHg) and lower than with the face mask (4 +/- 0.5 mmHg and 6.7 +/- 2 mmHg) (p = 0.0001 and p = 0.001, respectively). CONCLUSION: Because of the increased dead space/tidal volume ratio, breathing through a face mask required higher RR and expired minute volume than either the cuffed oropharyngeal airway or LMA, which, in contrast, showed similar effects on the quality of ventilation in spontaneously breathing anesthetized patients.

Analysis of Variance↗
PubMed1998

A transient neurological deficit following intrathecal injection of 1% hyperbaric bupivacaine for unilateral spinal anaesthesia.

We describe a case of transient neurological deficit that occurred after unilateral spinal anaesthesia with 8 mg of 1% hyperbaric bupivacaine slowly injected through a 25-gauge pencil-point spinal needle. The surgery and anaesthesia were uneventful, but 3 days after surgery, the patient reported an area of hypoaesthesia over L3-L4 dermatomes of the leg which had been operated on (loss of pinprick sensation) without reduction in muscular strength. Sensation in this area returned to normal over the following 2 weeks. Prospective multicentre studies with a large population and a long follow-up should be performed in order to evaluate the incidence of this unusual side effect. However, we suggest that a low solution concentration should be preferred for unilateral spinal anaesthesia with a hyperbaric anaesthetic solution (if pencil-point needle and slow injection rate are employed), in order to minimize the risk of a localized high peak anaesthetic concentration, which might lead to a transient neurological deficit.

Adult↗
PubMed1998

A double-blind study of axillary brachial plexus block by 0.75% ropivacaine or 2% mepivacaine.

Axillary brachial plexus block using 20 mL of 0.75% ropivacaine or 2% mepivacaine was compared in a prospective, randomized, double-blind study of two groups of 15 patients. The times to onset of sensory and motor block and to resolution of motor block, as well as the time to onset and degree of post-operative pain were recorded by an observer blinded to the identity of drug. Times to onset of sensory block were similar in the two groups (ropivacaine 10 min, mepivacaine 8 min). Resolution of motor block in the operated hand and the time to first requirement of post-operative analgesia occurred later with ropivacaine (9 h 50 min and 10 h) than with mepivacaine (3 h 50 min and 6 h), P < 0.01 for both measurements. Nine patients who received ropivacaine and two patients who received mepivacaine did not require further post-operative analgesia (P < 0.05). Ropivacaine is less toxic than other long-acting local anaesthetics, and 0.75% ropivacaine may be better for brachial plexus block when fast onset is required and prolonged pain relief is useful.

Adolescent↗
PubMed1998

Does speed of intrathecal injection affect the distribution of 0.5% hyperbaric bupivacaine?

We have evaluated the influence of speed of intrathecal injection on lateral distribution of 0.5% hyperbaric bupivacaine. We studied 60 patients undergoing lower limb surgery who were placed in the lateral position with the operative side in the dependent position. After dural puncture (25-gauge Whitacre spinal needle), the needle aperture was turned towards the dependent side and 0.5% hyperbaric bupivacaine 8 mg was injected randomly at a rate of 0.02 ml s-1 (group slow, n = 30) or 0.25 ml s-1 (group fast, n = 30). Lateral position was maintained for 15 min while a blinded observer recorded loss of pinprick sensation and degree of motor block on both surgical and non-surgical sides. There were no differences between the groups. Forty-five minutes after patients were turned to the supine position, spinal anaesthesia was unilateral in 17 patients in group slow (56%) and in 13 patients in group fast (43%). We conclude that using extremely low speeds for intrathecal injection were not clinically advantageous in obtaining unilateral spinal anaesthesia.

Adult↗
PubMed1998

Effects of spinal needle type on lateral distribution of 0.5% hyperbaric bupivacaine.

UNLABELLED: To evaluate the influence of needle type on the lateral distribution of 0.5% hyperbaric bupivacaine, 30 patients undergoing lower limb surgery were placed in the lateral position with the side to be operated on dependent and underwent dural puncture by either a 25-gauge Whitacre (n = 15) or a 25-gauge Quincke (n = 15) spinal needle. The needle hole was turned toward the dependent side and 8 mg of 0.5% hyperbaric bupivacaine was injected over 30 s. The lateral position was maintained for 15 min while a blind observer recorded loss of pinprick sensation and degree of motor block on both the dependent and nondependent sides every 5 min until regression of motor block by 1 degree on the dependent side. Thirty minutes after the patients were placed in the supine position, unilateral sensory block was observed in 10 patients in the Whitacre group (66%) and in 2 patients in the Quincke group (13%) (P < 0.05). No differences in the rate of unilateral motor block were observed (73% and 40% in Whitacre and Quincke groups, respectively). We conclude that when a small dose of 0.5% hyperbaric bupivacaine is injected slowly into patients in the lateral position for 15 min, the Whitacre spinal needle provides a more marked differential block of sensory nerve roots between dependent and nondependent sides compared with the Quincke needle. IMPLICATIONS: Because unilateral spinal anesthesia can be advantageous for lower limb surgery, we evaluated the influence of the Whitacre and Quincke spinal needle types on the lateral distribution of small-dose 0.5% hyperbaric bupivacaine injected slowly into adult patients.

Adult↗
PubMed1998

A double-blind comparison of ropivacaine, bupivacaine, and mepivacaine during sciatic and femoral nerve blockade.

UNLABELLED: No study has evaluated the efficacy of ropivacaine in peripheral nerve block of the lower extremity. The purpose of this prospective, randomized, double-blind study was to compare ropivacaine, bupivacaine, and mepivacaine during combined sciatic-femoral nerve block. Forty-five ASA physical status I or II patients scheduled for elective hallux valgus repair with thigh tourniquet were randomized to receive combined sciatic-femoral block with 0.75% ropivacaine (ROPI, n = 15), 0.5% bupivacaine (BUPI, n = 15), and 2% mepivacaine (MEPI, n = 15). Time required for onset of sensory and motor block on the operated limb (readiness for surgery) and resolution of motor block, as well as onset of postsurgical pain and time of first analgesic requirement, were recorded. The three groups were similar with regard to demographic variables, duration of surgery, and measured visual analog pain scores. Onset of sensory and motor blockade was similar in Groups ROPI and MEPI and significantly shorter than in Group BUPI (P = 0.002 and P = 0.001, respectively). Resolution of motor block occurred later in Groups ROPI and BUPI than in Group MEPI (P = 0.005 and P = 0.0001, respectively). Duration of postoperative analgesia was significantly longer in Groups ROPI (670+/-227 min) and BUPI (880+/-312 min) compared with Group MEPI (251+/-47 min) (P = 0.0001), with a significant decrease in postoperative pain medication requirements (P < 0.05). We conclude that for sciatic-femoral nerve block, 0.75% ropivacaine has an onset similar to that of 2% mepivacaine and a duration of postoperative analgesia between that of 0.5% bupivacaine and 2% mepivacaine. IMPLICATIONS: Quick onset of block with prolonged postoperative analgesia is an important goal in peripheral nerve blockade. We evaluated the clinical properties of 0.5% bupivacaine, 2% mepivacaine, and 0.75% ropivacaine for sciatic-femoral nerve block and demonstrated that ropivacaine has an onset similar to that of mepivacaine but allows for postoperative analgesia between that of bupivacaine and mepivacaine.

Adult↗
PubMed1998

Cardiovascular effects of two different regional anaesthetic techniques for unilateral leg surgery.

BACKGROUND: Cardiovascular function was assessed in 20 ASA I-II patients, scheduled for elective orthopaedic surgery with tourniquet in order to compare the haemodynamic changes induced by unilateral spinal anaesthesia and combined sciatico-femoral nerve block. METHODS: After baseline measurement of cardiovascular parameters, patients were randomized to receive unilateral spinal anaesthesia or combined sciatico-femoral nerve block. Spinal anaesthesia was obtained by 8 mg of hyperbaric bupivacaine 0.5% slowly injected (speed=0.02 ml s[-1]) through a 25-G Whitacre spinal needle with the bevel orientated towards the dependent side and patients lying on their operated side for 15 min (group S, n=10). Combined sciatico-femoral nerve block was obtained by 7 mg kg(-1) of mepivacaine 2% (group NB, n=10). Haemodynamic variables were recorded 5, 10, 15, and 30 min after anaesthetic injection before surgery was started. RESULTS: Anthropometric data, duration of surgery and acceptability of anaesthetic techniques were similar in the 2 groups. In 8 patients of group S, spinal block was restricted to the operated side (pinprick test and Bromage scale), while the other 2 patients developed bilateral spinal block after being turned supine. NB patients showed no haemodynamic changes during the study, whereas patients in group S showed a small but significant decrease of mean arterial blood pressure (P<0.002 vs baseline and P<0.04 vs NB), cardiac index (P<0.01 vs baseline and P<0.01 vs NB), and stroke volume index (P<0.01 vs baseline and P<0.01 vs NB). CONCLUSION: Both sciatico-femoral and unilateral spinal blockade provide adequate anaesthesia for unilateral leg surgery with tourniquet. The former technique affects cardiovascular performance less than the latter one.

Aged↗
PubMed1997

Cardiac performance during unilateral lumbar spinal block after crystalloid preload.

PURPOSE: The haemodynamic effects of crystalloid preload were evaluated in a randomised blind study in 20 ASA status I-II, 50-80 yr-old patients, undergoing unilateral spinal anaesthesia for leg surgery produced with low doses of hyperbaric bupivacaine. METHODS: Baseline non-invasive blood pressure (oscillometry), heart rate, stroke volume and cardiac index (transthoracic electrical bioimpedance) were recorded. Then, patients were randomly allocated to receive 10 ml.kg-1 Ringer's Lactate solution over 20 min (preload group, n = 10) or no crystalloid infusion (no-preload group, n = 10). Spinal block was performed using 8 mg hyperbaric bupivacaine 0.5% injected slowly at the L2-L3 interspace (0.02 ml.sec-1 through a 25-gauge Whitacre needle) with patients lying on their operated side and with the needle opening directed towards the dependent side. Lateral decubitus position was maintained for up to 15 min after anaesthetic injection to facilitate hyperbaric bupivacaine distribution towards dependent regions of the subarachnoid space. Haemodynamic variables were recorded 5, 10, 15 and 30 min after spinal injection, while sensory level and motor block were evaluated 10, 15 and 30 min after anaesthetic injection on both operated and unoperated side. RESULTS: No differences of upper sensory level and motor block were observed between the two groups on the operated and non-operated sides. Diastolic blood pressure was decreased compared with baseline in the no-preload group only (P = .0001). Systolic arterial pressure and heart rate did not change in either group. Stroke volume and cardiac index were decreased in the no-preload group compared with both baseline (P = .02; P = .001) and the preload group (P = .04; P = .02). CONCLUSION: Crystalloid preload influences cardiovascular function during spinal block, and may be useful when very low bupivacaine doses and lateral decubitus are used to achieve unilateral spinal block.

Aged↗
PubMed1997

Active warming, not passive heat retention, maintains normothermia during combined epidural-general anesthesia for hip and knee arthroplasty.

STUDY OBJECTIVE: to compare passive heat retention by low-flow anesthesia, alone and with additional thermal insulation by reflective blankets, with forced-air warming preventing intraoperative hypothermia during combined epidural-general anesthesia. DESIGN: Randomized, controlled study. SETTING: Inpatient anesthesia at a university department of orthopedic surgery. PATIENTS: 30 ASA physical status I and II patients, who were scheduled for elective hip or knee arthroplasty and were free from systemic disease. INTERVENTIONS: Patients received epidural block up to T10 by alkalinized lidocaine 2%, and then were administered standard general anesthesia by means of low-flow rebreathing system (fresh gas flow = 1 L/min). All procedures started between 8 and 10 AM, and operating room (OR) temperature was maintained between 21 degrees and 23 degrees C, with relative humidity ranging between 40% and 45%. For heat retention or warming therapy, patients received either low-flow anesthesia only (control, n = 10), low-flow anesthesia with additional reflective blankets (blanket, n = 10), or low-flow anesthesia with active forced-air warming (forced-air, n = 10). Tympanic temperature was measured at OR arrival (baseline); immediately following general anesthesia induction; 30, 60, 90, and 120 minutes from general anesthesia induction; and at the end of surgery. MEASUREMENTS AND MAIN RESULTS: Duration of anesthesia, invasiveness of surgery, and baseline core temperature were similar in the three groups. Core temperature decreased in all the three groups 30 minutes after general anesthesia induction compared with baseline (p < 0.01); afterwards, it progressively decreased in the control and blankets groups (p = 0.004), with a reduction from baseline values measured at the end of surgery of 2.0 degrees C and 1.6 degrees C, respectively. In the forced-air group, after the initial significant decrease (p = 0.01 vs. baseline), core temperature progressively increased to 35.8 +/- 0.6 degrees C, which was similar to preoperative values and significantly higher than either the control or blankets groups (p = 0.004). CONCLUSIONS: During combined epidural-general anesthesia for elective hip and knee arthroplasty, passive heat retention by means of low-flow anesthesia alone and in combination with reflective blankets is ineffective in maintaining intraoperative normothermia and definitely inferior to active forced-air warning.

Aged↗