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Biomedical subjects

G Torri

Publications and source records attributed to G Torri.

At least 91 records · Page 5Linked to original sources
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

Solid state NMR spectroscopy study of molecular motion in cyclomaltoheptaose (beta-cyclodextrin) crosslinked with epichlorohydrin.

Dry and hydrated insoluble cyclomaltoheptaose (beta-cyclodextrin, beta-CD) polymers have been investigated by solid state 13C NMR spectroscopy techniques such as cross polarization/magic angle spinning with dipolar decoupling (CP/MAS), magic angle spinning both with (DD-MAS) and without (MAS) dipolar decoupling and CP/MAS dipolar dephasing (dd-CP/MAS) to allow the assignment of the main 13C signals. In the solid state, the presence of water in the samples resulted in a better resolution reflecting increased mobility. Two distinct components (crosslinked beta-CD and polymerized epichlorohydrin) have been found. The molecular mobility of these two components has been analyzed in terms of relaxation parameters such as 13C spin lattice relaxation (T1) and 1H spin lattice relaxation in the rotating frame (T1 rho). The T1 values of the polymers show that the beta-CD trapped inside the polymers does not seem to undergo changes in its mobility whatever the amount of epichlorohydrin. The addition of water to beta-CD significantly increases the T1 values reflecting strong interaction between beta-CD and the solvent. The T1P values obtained reflect the homogeneous nature of the materials.

Carbohydrate Sequence↗
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↗
PubMed1998

Unexpected cardiac arrest during epidural anaesthesia.

We reported the case of sudden asystole requiring close chest cardiac massage in a 56-yrs-old health man receiving epidural anaesthesia for elective transurethral resection of bladder tumour (TURBT). The anaesthetic procedure was performed in a regional-block-room. Cardiac arrest developed few minutes after local anaesthetic injection, before the patient has been transferred to the operating room. The importance of patient monitoring during regional anaesthesia must be further on pointed out, especially when the anaesthetic procedure is performed out of the operating room (e.g. in the recovery room or in a "regional-block-room").

Adult↗
PubMed1998

[Interposed abdominal compression in mechanical cardiopulmonary resuscitation. Description of a clinical case].

Among the different techniques proposed to integrate the standard cardiopulmonary resuscitation (sCPR) protocol, mechanical CPR (mCPR) and interposed abdominal compression (IAC) were found to be particularly effective for the simplicity of the procedure and the significant results obtained. A case of a 54-year old male with cardiogenic shock following viral infection, in which prolonged mechanical cardiopulmonary resuscitation with interposed abdominal compression was performed, is presented. Five hours after admission in the ICU, the patient's condition worsened with subsequent cardiac arrest with pulseless electrical activity (PEA). Mechanical CPR was promptly started, subsequently associated with IAC and prolonged for 1 hour and 20 minutes. Although the patient survived for only eight hours following cardiac arrest, prolonged IAC-mCPR allowed to start extra corporeal circulation (CPP). The patient was then transferred to the cardiosurgical operating theatre for ventricular assistance by centrifugal pump (VAP). Cardiovascular data obtained from patients monitoring did not shown any cardiac lesions or adverse effects as observed by autoptic examination and suggest the reliability of this mechanical method, which allows a better performance when compared to standard CPR. In prolonged resuscitations a few contraindications to both mCPR and IAC suggest the application of the associated techniques at all times in cardiac arrest, combining the benefits of both procedures.

Abdomen↗
PubMed1997

Motional properties of E. coli polysaccharide K5 in aqueous solution analyzed by NMR relaxation measurements.

13C NMR relaxation measurements at three different magnetic field strengths have been used to analyse the motional properties of a low molecular weight K5 polysaccharide (delta UA-[-->4)-beta-D-GlcNAc(1-->4)-beta-D-GlcA(1-->]n-GlcNAcred) from E. coli. Two-dimensional double INEPT spectra with suppression of cross-correlation effects between dipolar and chemical shift anisotropy relaxation mechanisms were collected in order to determine carbon longitudinal and transverse relaxation times. The values of the overall correlation time and the rate of internal motions were obtained using the model free spectral densities. The data indicate that the overall motion of the molecule is non-isotropic and can be approximated with the symmetric top model with an axial ratio of approximately 22. The magnitude of the generalized order parameters (S2 approximately 0.8) and the internal motion correlation time (tau e approximately 30 ps) differ from those found for iduronic acid-containing glycosaminoglycans and suggest that the internal motions in K5 polysaccharide are more limited.

Carbohydrate Sequence↗
PubMed1997

Eleven X chromosome breakpoints associated with premature ovarian failure (POF) map to a 15-Mb YAC contig spanning Xq21.

Eleven balanced X-autosome translocations associated with premature ovarian failure (POF) were mapped to a YAC contig spanning most of Xq21 and constructed between the DXS223 and DXS1171 loci. The contig corresponds to a genomic region of about 15 Mb and contains the whole X-Y homologous region. The most proximal and most distal breakpoints associated with POF were mapped 15 Mb apart. The remaining breakpoints were localized along this large region, in the X-specific and in the X-Y homologous region. Four of the YACs contained two breakpoints in the same or in flanking STS intervals. Our results confirm the cytological findings and suggest that a minimum number of eight different genes in Xq21 may be involved with ovary development. Interruption of such loci could be the cause of POF.

Carrier Proteins↗
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↗
PubMed1997

Haemodynamic monitoring during alkalinized lignocaine epidural block: a comparison with subarachnoid anaesthesia.

Cardiovascular responses after epidural alkalinized lignocaine and subarachnoid hyperbaric bupivacaine administration were studied using a non-invasive cardiac output measurement in 32 ASA Grade I-II patients undergoing orthopaedic leg surgery (hip hemi-arthroplasty or Ender nailing). All patients achieved adequate surgical anaesthesia. The block onset time was faster (P = 0.003), and the range of final sensory level wider (P = 0.006) in patients receiving spinal anaesthesia compared with the epidural group. Diastolic arterial pressure was significantly reduced when compared with base-line (P = 0.002) only in the spinal group. No significant changes in stroke volume, systemic vascular resistance or left ventricular stroke work were observed in either group. Heart rate and cardiac index were significantly reduced in the spinal group when compared both with base line (P = 0.002; P = 0.04) and the epidural group (P = 0.001; P = 0.006). The results demonstrated that the block onset time and the cardiovascular effects produced by lumbar epidural anaesthesia, with alkalinized solutions, remain less than after spinal anaesthesia involving the same segments.

Anesthesia, Epidural↗