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Biomedical subjects

G Fanelli

Publications and source records attributed to G Fanelli.

103 records · Page 6Linked to original sources
PubMedDate not supplied

Frequency of hypotension during conventional or asymmetric hyperbaric spinal block.

BACKGROUND AND OBJECTIVES: The purpose of this randomized, double-blind study was to evaluate if use of an asymmetric spinal block affects the incidence of hypotension during spinal anesthesia. METHODS: With Ethical Committee approval and patient consent, 120 patients undergoing lower limb surgery were placed in the lateral position with the side to be operated on dependent, and received 8 mg 0.5% hyperbaric bupivacaine through a 25-gauge Whitacre spinal needle. Patients were randomized to one of two groups: (a) local anesthetic was injected with barbotage through a cranially directed needle orifice, then patients were immediately turned to supine (conventional, n = 60); (b) local anesthetic was injected without barbotage with the needle orifice turned toward the dependent side, then the lateral position was maintained for 15 minutes (unilateral, n = 60). A blind observer recorded noninvasive hemodynamic variables, as well as loss of cold and pinprick sensation and motor block on both sides. RESULTS: In the unilateral group, 31 patients (52%) showed a unilateral loss of cold sensation and 48 patients (80%) had no motor block on the nondependent side for the duration of the study, whereas all conventional patients had bilateral distribution of spinal block (P < .0001). The onset time and two-segment regression of sensory block on the dependent side were more rapid in the conventional group (18 +/- 7 minutes and 60 +/- 18 minutes) than in the unilateral group (22 +/- 8 minutes and 67 +/- 19 minutes) (P < .05 and P < .05, respectively). The incidence of hypotension (SAP decrease >30% from baseline) was higher in the conventional (22.4%) than unilateral group (5%) (P < .01). The maximum percentage changes from baseline values of systolic arterial blood pressure and heart rate were greater in conventional group (-28% +/- 16% and -19% +/- 10%) than in unilateral group (-8% +/- 16% and -12% +/- 18%) (P < .0001 and P < .01, respectively). CONCLUSIONS: Achieving an asymmetric distribution of spinal block by injecting a small dose of 0.5% hyperbaric bupivacaine through a Whitacre spinal needle into patients placed in the lateral position for 15 min reduces the incidence of hypotension during spinal anesthesia.

Adult↗
PubMedDate not supplied

Effects of speed of intrathecal injection on unilateral spinal block by 1% hyperbaric bupivacaine. A randomized, double-blind study.

BACKGROUND: To evaluate if the speed of intrathecal injection affects the lateral distribution of spinal block during unilateral spinal anaesthesia with 1% hyperbaric bupivacaine. METHODS DESIGN: prospective, randomized, double-blind study. SETTING: anaesthesia Department at a University Hospital. PATIENTS: 30 ASA physical status I-II patients, scheduled for elective orthopedic surgery involving one lower limb only (ankle and foot surgery). INTERVENTIONS: after placing the patients in the lateral decubitus position with the site to be operated on dependent, dural puncture was performed at L3-L4 interspace using a 25-Gauge Whitacre spinal needle. After the needle hole had been turned toward the dependent side, patients were randomized to receive 8 mg of 1% hyperbaric bupivacaine injected over either 40 sec (Group SLOW, n = 15) or 3 sec (Group FAST, n = 15). The lateral position was maintained for 15 min. MEASUREMENTS: a blind observer evaluated the evolution of sensory (pinprick test) and motor (modified Bromage scale) blocks on both the dependent and nondependent sides until the regression of motor block by one degree. RESULTS: No differences in the maximal sensory level on both the dependent and nondependent sides were observed in the two groups. Unilateral sensory block was onserved in 6 patients in group SLOW (40%) and in 5 patients in group FAST (33%), (p = not significant[NS]. Unilateral motor block was observed in 9 patients in group SLOW (60%) and in 10 patients in group FAST (66%) (NS). CONCLUSIONS: Extremely reduced speeds of intrathecal injection did not improve the lateral distribution of spinal block when injecting 8 mg of 1% hyperbaric bupivacaine through a pencil-point directional spinal needle.

Adult↗
PubMedDate not supplied

Shortening the discharging time after total hip replacement under combined spinal/epidural anesthesia by actively warming the patient during surgery.

BACKGROUND: To compare passive thermal insulation by reflective blankets with forced-air active warming on the efficacy of normothermia maintenance and time for discharging from the recovery room after combined spinal/epidural anesthesia for total hip arthroplasty. METHODS DESIGN: Prospective, randomized study. SETTING: Inpatient anesthesia at three University Departments of orthopedic surgery. PATIENTS: 50 ASA physical status I-III patients, who were scheduled for elective total hip arthroplasty. INTERVENTIONS: Patients received combined spinal/epidural anesthesia (CSE) with intrathecal injection of 15 mg of 0.5% hyperbaric bupivacaine. All procedures started 8-10 a.m., and operating room temperature was maintained between 21-23 degrees C, with relative humidity ranging between 40-45%. As warming therapy patients received either passive thermal insulation of the trunk, the two upper limbs and the unoperated lower limb with reflective blankets (group passive, n = 25), or forced-air active warming of the two upper limbs (group active, n = 25). Core temperature was measured before CSE placement (baseline), and then every 30 min until recovery of normothermia. RESULTS: Demographic data, duration of surgery, intraoperative blood losses, and crystalloid infusion were similar in the two groups. Arterial blood pressure decreased in both groups compared with baseline values, while no differences in heart rate were observed during the study. Core temperatures in passive group patients decreased more markedly than in actively warmed patients, with a 1 degree C difference between the two groups at the end of surgery (p < 0.0005). At recovery room entry seven patients in group active (24%) and 16 patients in group passive (64%) showed a core temperature < 36 degrees C (p < 0.01). Achievement of both discharging criteria and normothermia required 32 +/- 18 min in active group and 74 +/- 52 min in passive group (p < 0.0005). CONCLUSIONS: Forced-air cutaneous warming allows the anesthesiologist to maintain normothermia during combined spinal/epidural anesthesia for total hip replacement even if the convective blanket is placed on a relatively small skin surface with reflex vasoconstriction. Maintaining core normothermia decreased the duration of postanesthesia recovery and may, therefore, reduce costs of care.

Aged↗
PubMedDate not supplied

Interscalene brachial plexus anesthesia with either 0.5% ropivacaine or 0.5% bupivacaine.

BACKGROUND: To compare intra- and postoperative clinical properties of interscalene brachial plexus block performed with either 0.5% ropivacaine or 0.5% bupivacaine. METHODS EXPERIMENTAL DESIGN: prospective, randomized, double-blind study. SETTING: in patient at the University Hospital, Department of Orthopedic Surgery. PATIENTS: 30 ASA physical status I-II patients scheduled for elective shoulder surgery. INTERVENTIONS: interscalene brachial plexus block was performed using the multiple injection technique and a nerve stimulator by injecting 20 ml of either 0.5% ropivacaine (n = 15) or 0.5% bupivacaine (n = 15). Postoperative analgesia consisted of 100 mg intravenous ketoprofen, if required. A blind observer evaluated hemodynamic variables as well as sensory and motor blocks from the end of injection to achieve a surgical anesthesia (readiness for surgery: loss of pinprick sensation from C4 to C7 with the inability to elevate the operated limb against gravity). The time lasting from block placement to first requirement for postoperative pain medication was also recorded. RESULTS: No differences in anthropometric parameters and hemodynamic variables were observed throughout the study, and no signs of central nervous system (CNS) and cardiovascular toxicity, or other untoward events were reported in any patients. Readiness for surgery was obtained after 28 +/- 15 min with 0.5% bupivacaine and 22 +/- 8 min after 0.5% ropivacaine (p = NS). No differences in postoperative pain relief was observed between the two groups (11.1 +/- 5 hrs after 0.5% ropivacaine and 10.9 +/- 3.9 hrs after 0.5% bupivacaine, respectively). CONCLUSIONS: This study confirmed that 0.5% ropivacaine has clinical properties similar to those of 0.5% bupivacaine, when used for interscalene brachial plexus block, providing similarly long duration in postoperative pain relief. Compared with bupivacaine, ropivacaine has the further advantage of a lower potential for central nervous system and cardiovascular toxicity.

Adolescent↗
PubMedDate not supplied

The minimum effective dose of 0.5% hyperbaric spinal bupivacaine for cesarean section.

BACKGROUND: The aim of this prospective, blind study was to determine the minimum effective dose of hyperbaric bupivacaine required for cesarean section. METHODS: With Ethical Committee approval and written consent, 24 healthy women undergoing elective cesarean section received a combined spinal epidural anesthesia. We sought to determine the minimum effective dose of spinal bupivacaine using a staircase method. In each patient an arbitrary dose of 0.5% hyperbaric bupivacaine in relation to patient height was used. The initial dose was 0.075 mg/cm height, while the outcome of each patient's response determined the dose for the subsequent patient. When successful spinal block (sensory level = or < T4 with complete motor blockade) was achieved within 20 min from spinal injection, the dose of spinal bupivacaine for the next patient was decreased by 0.01 mg/cm height. Conversely, when successful spinal block was not observed, the dose of spinal bupivacaine for the next patient was increased by 0.01 mg/cm height. Sensory and motor blocks were evaluated every 5 min by an independent, blinded observer. If successful spinal block was not achieved within the designed period, a 5-8 ml epidural bolus of 2% lidocaine was given to achieve adequate surgical anesthesia. RESULTS: No complications were reported during the study, and all women delivered their baby uneventfully (APGAR scores 5 min after delivery ranged from 9 to 10) within 5 min from uterus incision. The duration of surgical procedure ranged from 30 to 48 minutes. The dose of hyperbaric bupivacaine providing adequate surgical anesthesia within 20 min from spinal injection in 50% of subjects was 0.036 mg/cm height (95% confidence intervals: 0.031-0.041 mg/cm height). The ED95 calculated from the probit transformation to provide effective spinal anesthesia for cesarean section was 0.06 mg/cm height. CONCLUSIONS: This prospective, blind study demonstrated that a dose as low as 0.06 mg/cm height represents the dose of intrathecal bupivacaine providing effective spinal block in 95% of women undergoing elective cesarean section.

Adult↗
PubMedDate not supplied

The use of hydrogen peroxide in the experimental therapy of cysts. An in vitro analysis.

AIM: Aim of the authors is to evaluate in vitro the histological alteration caused by hydrogen peroxide on a sample of radicular cysts. METHODS: Twelve radicular cysts were divided into 2 portions. The control group was histologically evaluated whereas the other portion, test, was treated with 3% hydrogen peroxide before histological analysis. Test and control portions were compared for integrity of the epithelium, inflammatory state of the cystic walls, presence of necrosis, stromal vacuolization and microvessel density (MVD). MVD was evaluated by immunohistochemistry using anti-CD34 monoclonal antibodies. RESULTS: Significantly lower epithelium integrity has been detected in the test group (p= or <0.007), (Wilcoxon test). Moreover, the test group presented a higher number of stromal vacuolization areas (p= or <0.004). However, necrosis and inflammation reported no significative differences. No significative differences were noticed for the MVD. CONCLUSION: Hydrogen peroxide showed a cytopathic and cytolytic activity in vitro. Those effects have been shown on both cysts tissues: epithelium and connective tissue. The present study did not reveal any statistically significant difference between the number of vessels in the control and in the test group. However, further in vitro and human studies are needed to validate this substance in the treatment of cysts.

Blood Vessels↗
PubMedDate not supplied

New technology for noninvasive brain monitoring: continuous cerebral oximetry.

Although the central nervous system is the primary endpoint of most general anesthetics, it is still the least monitored organ in clinical anesthesiology. In the last decade, technological research has expanded the application of near-infrared spectroscopy to allow continuous, non-invasive, and bedside monitoring of cerebral oxygen saturation (rSO(2)) through the scalp and skull, providing accurate information on the balance between brain oxygen supply and demand. The aim of this review is to provide an overview on relevant technological issues of cerebral oximetry, describe a systematic approach to its use, and summarize current information on its possible impact on our daily practice. We reviewed studies published on peer-reviewed journals about technological development and clinical application of rSO(2) monitoring in different fields of application to clinical practice. Due to the wide patient-to-patient variability of baseline rSO(2) values in each patient the baseline value should be determined before inducing general anesthesia, and cerebral ischemia is related more to the changes from baseline than to the absolute value: a reduction of 20% from baseline is usually accepted as clinical threshold of cerebral ischemia. If baseline rSO(2) is lower than 50% the critical threshold should be reduced to 15%. Routine use of rSO(2) monitoring in patients undergoing cardiac surgery to guide the anesthesia plan has been demonstrated to improve patient outcome and shorten hospital stay. However, rSO(2) monitoring does not seem to provide information accurate enough to indicate the placement of a Javid's shunt during carotid endarterectomy. In patients with neurological pathology or head trauma rSO(2) monitoring has been reported accurate enough in detecting early changes in cerebral blood flow that might result in cerebral ischemia. In aged patients undergoing major abdominal surgery rSO(2) monitoring to guide the anesthesia plan has been reported to reduce the exposition to cerebral ischemia with less effects on cognitive decline and shorter hospital stay. In conclusion several clinical conditions routinely encountered in our daily practice have the potential to disrupt the balance between the brain oxygen supply and demand, exposing to the risk of intraoperative cerebral ischemia. These alterations in brain oxygen balance remain totally undiagnosed if we do not specifically monitor it; while the possibility of monitoring regional cerebral oxygen saturation through a simple and totally non-invasive device has the potential for optimizing our anesthesia plan to the real needs of our main targeted organ: the brain.

Brain Chemistry↗
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Comparison between hemodynamic changes after single-dose and incremental subarachnoid anesthesia.

BACKGROUND AND OBJECTIVES: The depressant activity on sympathetic tone of subarachnoid anesthetic block is well known. The aim of this study was to compare cardiovascular response to an incremental dose of subarachnoid anesthesia administered through a small-bore microcatheter with the response to single-dose spinal anesthesia. METHODS: The 26 ASA I or II patients, 45-65 years old, who were undergoing elective gynecologic, urologic, or orthopaedic surgery, were randomized into two groups of 13 each: the first group (SSA) underwent single-shot spinal anesthesia with 1% hyperbaric bupivacaine (0.27 mg/kg), while the second group (CSA) received an incremental 5-mg bolus of the same solution via a subarachnoid 32-gauge microcatheter every 10 minutes. All patients were premedicated and prehydrated with Ringer's acetate 8-10 mL/kg, infused over a 30-minute period. Heart rate, systolic, mean, and diastolic arterial blood pressure, arterial blood gas analysis, and cardiac index (measured by the noninvasive indirect Fick method) were recorded prior to preoperative subarachnoid anesthesia and then 15, 30, and 45 minutes after the first local anesthetic administration. RESULTS: The anthropometric parameters of the patients were homogeneous. No problems regarding anesthetic procedures occurred during the study, and none of the patients developed neurologic sequelae prior to discharge from the hospital. No relevant changes in blood gas parameters were found during the study in either the CSA or the SSA group. With regard to hemodynamic parameters, a significant reduction of systolic, diastolic, and mean arterial blood pressure was found in the SSA group following subarachnoid local anesthetic injection, while arterial pressures did not decrease in the CSA group. Cardiac index showed a nonsignificant increase with respect to baseline values in both groups, with no differences between groups during the study. CONCLUSIONS: In well-hydrated, healthy patients incremental local anesthetics offer adequate subarachnoid anesthesia with minimal hemodynamic effects.

Aged↗
PubMedDate not supplied

Block distribution and cardiovascular effects of unilateral spinal anaesthesia by 0.5% hyperbaric bupivacaine. A clinical comparison with bilateral spinal block.

BACKGROUND: A low dose of hyperbaric local anaesthetic solution, pencil point needle and slow speed of intrathecal injection have been reported to obtain a unilateral distribution of spinal anaesthesia. This should also minimize cardiovascular effects of spinal block. The aim of this prospective, randomized, parallel group study was to evaluate cardiac performance during unilateral subarachnoid block and to compare it with that produced by standard bilateral spinal anaesthesia. METHODS: With Ethic Committee approval and patients' consent we studied 30 ASA I-II patients scheduled for one leg surgery. Dural puncture was performed by 25-G Whitacre needle with patients lying in the lateral position and the side to be operated on dependent. Patients then randomly received 8 mg of 0.5% hyperbaric bupivacaine injected over 80 sec with needle hole orientated towards the dependent side (Unilateral, n = 15), or 15 mg of the same solution injected over 6 sec with needle bevel cranially directed (Control, n = 15). Only patients of the Unilateral group remained in the lateral position for 15 min. Noninvasive Arterial blood pressure, heart rate, stroke volume index and cardiac index were measured before spinal block (baseline) and then at 5, 15, 30 and 45 min; while sensory and motor blocks were evaluated at 15, 30 and 45 min on both sides. RESULTS: Unilateral spinal anaesthesia was observed in 11 patients of the Unilateral group (73%). Three patients of the Control group (20%) required colloids for intraoperative hypotension. Mean arterial blood pressure and heart rate decreased from baseline only in the Control group (p = 0.001 and p = 0.0003 respectively), while heart rate was decreased in Control even when compared to Unilateral group (p = 0.01). The stroke volume index was unchanged in the two groups (p = 0.22), while the cardiac index showed a 15-20% decrease from baseline in Control group (p = 0.001), with a significant decrease at 30 and 45 min when compared to Unilateral (p = 0.01). DISCUSSION: The use of 8 mg of 0.5% hyperbaric bupivacaine slowly injected through a directional needle provided a spinal block relatively restricted to the operative side with minimal effects on cardiovascular homeostasis.

Aged↗
PubMedDate not supplied

Incidence of hypotension and bradycardia during integrated epidural/general anaesthesia. An epidemiologic observational study on 1200 consecutive patients. Italian Study Group on Integrated Anaesthesia.

BACKGROUND: Combined epidural/general anaesthesia might theoretically emphasise the cardiovascular effects of epidural block alone. The goal of the present investigation was to evaluate the incidence of both hypotension and bradycardia during integrated epidural/general anaesthesia in a multicentric, observational study. METHODS: The incidence of clinical hypotension (systolic arterial blood pressure decrease by 30% or more from baseline), and bradycardia (heart rate < 50 beats/min) and other side effects have been evaluated in 1200 consecutive patients receiving integrated epidural/general anaesthesia. The time from induction of epidural anaesthesia to induction of general anaesthesia was considered as preoperative; while the time after general anaesthesia induction was considered as intraoperative. RESULTS: Preoperatively hypotension developed in 85 patients (2.8%), and bradycardia in 54 patients (4.5%). Intraoperatively, hypotension was observed in 380 patients (31.6%), and bradycardia in 153 patients (12.7%). Hypotension and bradycardia were not influenced by the type of surgical procedure, the type of maintenance of general anaesthesia (inhalational versus total intravenous general anaesthesia) and the level of epidural block (lumbar versus thoracic); but they were more frequent in patients with ASA physical status II and III-IV compared to patients with ASA physical status I (p < 0.05). Prophylactic volume preload decreased the incidence of hypotension from 41.5% to 22.4% (p < 0.0001), while prophylactic atropine before epidural block did not affect the incidence of bradycardia. Patients receiving epidural clonidine showed an increased incidence of intraoperative bradycardia compared to those who did not receive it (p < 0.0001). DISCUSSION: Randomized, controlled studies should be advocated in order to compare the incidence of hypotension and bradycardia during integrated anaesthesia and during epidural block alone. Our results demonstrated that the use of integrated epidural/general anaesthesia produces an incidence of perioperative hypotension and bradycardia similar to that reported when central blocks are used alone.

Adult↗