PubMed Health⌕ Search

Biomedical subjects

N B Scott

Publications and source records attributed to N B Scott.

At least 19 recordsLinked to original sources

The risk of vertebral canal complications in 2837 cardiac surgery patients with thoracic epidurals.

BACKGROUND: Recent communications in the medical press have suggested that the rate of vertebral canal complications following epidural catheter placement is increasing in frequency, in particular the incidence of epidural abscess (Hearn M. Epidural abscess complicating insertion of epidural catheters. Br J Anaesth 2003; 90 (5): 706-7; Govasi C, Bland D, Poddar R, Horst C. Epidural abscess complicating insertion of epidural catheters. Br J Anaesth 2004; 92 (2): 294-5). We wished to investigate this in our population of cardiac surgical patients. METHODS: We performed a retrospective review of the data from all patients who had undergone coronary artery bypass grafting or valve replacement surgery in our hospital over the past 8 years. This involved a review of computer databases, logbooks, radiology records, admission records, intensive care transfers, pain team ward round data and follow-up outpatient data referrals. RESULTS: In total, 2837 patient admissions were examined and reviewed by the authors. No episodes of vertebral canal haematoma or abscess were observed. CONCLUSIONS: Retrospective analysis of our working practice indicates that thoracic epidural anaesthesia and analgesia are safe in patients receiving cardiac surgery. We found no epidural haematoma or abscess in 2837 patients.

Abscess↗

Spinal cord injury caused by direct damage by local anaesthetic infiltration needle.

We describe a case of spinal cord injury caused by direct trauma from a local anaesthetic infiltration needle. During local anaesthetic infiltration before placement of an epidural catheter, the patient suddenly rolled over onto her back, causing the infiltrating needle to advance all the way to its hub. She immediately showed signs of spinal cord injury, confirmed by MRI scan. However, her neurological status gradually improved, and on discharge she was able to walk, with a sensory deficit localized to her left foot.

Adult↗

A prospective randomized study of the potential benefits of thoracic epidural anesthesia and analgesia in patients undergoing coronary artery bypass grafting.

We performed an open, prospective, randomized, controlled study of the incidence of major organ complications in 420 patients undergoing routine coronary artery bypass graft surgery with or without thoracic epidural anesthesia and analgesia (TEA). All patients received a standardized general anesthetic. Group TEA received TEA for 96 h. Group GA (general anesthesia) received narcotic analgesia for 72 h. Both groups received supplementary oral analgesia. Twelve patients were excluded-eight in Group TEA and four in Group GA-because of incomplete data collection. New supraventricular arrhythmias occurred in 21 of 206 patients (10.2%) in Group TEA compared with 45 of 202 patients (22.3%) in Group GA (P = 0.0012). Pulmonary function (maximal inspiratory lung volume) was better in Group TEA in a subset of 93 patients (P < 0.0001). Extubation was achieved earlier (P < 0.0001) and with significantly fewer lower respiratory tract infections in Group TEA (TEA = 31 of 206, GA = 59 of 202; P = 0.0007). There were significantly fewer patients with acute confusion (GA = 11 of 202, TEA = 3 of 206; P = 0.031) and acute renal failure (GA = 14 of 202, TEA = 4 of 206; P = 0.016) in the TEA group. The incidence of stroke was insignificantly less in the TEA group (GA = 6 of 202, TEA = 2 of 206; P = 0.17). There were no neurologic complications associated with the use of TEA. We conclude that continuous TEA significantly improves the quality of recovery after coronary artery bypass graft surgery compared with conventional narcotic analgesia.

Analgesia, Epidural↗

A comparison of the antibacterial activity of levobupivacaine vs. bupivacaine: an in vitro study with bacteria implicated in epidural infection.

The purpose of the study was to compare the antibacterial activity of bupivacaine with levobupivacaine against a range of bacteria implicated in epidural infection to determine whether any differences existed between the two drugs. Concentrations of 0.125%, 0.25% and 0.5% bupivacaine and levobupivacaine were inoculated with suspensions of either Staphylococcus epidermidis, Staphylococcus aureus or Enterococcus faecalis. After incubation, the mixtures were plated onto blood agar and colony counts were recorded after a further period of incubation. The minimum bactericidal concentration of local anaesthetic against the three bacteria studied was found to be 0.25% for bupivacaine and 0.5% for levobupivacaine showing racemic bupivacaine to have a more potent antibacterial action than levobupivacaine. This finding suggests that the dextrobupivacaine isomer of racemic bupivacaine has a more potent antibacterial action than the levobupivacaine isomer.

Anesthesia, Epidural↗

An epidural scoring scale for arm movements (ESSAM) in patients receiving high thoracic epidural analgesia for coronary artery bypass grafting.

Thoracic epidural analgesia appears to improve the outcome of patients undergoing coronary artery bypass graft surgery. Cranial extension of nerve blockade involving the third, fourth and fifth cervical nerve roots can cause apnoea. However, progressive paraesthesia and weakness due to cephalad spread of thoracic epidural analgesia will affect the arms before the diaphragm. A scale was designed to test three active movements of the arms bilaterally: hand grip (T1/C8), wrist flexion (C8/7) and elbow flexion (C6/5). This epidural scoring scale for arm movements (ESSAM) consists of four grades (0-3) based on the number of absent movements, and suggests appropriate action. The reliability of this scale was tested in 40 patients undergoing coronary artery bypass surgery. Twelve of the 40 patients had their epidural infusion reduced on the basis of the scale. Of these 12 patients, eight had a worst ESSAM score of 1, three had a worst score of 2 and one had a worst score of 3. In each patient, motor power returned following the reduction in infusion rate, taking between 30 min and 3 h. This scale appears to be a simple and reliable method for the early detection of the cephalad spread of thoracic epidural analgesia.

Adult↗

Extradural S(-)-bupivacaine: comparison with racemic RS-bupivacaine.

Bupivacaine has a chiral centre and is currently available as a racemic mixture of its two enantiomers: R(+)-bupivacaine and S(-)-bupivacaine. Preclinical studies have demonstrated that there is enantiomer selectivity of action with the bulk of central nervous system and cardiovascular toxicity residing with the R(+) isomer. The aim of this study was to compare the clinical efficacy and safety of S(-)-bupivacaine with racemic RS-bupivacaine for extradural anaesthesia. We studied 88 patients undergoing elective lower limb surgery under lumbar extradural anaesthesia who received 15 ml of 0.5% or 0.75% S(-)-bupivacaine, or 0.5% RS-bupivacaine in a randomized, double-blind study. There was no difference in onset time, maximum spread of sensory block or intensity of motor block between the three groups. Duration of sensory block was significantly longer for 0.75% S(-)-bupivacaine. We conclude that S(-)-bupivacaine has similar local anaesthetic characteristics to RS-bupivacaine when used for extradural anaesthesia.

Adult↗

Comparison of S(-)-bupivacaine with racemic (RS)-bupivacaine in supraclavicular brachial plexus block.

Bupivacaine is used widely as a local anaesthetic but has potential for severe cardiovascular and central nervous system (CNS) toxicity. It has an asymmetric carbon atom giving it a chiral centre, and the commercial preparation is a racemic mixture of its two enantiomers: dextro or R(+)-bupivacaine and levo or S(-)-bupivacaine. Preclinical studies have demonstrated reduced cardiotoxicity and CNS toxicity for S(-)-bupivacaine. In this study we have compared the clinical efficacy of S(-)-bupivacaine with racemic RS-bupivacaine for supraclavicular brachial plexus block in 75 patients undergoing elective hand surgery. Patients received 0.4 ml kg-1 of either 0.25% or 0.5% S(-)-bupivacaine or 0.5% RS-bupivacaine in a randomized, double-blind study. Clinical assessments of sensory and motor block were performed at regular intervals. There were no significant differences in onset time, dermatomal spread or duration of both sensory and motor block between the three groups (the power of the study was 81% to detect a 4-h difference in duration). Duration of sensory block was prolonged with wide interpatient variation: 892 (SD 250) min, 1039 (317) min and 896 (284) min for 0.25% S(-)-bupivacaine, 0.5% S(-)-bupivacaine and 0.5% RS-bupivacaine, respectively. There were no differences in the overall success rate of the technique. We conclude that S(-)-bupivacaine was suitable for local anaesthetic use in brachial plexus block anaesthesia.

Adult↗

Antibacterial activity of lidocaine in mixtures with Diprivan.

We have studied the antibacterial activity of different concentrations of 0.005-2% lidocaine (lignocaine) in mixtures with Diprivan (propofol), against micro-organisms commonly implicated in sepsis as a result of extrinsically contaminated Diprivan. Bacterial colony counts were reduced progressively with increasing concentrations of lidocaine. Bacteriostatic and bactericidal concentrations of lidocaine were 0.2-2%. Lidocaine 2% was not bactericidal for one of the seven organisms tested. By inhibiting bacterial replication, lidocaine, when added to Diprivan to reduce pain on injection, may possibly reduce the harmful consequences if extrinsic contamination occurs.

Anesthetics, Combined↗

Public perceptions of postoperative pain and its relief.

In order to evaluate the general public's knowledge of postoperative pain and its management, a simple questionnaire was devised and sent out to five general practices in Scotland and Yorkshire. Questionnaires were completed voluntarily by 529 people attending their general practitioner for reasons not related to surgery. Five hundred and fifteen completed questionnaires were analysed. Two hundred and thirty-nine (46.4%) responders had undergone previous major surgery whereas 267 (51.8%) had not. Attitudes to pain varied greatly and confirm the findings of other surveys that amongst the general public there is little or no understanding of the nature of postoperative pain or of the methods available to treat it. Despite the published literature, the public have a high degree of confidence in the ability of doctors and nurses to treat such pain. Widespread public and professional education is required before further improvements can be made to such a universal and basic clinical problem.

Adolescent↗

Thoracic epidural anaesthesia for coronary artery bypass graft surgery. Effects on postoperative complications.

We have performed a retrospective analysis of the peri-operative course of 218 consecutive patients who underwent routine coronary artery bypass graft surgery in this institution. All patients received a standardised general anaesthetic using target-controlled infusions of alfentanil and propofol. One hundred patients also received thoracic epidural anaesthesia with bupivacaine and clonidine, started before surgery and continued for 5 days after surgery. The remaining 118 patients received target-controlled infusion of alfentanil for analgesia for the first 24 h after surgery, followed by intravenous patient-controlled morphine analgesia for a further 48 h. Using computerised patient medical records, we analysed the frequency of respiratory, neurological, renal, gastrointestinal, haematological and cardiovascular complications in these two groups. New arrhythmias requiring treatment occurred in 18% of the thoracic epidural anaesthesia group of patients compared with 32% of the general anaesthesia group (p = 0.02). There was also a trend towards a reduced incidence of respiratory complications in the thoracic epidural anaesthesia group. The time to tracheal extubation was decreased in the epidural group, with the tracheas of 21% of the patients being extubated immediately after surgery compared with 2% in the general anaesthesia group (p < 0.001). There were no serious neurological problems resulting from the use of thoracic epidural analgesia.

Adult↗

Continuous thoracic epidural analgesia versus combined spinal/thoracic epidural analgesia on pain, pulmonary function and the metabolic response following colonic resection.

BACKGROUND: The neuroendocrine response following major surgery has not been previously influenced by either regional anaesthetic techniques or opioid analgesia probably due to insufficient intraoperative afferent neural blockade. In this study we attempted to determine whether significant inhibition of these pathways could be achieved by combining preoperative high spinal anaesthesia with postoperative thoracic epidural anaesthesia. In theory too, there may be additional benefits over perioperative thoracic epidural anaesthesia on pain and pulmonary dysfunction. METHODS: 20 ASA 1-3 patients undergoing elective colonic surgery were studied. Gp 1 (n = 10) received a high spinal intraoperative block to T4 using 6mls of 0.5% bupivacaine plus continuous epidural 0.125% bupivacaine/0.0025% diamorphine. Gp 2 (n = 10) patients received epidural 0.5% bupivacaine block to T4 plus continuous epidural infusion of 0.125% bupivacaine/0.0025% diamorphine. We measured a) plasma glucose and cortisol at 0, 1, 2, 3, 4, 8 and 24 h; b) forced vital capacity (FVC), forced expiratory volume in the first second (FEV1) and peak flow rate (PFR) preoperatively, at 8 and 24 h; c) visual analogue pain scores (VAS 0-10) at rest, cough and mobilisation at 8 and 24 h; d) block height every hour for 12 hours then 3 hourly; e) 24-hour urine volumes for dopamine, adrenaline and noradrenaline f) 24-hour PCA morphine requirements. RESULTS: The two groups did not differ in age, sex, height, weight, duration of surgery, blood loss or serum albumin. Pain relief was excellent and similar in both groups. The average 24 hour morphine consumption was 10 mg in both groups with no differences in the block height. All the patients had a 30-50% reduction in FEV1, FVC and PFR (P > 0.05). Metabolically, there was no statistical difference between the 2 groups except a higher rise in glucose in Gp1 at 2 and 3 h (P = 0.0312 and 0.014). 24-hour catecholamine studies showed no differences for noradrenaline (P = 0.8), adrenaline (P = 0.47) and dopamine (P = 0.36). CONCLUSIONS: Thoracic epidural bupivacaine/diamorphine infusion provided excellent postoperative analgesia following colonic surgery. An intraoperative combined spinal/epidural technique conferred no additional benefit on analgesia, pulmonary function and the neuroendocrine response.

Adult↗

Prolonged postoperative analgesia for arthrolysis of the elbow joint.

We describe the provision of postoperative analgesia for 6 days for a patient undergoing arthrolysis of the elbow joint. Mobilization of the elbow immediately after operation is essential to maintain movement achieved with surgery and this can be obtained only with effective pain relief. We used continuous infusion of 0.125% bupivacaine and subsequent addition of fentanyl to the infusate, via a catheter inserted supraclavicularly into the sheath of the brachial plexus.

Brachial Plexus↗

The effect of parenteral diclofenac and morphine on duration and height of blockade of continuous epidural infusion of bupivacaine 0.5%.

Twenty-six patients undergoing abdominal hysterectomy (ASA 1-2) were entered into a double-blind randomised trial to determine: (a) whether diclofenac given intravenously could influence the effective duration of a continuous epidural infusion of bupivacaine 0.5%, and (b) whether morphine given intravenously altered the height of the regressing block. A block to T4 was established pre-operatively and a continuous infusion of 0.5% bupivacaine 8 ml.h-1 ran for 14 h. Thirteen patients received 50 mg diclofenac intramuscularly before surgery repeated at 4 and 10 h later and 13 patients received saline intramuscularly. The height of blockade and pain scores were measured hourly. Effective block duration was defined as regression to T10 or lower and/or a pain score of 2 or more. At this point 10 mg of morphine was given intravenously and the height of the block reassessed. Duration of blockade was not significantly prolonged (p > 0.05), but pain scores were significantly reduced with diclofenac (p < 0.01). Morphine did not alter blockade height. It is concluded that epidural bupivacaine and diclofenac act additively on postoperative pain.

Adult↗