Predictors of the variability in neuromuscular block duration following succinylcholine: A prospective, observational study.

Background: The duration of neuromuscular block (NMB) following succinylcholine administration is characterised by a high interindividual variability. However, this has not yet been quantified in a large sample of surgical patients. The significance of underlying clinical factors is unknown.

Perioperative administration of fibrinogen does not increase adverse cardiac and thromboembolic events after cardiac surgery.

Background: Although infusion of fibrinogen concentrate is increasingly used in bleeding patients after cardiac surgery, safety data are scarce. We aimed to evaluate the effect of perioperative administration of fibrinogen concentrate on postoperative morbidity and mortality in patients undergoing cardiac surgery.

Methods: During a 2 yr study period, 991 patients underwent cardiac surgery at a single university centre and were eligible for propensity score (PS) matching.

Spinal anesthesia revisited: toxicity of new and old drugs and compounds.

Purpose Of Review: Neural toxicity of substances injected into the intrathecal space has been a matter of debate since the introduction of spinal anesthesia in clinical practice. In recent years, new local anesthetics and adjuvants have been proposed for intrathecal use, and new techniques such as the use of ultrasound have been propagated. The present review summarizes recent clinical and experimental data on the neurotoxic effects of drugs and substances used for or in conjunction with spinal anesthesia.

Speed spinal anesthesia revisited: new drugs and their clinical effects.

Purpose Of Review: Spinal anesthesia (SPA) has not been popular for day-case surgery because of prolonged neurologic blockade with long-acting local anesthetics such as bupivacaine, thereby delaying discharge. Although the intermediate duration of action of lidocaine and mepivacaine appears to be more suitable for day-case surgery, their use is not deemed appropriate by many because of a high incidence of transient neurologic symptoms (TNSs). The present review summarizes recent clinical data on the intrathecal use of alternative local anesthetics and adjuvants that may offer valuable alternatives to general anesthesia in day-case surgery.

Bupivacaine concentrations in lumbar cerebrospinal fluid in patients with failed spinal anaesthesia.

Background: Spinal anaesthesia (SA) has high success rates. However, inadequate block after SA has been reported even in the absence of technical problems. Various mechanisms for failed SA (FSA) have been proposed, but reports of cerebrospinal fluid (CSF) concentrations of local anaesthetics (LA) after FSA are scarce.

Toxicity of spinal local anaesthetics.

Recent reports of severe neurological injury after spinal anaesthesia have generated concerns about the neurotoxic potential of local anaesthetics and, in particular, of lignocaine. Further, there is an increasing body of evidence indicating that transient neurological symptoms commonly occur after uneventful lignocaine spinal anaesthesia but not after bupivacaine. Results from an epidemiological study suggest that patient positioning and outpatient status are major co-factors.

Epinephrine increases the neurotoxic potential of intrathecally administered lidocaine in the rat.

Background: Epinephrine is commonly added to lidocaine solutions to increase the duration of spinal anesthesia. Despite this common usage, the effect of epinephrine on the neurotoxic potential of this anesthetic is not known. The current experiments investigated whether adding epinephrine increases functional impairment or histologic damage induced by spinal administration of lidocaine in the rat.

Teaching the use of fiberoptic intubation in anesthetized, spontaneously breathing patients.

Unlabelled: In patients with difficult airways, the standard of care involves fiberoptic intubation under spontaneous ventilation. However, the safety and feasibility of a fiberoptic intubation teaching program has only been documented in paralyzed and apneic patients, whereas data obtained in patients under spontaneous respiration are limited and conflicting. We evaluated 100 anesthetized patients undergoing orotracheal fiberoptic intubation.

Mechanism of antinociceptive action of clonidine in nonmyelinated nerve fibres.

Despite a large body of clinical evidence in favour of a local anesthetic effect of clonidine, the underlying mechanism has not yet been elucidated. In this study we have used the sucrose-gap method to measure the effects of clonidine on the electrophysiological properties of nonmyelinated nerve fibers in the rabbit vagus nerve. The results showed that clonidine enhanced the hyperpolarizing and reduced the depolarizing afterpotential that follow compound action potentials during electrical activity.

Gastric intramucosal pH-guided therapy in patients after elective repair of infrarenal abdominal aneurysms: is it beneficial?

Objective: To determine if gastric intramucosal pH (pHi)-guided therapy reduces the number of complications and length of stay in the intensive care unit (ICU) or the hospital after elective repair of infrarenal abdominal aortic aneurysms.

Design: Prospective, randomized study.

Setting: Surgical intensive care unit (SICU) of a University Hospital.

Propofol reduces succinylcholine induced increase of masseter muscle tone.

Purpose: Succinylcholine is known to increase the tone of the masseter muscles. As excessive jaw tension may complicate rapid sequence induction, we investigated three induction techniques, all including the use of succinylcholine, with respect to masseter muscle tone, neuromuscular blockade, intubation conditions, and time course of intubation.

Methods: Sixty adult patients were allocated to one of three induction groups: Group THIO received 5 mg.

Lidocaine toxicity in primary afferent neurons from the rat.

Evidence from both clinical studies and animal models suggests that the local anesthetic, lidocaine, is neurotoxic. However, the mechanism of lidocaine-induced toxicity is unknown. To test the hypothesis that toxicity results from a direct action of lidocaine on sensory neurons we performed in vitro histological, electrophysiological and fluorometrical experiments on isolated dorsal root ganglion (DRG) neurons from the adult rat.

Combined effect of patient variables on sensory level after spinal 0.5% plain bupivacaine.

Background: The combined effect of age, weight, height, and vertebral column length (VCL) on the distribution of isobaric 0.5% bupivacaine within the subarachnoid space is unclear. The aim of the present study was to evaluate the combined influence of these patient variables on the upper sensory level and on its predictability.

Preoperative anxiolysis with minimal sedation in elderly patients: bromazepam or clorazepate-dipotassium?

Background: In elderly patients undergoing ophthalmic surgery the loss of co-operation due to over-sedation, induced by drugs given preoperatively, may jeopardise the success of microsurgery performed under regional anaesthesia. The aim of this study was to compare the psychotropic effects of bromazepam and clorazepate-dipotassium, two benzodiazepines with predominantly anxiolytic and only weak sedative action.

Methods: A randomised, placebo-controlled, double-blind study was designed to include 60 patients, ASA physical status II-III, older than 60 years scheduled for ophthalmic surgery under regional anaesthesia.

Transient neurologic symptoms after spinal anesthesia: a lower incidence with prilocaine and bupivacaine than with lidocaine.

Background: Recent evidence suggests that transient neurologic symptoms (TNSs) frequently follow lidocaine spinal anesthesia but are infrequent with bupivacaine. However, identification of a short-acting local anesthetic to substitute for lidocaine for brief surgical procedures remains an important goal. Prilocaine is an amide local anesthetic with a duration of action similar to that of lidocaine.

[Perioperative gastrointestinal ischemia in abdominal aortic aneurysm operations].

Questions Under Study: Surgery of abdominal aortic aneurysms involves a high risk of postoperative complications. It has been suggested that the incidence of postoperative complications is related to the development of gastrointestinal acidotic episodes of the mucosa. The goal of this study was, therefore, to determine the incidence of gastrointestinal acidotic episodes during repair of abdominal aortic aneurysms, and to test the hypothesis that these episodes predict an adverse postoperative course.

Teaching the use of fiberoptic intubation for children older than two years of age.

Unlabelled: In 144 anesthetized children aged 2-9 yrs, the safety and feasibility of orotracheal fiberoptic intubation, with and without an airway endoscopy mask, were assessed and compared with laryngoscopic intubation. Eight anesthesia residents with experience in adult fiberoptic intubation, but who were beginners in pediatric anesthesia, participated in this study. In a randomized fashion, each resident intubated 18 children (6 in each group).

A similar incidence of transient neurologic symptoms after spinal anesthesia with 2% and 5% lidocaine.

Recent reports suggest that transient neurologic symptoms are common after spinal anesthesia with 5% lidocaine. To determine whether reducing the anesthetic concentration might decrease the incidence of symptoms, 50 ASA class I or II patients undergoing brief gynecologic procedures under spinal anesthesia were randomly allocated to receive 1 mg/kg of either 5% or 2% lidocaine in 7.5% glucose.

Transient radicular irritation after single subarachnoid injection of isobaric 2% lignocaine for spinal anaesthesia.

Several cases have been reported recently in which symptoms suggestive of transient radicular irritation occurred following the use of hyperbaric 5% lignocaine for spinal anaesthesia. We report on three patients in whom we observed similar symptoms attributable to this kind of radicular irritation following uneventful spinal anaesthesia using isobaric 2% lignocaine. All three patients underwent minor gynaecological procedures and developed burning pains in the buttocks within 24 h of surgery.

Intravenous sedation for retrobulbar injection and eye surgery: diazepam and/or propofol?

Principle goals of sedation for eye surgery are to provide patient comfort and to allow the patient to stay calm during both retrobulbar injection and surgery. Insufficient sedation may not prevent the patient from moving during retrobulbar injection, whereas very deep sedation may result in respiratory complications during surgery. The aim of the present study was to evaluate the effectiveness and suitability of a combination of diazepam and propofol for sedation for both application of retrobulbar block and subsequent elective eye surgery.

Transient neurologic symptoms after spinal anesthesia.

We recently reported several cases consistent with transient radicular irritation after spinal anesthesia with hyperbaric 5% lidocaine. The present prospective, blind, nonrandomized study was performed to determine the incidence of these transient neurologic symptoms and to identify factors that might be associated with their occurrence. We studied 270 patients scheduled for gynecologic or obstetric procedures under spinal anesthesia.

Hyperosmolarity does not contribute to transient radicular irritation after spinal anesthesia with hyperbaric 5% lidocaine.

Background And Objectives: In addition to major neurologic injury, local anesthesia toxicity may also include less severe but more common neurologic side effects. The authors recently observed symptoms suggestive of transient radicular irritation in one third of patients after spinal anesthesia with hyperbaric 5% lidocaine, whereas evidence of neurologic symptoms was lacking with hyperbaric 0.5% bupivacaine.

Perioperative administration of caffeine tablets for prevention of postoperative headaches.

Interruption of daily caffeine consumption can cause caffeine withdrawal headache. As headache ranks among the most frequent minor postoperative sequelae, the impact of perioperative substitution of caffeine on the incidence of postoperative headache was evaluated. Forty patients undergoing minor surgical procedures with general anaesthesia were randomly allocated to receive either placebo or caffeine tablets at a dosage equal to their individual average daily caffeine consumption.