Best practice & research. Clinical anaesthesiology
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Best Pract Res Clin Anaesthesiol · Sep 2003
Review Comparative StudyNeurotoxicity of intrathecal local anaesthetics and transient neurological symptoms.
Local anaesthetics have been placed in the intrathecal space for approximately 100 years. Currently used intrathecal local anaesthetics appear to be relatively benign on the basis of the low incidence of permanent neurological deficits. In large retrospective surveys of 4000-10 000 patients, the incidence of persistent neurological sequelae after subarachnoid anaesthesia varies between 0.01 and 0.7%. ⋯ Concern about the use of spinal lidocaine began in 1991 with published reports of cauda equina syndrome after continuous spinal anaesthesia. In 1993, Schneider published a case report of four patients undergoing spinal anaesthesia who postoperatively experienced aching and pain in the buttocks and lower extremities. This chapter reviews the neurotoxicity of spinal local anaesthetics, as well as the incidence, possible aetiology, and treatment of transient neurological symptoms after lidocaine spinal anaesthesia.
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Best Pract Res Clin Anaesthesiol · Sep 2003
ReviewPhysiology of spinal anaesthesia and practical suggestions for successful spinal anaesthesia.
There are numerous physiological effects of spinal anaesthesia. This chapter focuses on the physiological effects that are of clinical relevance to the anaesthesiologist, and provides suggestions for successful management of this simple and popular technique. The mechanisms and clinical significance of spinal-anaesthesia-induced hypotension, bradycardia and cardiac arrest are reviewed. ⋯ The importance of thermoregulation during spinal anaesthesia, and the clinical consequences of spinal-anaesthesia-induced hypothermia are reviewed. Effects of spinal anaesthesia on ventilatory mechanics are also highlighted. Lastly, the sedative and minimum-alveolar-concentration-sparing effects of spinal anaesthesia are discussed to reinforce the need for the judicious use of sedation in the perioperative setting.
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Best Pract Res Clin Anaesthesiol · Sep 2003
Review Comparative StudyLocal anaesthetics and additives for spinal anaesthesia--characteristics and factors influencing the spread and duration of the block.
Different characteristics of patients and local anaesthetic formulations will influence the spread of spinal anaesthesia. The predictability of the spread of spinal anaesthesia can be improved by altering both baricity of the solution, and the position of the patient during the intrathecal local anaesthetic injection. The role of adrenaline and clonidine in prolonging the block and associated side effects is discussed. The role of opioids added to local anaesthetic solutions is discussed from a cost/benefit point of view.
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Best Pract Res Clin Anaesthesiol · Sep 2003
Review Comparative StudySpinal anaesthesia for outpatient surgery.
Spinal anaesthesia in the outpatient is characterized by rapid onset and offset, easy administration, minimal expense, and minimal side effects or complications. Spinal anaesthesia offers advantages for outpatient lower extremity, perineal, and many abdominal and gynaecological procedures. Development of small-gauge, pencil-point needles are responsible for the success of outpatient spinal anaesthesia with acceptable rates (0-2%) of postdural puncture headache (PDPH). ⋯ Lidocaine remains the most useful agent for outpatient spinal anaesthesia. For longer procedures, mepivacaine is an excellent spinal anaesthetic agent. Attention to technique, reduction of dose and addition of fentanyl to lidocaine result in effective spinal anaesthesia with rapid recovery and a low incidence of significant side effects or complications.
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In the treatment of chronic benign pain, the administration of an intrathecal opioid produces a potent analgesia without interfering with the motor and sensory functions of the lower extremities. An intrathecal opioid should be considered only when pain control with conventional oral and systemic administration is inadequate or is associated with unmanageable side effects. A trial period and a psychological evaluation are mandatory prior to implantation of a permanent device. ⋯ Catheter granulomas can form with high concentrations of morphine. Adjuvant drugs such as bupivacaine, clonidine and ketamine might be necessary to deal with the development of tolerance to morphine. The sophistication of available technology for intrathecal infusion today far exceeds our knowledge of the potential neurological effects of this treatment modality.