Background and objective To investigate the effects of the perineural injection of lidocaine or corticosteroids on radicular blood flow during spinal surgery.

Methods After lumbar discectomy, a probe for laser Doppler flowmetry was placed directly on the 4th or 5th lumbar nerve root. Thirty patients undergoing lumbar discectomy were randomly assigned to one of three groups. Each group received one of three protocols for a perineural injection to the nerve root: 1.0 mL 0.9% saline in group A, 1.0 mL 1% lidocaine in group B or 1.0 mL dexamethasone (4 mg) in group C. Measurements included radicular blood flow, mean arterial pressure, haemoglobin concentration, percutaneous oxygen saturation and end-tidal carbon dioxide tension. Radicular blood flow was measured by laser Doppler flowmetry before the injection and 15 min after these injections. The three groups were similar with respect to mean arterial pressure, haemoglobin concentration, percutaneous oxygen saturation and end-tidal carbon dioxide tension.

Results Radicular blood flow did not change after the injection in any of the groups.

Conclusions The results suggest that the perineural injection of 1% lidocaine or dexamethasone does not affect radicular blood flow during lumbar discectomy.

As is often the case in medicine, the risk to benefit ratio of blood transfusion requires careful examination. The decision to transfuse a patient cannot be based only on the haemoglobin or the haematocrit concentration. In a given clinical situation, tolerance to anaemia will depend on the ability of the patient to recruit his compensatory mechanisms in accordance with his metabolic demand. Maintenance of circulating volume is of paramount importance. In the absence of a universal transfusion trigger, decision to transfuse a patient with an haemoglobin concentration between 7.0 and 10.0 g dL−1 depends primarily on clinical judgement. With the exception of emergency situations, blood transfusion will be realized on a unit-by-unit basis, and the efficacy of treatment should be evaluated after each transfused unit.

The aim of specific monitoring in neuroanaesthesia is to detect, as quickly as possible, intraoperative ischaemic insults so that the brain and the spinal cord may be protected from harmful and frequently inevitable events due to the type of surgery, patient positioning, haemodynamic changes or any intercurrent event. New monitors are being introduced into the operating theatre, but only a few are considered to be an absolute standard of care in neurosurgery, e.g. facial nerve monitoring for surgery of acoustic neuromas and recording of evoked potentials during repair of scoliosis. In the past decade, new monitoring devices have moved from the experimental stage to the operating theatre and although most are still in a phase of technological development and/or definition of their field of applicability they are being used as guides for clinical practice in those instances where cerebral well-being might be impaired. The metabolic consequences of hyperventilation, pharmacological electroencephalogram burst suppression, hypothermia, etc. can now be assessed in the operating theatre. Non-invasive monitoring is being rapidly integrated into our daily work because of its lack of secondary effects. Nevertheless, each new development is regarded as an addition rather than as a substitute for existing equipment. The perfect combination of monitors to provide essential information during an individual surgical procedure to influence a better patient outcome, is still uncertain and needs extensive clinical research.

Health care systems throughout the world are faced with continuously rising health care expenditure. In Germany, a fee per capita system will be introduced by 2003 to keep the budgets for hospital care within limits. As a result, numbers of hospital beds and hospitals will be cut in the coming years. On the other hand, more and more patients and health care providers are asking if they are really receiving an adequate value for their money in the treatment they receive. All this will have a strong impact on the anaesthesiologist's work and her/his perception of the different facets of quality.

Quality has various aspects for the anaesthesiologist. The patient as a customer should not incur any detrimental effects after a surgical procedure, and is accompanied by the anaesthesiologist throughout the perioperative setting. The surgeon needs optimal conditions to perform a procedure. The hospital must balance equally costs and income; this requires optimal operating room utilization. Finally, health insurance companies and the government are responsible for covering the cost of treatment according to the quality of the care delivered.

Quality assessment concerning structure, process and outcome has to take these demands into account. Continuous quality improvement in the spirit of Deming's ‘plan-do-check-act cycle’ has to be part of anaesthesiologist's everyday routine. In future, the traditional barriers between the specialities treating a patient will be disrupted when reimbursement for treatment is made according to quality and efficacy of treatment.

Malignant hyperthermia is an autosomal-dominant inherited disorder of the skeletal muscle cell characterized by a hypermetabolic response to all commonly used inhalational anaesthetics and depolarizing muscle relaxants. The clinical syndrome includes muscle rigidity, hypercapnia, tachycardia and myoglobinuria as result of increased carbon dioxide production, oxygen consumption and muscle membrane breakdown. In human beings and animals susceptible to malignant hyperthermia, it is generally accepted that an increase in the level of myoplasmic free calcium is the cause of the syndrome. Various hypotheses have been proposed to account for the increase of intracellular calcium levels, e.g. a defect in the calcium release channel of the sarcoplasmic reticulum (ryanodine receptor), an abnormality of the excitation-contraction coupling mechanisms, or alterations in second messenger systems of skeletal muscles. This review gives an overview of the main features of this disease and recent advances in research including pathophysiology, treatment, diagnosis and genetics as well as association with other disorders.