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.

Background and objective This study compares the effect of oral clonidine vs. hydroxyzine on the haemodynamic and catecholamine responses to microlaryngoscopy.

Methods Thirty-five ASA II-III patients were included in this double-blind randomized trial. The patients received either hydroxyzine 1 mg kg−1 (n=18) or clonidine 3 μg kg−1 (n = 17) for their oral premedication 100 min before an intravenous induction of anaesthesia using propofol (2–3 mg kg−1) and fentanyl (2 μg kg−1). Arterial pressure and heart rate were measured before premedication, and throughout the procedure and recovery. Plasma catecholamine levels were determined before premedication, after induction, and 1.5, 30 and 120 min after laryngoscopy.

Results Mean arterial pressure was significantly lower after clonidine, whereas there was no difference in heart rate and plasma catecholamine levels between the two groups.

Conclusions Clonidine for premedication significantly decreased mean arterial pressure during microlaryngoscopy and the following recovery phase but did not modify the overall haemodynamic response to the suspension microlaryngoscopic nociceptive stimulus.

Background and objective The amount of procalcitonin eliminated in the urine and the plasma disappearance rate of procalcitonin were evaluated in patients with normal and impaired renal function, because patients with sepsis are a main target group for procalcitonin measurement, and these patients often develop renal dysfunction.

Methods Elimination of procalcitonin in the urine (μg 12 h−1) was measured in 76 patients. In another 67 patients, the 50% plasma disappearance rate (t½, h) was evaluated 48 h after peak concentrations (procalcitonin >2 μg L−1). Renal function was assessed by creatinine clearance.

Results Procalcitonin elimination in the urine was significantly reduced in patients with severe renal dysfunction. However, the plasma disappearance rate correlated only weakly with renal dysfunction (Spearman's rank correlation R = −0.36, P = 0.004, regression t½ = 49.87−0.15 creatinine clearance). The 25% quartile and median were 25.2 h and 30.0 h in patients with normal renal function, and 36.3 h and 44.7 h in patients with severely impaired renal function (creatinine clearance <30 mL min−1).

Conclusions Renal elimination of procalcitonin is not a major mechanism for procalcitonin removal from the plasma. Although the plasma disappearance rate may be prolonged up to 30–50% in some patients with renal dysfunction, clinical diagnostic decisions may not be severely influenced by this moderate prolongation of procalcitonin elimination. We conclude that procalcitonin can be used diagnostically in patients with renal failure as well as in those with normal renal function.

Background and objective To investigate whether the administration of ketamine before induction with propofol produces a smaller decrease in arterial pressure.

Methods Twenty-two patients were assigned to one of two groups to receive either propofol with ketamine (n = 11) or propofol alone (n = 11, control). Anaesthesia was induced with 2 mg kg−1 propofol and 0.5 mg kg−1 ketamine or 2 mg kg−1 propofol alone. Ketamine was administered 1 min prior to induction with propofol. Immediately after induction with propofol, vecuronium (0.15 mg kg−1) was administered. Four minutes after administration of vecuronium, tracheal intubation was performed. Anaesthesia was maintained using sevoflurane (0.5%) in 66% nitrous oxide until 3 min after intubation. Systolic, diastolic and mean arterial pressure and heart rate were recorded on arrival, directly before induction with propofol, prior to tracheal intubation, immediately after intubation and at 3 min after intubation.

Results and conclusions Administration of ketamine before induction with propofol preserved haemodynamic stability compared with induction with propofol alone.

Background and objective Imbalance between cerebral oxygen supply and demand is thought to play an important role in the development of cerebral injury during cardiac surgery with cardiopulmonary bypass.

Methods We studied jugular bulb oxygen saturation, jugular bulb oxygen tension, arterial–jugular bulb oxygen content difference and oxygen extraction ratio in 20 patients undergoing warm coronary artery bypass surgery (34–37°C) with pH-stat blood gas management.

Results Only two patients showed desaturation (jugular bulb oxygen saturation <50%) at 5 min on bypass, and none from 20 min onwards. Multiple regression models were performed after using bypass temperature, mean arterial pressure, cerebral perfusion pressure, haemoglobin concentration and arterial carbon dioxide tension as independent variables, and arterial–jugular bulb oxygen content difference, jugular bulb oxygen saturation, oxygen extraction ratio and jugular bulb oxygen tension as individual dependent variables.

Conclusions We found that jugular bulb oxygen saturation, jugular bulb oxygen tension and oxygen extraction ratio are mainly dependent on arterial carbon dioxide tension, and arterial–jugular bulb oxygen content difference is dependent on arterial carbon dioxide tension and the bypass temperature. Our results suggest jugular bulb oxygenation is mainly dependent on arterial carbon dioxide tension during warm cardiopulmonary bypass.

Background and objective Patients undergoing coronary artery bypass grafting often require volume loading after operation. In this situation hypertonic saline may be beneficial in restoring the haemodynamic balance and removing excess extravascular fluid.

Methods Forty coronary artery bypass grafting patients were randomly assigned to receive either hypertonic saline 7.5% (20 patients) or 0.9% saline (20 patients) as a single dose of 4 mL kg−1 over 30 min in the postoperative rewarming phase in the intensive care unit.

Results Mean arterial pressure increased in the hypertonic saline group from 82 ± 10 (SD) to 104 ± 17 mmHg (P = 0.002 vs. the normal saline group), and the cardiac index rose from 2.3 ± 0.5 to 3.4 ± 0.8 L min−1 m2 (P = 0.002 vs. the normal group). The haemodynamic effect of hypertonic saline lasted only about 1 h. Diuresis was greater in the hypertonic saline group both at 1 h (hypertonic saline: 490 ± 274 vs. normal saline: 204 ± 130mL; P = 0.001) and 10 h (hypertonic saline: 1952 ± 554vs. normal saline: 1421 ± 514mL; P = 0.003).

Conclusions No adverse effects were seen. The hypertonic saline had a strong diuretic effect and may be beneficial in coronary artery bypass graft patients after operations. This is because of its value as a short-term plasma expander and the diuresis eliminates excessive fluid from the body. A larger study is needed to determine whether the benefits outweigh the possible side-effects in these patients.

Background and objective To compare the effects on cardiovascular changes induced by tracheal intubation when small doses of either remifentanil or sufentanil are used in the presence of midazolam.

Methods Thirty normotensive, ASA physical status I–II patients, receiving general anaesthesia for major abdominal surgery, received an intravenous midazolam premedication (0.05 mg kg−1) 10 min before induction. They were randomly allocated to receive in a double-blind fashion an intravenous bolusofeither(a)remifentanil given as a bolus dose 1 μg kg−1 (n = 15), or else (b) sufentanil 0.1 μg kg−1 infused over 60s (n = 15). In each instance this loading dose was followed by a continuous intravenous infusion (0.1 μg kg−1 min−1 or 0.01 μg kg−1 min−1 of remifentanil or sufentanil, respectively). General anaesthesia was induced with propofol (2 mg kg−1), followed by atracurium besilate (0.5 mg kg−1) to facilitate tracheal intubation. Following intubation, the lungs were mechanically ventilated with a 60% nitrous oxide in oxygen mixture and a 1% inspired sevoflurane.

Results Arterial pressure and heart rate were recorded before induction of anaesthesia (baseline), immediately before intubation, immediately after tracheal intubation and every minute for the first five minutes thereafter. No differences in systolic and diastolic arterial pressures were observed between the two groups. At the end of the study period, systolic and diastolic pressures slightly decreased from preinduction values in both groups. Four patients in the remifentanil group (26%) and five patients in sufentanil group (33%) showed at least one systolic pressure value <90 mm Hg during the study period (P = not significant); however, the observed decreases in systolic pressure were transient and did not require treatment. Heart rate values were not affected by tracheal intubation in either group.

Conclusions In healthy normotensive patients without cardiovascular disease the use of a relatively small dose of either remifentanil or sufentanil after standard midazolam premedication results in a similar and clinically acceptable effectiveness in blunting the cardiovascular changes induced by tracheal intubation.

Perioperative myocardial infarction or ischaemia is a potential consequence of cardiac surgery and elevated free fatty acids can increase the severity of myocardial ischaemic damage. We investigated perioperative changes in serum free fatty acids, and other serum lipids, as a consequence of using propofol infusions for cardiac surgery during cardiopulmonary bypass. Twenty-five patients undergoing elective coronary artery bypass grafting were allocated to two groups. One group of 12 patients was given a continuous infusion of propofol and the other group of nine patients received intermittent boluses of midazolam as a hypnotic agent. Serum lipid concentrations were measured at four periods perioperatively. Changes in free fatty acid concentrations were similar between the two groups. Lipid concentrations related to triglyceride in the propofol group decreased on one occasion but subsequently returned to control value. On the other hand, such values in the midazolam group remained lower than control values. Propofol is not a contraindication as an anaesthetic for cardiac surgery in respect of concern regarding the effects of free fatty acids.

A 92-year-old female was scheduled for laparoscopic cholecystectomy. Following intraperitoneal carbon dioxide insufflation and removal of her gallbladder, the patient developed serious haemodynamic deterioration associated with a decrease of both end-tidal carbon dioxide concentration (ETCO2) and chest compliance. Carbon dioxide embolism was suspected and the diagnosis was confirmed by aspiration of 20 mL of foamy blood from the central venous line. The patient was successfully resuscitated after discontinuation of carbon dioxide insufflation and ventilation of the lungs with 100% oxygen. Carbon dioxide embolization must always be suspected during laparoscopic surgery whenever sudden haemodynamic deterioration associated with a decrease in ETCO2 and chest compliance occur.