Effect of a fluid challenge on the Surgical Pleth Index during stable propofol-remifentanil anaesthesia.
; VERSCHEURE, Sara ; et al
in Acta Anaesthesiologica Scandinavica (2012), 56(6), 787-96
BACKGROUND: The Surgical Pleth Index (SPI), derived from pulse amplitude and heartbeat interval, is proposed to monitor anti-nociception during anaesthesia. Its response to noxious stimulation can be ... [more ▼]
BACKGROUND: The Surgical Pleth Index (SPI), derived from pulse amplitude and heartbeat interval, is proposed to monitor anti-nociception during anaesthesia. Its response to noxious stimulation can be affected by the intravascular volume status. This study investigated the effect of a fluid challenge (FC) on SPI during steady-state conditions. METHODS: After Institutional Review Board approval, 33 consenting patients undergoing neurosurgery received a 4 ml/kg starch FC over less than 5 min under stable surgical stimulation conditions and stable propofol (Ce(PPF) ) and remifentanil (Ce(REMI) ) effect-site concentrations as estimated by target-controlled infusion systems. Intravascular volume status was assessed using the Delta Down (DD). We looked at the SPI response to FC according to DD, Ce(PPF) , and Ce(REMI) . RESULTS: Following FC, SPI did not change in 16, increased in 12, and decreased in 3 patients. Ce(REMI) poorly affected the SPI response to FC. In normovolaemic patients, the probability of an SPI change after FC was low under common Ce(PPF) (0.9 to 3.9 mug/ml). A decrease in SPI was more probable with worsening hypovolaemia and lowering Ce(PPF) , while an increase in SPI was more probable with increasing Ce(PPF) . SPI changes were only attributable to modifications in pulse wave amplitude and not in heart rate. CONCLUSIONS: During stable anaesthesia and surgery, SPI may change in response to FC. The effect of FC on SPI is influenced by volaemia and Ce(PPF) through pulse wave amplitude modifications. These situations may confound the interpretation of SPI as a surrogate measure of the nociception-anti-nociception balance. [less ▲]Detailed reference viewed: 38 (6 ULg)
Effect of an intravenous infusion of lidocaine on cisatracurium-induced neuromuscular block duration: a randomized-controlled trial.
Hans, Grégory ; Defresne, Aline ; et al
in Acta Anaesthesiologica Scandinavica (2010), 54(10), 1192-6
BACKGROUND: Intravenous lidocaine can be used intraoperatively for its analgesic and antihyperalgesic properties but local anaesthetics may also prolong the duration of action of neuromuscular blocking ... [more ▼]
BACKGROUND: Intravenous lidocaine can be used intraoperatively for its analgesic and antihyperalgesic properties but local anaesthetics may also prolong the duration of action of neuromuscular blocking agents. We hypothesized that intravenous lidocaine would prolong the time to recovery of neuromuscular function after cisatracurium. METHODS: Forty-two patients were enrolled in this randomized, double-blind, placebo-controlled study. Before induction, patients were administered either a 1.5 mg/kg bolus of intravenous lidocaine followed by a 2 mg/kg/h infusion or an equal volume of saline. Anaesthesia was induced and maintained using propofol and remifentanil infusions. After loss of consciousness, a 0.15 mg/kg bolus of cisatracurium was administered. No additional cisatracurium injection was allowed. Neuromuscular function was assessed every 20 s using kinemyography. The primary endpoint was the time to spontaneous recovery of a train-of-four (TOF) ratio >/= 0.9. RESULTS: The time to spontaneous recovery of a TOF ratio >/= 0.9 was 94 +/- 15 min in the control group and 98 +/- 16 min in the lidocaine group (P=0.27). CONCLUSIONS: No significant prolongation of spontaneous recovery of a TOF ratio >/= 0.9 after cisatracurium was found in patients receiving intravenous lidocaine. [less ▲]Detailed reference viewed: 26 (0 ULg)
Cerebral subarachnoid blood migration consecutive to a lumbar haematoma after spinal anaesthesia
Hans, Grégory ; Senard, Marc ; Ledoux, Didier et al
in Acta Anaesthesiologica Scandinavica (2008), 52Detailed reference viewed: 24 (3 ULg)
Assessment of postoperative nausea using a visual analogue scale.
; ; Seidel, Laurence et al
in Acta Anaesthesiologica Scandinavica (2000), 44(4), 470-4
BACKGROUND: Assessment of postoperative nausea intensity is difficult because nausea is a subjective and unpleasant sensation. We propose using the Visual Analogue Scale (VAS) device to increase the ... [more ▼]
BACKGROUND: Assessment of postoperative nausea intensity is difficult because nausea is a subjective and unpleasant sensation. We propose using the Visual Analogue Scale (VAS) device to increase the efficiency and precision in the assessment of nausea. We carried out a pilot study on postoperative patients suffering from nausea to measure the degree of agreement between the VAS scores and those given on a 4-point verbal descriptive scale (VDS). METHODS: Postoperative nausea was evaluated by means of a classical VAS (0-10 cm) device and a 4-point VDS (0=no nausea, 1=mild, 2=moderate, 3=severe) in 128 surgical spontaneously complaining patients. Evaluation was repeated 45 min after rescue medication given if nausea was intractable, lasted more than 10 min or at the request of the patient. Ordinal logistic regression was used to measure the association between VAS and VDS and to determine cut-off points on the VAS. RESULTS: The VAS device was easily understood and used by patients. VAS scores decreased significantly from 5.5+/-2.3 to 1.4+/-1.8 after rescue medication (P=0.002). Application of ordinal logistic regression to pre- and post-medication data combined yielded an agreement of 86% between VAS and VDS and the cut-off points on the VAS were estimated as follows: 0-1 (no nausea), 1+/-4 (mild), 4+/-7 (moderate) and 7+/-10 (severe). CONCLUSION: The VAS method proved to be useful for assessing quantitative nausea intensity and for testing the efficacy of rescue medication. It was found that a cut-off value of 4 on the VAS may be considered as a critical threshold triggering anaesthesiologists or nurses to administer rescue medication. [less ▲]Detailed reference viewed: 8 (1 ULg)
Correction of Pressure Waveforms Recorded by Fluid-Filled Catheter Recording Systems: A New Method Using a Transfer Equation
Lambermont, Bernard ; Gérard, Paul ; Detry, Olivier et al
in Acta Anaesthesiologica Scandinavica (1998), 42(6), 717-20
BACKGROUND: Pressure measuring systems using fluid-filled catheters can result in the recording of distorted pressure waveforms. It results in phase delay, overestimation of systolic and, to a lesser ... [more ▼]
BACKGROUND: Pressure measuring systems using fluid-filled catheters can result in the recording of distorted pressure waveforms. It results in phase delay, overestimation of systolic and, to a lesser extent, of diastolic pressure. We designed and evaluated a method to correct this pressure waveform distortion using an appropriate transfer equation obtained from the dynamic response of the fluid-filled catheter. This transfer equation is based on the principle that a fluid-filled catheter recording system is considered as an underdamped dynamic system fully characterized by its natural frequency (omega n) and damping ratio (zeta). METHODS: Pressure waveforms, simultaneously recorded in vitro or in vivo by a fluid-filled catheter (Pc) and a micromanometer-tipped catheter (Pref), were used to validate the method. Dynamic response of the catheter used was obtained from a fastflush test. The corrected signal (Ppred) was obtained using omega n, zeta and the following transfer equation: d2Pc/dt2 + 2 omega n zeta dPc/dt + omega n 2Pc = C Ppred (t) After correction of Pc, Ppred was compared, using a linear regression, with Pref taken as reference. RESULTS: Our results showed that Ppred was fitted to Pref with excellent coefficient correlation (0.99). The mean error and the standard error of estimate were respectively -1.16 mmHg and 1.4 mmHg. CONCLUSION: This new method can convert the distorted pressure waveforms transmitted by any fluid-filled catheters into high-fidelity signals. It suppresses the phase delay and the over-estimation of systolic pressure induced by fluid-filled catheters. [less ▲]Detailed reference viewed: 20 (2 ULg)
Scintigraphic visualization of intrathecal liposome biodistribution.
; ; et al
in Acta Anaesthesiologica Scandinavica (1997), 41(1 Pt 1), 25-34
BACKGROUND: Liposomes containing local anaesthetics have been administered intrathecally and in the epidural space. Poor attention has been given to the pharmacokinetics of liposomes as drug carriers ... [more ▼]
BACKGROUND: Liposomes containing local anaesthetics have been administered intrathecally and in the epidural space. Poor attention has been given to the pharmacokinetics of liposomes as drug carriers. Therefore, we observed the biodistribution of liposomes after intrathecal injection in rats by scintigraphic imaging during 24 h. METHODS: We administered 99mTc-labeled multilamellar (MLV) and small unilamellar vesicles (SUV) of defined size and volume dispersities into the cerebrospinal fluid at the lumbar level. Those vesicles were free of contamination by radiolabeled colloids as visualized by light and electron microscopy and of neurotoxic products from phosphatidylcholine hydrolysis and peroxidation, both during the preparation process and after 24 h incubation in cerebrospinal fluid at 37 degrees C in vitro. RESULTS: SUV immediately diffused from the lumbar site of injection to the head and were cleared between 1 and 24 h after injection. MLV were cleared more slowly from the spinal space and appeared in the head region 1 h after injection where they accumulated up to 24 h. These differences were explained in terms of vesicle sizes and volumes. SUV with 0.05 micron diameters were rapidly absorbed into the blood through the arachnoid granulations. In contrast, particles larger than the upper size limit of the arachnoid granulations permeability (+/- 8 microns) could accumulate in the head with a slow elimination rate. CONCLUSION: This difference in clearance from the intrathecal space outlines the importance of defining the size of the liposomes, the distribution of a tracer or a drug inside the liposomal preparation, the chemical stability and the absence of toxic degradation products of liposome formulations before clinical use. [less ▲]Detailed reference viewed: 4 (0 ULg)
Plasma Vitamin E, Total Lipids and Myeloperoxidase Levels During Spinal Surgery. A Comparison between Two Anesthetic Agents: Propofol and Isoflurane
Hans, Pol ; Canivet, Jean-Luc ; Pincemail, Joël et al
in Acta Anaesthesiologica Scandinavica (1991), 35(4), 302-5
Plasma levels of vitamin E (Vit. E), total lipids (TL), Vit. E to TL ratio and myeloperoxidase (MPO) were studied in 20 patients undergoing lumbar spinal surgery and randomly allocated to two anesthetic ... [more ▼]
Plasma levels of vitamin E (Vit. E), total lipids (TL), Vit. E to TL ratio and myeloperoxidase (MPO) were studied in 20 patients undergoing lumbar spinal surgery and randomly allocated to two anesthetic groups: propofol (bolus dose + continuous infusion and thiopental/isoflurane. Peripheral blood samples were withdrawn prior to induction, each hour during anesthesia and 1 h after the end of surgery. Mean Vit. E and TL levels as well as mean Vit. E to TL ratios remained in the normal range over the entire period of study whatever the anesthetic regimen. MPO levels rose significantly in the post-operative period only, but without statistical difference between the two groups. Therefore, anesthesia with propofol or thiopental/isoflurane modifies neither total lipid concentrations nor plasma Vit. E, which is a potent endogenous inhibitor of lipid peroxidation bound to lipoproteins. The rise of plasma MPO suggests a moderate post-operative neutrophil activation which is not influenced by anesthetic techniques. [less ▲]Detailed reference viewed: 16 (0 ULg)