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T Deloof

Publications and source records attributed to T Deloof.

At least 19 recordsLinked to original sources
PubMed2005

Large bolus dose vs. continuous infusion of cisatracurium during hypothermic cardiopulmonary bypass surgery.

BACKGROUND AND OBJECTIVE: We investigated whether a high bolus dose of cisatracurium (8x ED95) given at induction can provide muscle relaxation for the major part of a cardiac procedure with hypothermic cardiopulmonary bypass, avoid important postoperative residual curarization and cause no waste of product. METHODS: Twenty patients were randomly assigned either to Group 1 (n = 10) or Group 2 (n = 10). Those in Group 1 were given cisatracurium in a high bolus dose (0.4 mg kg(-1)). Those in Group 2 received cisatracurium 0.1 mg kg(-1) at induction followed after 30 min by a continuous infusion of cisatracurium. As an escape medication in case of patient movement, a bolus dose of cisatracurium 0.03 mg kg(-1) was given. RESULTS: In Group 1 (large cisatracurium bolus dose), the clinical duration of effect (until T1/T0 = 25%) was 110 min. Six of 10 patients in Group 1 required additional boluses of cisatracurium intraoperatively. Four of these six had received an additional bolus near the end of surgery and had a train-of-four (TOF) ratio = 0 at the end. The other four patients in Group 1 had a final TOF ratio >0.9. In Group 2 (continuous cisatracurium infusion), only two patients had a TOF ratio >0.9 at the end of surgery, no patient moved and none received additional boluses. The total amount of cisatracurium used in the bolus and infusion Groups was 34.5 +/- 7.8 and 21.3 +/- 5.7 mg, respectively (P = 0.0004). CONCLUSIONS: For continued neuromuscular block during hypothermic cardiac surgery, a high bolus dose of cisatracurium appears to be safe, although it is not an alternative to a continuous infusion, as its neuromuscular blockade does not cover the intraoperative period and a high incidence of movements occurs. In the patients who received a high bolus dose of cisatracurium, postoperative residual curarization appeared after additional boluses had been given. The consumption of cisatracurium by high bolus was significantly greater than with continuous infusion.

Aged↗
PubMed2003

Implications of the use of neuromuscular transmission monitoring on immediate postoperative extubation in off-pump coronary artery bypass surgery.

BACKGROUND AND OBJECTIVE: When continuous infusions of neuromuscular blocking drugs are administered during lengthy interventions and no routine antagonism of their effects is applied, there is a dramatic incidence of residual curarization. We have examined whether the use of neuromuscular transmission monitoring results in differences in the incidence of postoperative residual curarization, the use of antagonist agents, and the endotracheal extubation rate and outcome after continuous infusion of rocuronium in patients undergoing off-pump coronary artery bypass surgery. METHODS: Twenty patients were assigned to group 1 (n = 10, non-blinded neuromuscular transmission monitoring) or group 2 (n = 10, blinded neuromuscular transmission monitoring). In group 1, patients were given rocuronium at an infusion rate of 6 microg kg(-1) min(-1). The rate was manually adjusted in order to maintain T1/T0 at 10%. In group 2, a rocuronium infusion was started 30 min after induction of anaesthesia, at a rate of 6 microg kg(-1) min(-1); this rate was left unchanged during surgery. The rocuronium infusion was discontinued on completion of all vascular anastomoses; propofol was stopped at the beginning of closure of the subcutis and pirinitramide (piritramide) 15 mg was administered intravenously. Remifentanil was discontinued at the beginning of skin closure and neostigmine (50 microg kg(-1)) administered at the end of surgery when the train-of-four ratio was < 0.9 in group 1, and routinely in group 2. A 20 min test period for spontaneous ventilation was allowed once surgery had been accomplished. When the train-of-four ratio was > or = 0.9 (group 1), patients were extubated if also breathing spontaneously, fully awake and able to follow commands. When they met the clinical criteria for normal neuromuscular function after induced blockade, patients in group 2 were extubated when fully awake and able to follow commands. RESULTS: In group 1, the rate of rocuronium infusion required to keep T1/T0 at 10% was 5 +/- 1.9 microg kg(-1) min(-1); this was not significantly different from the fixed rate in group 2 (P = 0.15). One patient in group 2 was excluded. Eight out of 10 and eight out of nine patients in groups 1 and 2, respectively, reached the extubation criteria. Three out of eight, and five out of eight, patients from groups 1 and 2, respectively, were extubated in the operating room. At that time of endotracheal extubation, all three patients from group 1, but only four of the five patients from group 2 had a train-of-four ratio > or = 0.9. In group 2, one patient was reintubated in the intensive care unit. The incidence of pharmacological reversal was high in group 1. CONCLUSIONS: Although we found no additional benefit of using neuromuscular transmission monitoring, it seems an absolute necessity for safety reasons. Pharmacological antagonism was mandatory. However, in our opinion, it is not wise routinely to perform immediate postoperative extubation in off-pump coronary artery bypass surgery.

Aged↗
PubMed2001

Air-oxygen mixtures in circle systems.

STUDY OBJECTIVE: To determine the effect of different air-O(2) mixtures and fresh gas flows (FGF) on the relationship between the delivered (F(Del)O(2)) and inspired O(2) fraction (FIO(2)) in a circle system. STUDY DESIGN: Randomized clinical study. SETTING: Large teaching hospital. PATIENTS: 160 ASA physical status I, II, and III patients undergoing a variety of cardiovascular procedures with general endotracheal anesthesia. INTERVENTIONS: 160 patients were randomly assigned to one of 20 groups (n = 8 each), depending on the combination of total FGF (0.5, 1, 2, 4, or 8 L/min) and air-O(2) mixture used (ratios of 4/1, 3/2, 2/3, or 1/4), corresponding to a F(Del)O(2) of 0.37, 0.53, 0.68, and 0.84. For each combination of FGF and air-O(2) mixture, FIO(2) after equilibration was compared with F(Del)O(2). MEASUREMENTS AND MAIN RESULTS: With any air-O(2) mixture with a FGF < or = 2 L/min, FIO(2) became lower than F(Del)O(2). Because FIO(2) decreased below 0.25 after 13 and 26 minutes in the first two patients of the 4/1 0.5 L/min air-O(2) group, this study limb was terminated. CONCLUSIONS: When using air-O(2) mixtures in a circle system, FIO(2) becomes lower than the F(Del)O(2) with FGF < or = 2 L/min. The relative proportion of O(2) in the FGF has to be increased accordingly.

Air↗
PubMed2001

The analgesic efficacy of tramadol is impaired by concurrent administration of ondansetron.

Tramadol has weak opioid properties, and an analgesic effect that is mediated mainly by inhibition of the reuptake of norepinephrine and serotonin (5-hydroxytryptamine [5-HT]) and facilitation of 5-HT release (1,2) at the spinal cord. Because 5-HT3 receptors play a key role in pain transmission at the spinal level (3), the 5-HT3 antagonist ondansetron may decrease the efficacy of tramadol, as suggested in an abstract by Maroof et al. In that study, a small dose of 1 mg/kg tramadol was administered along with ondansetron 0.1 mg/kg or placebo, 15 min before the induction of anesthesia. Early postoperative pain scored differed significantly between the test groups. We therefore tested the hypothesis that the tramadol requirement by patient-controlled analgesia (PCA) may be increased when ondansetron is administered for antiemetic prophylaxis.

Adult↗
PubMed2001

The ADU vaporizing unit: a new vaporizer.

UNLABELLED: We determined the performance of the vaporizer of the ADU machine (Anesthesia Delivery Unit; Datex-Ohmeda, Helsinki, Finland). The effects of carrier gas composition (oxygen, oxygen/N(2)O mixture, and air) and fresh gas flow (0.2 to 10 L/min) on vaporizer performance were examined with variable concentrations of isoflurane, sevoflurane, and desflurane across the whole range of each vaporizer's output. In addition, the effects of sudden changes in fresh gas flow and carrier gas composition, back pressure, flushing, and tipping were assessed. Vaporizer output depended on fresh gas flow, carrier gas composition, dial settings, and the drug used. Vaporizer output remained within 10% of dial setting with fresh gas flows of 0.3-10 L/min for isoflurane, within 10% of dial setting with fresh gas flows of 0.5-5 L/min for sevoflurane, and within 13% of dial setting with fresh gas flows of 0.5 to 1 L/min for desflurane. Outside these fresh gas flow ranges, output deviated more. The effect of sudden changes in fresh gas flow or carrier gas composition, back pressure, flushing, and tipping was minimal. We conclude that the ADU vaporizer performs well under most clinical conditions. Despite a different design and the use of complex algorithms to improve accuracy, the same physical factors affecting the performance of conventional vaporizers also affect the ADU vaporizer. IMPLICATIONS: The ADU vaporizer performs well under most clinical conditions. Despite a different design and the use of complex algorithms to improve accuracy, the same physical factors affecting the performance of conventional vaporizers also affect the ADU vaporizer.

Anesthesiology↗
PubMed2000

Maintaining sevoflurane anesthesia during low-flow anesthesia using a single vaporizer setting change after overpressure induction.

STUDY OBJECTIVE: A sevoflurane vaporizer dial setting of 1.9% was previously found to maintain the end-expired sevoflurane concentration (Et(sevo)) at 1.3% during maintenance of anesthesia for procedures up to one hour with an O(2) FGF of 1 L/min. We examined whether applying these parameters could simplify low-flow sevoflurane anesthesia after overpressure induction using two slightly different techniques. DESIGN: Prospective clinical study. SETTING: Large teaching hospital. PATIENTS: Sixteen patients receiving general anesthesia for a variety of peripheral procedures. INTERVENTIONS: Anesthesia was induced with overpressure with sevoflurane (8%) in an 8 L. min(-1) O(2)/N(2)O mixture (30%/70%). After a laryngeal mask airway (LMA) was placed, fresh gas flow (FGF) was lowered to 1 L. min(-1) using O(2) and N(2)O (FiO(2) 30%) with patients breathing spontaneously. In group I patients (n = 8), the vaporizer dial was set at 1.9% at the same time the FGF was lowered. In group II patients (n = 8), the vaporizer was turned off until Et(sevo) had decreased to 1.3%, after which the dial was set at 1.9%. The course of Et(sevo) in the two groups was examined. MEASUREMENTS AND MAIN RESULTS: In group I, Et(sevo) after 3 min was 4.88 +/- 1. 12%. Et(sevo) decreased slowly after reduction of FGF to 1.83 +/- 0. 19%, 1.59 +/- 0.18%, and 1.52 +/- 0.19% at 10, 20, and 30 min, respectively. In group II, Et(sevo) after 3 min was 4.34 +/- 0.84%, and decreased more rapidly after reduction of FGF to 1 L. min(-1) than in group I. Et(sevo) was 1.40 +/- 0.09%, 1.40 +/- 0.11%, and 1. 38 +/- 0.13% at 10, 20, and 30 min, respectively. CONCLUSIONS: After high-flow overpressure induction with sevoflurane, a single change in vaporizer setting (to 1.9%) and FGF (to 1 L. min(-1)) suffices for the Et(sevo) to approach the predicted Et(sevo) (1.3%) within 10-15 min; thereafter the Et(sevo) remains nearly constant. As expected, the predicted Et(sevo) is attained slightly faster when the vaporizer is temporarily turned off. Clinically applying previously derived pharmacokinetic parameters simplifies low-flow sevoflurane anesthesia after overpressure induction.

Adult↗
PubMed2000

Dose requirements of infusions of cisatracurium or rocuronium during hypothermic cardiopulmonary bypass.

We investigated the influence of mild hypothermic cardiopulmonary bypass (CPB) on the dose requirements of cisatracurium or rocuronium used as a continuous infusion. We studied eight patients given cisatracurium and nine given rocuronium. They were ASA class III and IV and scheduled for elective coronary artery bypass grafting. Neuromuscular transmission was monitored electromyographically. After recovery of T1/T0 to 10%, a cisatracurium infusion or a rocuronium infusion was started at a rate of 1.5 or 10 micrograms kg-1 min-1, respectively, and adjusted to maintain T1/T0 at 15%. Infusion rate and duration were recorded before, during and after CPB in each patient and the mean infusion rates were calculated. One-way ANOVA showed a statistically significant difference between the cisatracurium infusion rates before, during and after CPB: A T1/T0 of 15% could be achieved with a mean infusion rate of 1.1, 0.75 and 0.98 micrograms kg-1 min-1 before, during and after CPB, respectively. There was no significant difference between the rocuronium infusion rates before, during and after CPB. The mean rocuronium infusion rate required to maintain T1/T0 at 15% throughout the procedure was 4.1 micrograms kg-1 min-1. Cisatracurium infusion rates should be halved during CPB. Even after CPB, requirements are reduced. The same tendency occurs with rocuronium, but the changes in infusion rate were not statistically significant.

Aged↗
PubMed1999

Catheter entrapment by atrial suture during minimally invasive port-access cardiac surgery.

PURPOSE: The port-access approach allows surgeons to perform heart operations through small intercostal openings, or "ports". This technique requires new skills for anesthesiologists. A pulmonary artery venting (PAV) catheter and, in some cases, a coronary sinus catheter (for administration of retrograde cardioplegia) are positioned with the aid of fluoroscopy and transesophageal echography (TEE). Both catheters have a wider diameter than the more commonly used conventional PA catheter and present distinctive features. We report a case in which a pulmonary artery venting catheter was entrapped by a suture during a port-access procedure. CLINICAL FEATURES: A 35-yr-old man with severe mitral valve insufficiency was scheduled for valve repair. After a successful bypass procedure, resistance was felt while attempting to withdraw the PAV catheter. On fluoroscopy, fixation of the catheter at the heart level was established and perforation by suture was confirmed after injection of a contrast agent. Because of the risk of cardiac wall rupture and tamponade, the thorax was reopened. After release of some atrial sutures, the catheter could be withdrawn easily. Transfixion by a suture was confirmed by visual examination. CONCLUSION: The more frequent use of a PAV catheter in minimally invasive cardiac surgery with the port-access technique should remind the anesthesiologist of the higher risk of entrapment by surgical sutures. Surgeons should be aware of the risk of accidentally transfixing this catheter during closure of the atriotomy via the port.

Adult↗
PubMed1998

Post-operative effects of tramadol administered at wound closure.

The aim of this prospective, randomized and double-blind study was to assess the effects of a high dose of the analgesic tramadol administered at the conclusion of surgery on extubation time, sedation, and post-anaesthetic shivering. Forty adult patients, ASA physical status I or II, underwent laparoscopic surgery of about 1 h duration and received a standardized anaesthesia that was maintained with isoflurane in O2/N2O. Tramadol 3 mg kg-1 (n = 20) was administered intravenously at the beginning of wound closure, and was compared with saline (n = 20). Post-anaesthetic shivering did not occur in any patient who received tramadol, whereas it occurred in 60% of the control group (P < 0.001). There were no adverse effects on time to extubation and sedation, and discharge-ready time was shorter in the tramadol group (P < 0.05 compared with control). Pain scores in the post-anaesthesia care unit (PACU) were statistically not different between the two groups, but significantly more supplemental medication was administered in the control group to treat shivering and/or pain. In conclusion, administration of a high dose of tramadol at the end of surgery prevents post-anaesthetic shivering without prolongation of extubation time, and shortens the PACU/discharge-ready time.

Adolescent↗
PubMed1997

Tramadol in the treatment of postanesthetic shivering.

BACKGROUND: As an inhibitor of the reuptake of serotonin and norepinephrine in the spinal cord, the mechanism of action of tramadol resembles that of nefopam, which has been used in the treatment of postanesthetic shivering. METHODS: In a randomized, placebo-controlled, double-blind study, we assessed the effects of tramadol (0.5 mg.kg-1, 1 mg.kg-1 and 2 mg.kg-1 i.v.) or normal saline on shivering after a standardized general anesthesia in 40 adult patients, ASA physical status I or II (group 1), and in 64 adult patients regardless of the foregoing general anesthesia and ASA physical status (group 2). RESULTS: Tramadol 1 mg.kg-1 or more abolished shivering completely 5 min after treatment in all patients of groups 1 and 2. In group 1, the three dosages of tramadol were not statistically different in lowering the severity and prevalence of postanesthetic shivering. Tramadol 0.5 mg.kg-1 was significantly slower than tramadol 1 or 2 mg.kg-1 in tempering the severity as well as lowering the prevalence of postanesthetic shivering in group 2. CONCLUSION: Tramadol's distinct features in the treatment of shivering reside in its high safety profile and weak sedative properties, particularly in patients with poor cardiorespiratory reserve, in outpatients and on recurrence of shivering.

Adult↗
PubMed1995

Free-hand sewn allografts, stentless (Prima Edwards) and stented (CESA) porcine bioprostheses. A comparative hemodynamic study.

In a retrospective, non-randomized study, the clinical and hemodynamic properties of 50 consecutively implanted hand-sewn allografts (group I), 50 stentless bioprostheses (group II) and 50 stented bioprostheses (group III) were compared. Preoperative hemodynamic and clinical data were identical in the three groups, except for age (group I: 54.4 +/- 8.7, group II: 67.0 +/- 5.1, group III: 70.0 +/- 5.1). Peak and mean gradients and flow characteristics with echo Doppler were performed at 1 week, 6 and 12 months. For the 21, 23 and 25 diameter prostheses, group differences between groups II and III in peak and mean gradients were not significant after 1 week and 1 year. In all groups, allografts had significantly lower gradients. Regurgitation (I-II) was present after 1 week and 1 year in group I: in 17/48 and 22/42 patients respectively, in group II 7/49 and 11/44 patients and in group III: in 1/49 and 2/44 patients. Early mortality and morbidity were comparable in all groups. Allografts have superior hemodynamic properties. Differences in gradients in groups II and III were not significant, though differences in technique allowed the implantation of a larger bioprostheses in group II. Regurgitation was most prominent in the allograft group. Immediate postoperative results were not influenced by the type of prosthesis.

Adult↗
PubMed1992

Reliability of auscultation in positioning of double-lumen endobronchial tubes.

Auscultation is a well-established technique to confirm the position of double-lumen endobronchial tubes (DLTs). However, some authors have recommended that fibreoptic bronchoscopy (FOB) is also indicated. The aims of this study were to determine first if bronchoscopy after blind placement of DLTs improved positioning; and second if preoperative bronchoscopy could detect difficult intubation. Twenty-four patients undergoing aortic or lung surgery were studied. After intubation with a single-lumen tube, an initial FOB was performed by an independent observer to check the airway anatomy. Then, the single-lumen tube was replaced by a DLT using a classical "blind" intubation method. Subsequent FOB was performed first by the independent observer to record the DLT position and next by the investigators for improvement or correction of their positioning under visual control. Fibreoptic bronchoscopy after blind placement of DLTs resulted in repositioning 78% left-sided DLTs and 83% right-sided DLTs. Preoperative bronchoscopy did not always detect an airway abnormality which might lead to difficult positioning of the DLTs. In conclusion, auscultation is an unreliable method of confirming the position of DLTs and should be followed by fibreoptic bronchoscopy.

Adult↗