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Biomedical subjects

C Ecoffey

Publications and source records attributed to C Ecoffey.

At least 19 recordsLinked to original sources
PubMed1992

Continuous monitoring of mixed venous oxygen saturation during orthotopic liver transplantation.

Hemodynamic management is an important issue concerning anesthesia for orthotopic liver transplantation (OLT). Mixed venous oxygen saturation (SvO2) is considered a good index of tissue oxygenation, but controversy exists about the usefulness of monitoring this parameter in different types of surgery. Therefore, a prospective study was performed to determine changes in SvO2 during OLT and to study the correlation between SvO2 and hemodynamic measurements. Thirty patients undergoing transplantation for end-stage liver disease were divided into two groups: group 1 (n = 15, aged 42 +/- 11 years [mean +/- SD]) without venovenous bypass (VVB), and group 2 (n = 15, aged 43 +/- 10 years) with VVB. SvO2 was greater than 74% throughout the procedure and remained stable during dissection and the anhepatic phase. There was a significant increase in SvO2 after unclamping the portal vein in group 1, whereas a significant decrease was observed during the first hour following reperfusion in group 2. There was no correlation among SvO2 and oxygen consumption, arterial oxygen saturation, (SaO2), or hemoglobin concentrations. A statistically significant correlation was found between SvO2 and cardiac index in both groups (group 1: r = 0.58, P = 0.01; group 2: r = 0.51, P = 0.01), but the correlation was relatively poor. Continuous monitoring of SvO2 may be useful, but cannot substitute for intermittent determinations of other hemodynamic or oxygenation parameters.

Adult↗
PubMed1992

[EMLA analgesic cream for venopuncture during anesthetic induction in children].

A prospective study was designed to assess the quality of skin analgesia provided by the EMLA anaesthetic cream, an eutectic mixture of local anaesthetics (prilocaine and lidocaine). The children, aged 3 months to 15 years, and scheduled for genital and urinary surgery, were allocated to two groups, those aged less than or equal to 5 years (35 +/- 14 months, n = 17), and those aged greater than 5 years (97 +/- 26 months, n = 22). The cream (1.6 +/- 0.6 g) was applied by a nurse in the ward as a thick layer on the area of skin to be anaesthetised (on the dorsum of the hand and at the elbow), and covered by a closed adhesive dressing. This required 2.6 +/- 1.7 min, and was considered to be very easy (72%) or easy (28%). The venepuncture (22 or 20 gauge catheter) was carried out by one of the seven anaesthetists of the paediatric surgical units, 92 +/- 51 min after the cream had been applied. The children aged less than or equal to 5 years complained of pain of intensity 7.5 +/- 2.2 (CHEOPS scale, range 4 to 13) and, for those aged greater than 5 years, 24 +/- 21 on a visual analogic scale (range 0 to 100). Local adverse effects occurred in ten patients (skin paleness, erythema, or both). It was concluded that EMLA cream provides convenient analgesia for venepuncture in toddlers and children.

Administration, Cutaneous↗
PubMed1992

[Caudal block in children: analgesia and respiratory effect of the combination bupivacaine-fentanyl].

A study of the duration of analgesia and of the respiratory response to hypercapnia was carried out in 14 children who had had a caudal block with either bupivacaine alone (group B) or combined with fentanyl (Group B+F). Fourteen ASA I or II 5 to 10-year-old children undergoing genital and urinary surgery were included. They were not premedicated. At first, general anaesthesia was induced with halothane and nitrous oxide in oxygen. Thereafter, caudal anaesthesia was then carried out with 1 ml.kg-1 of 0.25% bupivacaine with adrenaline 1 in 200,000. Group B+F patients were also given 1 microgram.kg-1 of fentanyl in 1 ml of normal saline, and those in Group B 1 ml of normal saline. The level of sensory loss on leaving the operating theatre as well as the duration of motor paralysis were monitored. Postoperative pain was scored with Hannalah and Broadman's score (0 to 10) 2, 4, 8 and 24 h after the caudal block. Respiratory rate (fR), tidal volume (VT) and minute ventilation (VE) were assessed 10 min before induction of general anaesthesia, and 30, 60 and 120 min after the caudal anaesthesia. Petco2 was also measured before induction of general anaesthesia, and 60 and 120 min after caudal anaesthesia; at the same times, the ventilatory response to hypercapnia was assessed using Read's method with a Douglas bag containing 7% CO2 and 93% O2.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Caudal↗
PubMed1992

Extrahepatic metabolism of propofol in man during the anhepatic phase of orthotopic liver transplantation.

We have investigated extrahepatic metabolism of propofol in 10 patients undergoing orthotopic liver transplantation (group 1) (mean age 38 yr, mean weight 60 (SD 7) kg) and compared it with that in 10 patients without liver dysfunction undergoing extrahepatic abdominal surgery (group 2) (mean age 56 yr, mean weight 68 (11) kg). A single i.v. bolus dose of propofol 0.5 mg kg-1 was injected into a peripheral vein 5 min after the beginning of the anhepatic phase in group 1 and 60 min after the induction of anaesthesia in group 2. Arterial blood samples were obtained at 5, 10, 15, 20, 30, 40, 50 and 60 min after injection and urine samples were collected every 15 min. Propofol concentrations in whole blood and urine were measured by high performance liquid chromatography with fluorescence detection. Propofol glucuronide was measured in urine by incubation with a specific beta-glucuronidase. The area under the time-blood concentration curve from 0 to 60 min was found to be significantly greater in group 1 (13743 (2830) micrograms litre-1 h-1) than in group 2 (7992 (4895) micrograms litre-1 h-1) (P less than 0.05). Unchanged propofol was not detected in the urine of either group. No significant difference was found in the amount of propofol glucuronide excreted by patients in group 1 (457 (269) micrograms) and in group 2 (921 (672) micrograms). The presence of a propofol metabolite in urine when the liver was excluded from the circulation suggests that extrahepatic metabolism occurred.

Adult↗
PubMed1992

The failure of venovenous bypass to prevent graft liver postreperfusion syndrome.

We studied 58 patients undergoing orthotopic liver transplantation, aged 42 +/- 10 years (mean +/- SD), and weighing 65 +/- 14 kg. Anesthesia was maintained with fentanyl, midazolam, and vecuronium. Serum bicarbonate, serum potassium, serum ionized calcium and pH did not change significantly throughout the study. Usual hemodynamic parameters were recorded. Hemodynamic tolerance was assessed by a trial of clamping of the inferior vena cava, above and below the liver and the portal vein; patients were allocated to two groups: the group without venovenous bypass (NBP, n = 29) consisted of patients whose MAP did not decrease by more than 30% and/or cardiac output did not decrease by more than 50%; the group with venovenous bypass (BP, n = 29) consisted of patients whose MAP decreased by more than 30% and/or cardiac output decreased by more than 50% or required venovenous bypass for easier surgical dissection. After clamping of the vena cava and the portal vein, the cardiac index (CI) and mean pulmonary arterial pressure (MPAP) decreased significantly, whereas systemic vascular resistances (SVR) increased. After unclamping the inferior vena cava suprahepatically and infrahepatically, no hemodynamic change was observed. After unclamping the portal vein, MAP decreased, despite the increase in the CI, because of an significant decrease in SVR; in addition MPAP increased despite the decrease in pulmonary vascular resistances. The decrease in MAP of more than 30% during at least 1 min occurred in 6 patients (20%) in the NBP group and in 6 patients (20%) in the BP group. We concluded that the occurrence of the syndrome of cardiovascular collapse following liver reperfusion was similar whether venovenous bypass was used or not.

Adult↗
PubMed1992

Does adult liver transplantation without venovenous bypass result in renal failure?

Thirty-eight adult orthotopic liver transplant recipients were studied to compare renal hemodynamics and renal function with (17 patients) and without (21 patients) venovenous bypass. Bypass was used when mean arterial blood pressure decreased by greater than 30% or cardiac index decreased by greater than 50%, or both, during a 5-min trial of clamping of the suprahepatic and infrahepatic vena cava and portal vein. Intraoperative measurements were performed 2 h after induction of anesthesia, 10 min before the end of the anhepatic phase, and 2 h after cava unclamping. During the anhepatic stage, renal perfusion pressure decreased significantly in the group with no bypass (79 +/- 20 vs 60 +/- 17 mm Hg, P less than 0.05) (mean +/- SD), whereas it remained unchanged in the group with bypass (77 +/- 14 vs 74 +/- 16 mm Hg, NS); urinary output was not modified in the bypass group, whereas it decreased significantly in the group with no bypass compared with the dissection phase (0.7 +/- 0.6 vs 1.7 +/- 2.0 mL.kg-1.h-1, P less than 0.05). However, during the postreperfusion phase, urinary output was similar in both groups and was more when compared with the dissection phase (P less than 0.05). Serum creatinine level was increased in both groups on the third postoperative day, but no difference occurred between the groups (bypass group 107 +/- 49 mmol/L; nonbypass group 126 +/- 95 mmol/L). No patient required dialysis in either group in the postoperative period. This study suggests that in patients without preoperative renal failure and who tolerate the trial of clamping well, venovenous bypass is not required to maintain postoperative renal function after liver transplantation.

Adult↗
PubMed1992

[Pharmacokinetics of local anesthetics in children].

Anatomical and physiological differences between children and adults may induce changes in absorption, distribution and elimination of local anesthetics throughout life. Absorption is faster and the Cmax may be higher in children than in adults. In addition, the volume of distribution is larger, and the Cmax is lower and the terminal half-life is longer in children than in adults. The low level of albumin and alpha-1-acid-glycoprotein until 6 months of life, may result in an increase in free fraction of drugs, as it has been demonstrated for bupivacaine. In clinical practice, the decrease in protein binding in infants may lead to careful use before the age of 6 months. It seems preferable to use drugs with moderate protein binding and high hepatic extraction ratio such as lidocaine; the repeated injection of epidural bupivacaine should be careful used because of the longer terminal half-life; maximum dosage regimens are for lidocaine 10 mg.kg-1 and for bupivacaine 2.5 mg.kg-1.

Absorption↗
PubMed1991

[What is the method of choice for hemodynamic monitoring in liver transplantation?].

Orthotopic liver transplantation requires close hemodynamic monitoring. Technological advances provide new possibilities of improving this monitoring. The most recent devices are the mixed venous oxygen saturation catheter, which gives continuous SVO2 values, and the right ejection fraction catheter used discontinuously. Our experience of 100 liver transplantations has enabled us to investigate the advantages of these catheters over the conventional Swan Ganz catheters.

Catheterization↗
PubMed1991

Decrease in renal vascular resistance in University of Wisconsin solution preserved kidney transplants.

Renal vascular resistance was compared in 2 groups of renal grafts: group 1-16 kidneys perfused with University of Wisconsin solution and group 2-16 kidneys perfused with Euro-Collins solution. Both groups had comparable donors and recipient criteria. Renal blood flow was measured by a miniaturized pulsed Doppler probe fixed on the graft renal artery. Renal vascular resistance was calculated either according to the formula: renal vascular resistance (mm. Hg/ml. per second) = systemic arterial pressure (P)/renal blood flow or through the renal vascular resistive index (RVRI): RVRI = systolic flow velocity - diastolic flow velocity/systolic flow velocity = (S-D)/S. Renal vascular resistance estimation seems to be more contributory than renal blood flow in assessment of renal graft reperfusion disorders. Our results show that University of Wisconsin solution seems to preserve intrarenal arterial caliber better with a decrease in intrarenal vascular resistance, thus, allowing for a higher arterial graft perfusion flow.

Adenosine↗
PubMed1991

Ventilatory response to carbon dioxide after epidural clonidine injection.

The authors studied the effects of epidural clonidine (300 micrograms) on circulation and ventilatory control in seven healthy unpremedicated subjects. After clonidine injection, arterial blood pressure decreased significantly in all subjects (range, 13%-25% for systolic blood pressure and 13%-32% for diastolic blood pressure). Heart rate decreased significantly by 10%-16% between 75 and 105 min after injection. The slope of the ventilatory response to CO2 decreased significantly from 2.06 +/- 0.70 (baseline) to 1.37 +/- 0.68, 1.25 +/- 0.65, and 1.33 +/- 0.67 L.min-1.mm Hg-1 (mean +/- SD, P less than 0.05) at 15, 60, and 120 min. The authors conclude that epidural clonidine induces mild ventilatory and circulatory depression.

Adult↗
PubMed1991

Ventilatory effects of premedication with clonidine.

Clonidine has been proposed as a premedication before surgery because of its beneficial effects on hemodynamics, especially in patients with a high cardiovascular risk. However, reports on the effects of clonidine on ventilation are conflicting. Accordingly, eight fasting ASA physical status I volunteers received in a double-blind randomized order 300 micrograms of oral clonidine, the effects of which were compared with placebo given in a crossover design. Hypotension, bradycardia, and sedation were significantly more profound and of longer duration after clonidine. Clonidine did not decrease minute ventilation more than the placebo, and separate analysis of tidal volume and respiratory rate changes also showed the absence of a significant difference between the two groups. However, clonidine produced episodes of obstructive pattern associated with moderate decreases in oxygen saturation, which were not observed with placebo. We conclude that the potential detrimental effects of these obstructive airway patterns of clonidine should be taken into account when prescribing this drug for premedication.

Administration, Oral↗
PubMed1991

[Secondary effects of opioids administered by the regional route].

The administration of narcotics in the subarachnoid or the epidural space is gaining acceptance for postoperative pain relief. However, the potential side effects of intrathecal and epidural use of opioids are the following: early and late respiratory depression, pruritus, nausea and vomiting, urinary retention. Early respiratory depression is low and may occur 6 or 12 hours after the epidural narcotics injection. Many factors contribute to the delayed phase of breathing disorders and a close respiratory monitoring is needed during at least 24 hours after epidural morphine injection. Naloxone can be used to reverse the depression. Pruritus can occur in 10 to 30% of patients receiving morphine; 10 to 30% nausea and vomiting, and urinary retention occurs in 20 to 50% of patients.

Analgesia, Epidural↗
PubMed1991

Dose requirements of vecuronium, pancuronium, and atracurium during orthotopic liver transplantation.

To further elucidate the role of the liver in the clearance of vecuronium, atracurium, and pancuronium, 30 patients undergoing orthotopic liver transplantation were randomly assigned to three comparable groups to receive a continuous infusion of vecuronium, atracurium, or pancuronium. The evoked integrated compound action potential of the hypothenar eminence in response to train-of-four ulnar nerve stimulation was measured and recorded. Anesthesia was induced with 3-5 mg/kg of thiopental, 50 micrograms/kg of midazolam, and 1-5 micrograms/kg of fentanyl IV and was maintained with continuous infusions of midazolam and fentanyl while the lungs were ventilated with an air-oxygen mixture. The infusion rates of vecuronium, atracurium, and pancuronium were adjusted to achieve a T1/Tc ratio of between 0.02 and 0.10 (T1 = height of first twitch, Tc = height of control twitch). Vecuronium and pancuronium requirements, which were 0.072 +/- 0.022 and 0.042 +/- 0.015 mg.kg-1.h-1 (mean +/- standard deviation) respectively during the dissection phase, decreased significantly during the anhepatic phase to 0.036 +/- 0.021 and 0.018 +/- 0.012 mg.kg-1.h-1 and returned toward the initial values in the postreperfusion phase (0.055 +/- 0.018 and 0.032 +/- 0.012 mg.kg.-1.h-1); whereas atracurium requirements remained unchanged during the three phases (0.667 +/- 0.199, 0.567 +/- 0.142, and 0.692 +/- 0.254 mg.kg-1.h-1). These data suggest that the liver has an important role in the elimination of vecuronium and pancuronium, whereas the elimination of atracurium is unaltered during exclusion of the liver from the circulation.

Adult↗