Anesthesia and analgesia
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Anesthesia and analgesia · Dec 2003
Case ReportsTransnasal placement of biplane transesophageal echocardiography probe intraoperatively in an adolescent with congenital heart disease.
Intraoperative transesophageal echocardiography (TEE) is frequently used in children with congenital heart disease (CHD). Although transnasal TEE is being used in various settings in the adult population, there are no descriptions of its use intraoperatively in patients with CHD. This report describes the successful use of transnasal TEE after multiple unsuccessful transoral attempts in an adolescent male undergoing subaortic stenosis repair. ⋯ Transnasal transesophageal echocardiography (TEE) is being used in various settings in the adult population. The author describes its use intraoperatively in an adolescent undergoing surgery for congenital heart disease after unsuccessful transoral attempts.
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Anesthesia and analgesia · Dec 2003
Validation of an original mathematical model of CO(2) elimination and dead space ventilation.
We present an original, mathematical model of ventilation and gas-exchange. Our aim was to validate it using data from previous clinical investigations, allowing our use of it in future investigations. The first previous investigation used a low-dead space, double-lumen, tracheal tube (DLT). We matched the model's PaCO(2) and airway pressures (P(AW)) to the patient mean during use of the DLT and a single-lumen tube (SLT). The model's resulting PaCO(2), PECO(2) and P(AW) were compared with the patients' as tidal volume (VT) changed with constant minute volume. The second investigation examined dead space during anesthesia. The model's VT, respiratory rate, CO(2) production, temperature, and alveolar and anatomical dead spaces were matched to each mechanically ventilated subject. Bias and precision in predictions of PaCO(2) and PECO(2) were calculated. The model's bias in prediction of dead space reduction by the DLT was 6.9%. Bias in prediction of P(AW) was 0.1% (peak) and -5.13% (mean), of PaCO(2) was 1.2% (DLT) and 1.5% (SLT) and of PECO(2) was 1.7% (DLT) and 1.3% (SLT). Prediction of PaCO(2) and PECO(2) in the second investigation (as 95% confidence interval of bias): PaCO(2) -2.6% to 0.8% and PECO(2) -4.9% to 1.2%. This validation allows future application of our model in appropriate theoretical investigations. ⋯ We present an original, mathematical model of ventilation and gas exchange. We validate it against previously published clinical data to allow its use in future theoretical investigations where data may be unavailable from patients.
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Anesthesia and analgesia · Dec 2003
The dose-related effects of ketamine on mortality and cytokine responses to endotoxin-induced shock in rats.
In our previous study, ketamine administration was found to inhibit hypotension, metabolic acidosis, and cytokine responses in endotoxemia. However, only a few studies have indicated whether ketamine has the dose-related beneficial effects after endotoxin injection. Our objective was to clarify the dose-related effects of ketamine on mortality and cytokine responses to endotoxemia in rats. ⋯ Ketamine administration thus clearly had a beneficial effect on mortality rates, with that for group M lower than for groups L and H (P < 0.05). The cytokine responses to endotoxin were somewhat suppressed in group M but not in group L. Ketamine administration dose-independently inhibited hypotension, metabolic acidosis, and cytokine responses in rats injected with endotoxin.
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Anesthesia and analgesia · Dec 2003
Clinical TrialEndotracheal tube cuff pressure is unpredictable in children.
The use of cuffed tracheal tubes in children younger than 8 yr of age has recently increased, although cuff hyperinflation may cause tracheal mucosal damage. In this study, we sought to measure the cuff pressure (P(cuff)) after initial free air inflation (iP(cuff)) and to follow its evolution throughout the duration of 50% nitrous oxide (N(2)O) anesthesia. One-hundred-seventy-four children, aged 0 to 9 yr, fulfilling the following criteria, were studied: 1). weight of 3-35 kg; 2). ASA physical status I or II; 3). elective surgery; 4). anesthesia with tracheal intubation using a cuffed tube and lasting at least 45 min; and 5). gas mixture containing 50% N(2)O. Free air inflation results in variable iP(cuff), with hyperinflation in 39% of cases. Numerous gas removals were required to maintain P(cuff) less than 25 cm H(2)O in 85% of the patients. The number of deflations decreased with the duration of mechanical ventilation and was small after 105 min. No difference was observed among the different cuffed tube sizes. We conclude that iP(cuff) is unpredictable after free air inflation and that numerous gas removals are required to maintain P(cuff) less than 25 cm H(2)O during N(2)O anesthesia in children. ⋯ Free inflation of the tracheal tube cuff, controlled only by the palpation of the pilot balloon, is not reliable and results in extremely variable (and sometimes very high) initial cuff pressures in children. In addition, nitrous oxide anesthesia may result in cuff hyperinflation requiring numerous gas removals.
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Anesthesia and analgesia · Dec 2003
Case ReportsEpidural analgesia at end of life: facing empirical contraindications.
In a patient with unbearable cancer pain at the end of life, long-lasting analgesia without impairment of consciousness could only be achieved with an epidural infusion of local anesthetics combined with opioids and clonidine. Despite leptomeningeal infection during prolonged treatment, epidural analgesia at the lumbar level provided analgesia using very large doses of local anesthetics combined with clonidine and morphine. Thus, terminal sedation was avoided, allowing the patient's end-of-life planning of an "aware" death surrounded by her family. It may be useful to reconsider institutional pain management standards when unbearable pain occurs in patients with limited life expectancy. ⋯ We report a patient with severe visceral and neurogenic pain from metastatic carcinoma of the colon resistant to multimodal oral analgesic therapy. Although there were empirical contraindications, epidural analgesia was successful, allowing the patient's end-of-life planning of an "aware" death surrounded by the family.