Der Anaesthesist
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Randomized Controlled Trial Comparative Study Clinical Trial
[The effect of different types of anesthetic respirators on oxygenation and ventilation in infants during short-term anesthesia. A study using transcutaneous PO2 and PCO2 monitoring].
Monitoring of ventilation in infants is difficult and often not very reliable. In this study, transcutaneous measurement of blood gas tensions was used to investigate the influence of four different modes of ventilation on oxygenation and ventilation in anaesthetized infants. METHODS. ⋯ The group-specific differences in degree of dysventilation with manual ventilation show that the type of breathing system is important with regard to the size of the tidal volume delivered. Thus, tidal volumes will be unintentionally increased by the high fresh gas flow needed when a T-piece system is used. The lower flow and preadjusted pressure limit may prevent the delivery of excessive tidal volumes with the paediatric circuit system...
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A 34-year-old male (190 cm/100 kg) was scheduled for surgery of the nasal septum. He had had uneventful anaesthesia for appendicectomy 14 years earlier: following 600 mg thiopentone, 180 mg suxamethonium and up to 2 vol.% halothane for 20 min had been used and no symptoms of malignant hyperthermia (MH) were recorded. Following oral premedication with 2 mg flunitrazepam at 7.00 a.m. anaesthesia was induced with a priming dose of atracurium at 8.45 a.m. followed by 0.2 mg fentanyl, 500 mg thiopentone, and 100 mg suxamethonium. Endotracheal intubation was accomplished easily, and the patient was ventilated manually in a semi-closed circle system until spontaneous ventilation resumed. Enflurane (1.5% for 5 min, 1.0% for 10 min, and 0.8% until the diagnosis of MH was suspected) was given in 33% O2/66% N2O. Seventy minutes after induction it was noted that the spontaneous respiratory rate and minute volume had risen continuously from 10/min and 6 l/min, respectively, to 20/min and 12 l/min. Attempts at deepening anaesthesia with repeated doses of fentanyl up to a total dose of 0.95 mg failed to reduce the hyperventilation. In spite of a high fresh gas flow of 6 l/min and assisted manual ventilation, the FIO2 started to fall from 0.34 to 0.28 at 10:20 a.m. The O2/N2O ratio was changed to 1:1, but the FIO2 remained at 0.3. MH was suspected, enflurane was discontinued, and an arterial blood gas analysis was done (Table 2). When marked acidosis and hypercarbia were found, dantrolene 2.5 mg/kg was given, the operation was terminated, and the patient's trachea was extubated and he was monitored closely in the intensive care unit for 24 h. Vital signs were stable (Table 3) and no further complications were observed. The patient did not mention pain or uneasiness postoperatively. About 6 months later, a muscle biopsy was done according to the European MH Protocol and the patient was found to be MHEh. ⋯ It is concluded that the hypercarbia and mixed acidosis were caused by hypermetabolism. A thorough postoperative examination by an internist did not reveal any thyroid, pulmonary, endocrine, or circulatory reason for our intra- and postoperative findings. Iatrogenic factors like superficial anaesthesia or systemic side effects of adrenaline admixture to local anaesthetics can cause hypermetabolism without striking clinical signs, but they do not cause mixed acidosis lasting longer than 6 h (Table 2). The most suitable explanation in this case is an abortive form of MH. Even patients who are MHS positive on muscle biopsy do not necessarily go through an MH crisis every time they have stress or undergo anaesthesia. The diagnosis of a fulminant MH crisis is a clinical one. Therefore, we are aware that there is no direct scientific ev
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Randomized Controlled Trial Clinical Trial
[Wound infiltration with bupivacaine following pelviscopy does not reduce postoperative pain intensity. Results of a placebo-controlled, double-blind study].
The analgetic efficacy of intraoperative infiltration with bupivacaine 0.5% or saline of the skin incisions for the endoscopic trocars was examined in 30 female patients following operative endoscopic pelviscopy in a double-blind study. Infiltration of the peritoneum, abdominal wall, and subcutaneously was performed by endoscopic view before skin suture. There were no significant differences between the two groups in age, duration of surgery, operative technique, intensity of preoperative acute and chronic pain, or state of anxiety. ⋯ Pain due to skin incision was noted less, but in equal numbers in both groups. Of the patients in the bupivacaine group 77% and in the control group 80% started with PCA due to increasing pain scores within 60 to 120 min. The numbers of tramadol demands and given doses did not differ (Fig. 2).(ABSTRACT TRUNCATED AT 250 WORDS)
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Randomized Controlled Trial Clinical Trial
[Local oxygen supply to the cerebral cortex during thiopental and propofol anesthesia. First results].
Because the brain is highly vulnerable to damage from even a brief imbalance of oxygen delivery and demand, intraoperative disturbances of local oxygen supply must be avoided. Until now, there has been no method allowing fast and reliable intraoperative measurement of the local oxygen supply in the human brain. Intraoperative investigations were therefore performed using the Erlangen micro-lightguide spectrophotometer. ⋯ In all patients receiving propofol anaesthesia higher local SO2 values were found, even if the patients first received thiopentone (values in parenthesis). The mean local SO2 amounted to 65.4% (57.3%) in the propofol group and 38.8% (45.2%) in the thiopentone group. The number of values below 25% SO2 was 5.6% (5.8%) in the propofol group and 18.7% (19.1%) in the thiopentone group.