Der Anaesthesist
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Randomized Controlled Trial Clinical Trial
[Addition of fentanyl to bupivacaine--peridural analgesia in cesarean section].
Epidural anaesthesia for elective caesarean section can have advantages over general anaesthesia. The anaesthesiologist can avoid endotracheal intubation as well as fetal depression following placental transfer of systemic anaesthetics. However, despite reaching an effective blockade preoperatively, intraoperative discomfort and pain may occur during epidural anaesthesia with local anaesthetics alone, necessitating supplemental systemic analgesics or even conversion to general anaesthesia [21]. Addition of epidural fentanyl has been shown to improve onset and quality of perioperative analgesia without evident side effects for mother or newborn [24]. Nevertheless, administration of epidural opioids before cord clamping is still hotly debated, some fearing maternal and or neonatal depression [6, 26]. The aim of the present study was to investigate the quality of analgesia, associated side effects and the resulting maternal and neonatal plasma opiate concentrations after a single preoperative addition of 0.1 mg fentanyl to epidural bupivacaine analgesia in comparison to epidural bupivacaine analgesia alone. ⋯ Groups were comparable regarding age, weight and time of gestation. Total bupivacaine doses and injection to delivery times were similar in both groups. Figure 1 shows that there were 40% more pain-free (VAS = 0) patients in the B+F group during uterine eventration and wound closure (P < 0.05). Mean postoperative duration of analgesia was significantly longer in the B+F group (382 vs 236 min). The rate of nausea and mild itching was significantly higher in the B+F group. Respiratory depression was never detected in patients or newborns. Small group differences in blood pressure or respiratory rate were inconstant and clinically irrelevant, as were differences in umbilical venous pCO2. One hundred and twenty-five blood samples were analysed for fentanyl concentrations. The mean fentanyl concentration before epidural injection was not zero, but 0.25 ng/mg (range 0.02-0.32). Maternal concentrations at 20 and 40 min after injection were 0.55 ng/ml (0.12-1.14) and 0.52 ng/ ml (0.26-1.04) (Fig. 3). At delivery, mean maternal fentanyl concentration was 0.58 ng/ml (0.14-1.18); mean umbilical arterial and venous concentrations were 0.51 ng/ml (0.04-1.8) and 0.41 ng/ml (0.18- 1.2), respectively. Rare results of fentanyl concentrations > 1.0 ng/ml correlated neither with sedation, maternal respiratory rate and side effects, nor with Apgar scores and umbilical blood gas values. No Apgar score at 5 min was below 9, and no umbilical pH was below 7.20. (ABSTRACT TRUNCATED)
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Recently, professional anaesthesiologists organizations, have set up recommendations for intraoperative monitoring. These recommendations are based upon the assumption that anaesthesia-related deaths are largely preventable and that extensive monitoring will reduce mortality. Hypoxaemia appears to be an important pathophysiological mechanism, and this is why oxygen monitoring is given a high priority in safety standards in anaesthesia. ⋯ Pulse oximetry is certainly highly recommended, but also has some deficiencies which are not sufficiently well known considering the popularity of this technique. Transcutaneous PO2 is considered mainly for historical reasons. Near infrared spectrometry is a new technique offering noninvasive and continuous monitoring of intracerebral oxygenation.
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Immediate-type hypersensitivity due to natural rubber (latex) products is an increasing problem for the anaesthetist, because a major part of products used for anaesthesia contains natural rubber. If the patient has a positive history of allergic symptoms after contact to natural rubber like urticaria, bronchospasm or anaphylaxis, preoperative skin tests, in vitro tests, and if necessary even the latex-glove-wearing test should be performed. If preoperative diagnosis of natural latex allergy is established, latex free anaesthesia is strictly recommended; otherwise life-threatening complications may ensue. ⋯ In addition to the treatment with drugs, latex-containing products should be immediately replaced by latex-free ones, in particular all persons should put on latex-free gloves. For prevention of anaphylactic episodes in sensitized patients the reader is provided with an exemplary list of latex-free products for anaesthesia. Because the incidence of immediate-type reactions to latex is still increasing, intraoperative occurrence of an anaphylactic reaction to an unknown agent is likely to be due to allergy to natural rubber.
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Hypoxic pulmonary vasoconstriction (HPV) was first described by von Euler and Liljestrand in 1946 and is still the only known vascular feedback control mechanism in the lung. This technique results in a redistribution of blood flow away from poorly ventilated areas into better ventilated regions, thus reducing shunt. HPV functions as a local mechanism that acts in response to alveolar hypoxia but in the smallest areas of the lung, making it an important mechanism in all situations where ventilation perfusion mismatch occurs. to be effective, HPV needs normal pulmonary areas into which blood flow can be diverted. ⋯ Examination of a histological lung section emphasizes that the small arteries are closely surrounded by alveoli gas on the outside and by mixed venous blood on the inside. Thus, the response is believed to be accounted for by each smooth muscle cell in the pulmonary arterial wall responding proportionally to the local oxygen tension in its vicinity and depending on alveolar as well as mixed venous oxygen pressure. The biochemical intracellular mechanism remains unknown.
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In 1993, we conducted a postal survey to assess the use of autologous blood transfusion (ABT) in the Federal Republic of Germany after reunification. The results of this survey have already been reported in a previous paper, but without differentiation between the "old" and "new" states (former West Germany and former German Democratic Republic, respectively). In the present study, the data of our 1993 survey were further analysed to see if there were differences in the use of ABT between the "old" and "new" states. ⋯ CONCLUSION. We conclude that ABT is more widely used in the "old" than the "new" states of the Federal Republic of Germany. ABT is regarded as a desirable alternative to homologous blood transfusion, and in the interest of equal standards of medical care throughout the nation, the use of ABT should be further promoted, especially in the "new" states of the Federal Republic of Germany.