[Current practices in anesthesia for cesarean section in german university clinics. Results of a survey in the year 1996]

[Anesthesiological management of Caesarean sections : nationwide survey in Germany]

BACKGROUND

The rate of Caesarean sections in Germany continues to rise. The change in anesthetic technique of choice from general to spinal anesthesia began later than in other countries and at the last survey in 2002 was not widely established. The literature on the anesthetic management of Caesarean sections contains many controversies, for example fluid preload before performing spinal anesthesia and the vasopressor of choice. Other issues have received relatively little attention, such as the level of experience of anesthesiologists working autonomously on the labour ward or the timing of antibiotic prophylaxis. The aim of the current survey was to provide an updated overview of anesthetic management of Caesarean sections in Germany.

MATERIAL AND METHODS

A questionnaire was sent out to 709 departments of anesthesiology serving obstetric units in Germany. The questionnaire concerned various aspects of anesthetic management of Caesarean sections.

RESULTS

A total of 360 questionnaires (50.8%) were returned of which 346 were complete and could be analyzed, accounting for 330,000 births and 90,000 Caesarean sections per year. The predominant anesthetic method used for Caesarean sections was spinal anesthesia (90.8%) using hyperbaric bupivacaine and in approximately one third of the hospitals surveyed without administering intrathecal opioids. Approximately 12% of the departments surveyed used traumatic Quincke needles. In 86.2% the vasopressor of choice was caffedrine/theodrenaline. Nitrous oxide was used in only 19.2% of departments surveyed when general anesthesia is performed. An antibiotic drug was administered in only 11% of hospitals before cord clamping. In 43.1% no neonatologist was available to treat unexpected critically ill newborns. In 32.1% of departments surveyed residents with less than 2 years experience worked autonomously on the labour ward.

CONCLUSIONS

Currently the predominant anesthetic technique of choice in Germany is spinal anaesthesia and at a much higher rate than in 2002. In addition 12% of departments use traumatic Quincke needles which are associated with a higher incidence of postpuncture headache. Nitrous oxide is no longer frequently used in Germany. Finally, the administration of an antibiotic before cord clamping has been shown to lead to lower rates of endometritis and postoperative wound infection without detrimental effects on the newborn. This is practiced in only a small minority of departments across Germany.

Umfrage zur aktuellen Situation der Regionalan�sthesie im deutschsprachigen Raum

The practice of regional anaesthesia in German speaking countries was investigated by a survey. The last part of the trilogy contains the presentation and evaluation of the data about the methods in obstetric anaesthesia. In 2002 questionnaires were mailed to 750 randomly selected departments of anaesthesia, 384 hospitals (51.2%) responded of which 278 had an obstetric unit. Caesarean section rate was 22.5+/-8.2% and for elective caesarean section spinal anaesthesia was mostly used. General anaesthesia was never used in 58.3% of Swiss, 10.2% of German, and 21.1% of Austrian hospitals. For non-elective caesarean section 42.1% of the hospitals often used a spinal anaesthesia, and 44.8% sometimes, in Switzerland these were 92.9% and 7.1%, respectively. Pain relief for labour was usually achieved with epidural anaesthesia or drugs. The trend from general to regional anaesthesia for caesarean section is continued, as is the trend from local infiltrative techniques to epidural anaesthesia for vaginal delivery. Switzerland was in the forefront for these developments.

Effects of vaginal birth versus caesarean section birth with general anesthesia on blood gases and brain energy metabolism in neonatal rats

Using a rat model, several laboratories have demonstrated long-term effects of Caesarean section (C-section) birth or of global hypoxia during C-section birth on a variety of central nervous system (CNS) parameters. These studies used C-section delivery from rapidly decapitated dams, to avoid confounding anesthetic effects, or from dams anesthetized with halothane or ether under unspecified conditions. Systemic oxygenation or cerebral energy metabolites in the pups at birth have not been systematically measured in this model. To develop and characterize a C-section model with relevance to the human situation, the present study measured arterial/venous blood gases and pH and brain ATP and lactate, a widely accepted measure of CNS hypoxia, in pups born either vaginally, by C-section from decapitated dams, or by C-section from dams anesthetized with nitrous oxide (N2O) and increasing concentrations of isoflurane under well-defined conditions. Immediately after birth, pups born vaginally, by C-section with maternal decapitation, or by C-section with 2.5% isoflurane showed no group differences in systemic pO2 or pH or brain ATP levels, but pCO2 was elevated in the C-section/2.5% isoflurane group. Pups born by C-section with 3.0, 3.5, or 4.0% isoflurane, showed progressive reductions in blood pO2 and increases in pCO2 and blood pH was reduced with 3.5% isoflurane. Relative to vaginal birth, brain lactate levels were unchanged in pups born by C-section with any concentration (2.5-4.0%) of isoflurane, but reduced in pups born by C-section from decapitated dams. At 1 h (and 4 h) after birth, in both vaginally born controls and the 2.5% isoflurane group, brain lactate fell while blood pO2 and brain ATP remained stable. In the 3.0, 3.5, or 4.0% isoflurane groups, blood gases and pH and brain lactate also normalized to control values. In conclusion, rat neonates show minimal signs of systemic or CNS hypoxia following C-section birth under 2.5% isoflurane with N2O. However, there is a rather narrow window of isoflurane concentrations which produces effective maternal anesthesia without producing respiratory compromise in the neonate. Thus the results indicate that the level of maternal anesthesia employed is an important factor influencing neonatal systemic and CNS oxygenation during C-section birth.

Surveys on the use of regional anaesthesia in obstetrics

Regional anaesthetic techniques in obstetrics have gained more and more importance during the last few years. Several surveys published recently show a remarkable increase in caesarean sections performed under regional anaesthesia, in many countries. Furthermore, epidural analgesia has proved to be one of the most effective methods of pain relief during vaginal delivery. Especially in patients at risk of an abdominal delivery, an epidural catheter already in place during labour can be used for consecutive caesarean section without delay and is used as a strong argument in favour of epidural anaesthesia. This article gives an overview of recent surveys of regional anaesthesia in obstetrics.