Influence of intraoperative remifentanil and sufentanil on sensory perception: a randomized trial.

OBJECTIVE: The clinical relevance of pro- and hyperalgesic effects of opioids is still a matter of debate. Particularly for remifentanil, an increased postoperative need for analgesics has been demonstrated suggesting opioid-induced hyperalgesia as a possible cause. The aim of the study was therefore to investigate the effect of intraoperatively applied remifentanil compared to sufentanil on somatosensory thresholds investigated with the quantitative sensory testing (QST) battery of the German Research Network on Neuropathic Pain (DFNS). RESEARCH DESIGN AND METHODS: Twenty-three patients undergoing surgery of the female breast were randomly assigned to intraoperative remifentanil (0.4 µg × kg-1 × min-1) or sufentanil (0.25 µg × kg-1 bolus, 0.15 µg × kg-1, repetition after 60 min) application. Anesthesia was maintained BIS-guided (Bispectral indexTM) with propofol and postoperative analgesia was ensured with paracetamol (max. 3 g/24 h). Quantitative sensory testing was performed in the region of dermatome Th 5 in the mid-axillary line preoperatively and 20 h postoperatively. CLINICAL TRIAL REGISTRATION: The study was registered at the German registry for clinical studies (DRKS00009002). MAIN OUTCOME MEASURES: Comparison of somatosensory thresholds before versus after surgery and application of intraoperative remifentanil or sufentanil. RESULTS: Sixteen patients could be finally included in the analysis. No differences of mechanical or thermal detection or pain thresholds were observed between pre- and postoperative testing or between remifentanil and sufentanil. CONCLUSION: A change of somatosensory thresholds or a clinically relevant opioid-induced hyperalgesia in the selected small patient sample (segmental resections or mastectomy with or without sentinel lymph node biopsy, surgery length <90 minutes, sufficient postoperative pain medication with paracetamol due to rather low postoperative pain intensities) with remifentanil or sufentanil was not detected 20 h after surgery.

[Anesthesia in obstetrics: Tried and trusted methods, current standards and new challenges]. / Anästhesie in der Geburtshilfe: Altbewährtes, gegenwärtige Standards und neue Herausforderungen.

Obstetric analgesia and anesthesia have some specific aspects, which in particular are directly related to pathophysiological alterations during pregnancy and also to the circumstance that two or even more individuals are always affected by complications or therapeutic measures. This review article deals with some evergreens and hot topics of obstetric anesthesia and essential new knowledge on these aspects is described. The article summarizes the talks given at the 16th symposium on obstetric anesthesia organized by the Scientific Committee for Regional Anaesthesia and Obstetric Anaesthesia within the German Society of Anaesthesiology. The topics are in particular, special features and pitfalls of informed consent in the delivery room, challenges in education and training in obstetric anesthesia, expedient inclusion of simulation-assisted training and further education on risk minimization, knowledge and recommendations on fasting for the delivery room and cesarean sections, monitoring in obstetric anesthesia by neuraxial and alternative procedures, the possibilities and limitations of using ultrasound for lumbal epidural catheter positioning in the delivery room, recommended approaches in preparing peridural catheters for cesarean section, basic principles of cardiotocography, postoperative analgesia after cesarean section, the practice of early bonding in the delivery room during cesarean section births and the management of postpartum hemorrhage.

Changes in heart rate variability may reflect sympatholysis during spinal anaesthesia.

BACKGROUND: To investigate if changes in low-to-high frequency ratio (LF/HF), low frequency (LF) and high frequency (HF) heart rate variability reflect autonomic regulation during spinal anaesthesia (SA) in pregnant women scheduled for elective Caesarean section. METHODS: Prospective clinical trial. Systolic blood pressure (SBP) and heart rate variability were analysed at baseline, 5 min after SA and 15 min after SA. Patients were assigned by baseline LF/HF. Group LF/HF < 2.5 (n= 52) was compared to group LF/HF > 2.5 (n= 48). Non-parametric tests for statistical analysis. RESULTS: Group LF/HF > 2.5 showed a significant decrease in LF/HF and LF as well as an increase in HF during SA (median, range): baseline LF/HF [4.0 (3.2/4.8)] decreased to 2.3 (1.3/3.4) at event 15 min after SA (P < 0.001). Baseline LF = 59(43/71)% decreased to 40 (27/55)% at event 15 min after SA (P < 0.05). Baseline HF = 15(13/22)% increased to 26(15/41)% at event 15 min after SA (P < 0.05). In contrast, group LF/HF < 2.5 demonstrated only moderate changes in LF/HF, LF and HF during SA. SBP decreased significantly in group LF/HF > 2.5 (median and range) lowest SBP group LF/HF > 2.5: 80 (50/127 mmHg vs. group LF/HF < 2.5: 109 (104/142) mmHg, P < 0.001. Decrease of SBP before and after SA was correlated with a decrease in LF/HF, LF, and HF, respectively: LF/HF - SBP: r= 0.30, r(2)= 0.09, P < 0.001; LF - SBP: r= 0.25, r(2)= 0.06, P < 0.05, HF, NS. CONCLUSIONS: Changes in heart rate variability parameters in the course of SA may reflect a decrease in sympathetic activity and relative increase in parasympathetic activity as a result of the block. In the course of SA, the more pronounced the changes in heart rate variability were the more distinct the hypotension.

Attenuation of sepsis-related immunoparalysis by continuous veno-venous hemofiltration in experimental porcine pancreatitis.

OBJECTIVES: In light of evidence suggesting that hemofiltration favorably influences septic diseases by removing sepsis mediators, the impact of different modalities of continuous veno-venous hemofiltration (CVVH) on outcome and immunologic derangements in porcine pancreatogenic sepsis was evaluated. DESIGN: Randomized, controlled intervention trial. SUBJECTS: Forty-eight minipigs of either sex. INTERVENTIONS: Pancreatitis was induced by intraductal injection of sodium taurocholate (4%, 1 mL/kg body weight [BW]) and enterokinase (2 U/kg BW). Animals were allocated either to untreated controls-group 1-or to one of three treatment groups-group 2: low-volume CVVH (20 mL/kg BW), no change of hemofilters; group 3: low-volume CVVH, filters changed every 12 hrs; and group 4: high-volume CVVH (100 mL/kg BW), filters changed every 12 hrs. Survival represented the major parameter of the study. Serum cytokine levels, sepsis-related down-regulation of major histocompatibility complex II and CD14 expression on leukocytes, bacterial translocation, and endotoxemia were further parameters evaluated in the study. MEASUREMENTS AND MAIN RESULTS: High-volume CVVH combined with periodic filter change was significantly superior compared with less intensive treatment modalities (low-volume CVVH, no filter change) in sepsis protection. Long-term survival (>60 hrs) was found in 67% of group 4 and 33% of group 3 animals (p <.05), whereas in controls and group 2 no animal survived. CVVH ameliorated the initial serum tumor necrosis factor-alpha response and prevented sepsis-induced in vitro endotoxin hyporesponsiveness. Down-regulation of major histocompatibility complex II and CD14 expression on monocytes was significantly improved by CVVH. Improved oxidative burst and phagocytosis capacity in polymorphonuclear leukocytes suggested that leukocyte function was stabilized by CVVH. Also, CVVH significantly reduced bacterial translocation and endotoxemia. CONCLUSIONS: Hemofiltration reversed sepsis-induced immunoparalysis in a porcine model of bile acid-induced pancreatitis. Implications for human pancreatitis must be validated in prospective, clinical protocols.