Platelet dysfunction in a large-animal model of endotoxic shock; effects of inhaled nitric oxide and low-dose steroid.

OBJECTIVE: The role of inhaled nitric oxide in the treatment of shock remains controversial and further translational research is needed. Long-term observation studies using a model of endotoxin-induced shock to assess the effect of inhaled nitric oxide on platelet aggregation have not yet been reported. APPROACH AND RESULTS: The tests were carried out in an animal model of shock in two 10-h periods. During the first 10 h, endotoxin was infused and the inhibition of platelet aggregation was evaluated; following the termination of endotoxin infusion, the restoration of platelet aggregation was assessed for 10 h. A total of 30 pigs were used (NO group, N = 14; control, N = 16). In the NO group, nitric oxide inhalation (30 ppm) was started 3 h after endotoxin infusion and continued until the end of the study. Treatment with NO selectively decreased pulmonary artery pressure at 4 (p = 0.002) and 8 h (p = 0.05) of the experiment as compared to the control. Endotoxin significantly reduced platelet aggregation, as indicated by the decreased activity of platelet receptors: ASPI, ADP, collagen, and TRAP during the experiment (p < 0.001). Endotoxin had no significant effect on changes in the response of the receptor after ristocetin stimulation. After stopping endotoxin infusion, a significant restoration of receptor activity was observed for collagen and TRAP, while ASPI and ADP remained partially depressed. Inhaled nitric oxide did not cause additional inhibition of platelet aggregation, either during or after endotoxin challenge. CONCLUSIONS: A profound reduction in platelet aggregation was observed during endotoxic shock. After stopping endotoxin infusion a restoration of platelet receptor activity was seen. The inhibition of platelet aggregation induced by endotoxin infusion was not intensified by nitric oxide, indicating there was no harmful effect of inhaled nitric oxide on platelet aggregation.

Transversus abdominal plane (TAP) block for postoperative pain management: a review.

Transversus abdominal plane (TAP) block has a long history and there is currently extensive clinical experience around TAP blocks. The aim of this review is to provide a summary of the present evidence on the effects of TAP block and to provide suggestions for further studies. There are several approaches to performing abdominal wall blocks, with the rapid implementation of ultrasound-guided technique facilitating a major difference in TAP block performance. During surgery, an abdominal wall block may also be applied by the surgeon from inside the abdominal cavity. Today, there are more than 11 meta-analyses providing a compiled evidence base around the effects of TAP block. These analyses include different procedures, different techniques of TAP block administration and, importantly, they compare the TAP block with a variety of alternative analgesic regimes. The effects of TAP block during laparoscopic cholecystectomy seem to be equivalent to local infiltration analgesia and also seem to be beneficial during laparoscopic colon resection. The effects of TAP are more pronounced when it is provided prior to surgery and these effects are local anaesthesia dose-dependent. TAP block seems an interesting alternative in patients with, for example, severe obesity where epidural or spinal anaesthesia/analgesia is technically difficult and/or poses a risk. There is an obvious need for further high-quality studies comparing TAP block prior to surgery with local infiltration analgesia, single-shot spinal analgesia, and epidural analgesia. These studies should be procedure-specific and the effects should be evaluated, both regarding short-term pain and analgesic requirement and also including the effects on postoperative nausea and vomiting, recovery of bowel function, ambulation, discharge, and protracted recovery outcomes (assessed by e.g., postoperative quality of recovery scale).