Inflammatory response to cardiac bypass in ewe fetuses: effects of steroid administration or continuous hemodiafiltration.

OBJECTIVES: We sought to investigate the effectiveness of glucocorticoid administration or continuous venovenous hemodiafiltration on endothelin and corticotropin-releasing factor release or clearance during prolonged fetal cardiac bypass and on the overall performance of fetuses. METHODS: Circulating endothelin 1, 2, and 3 and corticotropin-releasing factor levels were measured in fetal ewes during a 60-minute cardiac bypass period performed with an inline axial flow pump. Blood samples were collected before, during, and 90 minutes after cardiac bypass. Animals were divided into 4 groups. The betamethasone group (n = 6) received maternal treatment with 12 mg of betamethasone 1 and 2 days before the experiment. The methylprednisolone group (n = 5) received fetal treatment with 40 mg/kg intravenous methylprednisolone at the beginning of cardiac bypass. The continuous venovenous hemodiafiltration group (n = 4) underwent continuous venovenous hemodiafiltration with a 0.3-m(2) polysulfone filter during cardiac bypass. The final group was the control group (n = 4). RESULTS: Maternal steroid pretreatment failed to decrease endothelin or corticotropin-releasing factor production when compared with levels in the control animals. Fetal treatment with methylprednisolone produced a significant decrease in endothelin 2 production during cardiac bypass (P <.02) and endothelin 1 production at the end of the experiment (P <.02). Continuous venovenous hemodiafiltration blocked completely the increase of endothelin and corticotropin-releasing factor levels during cardiac bypass (P <.02), which was maintained 90 minutes after cardiac bypass. Acid-base balance was preserved during cardiac bypass by the continuous venovenous hemodiafiltration but worsened after disconnection of the extracorporeal circuit, whereas animals treated with methylprednisolone had better pH, Paco(2), and bicarbonate levels by the end of the experiment. The overall tolerance of the procedure was better in the continuous venovenous hemodiafiltration group during cardiac bypass and in the methylprednisolone group at the end of the experiment. CONCLUSIONS: Continuous venovenous hemodiafiltration provides sustained stability of endothelin levels during fetal cardiac bypass. This technique might help, in association with fetal steroid treatment, to contain the inflammatory response leading to postbypass placental dysfunction.

Neuroendocrine stress response in patients undergoing benign ovarian cyst surgery by laparoscopy, minilaparotomy, and laparotomy.

STUDY OBJECTIVE: To quantify and compare neuroendocrine stress responses during and immediately after surgery by laparoscopy, minilaparotomy, and laparotomy for benign ovarian cysts. DESIGN: Prospective study (Canadian Task Force classification II-1). SETTING: Tertiary care university hospital. PATIENTS: Thirty healthy women with no major diseases and without endocrine disorders. INTERVENTIONS: Surgery for benign ovarian cysts performed by laparoscopy (10), minilaparotomy (10), or laparotomy (10). MEASUREMENTS AND MAIN RESULTS: Venous blood samples were collected at fixed times as follows: at 8 A.M. in the ward before transferring the patient to the operating room (time 0), 30 minutes after the beginning of surgery (time 1), at the end of surgery after extubation with the patient awake (time 2), and 2 and 4 hours after the end of surgery (times 3 and 4). We evaluated intraoperative and postoperative variations of the following stress-related markers: norepinephrine (NE), epinephrine (E), adrenocorticotropic hormone (ACTH), human growth hormone (hGH), prolactin (PRL), and cortisol, and postoperative pain. No differences were present in demographic characteristics and operating times in the three groups. No anesthesiologic or surgical complications occurred. Postoperative pain was similar in the laparoscopy and minilaparotomy group but significantly higher in the laparotomy group (p <0.001). Serum levels of markers were not significantly different among the groups at baseline. In the laparoscopy group the increase of hGH was limited to intraoperative time (p <0.05); increases in NE, E, ACTH, and PRL were limited to intraoperative and early postoperative time after extubation (p <0.01), with only PRL persisting with significantly higher levels after the end of surgery (p <0.05). In the minilaparotomy group no increase was detected for hGH, a significant intraoperative increase in cortisol was present (p <0.05), and NE, E, ACTH, and PRL were significantly higher even after the end of surgery (p <0.01). In this group levels of NE, E, and hGH were significantly higher than in the laparoscopy group 2 and 4 hours after the end of surgery (p <0.05). In the laparotomy group significant intraoperative increases were present for all stress markers and persisted until after extubation for ACTH (p <0.01) and to the postoperative period for NE (p <0.01), E (p <0.01), cortisol (p <0.01), PRL (p <0.05), and hGH (p <0.01). In this group levels of NE, E, ACTH, and hGH were significantly higher than those in the laparoscopy group from the beginning (NE p <0.05, E p <0.01, ACTH p <0.05, hGH p <0.01) until after the end of surgery. Comparison of laparotomy and minilaparotomy groups showed the former to have significantly higher plasma levels of E, cortisol, and hGH in intraoperative and postoperative times (p <0.001); significantly higher NE at sampling times 1 and 2 (p <0.001) and time 4 (p <0.01), and no difference at sampling time 3; and ACTH significantly higher only during surgery (p <0.01). CONCLUSION: Laparoscopic surgery causes minimal activation of stress hormones, which in some instances is confined to the intraoperative period. Minilaparotomy may be a valid alternative to laparoscopy in high-risk patients who cannot tolerate abdominal distention.