Β-Adrenergic agonist administration is not associated with secondary carcinoid crisis in patients with carcinoid tumor.

BACKGROUND: Patients with carcinoid tumors are at risk for profound intraoperative hypotension known as carcinoid crisis, which catecholamines are traditionally believed to trigger. However, data supporting this are lacking. METHODS: Anesthesia records were retrospectively reviewed for carcinoid patients treated with vasopressors. Hemodynamics for those with crisis were compared between those who received ß-adrenergic agonists (B-AA) versus those who did not. RESULTS: Among 293 consecutive operations, 58 were marked by 161 crises. There was no significant difference in the incidence of paradoxical hypotension with B-AA compared to non-B-AA (p = 0.242). The maximum percent decrease in mean arterial pressure following drug administration was significantly greater in those patients treated with non-B-AA than with B-AA (31.6% vs. 12.5%, p < 0.0001). There were no differences in crisis duration (p = 0.257) or postoperative complication rate (p = 0.896). CONCLUSIONS: ß-Adrenergic agonist use was not associated with paradoxical hypotension, prolonged carcinoid crisis, or postoperative complications in patients with intraoperative carcinoid crisis.

A prospective study of the pathophysiology of carcinoid crisis.

BACKGROUND: Sudden massive release of serotonin, histamine, kallikrein, and bradykinin is postulated to cause an intraoperative carcinoid crisis. The exact roles of each of these possible agents, however, remain unknown. Optimal treatment will require an improved understanding of the pathophysiology of the carcinoid crisis. METHODS: Carcinoid patients with liver metastases undergoing elective abdominal operations were studied prospectively, using intraoperative, transesophageal echocardiography, pulmonary artery catheterization, and intraoperative blood collection. Serotonin, histamine, kallikrein, and bradykinin levels were analyzed by enzyme-linked immunosorbent assay. RESULTS: Of 46 patients studied, 16 had intraoperative hypotensive crises. Preincision serotonin levels were greater in patients who had crises (1,064 vs 453 ng/mL, P = .0064). Preincision hormone profiles were otherwise diverse. Cardiac function on transesophageal echocardiography during the crisis was normal, but intracardiac hypovolemia was observed consistently. Pulmonary artery pressure decreased during crises (P = .025). Linear regression of preincision serotonin levels showed a positive relationship with mid-crisis cardiac index (r = 0.73, P = .017) and a negative relationship with systemic vascular resistance (r=-0.61, P = .015). There were no statistically significant increases of serotonin, histamine, kallikrein, or bradykinin levels during the crises. CONCLUSION: The pathophysiology of carcinoid crisis appears consistent with distributive shock. Hormonal secretion from carcinoid tumors varies widely, but increased preincision serotonin levels correlate with crises and with hemodynamic parameters during the crises. Statistically significant increases of serotonin, histamine, kallikrein, or bradykinin during the crises were not observed.

Continuous peripheral nerve block compared with single-injection peripheral nerve block: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND AND OBJECTIVES: Many practitioners consider continuous peripheral nerve blocks (cPNBs) to be superior to single-injection peripheral nerve blocks (siPNBs). Several randomized controlled trials have demonstrated improved pain control, patient satisfaction, and other outcomes for patients with cPNBs compared with patients with siPNBs, whereas other trials have not shown significant differences. We sought to clarify any potential advantages of cPNBs over siPNBs. METHODS: We conducted a systematic review and meta-analysis of all prospective, randomized trials comparing cPNBs with siPNBs. We used a validated systematic search strategy to identify potentially eligible studies. For studies meeting inclusion criteria, methodologic quality was scored independently by 2 reviewers. Data from the studies were abstracted and pooled for meta-analysis. RESULTS: Compared with siPNBs, cPNBs were associated with a decreased rating of worst pain on postoperative day 0 (effect size [ES], -1.29; 95% confidence interval [CI], -2.19 to -0.40; P = 0.005), postoperative day 1 (ES, -1.87; 95% CI, -2.44 to -1.31; P < 0.001), and postoperative day 2 (ES, -2.03; 95% CI, -2.78 to -1.290; P < 0.001); decreased overall opioid use (ES, -15.70; 95% CI, -21.84 to -9.55; P < 0.001); less nausea (ES, 0.633; 95% CI, 0.407-0.983; P = 0.043); and higher patient satisfaction scores (weighted mean difference, -2.04; 95% CI, 1.24-2.85; P < 0.001). CONCLUSIONS: Compared with siPNBs, cPNBs were associated with improved pain control, decreased need for opioid analgesics, less nausea, and greater patient satisfaction. The effect of cPNBs on other clinically relevant outcomes, such as complications, long-term functional outcomes, or costs, remains unclear.