Agreement between ccNexfin CO-trek cardiac output and intermittent cold-bolus pulmonary thermodilution in a prospective multicenter study.

BACKGROUND: The ccNexfin System uses the CO-trek algorithm to analyze a non-invasively obtained arterial pressure waveform and calculate cardiac output (NEXCO). It remains matter of debate whether NEXCO can replace invasive, pulmonary artery catheter-derived, cold-bolus pulmonary thermodilution cardiac output measurement (PACCO). This study aimed at testing NEXCO-PACCO agreement in a large sample size, multicenter study. We hypothesized that agreement between NEXCO and PACCO would be demonstrated by a mean accuracy (bias) <0.6 L/min with a percentage error <30%. METHODS: Patients undergoing cardiac surgery in three academic hospitals clinically requiring pulmonary artery catheterization were included. Exclusion criteria were aortic, pulmonary and tricuspid (valve) abnormalities, non-sinus rhythm and insufficient perfusion of the digits such as in Raynaud's disease. After induction of anesthesia, cardiac output was measured with four cold bolus thermodilution measurements and four averaged 30-second ccNexfin measurements randomized through the respiratory cycle to obtain one measurement pair. Mean accuracy and precision of ccNexfin were expressed as bias (mean of all NEXCO-PACCO differences) and limits of agreement (LOA) (1.96·SD of bias). Percentage error was calculated as [LOA / (NEXCO-PACCO average)]. RESULTS: Fifty-five patients were enrolled in the study, 51 completed the protocol. Median PACCO was 3.7 (IQR: 3.2 to 4.6) L/min and median NEXCO was 3.8 (IQR: 3.1 to 4.7) L/min. NEXCO-PACCO bias was 0.1 (LOA: -1.4 to +1.6) L/min with a 37% percentage error. CONCLUSIONS: In this study, cardiac output measurement with ccNexfin failed to meet the predefined criteria for agreement with cold-bolus pulmonary artery thermodilution.

Strategies for managing perioperative hypertension.

Acute perioperative hypertension is associated with a higher risk of perioperative myocardial ischemia, bleeding, stroke, and renal failure. The immediate concern of short-term antihypertensive therapy is to prevent excessive surgical bleeding from arterial anastomoses, myocardial ischemia, and neurologic complications while causing minimal adverse effects until oral therapy can be resumed. This article reviews perioperative hypertension emergencies/urgencies and various approaches for management.

Review article: The role of statins in reducing perioperative cardiac risk: Physiologic and clinical perspectives.

PURPOSE: To review the pathobiology and clinical implications of coronary vulnerable atherosclerotic plaques (VAPs), to discuss the role of statin therapy in VAP stabilization, and the potential benefits of perioperative statin therapy (PST) in reducing perioperative risk of acute coronary syndromes (ACSs). SOURCE: MEDLINE search using "perioperative", "cardiac morbidity", "atherosclerosis", "vulnerable plaque", "statins" and combinations of these terms as keywords. The reference lists of relevant articles were further reviewed to identify additional citations. PRINCIPAL FINDINGS: The nonstenotic, yet rupture-prone VAP causes most myocardial infarctions (MIs) and other ACSs, both in the nonsurgical and surgical patients. Large clinical trials in both primary and secondary prevention and in patients with ACSs have demonstrated that statin therapy will reduce cardiovascular morbidity and mortality across a broad spectrum of patient subgroups. These trials also suggest, and laboratory investigations establish, that statins possess favourable vascular effects independent of cholesterol reduction. Statins appear to interfere specifically with the pathophysiologic mechanisms implicated in atherothrombotic disease. Statins reduce vascular inflammation, improve endothelial function, stabilize VAPs, and reduce platelet aggregability and thrombus formation. Recent studies have shown that PST is associated with a reduced incidence of perioperative and long-term cardiovascular complications in high-risk patients. Combined therapy with statins and ss-blockers is a conceptually valid strategy targeting critical steps in the pathogenesis of an ACS. CONCLUSION: Emerging evidence for the efficacy and safety of PST is promising, especially when combined with ss-blocker therapy in patients at highest risk. Confirmation of this early evidence awaits the results of ongoing and future prospective randomized controlled trials.

Successful near-term pregnancy outcome after repair of a dissecting thoracic aortic aneurysm at 14 weeks gestation.

PURPOSE: We report the anesthetic management for a scheduled Cesarean section of a 29-yr-old female who previously had a repair of her dissecting thoracic aortic aneurysm during the 14th week of her pregnancy. CLINICAL FEATURES: A 29-yr-old female with a history of hypertension and previously diagnosed aortic dissection secondary to suspected Marfan's syndrome, presented to our institution for the first time after she became pregnant. A transesophageal echocardiogram revealed a dissecting aortic aneurysm greater than 8 cm in diameter beginning distal to the left subclavian artery and extending into the descending thoracic aorta. The patient was counseled in great detail about the risk of rupture with continuing pregnancy. She refused termination and chose elective repair of the aneurysm, with continuation of the pregnancy. Partial repair of the thoracic aneurysm was undertaken when the pregnancy was 13(5/7) weeks by ultrasound dates. She was subsequently maintained on labetolol and hydralazine for blood pressure control. A decision was made to proceed with a Cesarean section at 32 weeks. After placement of a radial artery catheter and two large peripheral iv catheters, she received a of 7 and 7 at one and five minutes was delivered. CONCLUSIONS: Aortic dissection in pregnancy may have catastrophic results. Undoubtedly, it presents unique challenges for anesthetic and obstetrical management. With appropriate care and surgical correction of the dissecting aneurysm early in pregnancy, a successful outcome for the pregnancy was possible.