A randomized, double-blind, placebo-controlled study assessing the anti-inflammatory effects of ketamine in cardiac surgical patients.

OBJECTIVE: To determine whether ketamine administration affects markers of inflammation in cardiac surgery with cardiopulmonary bypass (CPB) and to investigate differences between 2 low-dose ketamine regimens. DESIGN: Prospective, randomized, placebo-controlled trial. SETTING: Single-center university hospital. PARTICIPANTS: Patients undergoing cardiac surgery with CPB. INTERVENTION: Patients (n = 50) were randomized to 1 of 3 groups: ketamine, 0.25 mg/kg (n = 15); ketamine, 0.5 mg/kg (n = 18);or placebo (n = 17) in a double-blind manner at the time of induction of general anesthesia. MEASUREMENTS AND MAIN RESULTS: Serum C-reactive protein (CRP) and interleukin (IL)-6, IL-8, and IL-10 were measured at baseline, on intensive care unit (ICU) arrival, and on the first postoperative day (POD 1). Both ketamine doses decreased the serum IL-6 response at ICU arrival and POD 1 compared with placebo (p < 0.05). CRP was lower in the 0.5-mg/kg group than placebo on POD 1 (p = 0.003). IL-10 was lower in the ketamine groups (p = 0.01) at POD 1 compared with placebo; IL-8 levels were not affected by ketamine. Mean arterial pressure and systemic vascular resistance were higher at the end of surgery, arrival in the ICU, and POD 1 in the ketamine groups (p < 0.05). CONCLUSION: Low-dose ketamine (0.5 mg/kg) attenuates increases in CRP, IL-6, and IL-10 while decreasing vasodilatation after CPB.

End-tidal CO2 for prediction of cardiac output following weaning from cardiopulmonary bypass.

This prospective study included 32 patients undergoing cardiopulmonary bypass (CPB) for elective coronary artery bypass grafting correlates the respiratory end-tidal CO2 (ETCO2) during partial separation from CPB with cardiac output (CO) following weaning from CPB. After induction of general anesthesia, a pulmonary artery catheter was inserted for measurement of cardiac output by thermodilution. Patients were monitored using a 5-lead ECG, pulse oximeter, invasive blood pressure monitoring, rectal temperature probe, and end-tidal capnography. At the end of surgery, patients were weaned from CPB in a stepwise fashion. Respiratory ETCO2 and in-line venous oximetry were continuously monitored during weaning. The ETCO2 was recorded at quarter pump flow and after complete weaning from CPB. Following weaning from CPB, CO was measured by thermodilution. The CO values were correlated with the ETCO2 during partial bypass and following weaning from bypass. Regression analysis of ETCO2 at quarter-flow and post-bypass CO showed significant correlation (r = 0.57, p < .001). Also, regression analysis of ETCO2 after complete weaning from bypass and post-bypass CO showed significant correlation (r = 0.6, p = .002). The correlation between ETCO2 and CO showed that an ETCO2 >30 mm Hg during partial CPB will always predict an adequate CO following weaning from CPB. An ETCO2 <30 mm Hg may denote either a low or a normal cardiac output and hence other predictive parameters such as SvO2 must be added.

Variable hemodynamic fluctuations during resection of multicentric extraadrenal pheochromocytomas.

PURPOSE: To report the perioperative management and the serious hemodynamic fluctuations during manipulation of an organ of Zuckerkandl tumour in a patient undergoing resection of multicentric extraadrenal pheochromocytomas. CLINICAL FINDINGS: A 28-yr-old man who had undergone at age 12 a laparotomy for excision of an extraadrenal pheochromocytoma complained of paroxysmal headache, occasional sweating and palpitations. The arterial blood pressure (BP) was 200/100 mmHg. A 24-hr-urine collection showed catecholamines 5076 microg x 24 hr(-1) (normal < 25 microg x 24 hr(-1)). Computed tomography of the abdomen revealed two retroperitoneal masses, one adjacent to the lower pole of the right kidney and a second larger mass located at the aortic bifurcation in the region of the organ of Zuckerkandl. The patient was scheduled for excision of multiple extraadrenal pheochromocytomas. He was prepared preoperatively for two weeks with prazosin 1 mg po q six hours and propranolol 10 mg tid. Manipulation of the infrarenal tumour was uneventful but manipulation of the Zuckerkandl tumour resulted in severe hypertensive episodes with BP ranging from 200/100 to 320/120 mmHg. Surgery was interrupted temporarily; the hypertensive crisis was controlled by the infusion of sodium nitroprusside and by iv phentolamine and esmolol. CONCLUSION: In a patient undergoing resection of recurrent multicentric extraadrenal pheochromoctyomas, severe hypertensive episodes occurred during manipulation of one tumour but not during manipulation of the other. This may be attributed to inadequate preparation of the patient, difficult surgical dissection of the large Zuckerkandl pheochromocytoma, and/or secondary to an excessive and different pattern of release of catecholamines during manipulation of the Zuckerkandl tumour.

Intrathecal versus intravenous fentanyl for supplementation of subarachnoid block during cesarean delivery.

UNLABELLED: Forty-eight healthy parturients scheduled for elective cesarean delivery were randomly allocated to receive intrathecally either 12 mg of hyperbaric bupivacaine plus 12.5 microg of fentanyl (n = 23) or bupivacaine alone (n = 25). In the latter group, IV 12.5 microg of fentanyl was administered immediately after spinal anesthesia. We compared the amount of IV fentanyl required for supplementation of the spinal anesthesia during surgery, the intraoperative visual analog scale, the time to the first request for postoperative analgesia, and the incidence of adverse effects. Additional IV fentanyl supplementation amounting to a mean of 32 +/- 35 microg was required in the IV Fentanyl group, whereas no supple- mentation was required in the Intrathecal Fentanyl group (P = 0.009). The time to the first request for postoperative analgesia was significantly longer in the Intrathecal Fentanyl group than in the IV Fentanyl group (159 +/- 39 min versus 119 +/- 44 min; P = 0.003). The incidence of systolic blood pressure <90 mm Hg and the ephedrine requirements were significantly higher in the IV Fentanyl group as compared with the Intrathecal Fentanyl group (P = 0.01). Also, intraoperative nausea and vomiting occurred less frequently in the Intrathecal Fentanyl group compared with the IV Fentanyl group (8 of 23 vs 17 of 25; P = 0.02). IMPLICATIONS: Supplementation of spinal bupivacaine anesthesia for cesarean delivery with intrathecal fentanyl provides a better quality of anesthesia and is associated with a decreased incidence of side effects as compared with supplementation with the same dose of IV fentanyl.

Haemodynamic and EKG changes in patients undergoing minimally invasive direct coronary artery bypass.

BACKGROUND AND OBJECTIVES: The objective of the report is to monitor, in patients undergoing minimally invasive direct coronary artery bypass surgery (MIDCAB), the haemodynamic parameters, ST segment changes and the incidence of arrhythmias during clamping of the coronary artery and following reperfusion. METHODS: Twelve patients scheduled for elective MIDCAB surgery during isoflurane anesthesia were enrolled in the study. Patients were monitored by a pulmonary artery thermodilution catheter, an arterial line and 5 leads ECG. The different haemodynamic parameters, the ST segment changes, as well as the occurrence of arrhythmias during coronary clamping and ten minutes following reperfusion were compared to the control values. RESULTS: No significant changes in the cardiac index followed clamping of the coronary artery. However, the ST segment was significantly elevated. Following coronary reperfusion, the ST segment recovered to the baseline values, and the cardiac index significantly increased more than the baseline value (3.5 +/- 1.1 l/min/m2 vs 2.6 +/- 0.7 l/min/m2). However, reperfusion was associated with multiple ventricular extrasystoles in four patients. The elevation of the ST segments during coronary clamping was higher in the four patients who developed reperfusion arrhythmias (0.9 +/- 0.4 mm); one of the patients had preoperative frequent VPBs, two patients had history of unstable angina, while the fourth patient had 70% proximal stenosis of the LAD and recent myocardial infarction. CONCLUSIONS: Coronary occlusion in patients undergoing MIDCAB can result in ST segment elevation, followed by reperfusion ventricular extrasystoles. The reperfusion arrhythmias were observed in patients showing a significant elevation of the ST segment during coronary occlusion; risk factors included a preoperative history of arrhythmia, unstable angina, recent MI, and/or 70% LAD stenosis. The rapid restoration of the control ST segment level and the significant increase of cardiac output following coronary reperfusion suggest that isoflurane anesthesia may have provided a degree of myocardial protection during coronary clamping and reperfusion.

The pregnant cardiac woman.

Cardiac diseases are present in 0.5-4% of pregnancies, and they remain a frequent cause of death during pregnancy. Pregnancy per se imposes significant hemodynamic changes, placing a major burden on the cardiovascular system. The early recognition and close follow-up of patients with cardiac diseases will improve maternal tolerance to the cardiovascular burden imposed by pregnancy, promote fetal growth and neonatal survival. Rheumatic heart disease remains the most frequent heart disease in the pregnant population with pulmonary edema as the most frequent complication. Atrial septal defect is the most frequent congenital heart disease in the adult population, whereas tetralogy of Fallot is the most common cyanotic congenital heart disease. An improvement in modern techniques of monitoring, a better understanding of the pathophysiology of cardiac disease, as well as multidisciplinary care has led to a substantial improvement in outcome of the pregnant cardiac patient. Management should be initiated before conception as it will provide optimal clinical conditions and sufficient information on the underlying pathophysiology.

Anesthesia and myopathy.

PURPOSE OF REVIEW: This report reviews the derangements of neuromuscular transmission in the different types of myopathy. RECENT FINDINGS: The article covers recent literature on myopathy, whether prejunctional, junctional or postjunctional, as well as intensive care unit myopathy, and outlines the influence of myopathy on the action of both depolarizing and non-depolarizing muscle relaxants. SUMMARY: The review classifies myopathy according to its cause, and sheds light on the upregulation and downregulation of endplate acetylcholine receptors. These findings are important for both clinical practice, and for research into neuromuscular transmission.