Drug management for coronary revascularization without cardiac standstill: the use of high-dose esmolol

Anesthetic challenges in minimally invasive cardiac surgery: Are we moving in a right direction?

Continuously growing patient's demand, technological innovation, and surgical expertise have led to the widespread popularity of minimally invasive cardiac surgery (MICS). Patient's demand is being driven by less surgical trauma, reduced scarring, lesser pain, substantially lesser duration of hospital stay, and early return to normal activity. In addition, MICS decreases the incidence of postoperative respiratory dysfunction, chronic pain, chest instability, deep sternal wound infection, bleeding, and atrial fibrillation. Widespread media coverage, competition among surgeons and hospitals, and their associated brand values have further contributed in raising awareness among patients. In this process, surgeons and anesthesiologist have moved from the comfort of traditional wide incision surgeries to more challenging and intensively skilled MICS. A wide variety of cardiac lesions, techniques, and approaches coupled with a significant learning curve have made the anesthesiologist's job a challenging one. Anesthesiologists facilitate in providing optimal surgical settings beginning with lung isolation, confirmation of diagnosis, cannula placement, and cardioplegia delivery. However, the concern remains and it mainly relates to patient safety, prolonged intraoperative duration, and reduced surgical exposure leading to suboptimal treatment. The risk of neurological complications, aortic injury, phrenic nerve palsy, and peripheral vascular thromboembolism can be reduced by proper preoperative evaluation and patient selection. Nevertheless, advancement in surgical instruments, perfusion practices, increasing use of transesophageal echocardiography, and accumulating experience of surgeons and anesthesiologist have somewhat helped in amelioration of these valid concerns. A patient-centric approach and clear communication between the surgeon, anesthesiologist, and perfusionist are vital for the success of MICS.

The effect of landiolol on cerebral blood flow in patients undergoing off-pump coronary artery bypass surgery

PURPOSE

To examine the effect of landiolol on cerebral blood flow in patients with normal or deteriorated cardiac function.

METHODS

Thirty adult patients who were diagnosed with angina pectoris and who underwent elective off-pump coronary artery bypass surgery were studied. Patients were divided into two groups, one with a preoperative left ventricular ejection fraction (EF) of 50% or higher (normal EF group; n = 15) and the other with an EF of less than 50% (low EF group; n = 15). The mean cerebral blood flow velocity (Vmca) and pulsatility index (PI) in the middle cerebral artery were recorded using transcranial Doppler ultrasonography (TCD). Individual hemodynamic data were obtained using a pulmonary arterial catheter.

RESULTS

In both groups, landiolol produced a significant decrease in heart rate (HR), which then returned to baseline 15 min after administration was completed. A significant decrease in mean arterial pressure occurred in the low EF group, but the decrease was within 30% of the baseline. In the normal EF group, there was no decrease in cardiac index (CI), whereas in the low EF group, CI significantly decreased along with the decrease in HR. There were no significant differences in Vmca and PI between the two groups.

CONCLUSION

Continuous administration of landiolol at a dose of 0.04 mg/kg/min after 1 min rapid i.v. administration at a dose of 0.125 mg/kg/min decreases HR without causing aggravation of CBF during treatment of intraoperative tachycardia in patients with normal and deteriorated cardiac function.

The effect of landiolol on hemodynamics and left ventricular function in patients with coronary artery disease

STUDY OBJECTIVE

To examine the effect of landiolol (normal dose) on hemodynamics and left ventricular (LV) function.

DESIGN

Prospective, observational, repeated-measures study.

SETTING

University hospital.

PATIENTS

56 adult patients who were diagnosed with angina pectoris and who underwent elective off-pump coronary artery bypass surgery.

INTERVENTIONS

Patients were divided into two groups based on a preoperative LV ejection fraction (EF) 50% or higher (normal EF group, n = 28) and lower than 50% (low EF group, n = 28). Hemodynamics and LV function were recorded using a pulmonary artery catheter and transesophageal echocardiography at three time points (before administration of landiolol, immediately before completion of administration, and 15 minutes after completion of administration).

MEASUREMENTS

Individual hemodynamic data were obtained using a pulmonary artery catheter, and individual parameters were determined from LV short-axis views in transesophageal echocardiography.

MAIN RESULTS

Mean preoperative EFs were 57% +/- 5% and 47% +/- 3% in the normal and low EF groups, respectively. In both groups, landiolol produced a significant decrease in heart rate (HR), which then returned to baseline 15 minutes after completion of administration. A significant decrease in mean arterial pressure occurred in the low EF group, but the decrease was within 30% of baseline. In the normal EF group, there was no decrease in cardiac index, but a significant increase in stroke index, in addition to an increase in stroke volume. In the low EF group, cardiac index significantly decreased along with the decrease in HR, but there was no increase in end-diastolic volume or stroke volume.

CONCLUSIONS

Administration of landiolol using the presently recommended dosage and administration route causes a decrease in HR without aggravation of hemodynamics in patients with normal cardiac function, but in patients with preoperative EF lower than 50%, it may lead to further deterioration of cardiac function due to a decrease in HR.

Off-pump coronary artery surgery

Cardiopulmonary bypass has several associated deleterious effects that include a systemic inflammatory response, coagulopathy, central nervous system complications and a variable degree of end-organ damage. The recent upsurge in interest in "beating-heart" surgery attempts to avoid these deleterious effects. Advances in surgical technique, such as the use of intracoronary shunts and the Octopus retractor, have made beating-heart surgery a reality. The challenges for the anaesthetist are greater than for coronary artery surgery using cardiopulmonary bypass, and whilst some advantages are proven, such as the lack of the inflammatory response and the decreased need for blood or blood products, others have yet to be proved and there is a need for further research. The advantages and disadvantages need to be evaluated in randomised studies in order to confirm the safety and efficacy of these new techniques in terms of long-term graft patency and decreased morbidity.

Ostial left anterior descending coronary artery stent positioning: partial preinflation prevents stent oscillation and facilitates accurate deployment

Ostial intracoronary stent deployment is complicated by the influence of cardiac motion, which causes the stent to oscillate back and forth during the cardiac cycle. Accurate deployment can be facilitated by initial low pressure inflation of the balloon on which the stent is mounted. This stabilizes the stent within the stenosis, while still allowing adjustment of the exact stent location prior to deployment.

The effects of a new ultra-short-acting beta-adrenergic blocker, ONO-1101, on cardiac function during and after cardiopulmonary bypass

The administration of an ultra-short-acting beta-adrenergic antagonist, esmolol, has been introduced as a novel method for beating-heart surgery. In the present study, a new ultra-short-acting beta-blocker, ONO-1101, was administered during cardiopulmonary bypass (CPB) to investigate its effects on cardiac function and hemodynamics. Nine adult mongrel dogs underwent 60 min of CPB during which they were given either ONO-1101 (ONO group; n = 4) or saline (control group; n = 5). In the ONO group, the hearts became flaccid enough for surgery to be performed without cardiac standstill within 10 min after the commencement of ONO-1101 with significant decreases in the heart rate, the preload recruitable stroke work (PRSW), and the slope of the end-systolic left ventricular pressure-volume relationship (Emax). The mean arterial pressure and systemic vascular resistance also decreased, but were maintained above 50 mmHg during CPB without catecholamine. These indices increased to the control group level 20 min after the discontinuation of ONO-1101. The serum concentration of ONO-1101 decreased from the maximum level of 121 +/- 15 microg/ml soon after infusion to 11 +/- 5 microg/ml within 30 min after discontinuation. These data suggest that ONO-1101 may be useful to enable beating-heart surgery to be performed without aortic cross-clamp as an ultra-short-acting beta-adrenergic blocker.

Intraoperative considerations during minimal-access cardiac surgery

The range of minimal-access cardiac surgery approaches has many implications in intraoperative management. A modified anesthetic regimen is required to deal with the type of surgical exposure, hemodynamic instability, whether cardiopulmonary bypass is used, and early extubation. Intraoperative considerations include hemodynamic monitoring, one-lung ventilation, pharmacological stabilization of the myocardium, pacing, hypothermia, bleeding, and rapid emergence with a minimum of postoperative mechanical ventilation. As a result, anesthetic methods and intraoperative management were modified to meet these specific needs of minimally invasive cardiac procedures.

Esmolol resistance during anesthesia for thoracoscopically assisted coronary artery bypass grafting

The anesthetic technique for two patients who underwent thoracoscopic harvesting of the LIMA followed by a mini-thoracotomy for surgical myocardial revascularization of isolated LAD artery stenosis is reported. Both patients unexpectedly showed esmolol resistance during anastomosis of the LIMA to the LAD artery. However, excellent graft patency, early extubation, and rapid recoveries were achieved.