Relocation of patients after cardiac surgery: is it worth the effort?

BACKGROUND: Fast-track protocols may facilitate early patient discharge from the site of surgery through the implementation of more expedient pathways. However, costs may merely be shifted towards other parts of the health care system. We aimed to investigate the consequence of patient transfers on overall hospitalisation, follow-up and readmission rate after cardiac surgery. METHODS: A single-centre descriptive cohort study using prospectively entered registry data. The study included 4,515 patients who underwent cardiac surgery at Aarhus University Hospital during the period 1 April 2006 to 31 December 2012. Patients were grouped and analysed based on type of discharge: Directly from site of surgery or after transfer to a regional hospital. The cohort was obtained from the Western Denmark Heart Registry and matched to the Danish National Hospital Register. RESULTS: Median overall length of stay was 9 days (7.0;14.4). Transferred patients had longer length of stay, median difference of 2.0 days, p < 0.001. Time to first outpatient consultation was 41(30;58) days in transferred patients vs. 45(29;74) days, p < 0.001. 18.6% was readmitted within 30 days. Mean time to readmission was 18.4 ± 6.4 days. Median length of readmission was 3(1,6) days. There was no difference in readmissions between groups. Leading cause of readmission was cardiovascular disease with 48%. CONCLUSION: Transfer of patients does not overtly reduce health care costs, but overall LOS and time to first outpatient consultation are substantially longer in patients transferred to secondary hospitals than in patients discharged directly. Readmission rate is high during the month after surgery, but with no difference between groups.

Effects of levosimendan in patients with left ventricular hypertrophy undergoing aortic valve replacement.

BACKGROUND: Left ventricular hypertrophy is associated with adverse outcomes, including death, during cardiac surgery. This may be facilitated by an increased oxygen demand and diastolic dysfunction. Levosimendan augments haemodynamics without further oxygen consumption and improves echocardiographic indices of diastolic dysfunction. This study aimed to describe the haemodynamic effects of short-term pre- and intra-operative levosimendan infusion including advanced echocardiographic measures of diastolic and systolic heart function. METHODS: The study was randomised, double-blinded and placebo-controlled performed at a single-centre university hospital. Patients with left ventricular hypertrophy and ejection fraction > 45% scheduled for single procedure aortic valve replacement were included and randomised to infusion of either levosimendan 0.1 µg/kg/min or placebo from 4 h before anaesthesia to the end of surgery. Outcome measures were echocardiographic indices of left ventricular diastolic function: E/e' (primary endpoint), e', e'/a' and indices of systolic function: longitudinal strain, ejection fraction and s'. Patients were followed until 6 months after surgery. In addition, invasive haemodynamic measures were obtained perioperatively. RESULTS: The trial was prematurely terminated due to an overall high incidence of post-operative atrial fibrillation (15/20, P = 0.002) after inclusion of 20 patients. The relative decrease in perioperative cardiac index was lower (P = 0.016) in the levosimendan group. There was no difference in E/e', and similar results were found for all measures of systolic function. CONCLUSION: Short-term levosimendan caused a transient relative increase in cardiac index, but no effect was seen on the first post-operative day and up to 6 months post-operatively with indices of systolic and diastolic heart function.

High thoracic epidural analgesia decreases stress hyperglycemia and insulin need in cardiac surgery patients.

OBJECTIVE: Assuming that high thoracic epidural analgesia (HTEA) with the sympathetic block might decrease postoperative blood glucose (BG) level and reduce the need of insulin, the aim was to evaluate the effect of HTEA on the BG level and insulin requirement in patients undergoing cardiac surgery. MATERIALS AND METHODS: Forty-two low-risk patients age 65-79 years scheduled for elective coronary artery bypass grafting with or without aortic valve replacement were randomised to receive HTEA as supplement for general anaesthesia. BG and lactate were measured before and after cardiopulmonary bypass and postoperatively at least every 3 h together with administration of insulin. Postoperative pain was evaluated 30 min, 2, 4 and 6 h after extubation, and before discharge from the intensive care unit. RESULTS: Overall BG levels showed great variation over time (P < 0.001). No statistically significant difference was found in perioperative BG, but postoperative lower BG levels were found in HTEA patients (P = 0.042). The number of patients not receiving insulin in postoperative period was significantly higher in HTEA group (9 vs. 2, P = 0.032). No differences were seen in lactate levels. Patients in the HTEA group had significant lower pain scores (P < 0.001). CONCLUSION: HTEA preserves glucose metabolism better and leads to a lesser degree of 'stress hyperglycaemia' in cardiac surgery patients.

Agreement between cardiac outputs by four-dimensional echocardiography and thermodilution method is poor.

OBJECTIVE: The objective of the study was to determine the agreement of cardiac output (CO) measured by four-dimensional echocardiography (4D echo) to simultaneously obtain CO from pulmonary artery catheter (PAC) using thermodilution technique. MATERIALS AND METHODS: Sixty-three comparable readings from 27 patients scheduled for elective coronary artery bypass were included. All echocardiographic measurements were obtained by one experienced echocardiographer. All echo images were analyzed independently and blinded from PAC-obtained measurements. Analysis was primarily done by Bland and Altman plot. The collected data were further controlled for interobserver bias and image quality. RESULTS: Differences in CO measurements increased with higher CO, hence values were logarithmically transformed. On the logaritmic scale, the 4D echo underestimated CO by 0.37 l/min compared with PAC, indicating that PAC measurements were 1.45 times higher than the 4D echo (95% confidence interval 1.32-1.52) and limits of agreement 0.97-2.14). The interobserver bias of 4D echo measurement analysis was 0.29 l/min (95% confidence interval 0.16-0.42) and limits of agreement -0.8-1.38). No difference was seen in image quality between comparisons with good agreement compared with comparisons with poor agreement. CONCLUSION: The agreement between COs by 4D echo and standard PAC thermodilution technique was poor. 4D echo underestimates CO as compared with PAC. This is most likely caused by the analysis software or low frame rate inherent to the technique.

Sufentanil preserves hemodynamics and left ventricular function in patients with ischemic heart disease.

OBJECTIVE: Sufentanil has been reported to provide stable hemodynamics similar to other opioids. However, it has not been reliably established whether this stability can be attributed only to Sufentanil and translates into fully preserved left ventricular (LV) function. The purpose of this study was to evaluate the effect of Sufentanil on hemodynamics and LV systolic and diastolic function using invasive monitoring and echocardiography in patients with ischemic heart disease. METHODS: Prospective observational study of thirty patients acting as their own control undergoing echocardiographic imaging before and after bolus Sufentanil 1.5-2.0 µg/kg. Full invasive hemodynamic monitoring was established before Sufentanil administration. Global LV systolic function was evaluated with a global longitudinal peak systolic strain (GLPSS) by speckle tracking ultrasound; systolic displacement by tissue tracking (TT) and diastolic function was evaluated using Doppler tissue imaging and pulse wave Doppler. RESULTS: Hemodynamic monitoring showed a minor decline in systolic blood pressure from 159 to 154 mmHg (P=0.046). No changes were observed in the cardiac index, stroke volume index and heart rate. An unchanged TT score index (9.9 vs. 10.2 mm, P=0.428) and GLPSS (14.3 vs. 14.5%, P=0.658) indicated preserved LV global systolic function and unchanged E'/A' (0.95 vs. 0.89, P=0.110) and E/E' ratio (15.4 vs. 14.9, P=0.612) indicated unchanged diastolic function. CONCLUSION: Sufentanil preserves hemodynamic parameters as well as echocardiographic indices of LV systolic and diastolic function in patients with ischemic heart disease (IHD).

Variation in use of peroperative inotropic support therapy in cardiac surgery: time for reflection?

BACKGROUND: There is no well-established evidence-based clinical guidelines on the most appropriate use of peroperative inotropic support in cardiac surgery. We aimed to identify patient- and procedure-related factors associated with the use of peroperative inotropic support and to estimate physician-level variation. METHODS: A population-based study using data from the Western Denmark Heart Registry on 3585 consecutive cardiac surgery cases from three university hospitals. Inotropic support was defined as infusion of inotropic drugs or nor epinephrine at the separation from cardiopulmonary bypass. Poisson's regression modelling was used to determine predictors of inotropic support and to compare use of high-dose inotropic support among experienced cardiac anaesthesiologists. RESULTS: We identified a range of factors that were independently associated with an increased use of inotropic support therapy including pre-operative left ventricular dysfunction, pre-operative renal dysfunction, complex procedures, prior cardiac surgery, emergency surgery, pre-operative pulmonary hypertension, critical pre-operative state, extended extra corporal circulation-time and female gender. Further, we found substantial variation in use of inotropic support both at hospital- and at physician-level. The adjusted odds ratio of high-intensity inotropic support varied significantly at physician level from 2.3 [95% confidence interval (CI) 1.83-2.71] to 0.3 (95% CI 0.15-0.61) when the individual physicians were compared with the rest. CONCLUSION: The use of inotropic support during cardiac surgery is associated with the pre-operative state of the patient, as well as type of surgery. However, the present study indicates that use of peroperative inotropic support is also highly dependent on physician's preferences, indicating the need for an evidence-based approach when initiating inotropic therapy in cardiac surgery.

Ketamine reduce left ventricular systolic and diastolic function in patients with ischaemic heart disease.

OBJECTIVE: Ketamine may be followed by a general increase in haemodynamics and oxygen consumption, which may be of concern in patients with ischaemic heart disease. The purpose of this study was to evaluate the effect of ketamine on left ventricular (LV) systolic and diastolic function by different modalities of echocardiography and tissue Doppler imaging in patients with ischaemic heart disease. METHODS AND RESULTS: Prospective observational study of 11 patients acting as own control based on echocardiographic imaging before and after bolus ketamine 0.5 mg/kg. Simpson's 2 D-volumetric method was used to quantify left ventricular volume and ejection fraction. General global LV deformation was assessed by Speckle tracking ultrasound, systolic LV longitudinal displacement was assessed by Tissue Tracking score index and the diastolic function was evaluated from changes in early-(E') and atrial (A') peak velocities during diastole. Average heart rate (34%) and blood pressure (35%) increased significantly after ketamine (P<0.0001). Mean tissue tracking score index decreased from 11.2 ± 2.3 to 8.3 ± 2.6 (P=0.005) and Global Speckle tracking 2D strain from 17.7 ± 2.7 to 13.7 ± 3.6 (P=0.0014) indicating a decrease in LV global systolic function. The E'/A' ratio decreased from 1.11 ± 0.43 to 0.81 ± 0.46 (P=0.044) indicating impaired relaxation. CONCLUSION: Different modalities of echocardiography in combination with tissue Doppler indicate both diminished systolic and diastolic function after ketamine administration in patients with ischaemic heart disease.

High thoracic epidural analgesia improves left ventricular function in patients with ischemic heart.

BACKGROUND: In patients with ischemic heart disease, high thoracic epidural analgesia (HTEA) has been proposed to improve myocardial function. Tissue Doppler Imaging (TDI) is a tool for quantitative determination of myocardial systolic and diastolic velocities and a derivative of TDI is tissue tracking (TT), which allows quantitative assessment of myocardial systolic longitudinal displacement during systole. The purpose of this study was to evaluate the effect of thoracic epidural analgesia on left ventricular (LV) systolic and diastolic function by means of two-dimensional (2D) echocardiography and TDI in patients with ischemic heart disease. METHODS: The effect of a high epidural block (at least Th1-Th5) on myocardial function in patients (N=15) with ischemic heart disease was evaluated. Simpson's 2D volumetric method was used to quantify LV volume and ejection fraction. Systolic longitudinal displacement was assessed by the TT score index and the diastolic function was evaluated from changes in early (E'') and atrial (A'') peak velocities during diastole. RESULTS: After HTEA, 2D measures of left ventricle function improved significantly together with the mean TT score index [from 5.87 +/- 1.53 to 6.86 +/- 1.38 (P<0.0003)], reflecting an increase in LV global systolic function and longitudinal systolic displacement. The E''/A'' ratio increased from 0.75 +/- 0.27 to 1.09 +/- 0.32 (P=0.0026), indicating improved relaxation. CONCLUSION: A 2D-echocardiography in combination with TDI indicates both improved systolic and diastolic function after HTEA in patients with ischemic heart disease.

Cardiac surgery patients present considerable variation in pre-operative hemodynamic variables.

BACKGROUND: It is essential to control hemodynamics in cardiac surgery. Patients are often monitored extensively in order to optimize hemodynamic performance. However, pre-operative values are normally unknown. Furthermore, hemodynamic goals may seem arbitrary and the lack of an evidence-based consensus may lead to both under- and over-treatment. The aim of this study was to evaluate the variables most commonly used for hemodynamic guidance in the post-operative period. METHODS: Ten patients scheduled for elective cardiac surgery were followed with invasive hemodynamic monitoring the night before surgery. All data were recorded automatically and electronically. RESULTS: We found considerable inter-patient differences and intra-patient variation. The greatest intra-patient variation was found in the cardiac index (CI), ranging from 1.9 to 5.3 l/min/m(2). Four patients had periodic CI <2.4 l/min/m(2). Eight patients showed SpO2 values < or =92, four of them in more than 15% of the observations. Six patients had an SvO2 <70% in more than 40% of the observations and two an SvO2 < 64% in more than 20% of the observations. CONCLUSIONS: This study is unique because hemodynamic reference data in cardiac surgery patients have not been published previously. The intra-patient variations were unexpectedly high in most hemodynamic variables and demonstrate the difficulties of using hemodynamic parameters as a guidance for treatment and indicate that goal-oriented therapy using currently accepted values may result in over-treatment in some patients.

Intra-aortic balloon pumping increases renal blood flow in patients with low left ventricular ejection fraction.

Intra-aortic balloon pumping (IABP) has, for decades, been one of the key treatment modalities following impaired cardiac function after cardiac surgery. IABP increases cardiac output, decreases oxygen consumption of the heart and relieves the left ventricle. However, a number of complications have been reported in connection with IABP treatment. Only a few studies have evaluated renal blood flow and the purpose of this prospective study was to evaluate whether renal blood flow was affected by IABP treatment in high-risk patients. After approval from the county ethical committee and informed consent, seven consecutive patients with low left ventricular ejection fraction and scheduled for preoperative IABP treatment were allocated to the study. Assessment of renal blood flow was based on ultrasound spectral Doppler estimation of the flow velocity profiles in the interlobar kidney arteries. The result was described as balloon index (BI), which is maximal systolic velocity divided by the temporal mean velocity. Typical velocity profiles were demonstrated in all patients before, during and after IABP. BI measurement changed with time (p <0.05). BI was lower during IABP compared to both pre-IABP and post-IABP (p <0.025), indicating a higher renal blood flow. No statistically significant changes were seen in s-creatinine or creatinine clearance. Assuming unchanged diameter of kidney arteries and no considerable decrease in renal resistance and/or compliance, we conclude that the interlobar renal blood flow was significantly increased during IABP treatment, measured by ultrasound Doppler technique, but without a simultaneously significant change in creatinine clearance.

Perioperative feasibility of imaging the heart and pleura in patients with aortic stenosis undergoing aortic valve replacement.

BACKGROUND: The postoperative monitoring and treatment of the patient undergoing aortic valve replacement is a complex challenge. Echocardiography is the only method which provides dynamic and real-time bedside imaging of the heart. Focused assessed transthoracic echocardiography has been shown to provide a usable window for cardiac imaging in a mixed ICU population. The aim of this study was to evaluate the feasibility of perioperative imaging of the heart and pleura according to the focused assessed transthoracic echocardiography protocol in patients scheduled for aortic valve replacement. METHOD: Thirty-five adult patients scheduled for aortic valve replacement were followed perioperatively with focused assessed transthoracic echocardiography examinations. A Vivid-7 echo-machine and a 2.5 MHz matrix transducer with second-harmonic imaging were used for data acquisition. The image quality for the cardiac window was graded 1-5 (1 = no image, 2 = poor and unusable image quality, 3 = usable image quality, 4 = good image quality and 5 = perfect image quality). A score >or=3 equalled an image quality judged to be of sufficient quality to be interpreted and thereby to contribute to clinical decision-making. RESULTS: All patients had at least one usable window preoperatively. At least one usable window was obtained in 88% of patients on the first postoperative day, and in 97% at discharge. The image quality changed over time, with the poorest quality being observed on the first postoperative day. The apical view with the patient in the left lateral position provided the best cardiac window on all occasions. The presence of drains did not significantly affect the achievability of a satisfactory examination. The number of patients with pleural effusion was relatively high. On the first postoperative day, 10 subjects had unilateral and one subject had bilateral pleural effusions. At discharge, 14 patients had unilateral and four patients had bilateral effusions. CONCLUSIONS: We conclude that the image quality of the heart and pleura, according to the focused assessed transthoracic echocardiography concept, is sufficient to undergo interpretation and thereby contribute to the perioperative clinical decision-making in patients with aortic stenosis.