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.

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.

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).

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.

Bacterial contamination of 'Venflon' intravenous cannulae with valved injection sideport.

Eighty-eight intravenous cannulae with valved injection sideports were examined bacteriologically after approximately three days (64-80 h) normal clinical use. Three methods of culture of the cannulae were used, which distinguished contamination of the outer and inner surfaces as well as detecting bacteria remaining on the inner cannula surface following a washing procedure of the lumen. Of the cannulae sampled, 40.9 per cent were found to be contaminated on their inner surfaces and no correlation was obtained between use of the sideport and contamination of the cannulae at this site. It was concluded that contamination of a cannula lumen did not necessarily result in bacteraemia.

A comparative study of intravenous cannulae--'Venflon' with valved sideport and 'Intraflux' with membranous sideport.

The rate of contamination of the inner surface of 'Venflon' type cannulae with valved injection sideports was compared with that of 'Intraflux' type cannulae with membranous injection sideports. Of 46 'Venflon' cannulae and 34 'Intraflux' cannulae, 17.4 per cent and 20.6 per cent, respectively, were contaminated and no correlation of contamination of lumen was found with frequency of use of the sideports in the different cannulae, or with duration of use of the cannulae.

Contamination of central venous catheters. The skin insertion wound is a major source of contamination.

In a prospective controlled trial we compared the rates of catheter-tip contamination in central venous catheters inserted with or without skin contact. The study was designed so that each patient was their own control. All patients had a single-lumen central venous catheter and a Swan-Gantz sheet inserted through the skin. A Swan-Gantz catheter was inserted and retracted through the sheet thus avoiding contact with skin or subcutaneous tissue. Catheter-tip cultures were performed on removal of catheters. Thirty-three Swan-Gantz catheters were cultured and all were sterile. In the corresponding 33 sheets 16 (48.6%) yielded bacterial growth. Four of the sheets showed growth of more than 15 cfu. In the 26 single-lumen catheters, eight (30.8%) catheter-tips grew bacteria, and four of them had more than 15 colonies. The study supports the theory that the skin-insertion wound is a major source of catheter-contamination.

Contamination of subclavian vein catheters: an intraluminal culture method.

An intraluminal culture method was evaluated for central venous catheters and compared to conventional catheter tip cultures and cultures from the insertion site. The colonization-rate of the catheters was 43.7% using conventional tip culture, 34.4% with the intraluminal method and 40.1% at the skin puncture site. Only 37.5% of the catheters showed identical bacteria at the skin puncture site and catheter-tip, compared with 87.5% between intraluminal culture and catheter-tip culture (P less than 0.05).

Contamination of central venous catheters: use of infusion-lines does not increase catheter-contamination.

In a prospective controlled trial we compared the rates of intraluminal contamination between the two lumens of a double-lumen central venous catheter. One lumen was used for repeat infusions and injections, and the other was permanently connected to a slow infusion of 0.9% NaCl. The study was designed so that the patient was his own control. Twenty-eight catheters were examined and comparison with catheter-tip cultures was performed in 24. Intraluminal culture was performed 67-77 h after insertion of the catheter and catheter-tip culture was performed on removal of the catheter. The contamination rate from catheter-tips was 20.8%, which is acceptable compared with other studies. There was only one positive intraluminal culture in each group (3.6%), and thus no correlation was found between contamination rate and the number of times the infusion-line had been interrupted for use. As for catheter-tip contamination, we found no correlation between infusion of blood-products or parenteral nutrition and contamination rates.

Contamination of intravenous infusion systems--the effect of changing administration sets.

Intravenous administration sets were changed at varying time intervals between every 24 h and 120 h in 387 patients. The rates of intraluminal contamination of the cannulae and of local inflammation were measured in relation to the time interval between changing sets. There was no correlation between phlebitis and intraluminal contamination, but a significant association was found between phlebitis and fever, infusion of potassium at greater than 10 mmol l-1, Venflon type 140 and infusion of blood or intralipid. No correlation was found between septicaemia and intraluminal contamination of the infusion systems. Contamination of cannulae increased slightly with time, but this was not statistically significant. We conclude that there will be no clinical benefit by daily changing of administration sets, compared with changing up to every fifth day.

[Cesarean section in severe double valvular disease]. / Sectio ved svaer toklapsygdom.

During pregnancy haemodynamic changes are a stress to the cardiovascular system. Women with previously asymptomatic cardiovascular disease may develop life-threatening cardiac failure because of the extra demands of pregnancy. Early diagnosis, close control and treatment during pregnancy, delivery and the postpartum period are essential. We report a case where a woman with a mitral stenosis and insufficiency of the mitral and aortic valves gave birth to a child by caesarian section.

[Preoperative adrenergic beta receptor blockade and anesthesia. II. Effect on peroperative anxiety and cardiovascular response in epidural anesthesia]. / Praeoperativ beta-adrenoceptorblokade og anaestesi II. Virkning på peroperativ angst og kardiovaskuloert respons ved epidural anoestesi.

The effects of a preoperative beta-adrenoceptor antagonist, metoprolol, on peroperative anxiety, relaxation, general feeling, blood pressures and heart rate, were studied in patients undergoing orthopaedic surgery during epidural anesthesia. The study was double-blind and placebo controlled. Twenty non-consecutive patients were randomized to receive either metoprolol 100 mg or placebo orally 1-2 hours before anaesthesia. Patients receiving metoprolol scored statistically significantly better on anxiety, and general feeling. The average height of the epidural block was ThVIII. The average blood pressure was reduced by 5% during the first 45 minutes in both groups. The average maximum falls in mean blood pressure from preanaesthetic to the lowest measured after the epidural were 14% (metoprolol) and 7% (placebo). The heart rates were significantly lower after metoprolol. In conclusion, the patients felt subjectively better after metoprolol and no significant differences were found in blood pressure after metoprolol compared to placebo.

[Continuous measurements of cardiac output in the perioperative period]. / Kontinuerlig måling af hjertets minutvolumen i den perioperative periode.

Management of critically ill patients is based on knowledge of fundamental physiological variables. Automatized and continuous measurement of these variables is preferable. A new system based upon the thermodilution method has been developed to measure cardiac output automatically and continuously. We evaluated the system in the potentially unstable perioperative period with possible great and rapid changes in cardiac output. Twenty patients, scheduled for open heart or abdominal aortic aneurysm surgery, were included into the study, which was approved by the local ethical committee. The patients were monitored for up to 30 hours. At random intervals five iced bolus thermodilution cardiac output (BCO) determinations were made and compared to the continuous measurements (CCO). Two hundred and thirty-one pairs of data were obtained. The cardiac outputs ranged from 2.5-14.9 l/min. The absolute bias was 0.31 l/min (95% limits of agreement -1.4 l/min to 2.0 l/min). The mean relative error was 4.7% with a standard deviation of the relative error of 15.4%. The linear regression was represented by: CCO = 11.352 x BCO - 0.36. The correlation coefficient R was 0.90 (p < 0.001). In conclusion, the CCO measurement technique is a promising clinical method. The method is straightforward, requires no calibration, is independent of vascular geometry and measures with its limitations volumetric flow. Finally automatic and continuous patient monitoring provides more information and has potential to reveal previously undetected haemodynamic events.

[Transesophageal echocardiography for registration of hemodynamics. A new tool in anesthesiology]. / Transøsofageal ekkokardiografi til haemodynamisk registrering. Et nyt anoestesiologisk redskab.

During the last ten years, transesophageal echocardiography has become an important tool for cardiac monitoring. In other countries it is widely applied, especially in cardiac surgery, but the areas of application are still expanding. Transesophageal echocardiography is a non-invasive technique in contrast to most other methods available for monitoring central haemodynamics. The complication frequency is extremely low. However, correct therapeutic decisions depend on profound experience with the equipment and image interpretation. The scope of transoesophageal echocardiography as a new tool in haemodynamic monitoring is described in this paper together with preliminary results.

[Atrial fibrillation after coronary artery bypass surgery. The significance of preoperative vagus modulation and ectopic atrial activity]. / Atreiflimren efter koronar bypass-kirurgi. Betydningen af proeoperativ vagusmodulation og ektopisk atrieaktivitet.

To investigate the impact of pre-operative autonomic balance and atrial ectopic activity on the risk of atrial fibrillation or flutter after aorto-coronary artery bypass surgery 24-hour Holter monitoring was analyzed in 102 patients before coronary artery bypass grafting. Index for vagal tone was calculated as % successive RR-interval differences > 6%. Twenty-nine (28%) of the 102 patients developed atrial fibrillation or flutter. Independent predictors (90% confidence interval) of postoperative atrial fibrillation or flutter were identified by logistic regression analysis: the independent predictors were older age, relative risk 1.07/year (1.02-1.12), vagal index < 10%, relative risk 4.50 (1.40-14.5), > or= 10 ectopic supraventricular beats/24 hour, relative risk 3.03 (1.05-8.72), and one or more event of non-sustained supraventricular tachycardia, relative risk 3.02 (1.11-8.22). Thus, age of the patient, attenuated preoperative cardiac vagal modulation, ectopic supraventricular beats, and paroxysmal non-sustained supraventricular tachycardia are independent risk factors for the development of atrial fibrillation or flutter after coronary artery bypass surgery.