Jan F. Bugge

Cost of extracorporeal membrane oxygenation: evidence from the Rikshospitalet University Hospital, Oslo, Norway

OBJECTIVE The main objective is to describe and analyse hospital costs of the extracorporeal membrane oxygenation (ECMO) procedure. STUDY SAMPLE AND METHODOLOGY: Between January and December 2007, 14 ECMO patients were consecutively included in the study. Costs at the patient level were registered prospectively, while overhead costs were registered retrospectively. Patient costs were obtained from patient records and time-motion studies and included personnel resources, diagnostic and laboratory tests, radiology and operating room procedures, medication and blood products. Overhead costs were allocated to clinical departments and further to the individual patients by predefined keys. To achieve estimates of total costs, patient-specific costs and patient-specified overhead costs were summarised. RESULTS The mean estimated cost for the ECMO procedure was 73,122 USD (SD 34,786) and median 62,545 USD (range: 34,121-154,817). The mean estimated total hospital costs, including pre- and post-ECMO procedures, was 213,246 USD (SD 12,265), median 191,436 USD (range: 59,871-405,497). On average, 82% of costs for the total hospital stay were related to personnel use, and blood products constituted 7%, lab and radiology 2.5%, disposable items 3% and medication 1.5%. The mean duration of an ECMO procedure was 9.5 days (range: 4-23 days) and the average total length of stay in hospital was 51.5 days (range: 6-123 days). The cost data were converted from Norwegian kroner (NOK) to US dollars (USD), with an exchange rate of 1 USD=5.5 NOK. CONCLUSION ECMO procedure is a resource-demanding procedure.

Advantages of strain echocardiography in assessment of myocardial function in severe sepsis: an experimental study.

Objectives:Cardiovascular failure is an important feature of severe sepsis and mortality in sepsis. The aim of our study was to explore myocardial dysfunction in severe sepsis. Design:Prospective experimental study. Setting:Operating room at Intervention Centre, Oslo University Hospital. Subjects:Eight Norwegian Landrace pigs. Interventions:The pigs were anesthetized, a medial sternotomy performed and miniature sensors for wall-thickness measurements attached to the epicardium and invasive pressure monitoring established, and an infusion of Escherichia coli started. Hemodynamic response was monitored and myocardial strain assessed by echocardiography. Measurements and Main Results:Left ventricular myocardial function was significantly reduced assessed by longitudinal myocardial strain (–17.2% ± 2.8% to –12.3% ± 3.2%, p = 0.04), despite a reduced afterload as expressed by the left ventricular end-systolic meridional wall stress (35 ± 13 to 18 ± 8 kdyn/cm2, p = 0.04). Left ventricular ejection fraction remained unaltered (48% ± 7% to 49% ± 5%, p = 0.4) as did cardiac output (6.3 ± 1.3 to 5.9 ± 3 L/min, p = 0.7). The decline in left ventricular function was further supported by significant reductions in the index of regional work by pressure-wall thickness loop area (121 ± 45 to 73 ± 37 mm × mm Hg, p = 0.005). Left ventricular myocardial wall thickness increased in both end diastole (11.5 ± 2.7 to 13.7 ± 2.4 mm, p = 0.03) and end systole (16.1 ± 2.9 to 18.5 ± 1.8 mm, p = 0.03), implying edema of the left ventricular myocardial wall. Right ventricular myocardial function by strain was reduced (–24.2% ± 4.1% to –16.9% ± 5.7%, p = 0.02). High right ventricular pressures caused septal shift as demonstrated by the end-diastolic transseptal pressure gradient (4.1 ± 3.3 to –2.2 ± 5.8 mm Hg, p = 0.01). Conclusions:The present study demonstrates myocardial dysfunction in severe sepsis. Strain echocardiography reveals myocardial dysfunction before significant changes in ejection fraction and cardiac output and could prove to be a useful tool in clinical evaluation of septic patients.

Transcatheter Aortic Valve Implantation and Intraoperative Left Ventricular Function: A Myocardial Tissue Doppler Imaging Study

OBJECTIVE Transcatheter aortic valve implantation in patients turned down for surgical aortic valve replacement is a high-risk procedure. Severe aortic stenosis is associated with impaired left ventricular longitudinal motion, and myocardial peak systolic velocity is a measure of left ventricular function in these patients. The present study aimed to quantify the acute changes in left ventricular function during the procedure by using myocardial tissue Doppler imaging and transthoracic cardiac output measurements. DESIGN Prospective observational study. SETTING Tertiary care university hospital. PARTICIPANTS 40 patients with severe aortic stenosis scheduled for transcatheter aortic valve implantation. INTERVENTIONS Transesophageal 4-chamber and 2-chamber echocardiograms were performed immediately before and ~15 minutes after valve implantation. Longitudinal myocardial peak systolic velocity was obtained by tissue Doppler imaging from 8 basal segments and averaged. Cardiac output was measured by the lithium dilution method, and systemic vascular resistance index and stroke volume were calculated. MEASUREMENTS AND MAIN RESULTS Longitudinal myocardial peak systolic velocity improved immediately after valve implantation, from -2.3±0.8 to -3.0±1.1 cm/sec (p<0.001); this represented an average increase of 31%±33%. Cardiac output increased from 3.2±0.8 L/min to 3.6±0.9 L/min (15%±33%; p = 0.04). This was due to increased heart rate (59±9 beats/min to 72±12 beats/min; p<0.001) and not to an improved stroke volume. Systemic vascular resistance index was reduced from 2,937±984 dynes*sec/cm(5)/m(2) to 2,436±730 dynes*sec/cm(5)/m(2) (p = 0.003). CONCLUSION Intraoperative echocardiography tissue Doppler imaging detected immediate improvement in left ventricular long-axis motion after transcatheter aortic valve implantation. The method provided detailed information not obtainable by routine hemodynamic monitoring.

Long-term outcomes after transcatheter aortic valve implantation: the impact of intraoperative tissue Doppler echocardiography

OBJECTIVES Transcatheter aortic valve implantation improves survival in patients with severe aortic stenosis who are ineligible for surgical valve replacement; however, not all patients benefit from the procedure. We endeavoured to identify these patients using intraoperative echocardiography and hypothesized that intraoperative left ventricular function in response to the acute afterload reduction during the procedure was related to long-term outcomes. METHODS We prospectively included 64 patients who were scheduled for transcatheter aortic valve implantation and divided them into responders and non-responders based on their left ventricular intraoperative responses to the acute afterload reduction after valve deployment. Responders were defined by increases of ≥20% in left ventricular longitudinal peak systolic velocities determined by tissue Doppler echocardiography. All patients were assessed for the following outcomes at 12 months: cardiac mortality, adverse cardiac events, quality of life, New York Heart Association class, N-terminal pro-brain natriuretic peptide (NT-proBNP) and echocardiography. RESULTS Thirty-five patients (55%) were classified as responders and 29 patients (45%) as non-responders. Compared with responders, non-responders had higher risks of death (28 vs 9%, respectively, P = 0.04) and cardiac events (66 vs 26%, respectively, P < 0.01) during the 12-month follow-up. Significant long-term improvements in quality of life, NT-proBNP and left ventricular function were observed only in the responders. Preoperative risk stratification, intraoperative handling, aortic gradient and valve area were similar between groups. CONCLUSIONS Intraoperative assessment of left ventricular function by tissue Doppler echocardiography predicted long-term outcomes after transcatheter aortic valve implantation. Our results suggest that a preoperative test of myocardial contractile reserve might improve risk stratification and patient selection prior to the procedure.

Hypothermia Is Not an Inotropic Drug

e1258 www.ccmjournal.org December 2016 • Volume 44 • Number 12 velocities are tightly linked and determined by properties of the cardiac sarcomere, and will increase and decrease in parallel (7). Hypothermia reduces both velocities in all settings were velocities are measured (6, 7). Despite reductions in contraction and relaxation velocities, cardiac performance is well maintained during mild hypothermia. This is not related to changes in contractility, but to a reduced work load (reduced heart rate and reduced blood pressure), which may be important for the injured or failing heart. Hypothermia may thus have favorable effects on both cardiac and systemic oxygen supply-demand balance and contribute to the good outcome observed in patients with cardiogenic shock after out of hospital cardiac arrest. This work was performed at Rikshospitalet, Oslo University Hospital. Departmental funds from the Intervention Centre and the Department of Anesthesiology, Oslo University Hospital supported the costs. The authors have disclosed that they do not have any potential conflicts of interest.