PubMed Health⌕ Search

Biomedical subjects

M Tornic

Publications and source records attributed to M Tornic.

10 recordsLinked to original sources
PubMed2001

Transoesophageal echocardiography in cardiac and vascular surgery: implications and observer variability.

Transoesophageal echocardiography (TOE) has gained widespread acceptance among cardiac anaesthetists as a tool to facilitate peri-operative decision-making. This observational study analyses the impact of TOE and its inter-observer variability on intra-operative patient management during cardiac and major vascular surgery. From June 1996 to December 1998, standardized reports were obtained from 11 anaesthetists in 1891 adult cardiac and vascular surgery patients undergoing routine biplane or multiplane TOE. Inter-observer variability and the difference between variables of interest were tested using the chi-squared test or factorial analysis of variance as appropriate. TOE examinations were performed before and after the operation; 1,673 (88.5%) patients underwent cardiopulmonary bypass (CPB), and 218 (11.5%) patients had surgery without CPB, including 42 (2.2%) coronary revascularizations. In 923 patients (49%), TOE provided additional information that influenced the patient's therapy. In 968 patients (51%), TOE had only minor or no impact on clinical decision-making. In two patients (0.10%) the scheduled operation was not performed, and in another two patients the TOE examination led to major complications. Observer-dependent variables were: implications of TOE for intraoperative decision-making (P<0.0001), estimation of image quality (P < 0.0001), pre-operative left ventricular fractional area change (FAC) (P = 0.0026), difference between pre-operative FAC and post-operative FAC (P = 0.033), and requests for supervision (P < 0.0001). There was no significant difference in the case mix between observers. TOE had an important impact on intraoperative patient management. Inter-observer variability was significant for several variables but not for the frequency of additional surgical procedures.

Adult↗
PubMed1999

Continuous thermodilution cardiac output: clinical validation against a reference technique of known accuracy.

OBJECTIVE: To evaluate the accuracy and precision of continuous thermodilution (CCO) by using a validated bolus thermodilution (BCO) reference technique as criterion standard. DESIGN: Under circulatory steady state conditions, a CCO system (Vigilance, software versions 4.35 and 4.39) was validated with regard to CCO as well as iced and room temperature BCO. SETTING: Intensive care unit at a university hospital. PATIENTS: Method comparison was conducted in 56 cardiac surgical patients, 28 patients being allocated to one of the two software versions, and 14 within each group to either iced or room temperature BCO. MEASUREMENTS AND RESULTS: CCO readings were registered in duplicate before and after three to five bolus injections conducted with both the Vigilance and reference systems. Iced BCO showed excellent agreement between the Vigilance and reference systems, yielding SDs of bias of 0.41 and 0.37 l/min and linear correlation coefficients (r) of 0.97 and 0.96. With room temperature BCO, agreement was significantly less. CCO, irrespective of software version, showed higher SDs of bias (0.90 and 0.84 l/min) and lower r values (0.84 and 0.81) than iced BCO (p < 0.0001). CCO measurements with software version 4.39 yielded a similar SD of bias to that with room temperature BCO. CONCLUSION: Decreased precision of CCO as compared to iced BCO may, in clinical settings, be outweighed by the advantages of automated and continuous monitoring. Under research conditions, however, iced BCO remains the method of choice.

Adolescent↗
PubMed1999

Inhaled nitric oxide versus intravenous vasodilators in severe pulmonary hypertension after cardiac surgery.

UNLABELLED: Inhaled nitric oxide (iNO) is superior to i.v. vasodilators for treatment of pulmonary hypertension (PH) after cardiac surgery, but iNO is a potentially toxic gas, and patient subsets who benefit from iNO are not yet clearly defined. We administered iNO 40 ppm, prostaglandin E1 (PGE1) 0.1 microg x kg(-1) min(-1), and nitroglycerin (NTG) 3 to 5 microg x kg(-1) min(-1), in a randomized crossover study to 14 adult patients with severe PH after cardiac surgery. iNO, PGE1, and NTG were of similar efficacy in reducing pulmonary vascular resistance (P = 0.003). iNO induced selective pulmonary vasodilation, while PGE1 and NTG had significant concomitant systemic vasodilatory effects. iNO led to an increase in cardiac index (CI) (P = 0.012), and PGE1 increased CI (P = 0.006) and right ventricular (RV) ejection fraction (P = 0.015), while NTG had no effect on CI and RV performance. After study completion, patients continued with PGE1 administration with favorable in-hospital outcome. We conclude that PH per se, even if severe, does not necessarily imply postoperative RV dysfunction, and selective pulmonary vasodilation with iNO may not be superior to PGE1 with regard to CI and RV performance. IMPLICATIONS: In a prospective, randomized crossover study of inhaled nitric oxide (iNO) versus IV vasodilators, performed in adult patients with severe pulmonary hypertension but preserved right ventricular function after cardiac surgery, iNO was not superior to IV prostaglandin E1 with regard to cardiac index and right ventricular performance. Considering the potential toxicity of iNO, better definition of patient subsets with a positive benefit/risk ratio is warranted.

Administration, Inhalation↗
PubMed1993

Reliability of a new generation transesophageal Doppler device for cardiac output monitoring.

A new generation continuous-wave transesophageal Doppler (TED) device for cardiac output (CO) monitoring (Accucom 2, Datascope), which displays aortic blood flow velocity in real time, was evaluated by 140 simultaneous comparisons with thermodilution (TD) in 16 patients early after coronary artery bypass surgery. The aim was to determine whether this technologic advancement improves the accuracy of COTED assessment. Absolute COTED values showed a considerable scatter as compared to COTD [COTED = 1.77 + 0.75.COTD (L/min), r = 0.52]. The bias, i.e., the mean of individual CO differences (COTD-COTED) was -0.37 +/- 1.70 L/min (SD). In contrast, relative CO changes (delta CO, % of preceding value) showed a satisfactory agreement between TED and TD [delta COTED = 1.04 + 0.91.delta COTD (%), r = 0.84, n = 124], the bias (delta COTD-delta COTED) being -0.66 +/- 9.72%. In 8 of 124 situations (6.45%), however, significant COTED changes opposite in direction to that of significant COTD changes occurred. This frequency was significantly greater (P < 0.01) than the ideal frequency of 0%. The agreement between delta COTD and delta COTED improved (P < 0.05) when the aortic diameter changes induced by changes in mean arterial pressure were considered [delta COTEDMAPC = 1.10 + 0.95.delta COTD (%), r = 0.87, n = 124]. Compared with previous results, the reliability of the second generation device to monitor relative CO changes was considerably improved. Provided that the aortic blood flow velocity signal was stable and free from any disturbances, the second generation TED device may be regarded acceptable for CO trend monitoring in sedated, paralyzed patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Noninvasive versus invasive assessment of cardiac output after cardiac surgery: clinical validation.

The accuracy of noninvasive cardiac output (CO) measurement techniques, such as electrical bioimpedance (BIO), suprasternal continuous-wave Doppler (CWD), pulsed-wave Doppler (PWD), and transesophageal continuous-wave Doppler (TED) ultrasound has been variably judged in recent years. In addition, clinical comparisons are hampered by the fact that there is no generally accepted gold standard in CO measurement. After coronary artery bypass surgery in 25 patients, CO was simultaneously determined by invasive standard techniques (thermodilution [TD] and Fick methods) plus BIO, CWD, PWD, and TED. There was an excellent agreement found between TD and the Fick method (COF = 0.13 + 1.01.COTD; r = 0.96; n = 99). Thermodilution was thus chosen to be the reference method. Bioimpedance underestimated COTD (COBIO = 0.47 + 0.60.COTD; r = 0.78; n = 111). Allowing physiological ejection times only led to an improved agreement between BIO and TD (COBIO = 0.05 + 0.69.COTD; r = 0.82; n = 79), but BIO still significantly underestimated COTD (P less than 0.0005). Using physiologic ejection times during COCWD determination reduced the scatter of data as compared with TD; however, CWD still considerably overestimated COTD, when COCWD computation was based on the echocardiographic aortic diameter (ECHO) (COCWD ECHO = 0.79 + 1.40.COTD; r = 0.84; n = 52). With the surgical aortic diameter (SURG), the agreement improved (COCWD SURG = 0.75 + 1.16.COTD; r = 0.89; n = 44), but overestimation of COTD remained significant (P less than 0.05). Irrespective of the aortic diameter, COPWD values showed a considerable scatter of data compared with COTD (COPWD ECHO = 1.26 + 0.60.COTD; r = 0.62; n = 64 and COPWD SURG = 1.42 + 0.41.COTD; r = 0.47; n = 61). Correlation of absolute COTED values to thermodilution depended on the method used for calibration. All investigated noninvasive CO measurement techniques unreliably measured relative CO changes. Despite its invasiveness, TD remains the method of choice for accurate CO determination in adult patients following cardiac surgery.

Adult↗
PubMed1988

Performance characteristics of a disposable ventricle assist device.

A disposable ventricle assist device (VAD) including atrium, ventricle and trileaflet valves (all polyurethane) can be driven either a) by its original self adjusting drive unit (ABIOMED BVS 5000) or b) by a standard intra-aortic balloon pump console (DATASCOPE). Maximum flow in vitro was 4.3 l/min with the original drive console versus 9.2 l/min for activation with the intra-aortic balloon pump console. Performance characteristics of the VAD were evaluated in 11 bovine experiments. In vivo left ventricular assist for up to 24 hours with VAD and either original drive console or standard intra-aortic balloon pump console showed superior flow on activation with the intra-aortic balloon pump console (5.3 +/- 1.7 l/min) versus original drive console (3.5 +/- 0.5 l/min). After 6 hours of assist (before any transfusions) there was no significant difference in classic parameters for evaluation of blood trauma such as plasma hemoglobin production, LDH production and platelet depletion. We conclude that VAD is extremely simple to use. Activation by an intra-aortic balloon pump console enables significant increase of VAD-output without detectable increase of blood trauma. Successful weaning of VAD activated with standard intra-aortic balloon pump console was possible in a first clinical application.

Aortic Valve Insufficiency↗