Effects of sevoflurane increments on left ventricular systolic long-axis performance during sevoflurane-remifentanil anesthesia for cardiovascular surgery.

BACKGROUND: The direct impact of sevoflurane on intraoperative left ventricular (LV) systolic performance during cardiac surgery has not been fully elucidated. Peak systolic tissue Doppler velocities of the lateral mitral annulus (S') have been used to evaluate LV systolic long-axis performance. We hypothesized that incremental sevoflurane concentration (1.0-3.0 inspired-vol%) would dose-dependently reduce S' in patients undergoing cardiac surgery due to mitral or aortic insufficiency. METHODS: In 20 patients undergoing cardiac surgery in sevoflurane-remifentanil anesthesia, we analyzed intraoperative S' values which were determined after 10 min exposure to sevoflurane at 1.0, 2.0, and 3.0 inspired-vol% (T1, T2, and T3, respectively) with a fixed remifentanil dose (1.0 µg/kg/min) using transesophageal echocardiography. RESULTS: Linear mixed-effect modeling demonstrated dose-dependent declines in S' according to the end-tidal sevoflurane concentration increments (C(ET)-sevoflurane, p < 0.001): the mean value of S' reduction for each 1.0 vol%-increment of C(ET)-sevoflurane was 1.7 cm/s (95 % confidence interval 1.4-2.1 cm/s). Medians of S' at T1, T2, and T3 (9.6, 8.9, and 7.5 cm/s, respectively) also exhibited significant declines (by 6.6, 15.6, and 21.2 % for T1 vs. T2, T2 vs. T3, and T1 vs. T3, p < 0.001, =0.002, and <0.001 in Friedman pairwise comparisons, respectively). CONCLUSIONS: Administering sevoflurane as a part of a sevoflurane-remifentanil anesthesia regimen appears to dose-dependently reduce S', indicating LV systolic performance, in patients undergoing cardiac surgery. Further studies may be required to evaluate the clinical implications of these findings.

Comparison of the impact of the anesthesia induction using thiopental and propofol on cardiac function for non-cardiac surgery.

BACKGROUND: Thiopental and propofol have been widely used for general anesthesia induction, but their impacts on cardiac function have not been well described. A recent study speculated that anesthesia induction using propofol 2 mg/kg transiently reduced left ventricular (LV) contraction by analyzing tissue Doppler-derived imaging (TDI) during induction phase. The purpose of this study was to analyze and to compare the impacts of propofol- and thiopental-induction on LV function. METHODS: Twenty-four female patients with normal LV function undergoing non-cardiac surgery were randomly administered intravenous bolus thiopental (5 mg/kg, Thiopental-group, n = 12) or propofol (2 mg/kg, Propofol-group, n = 12) for anesthesia-induction. TDI of septal mitral annular velocity during systole (S'), early diastole (e') and atrial contraction (a') were determined by transthoracic echocardiography before and 1, 3, and 5 minutes after thiopental/propofol administration (T0, T1, T2, and T3, respectively). RESULTS: The bispectral index and systolic blood pressure declined significantly during anesthesia induction in both groups, however, more depressed in Thiopental-group compared with those in Propofol-group at T2 and T3 (all, p < 0.05). Among TDI two parameters demonstrated a significant inter-group difference: the S' in propofol was lower than that in Thiopental-group at T3 (p = 0.002), and a' velocities were persistently lower in Propofol-group, compared with same time values in Thiopental-group (T1, T2, and T3: p = 0.025, 0.007, and 0.009, respectively). CONCLUSION: Anesthesia induction using propofol revealed a more persistent and profound decline of LV and atrial contraction than that using thiopental. Further studies are needed to understand the clinical implication.

Usefulness of intraoperative real-time three-dimensional transesophageal echocardiography for pre-procedural evaluation of mitral valve cleft: a case report.

A precise pre-procedural evaluation of mitral valve (MV) pathology is essential for planning the surgical strategy for severe mitral regurgitation (MR) and preparing for the intraoperative procedure. In the present case, a 38-year-old woman was scheduled to undergo MV replacement due to severe MR. She had a history of undergoing percutaneous balloon valvuloplasty due to rheumatic mitral stenosis during a previous pregnancy. A preoperative transthoracic echocardiography suggested a tear in the mid tip of the anterior mitral leaflet. However, the "en face" view of the MV in the left atrial perspective using intraoperative real time three-dimensional transesophageal echocardiography (RT 3D-TEE) provided a different diagnosis: a torn cleft in the P2-scallop of the posterior mitral leaflet (PML) with rupture of the chordae. Thus, surgical planning was changed intraoperatively to MV repair (MVRep) consisting of patch closure of the PML, commissurotomy, and lifting annuloplasty. The present case shows that intraoperative RT 3D-TEE provides more precise and reliable spatial information of MV for MVRep and facilitates critical surgical decision-making.

The intermittent sequential compression device on the lower extremities attenuates the decrease in regional cerebral oxygen saturation during sitting position under sevoflurane anesthesia.

BACKGROUND: The sitting position has potential for serious complications such as cerebral ischemia and venous air embolism. This study investigated the effects of intermittent sequential compression device (SCD) on the changes in regional cerebral oxygen saturation (rSO2) during the sitting position. METHODS: Sixty-six healthy patients undergoing shoulder arthroscopy in sitting position were randomly assigned to either control (N = 33) or SCD (N = 33) groups. Hemodynamic variables and the rSO2 were measured 5 minutes after the induction of anesthesia (Tsupine, baseline values), and 1, 3, and 5 minutes after raising the patient to a 70-degree sitting position (T1, T3, and T5). The incidence of hypotension was recorded. RESULTS: The incidence of hypotension was significantly higher in the control group (8/33) than that in the SCD group (1/33) (P = 0.027, odds ratio 0.170, 95% CI 0.042-0.684). The rSO2 was significantly higher in the SCD group compared with those in the control group at T3 and T5. Within the group, rSO2 decreased significantly only in the control group compared with baseline value at T1, T3, and T5. The % change in rSO2 from T0 to T1, T3, and T5 were significantly lower in the SCD group compared to those in the control group. CONCLUSIONS: The application of SCD to the lower extremities during sitting position under sevoflurane anesthesia was a simple and effective method to attenuate the decrease in cerebral oxygen saturation.