Terence D. Rafferty

Hemodynamics in patients with severe toxemia during labor and delivery

Three patients with severe pre-eclampsia-toxemia were studied with thermodilution tip pulmonary artery catheters. All patients were delivered by cesarean section with general anesthesia and endotracheal intubation. The left ventricular stroke work indices (LVSWI) of these patients were higher than those of normal nonpregnant subjects. There was no evidence of myocardial depression in terms of either cardiac index or the LVSWi-pulmonary capillary wedge pressure (Frank-Starling) relationship. Pulmonary arteriolar resistance (PAR) was found to be within or below the normal nonpregnant range, suggesting that in severe toxemia the pulmonary vasculature is not involved in a primary vasospastic process. At delivery a rise in cardiac index (CI) and mean pulmonary capillary wedge pressure (PCWP) occurred. The PCWP was higher in the postpartum period than prior to delivery. This was felt to represent an increase in circulating blood volume. The therapeutic significance of these findings is discussed.

Transesophageal two-dimensional echocardiographic analysis of right ventricular systolic performance indices during coronary artery bypass grafting

Sixteen patients (aged 59 +/- 14 years) undergoing coronary artery bypass surgery were evaluated to delineate the intraoperative course of transesophageal echocardiographic right ventricular (RV) systolic performance indices. Pre-induction data included thermodilution RV ejection fraction (RVEFTD), 0.43 +/- 0.13, RV end-diastolic volume index (EDVI), 110 +/- 33 mL/m2, cardiac index (CI), 3.4 +/- 1.0 L/min/m2, RV end-diastolic pressure (EDP), 7.1 +/- 4.2 mmHg, and mean pulmonary artery pressure (PAP), 21 +/- 6 mmHg. Eleven patients had significant right coronary artery (RCA) disease (> 70% occlusion). Five patients arrived with an ongoing nitroglycerin infusion (1 to 3 micrograms/kg/min), which was maintained intraoperatively. Echocardiographic measurements included longitudinal-axis (LA) and short-axis (SA) planimetered area excursion fractions (2DLA and 2DSA, respectively) and LA maximal major and minor axis shortening fractions (max majorLA and max minorLA, respectively). Hemodynamic measurements included RVEFTD, EDVI, CI, EDP, and PAP. Measurements were determined following induction/endotracheal intubation, following sternotomy/pericardiotomy, and after cardiopulmonary bypass (CPB) with the chest open. All patients were maintained on vasodilator therapy post-CPB (nitroglycerin, 1 to 3 micrograms/kg/min [N = 16] and nitroprusside, 0.5 to 4.5 microgram/kg/min [N = 4]) post-CPB. Two patients received inotropic support (epinephrine, 0.2 to 0.3 microgram/kg/min). CPB was associated with significant decreases in max major axisLA and 2DLA (P < 0.05) as compared to measurements determined prior to CPB. Maximum major axisLA values pre-CPB were 0.35 +/- 0.06 and 0.33 +/- 0.08 versus post-CPB values of 0.24 +/- 0.08.(ABSTRACT TRUNCATED AT 250 WORDS)

The relationship between “Normal” transesophageal color-flow doppler-defined tricuspid regurgitation and thermodilution right ventricular ejection fraction measurements

Twenty coronary artery revascularization patients, aged 58 +/- 15 years, were studied intraoperatively to define the impact of Doppler-defined tricuspid regurgitation on measurement of thermodilution right ventricular ejection fraction (50 msec response pulmonary artery catheter). Right ventricular function was also estimated using a measurement technique independent of flow patterns across the tricuspid valve (transesophageal two-dimensional echocardiographic 5.0 MHz phased-array transducer). Measurements included transverse plane long- and short-axis planimetered area ratio, respectively, and tricuspid annular plane systolic excursion ratio (ratio = end-diastolic minus end-systolic value divided by end-diastolic value). Data were expressed as thermodilution-echocardiographic gradients, ie, thermodilution ejection fraction minus long-axis planimetered area ratio, short-axis planimetered area ratio, and tricuspid annular plane systolic excursion ratio, respectively. Tricuspid regurgitation was quantified by color-flow Doppler perimetry of maximal regurgitation jet area and analysis of transduced right atrial pressure waveform. Doppler estimates were expressed as absolute values and as a function of corresponding atrial area (tricuspid regurgitation index = planimetered jet area divided by right atrial area). Data were obtained following endotracheal intubation, sternotomy, pericardiotomy, cardiopulmonary bypass, and chest closure. Data were evaluated by regression analysis, with separate analyses performed for each time period. Profiles were unassociated with right atrial pressure waveform abnormalities. There was no significant relationship between thermodilution ejection fraction variance values and tricuspid regurgitation jet area or regurgitation index, respectively. In each measurement period, thermodilution-echocardiographic gradients were also unrelated to the tricuspid regurgitation estimates.(ABSTRACT TRUNCATED AT 250 WORDS)

Quality assurance for intraoperative transesophageal echocardiography monitoring: A report of 846 procedures

We evaluated our experience with 846 consecutive transesophageal echocardiography (TEE) intraoperative monitoring procedures performed between November 1989 and July 1991. TEE frequency was 36 +/- 11 per month (range 16-55) and represented 69.8% of cardiac valve surgery cases, 40.2% of coronary artery bypass graft cases, and 2.2% of total operative caseload. Major patient complications consisted of transient vocal cord paresis and ingestion of glutaraldehyde-disinfectant solution. Minor complications consisted of a chipped tooth (one case) and pharyngeal abrasions (three cases). The Quality Assurance (Q/A) Program evaluated both record keeping and quality of imaging, as judged by cardiologist echocardiographer reviewers. The percentage of completion for each Q/A indicator was as follows: medical record documentation, 88%; database form annotation, 94%; and provision of videotape recording, 91%. TEE database forms were analyzed further in terms of the percentage of fields completed. Completion scores were 73%. The following scoring system was utilized for videotape evaluation by the cardiologists: 1 = excellent; 2 = good; 3 = poor. The median grade for both two-dimensional echocardiography and color flow Doppler (CFD) examinations was 2. Poor quality images (grade 3) were present in 15.2% of two-dimensional echocardiography and 20.3% of color flow Doppler examinations, and disproportionately associated with 4/26 attendings. Supplemental audit of the cardiology reviewers performance demonstrated 569/846 videotapes showed no objective evidence of review. The cardiology reviewer forms of the remaining 277 videotapes were evaluated in terms of the percentage of fields completed. The completion score was 56%. These data suggest the need for formal Q/A for intraoperative TEE, both for anesthesiologists and reviewing cardiologists.

Transesophageal echocardiography interpretation: A comparative analysis between cardiac anesthesiologists and primary echocardiographers

Diagnostic interpretation of intraoperative transesophageal echocardiography (TEE) examinations may vary, particularly when the echocardiographer is also the anesthesiologist. We therefore evaluated the concordance of TEE interpretation as part of a process of continuous quality improvement (CQI). Ten cardiac anesthesiologists participating in a CQI program conducted 154 comprehensive TEE examinations, each consisting of 16 major fields describing cardiac anatomy and function. These examinations were subsequently interpreted off-line by two primary echocardiographers (a radiologist and a cardiologist). Agreement was assessed using the &kgr; coefficient and percent agreement. Overall &kgr; and percent agreement were 0.58 and 83% for anesthesiologists versus radiologist, 0.57 and 80% for anesthesiologists versus cardiologist, and 0.60 and 82% for radiologist versus cardiologist. Anesthesiologists with longer than 5 yr of TEE experience had higher levels of agreement with the radiologist when assessing the aorta, right atrium, pulmonary vein flow, transmitral flow, and fractional area change. Cardiac anesthesiologists supported by a CQI program interpret TEE examinations at a level comparable with physicians whose primary practice is echocardiography. Thus, the anesthesiologist and the intraoperative echocardiographer need not be mutually exclusive.

Thermodilution right ventricular ejection fraction measurement reproducibility : a study in patients undergoing coronary artery bypass graft surgery

ObjectiveTo assess the effects of heart rate, right ventricular systolic performance (ejection fraction), chamber dimensions, and flow rate (cardiac index) on the reproducibility of algorithm-derived triplicate thermodilution right ventricular ejection fraction measurements. DesignProspective study; combined hemodynamic and echocardiographic clinical evaluation. SettingOperating room in a university hospital. PatientsTwenty-one coronary artery bypass graft patients. Measurements and Main ResultsThe right atrial delivery site was positioned by analysis of transduced pressure waveform and echocardiographic imaging of tracer agitated saline cavitations. Measurement reproducibility was quantified by determining the variation (standard deviation) within 101 triplicate thermodilution measurement sets. There was no significant relationship between measurement reproducibility and estimates of right atrial area (21.6 ± 6.9 cm2), diameter (5.1 ± 0.8 cm) and supero-inferior length (5.1 ± 0.9 cm) and right ventricular maximal minor axis diastolic diameter (4.21 ± 1.05 cm). Reproducibility was also unrelated to right ventricular end-diastolic volume index (97.9 ± 32.7 mL/m2) and cardiac index (2.9 ± 0.9 L/min/m2). Measurement reproducibility was directly related to mean right ventricular ejection fraction (0.39 ± 0.14) and inversely related to heart rate (80.8 ± 18.6 beats/min) (p < .01 and < .001, respectively). ConclusionsThermodilution-derived right ventricular ejection fraction measurement reproducibility was unrelated to estimates of right atrial and ventricular dimensions and cardiac index. Measurement reproducibility was a direct function of right ventricular systolic performance and an indirect function of heart rate. Measurement should be interpreted with these constraints in mind.

Complications of Pulmonary Artery Catheterization in Obstetric Patients

Twenty‐one obstetric patients in whom pulmonary artery catheters had been inserted were studied. Complications were minor in nature and unassociated with adverse sequelae. They included transient premature ventricular contractions on insertion of the catheter in two cases and a ruptured balloon and a positive culture of the catheter tip in one case.

A clinical computer database entry form for an intraoperative anesthesiology-based transesophageal echocardiography monitoring service

Transesophageal echocardiography (TEE) has been increasingly applied to supplement and, in instances, to supplant conventional intraoperative cardiac monitoring. Our body of experience (>1600 intraoperative TEE procedures), combined with insights gleaned from an intramural quality assurance study, and clinical implications of certain recent advances in the field, led us to develop the following TEE computer database entry form. The form, completed intraoperatively, consists of a patient and surgical procedure demographics section, followed by fields based on the TEE examination. The scans encompass transverse plane basal short axis, long axis, and transgastric views of the heart and great vessels. The two-dimensional echocardiographic, saline-contrast, color flow and pulsed Doppler data represent both right and left ventricular performance, valvular function and specific lesions. This database entry form is intended to serve as a guide for performance of a nominally complete intraoperative study and facilitate maintenance of a TEE archive consistent with current advances.

Bicuspid Noncalcific Aortic Stenosis: Diagnostic Limitations of Intraoperative Transesophageal Echocardiography

calcific aortic stenosis requiring aortic valve replacement) The valves may be unicommissural, acommissural unicuspid, or, most commonly, bicuspid with two distinct leaflets and commissures. 4 Estimation of the severity of stenosis is most often determined by (1) direct short-axis measurement of the aortic valve area and (2) Doppler estimates of transvalvular gradients and valve area. 4 Measurement of the maximum, long-axis aortic cusp separation and qualitative assessment of leaflets motion may also be used to estimate severity of stenosis. This case highlights the pitfalls of both the direct short-axis and the Doppler methods of assessing severity of aortic stenosis by TEE, and the beneficial effects of a comprehensive, routine TEE examination on the diagnostic process. Reported success rates for short-axis planimetry of the true orifice of the aortic valve range from 13% to 85%. 5-8 One suggested reason for a low success rate is the imaging constraint imposed by supero-inferior motion of the aortic valve in and out of the imaging plane during the cardiac cycle. Further, systolic doming of the leaflets would be expected to compound the technical difficulties involved in obtaining valid short-axis measurements by furnishing the potential for the beam of interrogation to transect the leaflets before the actual stenotic valve orifice. Such a situation would provide an image of an apparently normal orifice (Fig 2). However, the true degree of stenosis was readily evident with long-axis imaging (Fig 3), Systolic doming of the leaflets, with overshoot of leaflet tissue