Jerome H. Abrams

Hemodynamic, respiratory, and metabolic effects of laparoscopic cholecystectomy

In 10 patients undergoing laparoscopic cholecystectomy, creation of pneumoperitoneum caused immediate venous hypertension and stasis in the lower extremities as measured by percutaneous catheter and duplex scanning. These changes disappeared after deflation. As measured by spirometry, significant reductions in forced vital capacity of 23% and forced expiratory volume in 1 second of 22% were present 24 hours after surgery, and plasma interleukin-6 levels rose to 18 pg/mL. The visual analogue scale of resting pain increased to a median value of 2.5 postoperatively. When compared with other studies of open cholecystectomy, our results showed fewer restrictions of ventilation, lower cytokine levels, and lower pain scores. The minimal soft tissue trauma and early ambulation after laparoscopic cholecystectomy may decrease the risk of thrombosis despite an acute episode of venous stasis.

Blood transfusion and cancer surgery outcomes: a continued reason for concern.

BACKGROUND The adverse effects of blood transfusion after cancer surgery have been recently challenged in older anemic persons or those with substantial intraoperative blood loss. We hypothesized that intraoperative blood transfusions continue to adversely impact short-term cancer surgery outcomes regardless of age or preoperative hematocrit levels. METHODS Using the 2005 to 2008 American College of Surgeons National Surgical Quality Improvement Program, we identified 38,926 patients who underwent cancer surgery. Pre-, intra-, and postoperative factors were compared by units of blood transfusion a patient received. Stratified multivariable analyses, by age and hematocrit level, were performed to assess the impact of blood transfusion on operative outcomes, adjusting for covariates. RESULTS Fourteen percent of patients received an intraoperative blood transfusion. Of those, >60% received only 1 to 2 units of blood. Receipt of intraoperative blood transfusion was associated with higher rates of 30-day operative mortality, major complications, total number of complications, and prolonged length of stay across age groups and in persons with low to normal hematocrit levels. CONCLUSION The present study shows that intraoperative blood transfusion adversely impacts short-term operative cancer surgery outcomes across all age groups and in those with low to normal hematocrit levels. These findings provide insightful implications on the patterns of blood transfusion during cancer surgery that deserve further investigation.

Respiratory sinus dysrhythmia persists in transplanted human hearts following autonomic blockade

1. The present study was performed to test whether beat‐to‐beat cardiovascular control in cardiac allograft recipients resides in cholinergic and/or adrenergic nerves that are intrinsic to the heart.

Application of nocturnal electrobioimpedance volumetric assessment: a feasibility study in men without erectile dysfunction.

PURPOSE Electrobioimpedance volumetric assessment is based on the principle of delivering a constant, nondetectable alternating current to a tissue segment. A potential difference measured between the electrodes is converted to impedance. Since impedance changes with variations in blood flow, penile volumetric change is measured noninvasively. We applied this procedure to the development of a new device to evaluate erectile activity nocturnally, and we report our findings in men with no history of erectile dysfunction. MATERIALS AND METHODS Our study group comprised 10 men with a mean age of 44 years who had no history of erectile dysfunction. The NEVA device consists of a small recording device attached to the upper thigh, and 3 small adhesive electrode pads placed over the hip and on the penile base and glans, respectively. Each subject used the NEVA device for 2 nights. RESULTS Overall 20 nights of electrobioimpedance volumetric assessment were recorded. Tumescence monitoring revealed 3 to 6 erections per night per subject (mean 3.45) lasting 10 to 50 minutes (mean 17). As determined from the impedance measurements, mean volume change was 14.4 ml. with a 213% mean volume change over baseline. CONCLUSIONS The new NEVA device is small, comfortable to wear and easy to use. It determines the number and duration of erectile events and percentage increase of blood volume changes during these events in normal men in a noninvasive manner. Future directions of study include a comparison to men with erectile dysfunction and analysis of the dynamic information of the NEVA data.

Low-frequency positive-pressure ventilation with extracorporeal carbon dioxide removal

Successful use of a new technique, low-frequency positive-pressure ventilation with extracorporeal CO2 removal (LFPPV-ECCR) is presented. The association of fulminant respiratory failure with CNS hemangio-blastoma, described in the present patient, has been reported only once before, in 1928. (Crit Care Med 1990; 18:218)

Use of a needle valve variable resistor to improve invasive blood pressure monitoring.

Inaccurate measurements using in-line systems are partly due to the resonance frequency. A variable acoustic resistor designed to change the damping coefficient of these monitoring systems was evaluated under clinical conditions. The device improved pressure transmission characteristics in measurements on 12 of 13 patients. Use of the device and of the bedside step-impulse test for calibration should improve the reliability of inline blood pressure monitoring.

Nocturnal electrobioimpedance volumetric assessment of patients with erectile dysfunction

OBJECTIVES Electrobioimpedance volumetric assessment is a procedure that can measure penile length, cross-sectional area, and volume. From these variables, the number and duration of erectile events, volume change, and percentage of volume increase from baseline can be determined. This procedure was performed on patients with erectile dysfunction (ED) and findings were compared with patients with no history of ED. Examples of etiology are reported. METHODS Two groups of patients with ED were evaluated by electrobioimpedance assessment. Group 1 patients (n = 23), ranging in age from 26 to 60 years (mean 50), were involved in simultaneous electrobioimpedance assessment and duplex Doppler ultrasound penile volume measurements. A tissue correction was derived. Group 2 patients (n = 10), ranging in age from 38 to 64 years (mean 50), used nocturnal electrobioimpedance volumetric assessment (NEVA) at home for 2 consecutive nights. RESULTS After deriving an expression to correct for tissue volume, simultaneous measurement of penile blood volume by NEVA and duplex Doppler showed that the regression line for study participants and the identity line was not significantly different by analysis of variance. Using NEVA in comparing patients with ED to a reference population with no history of ED, and using a two-tailed Students t test for means, the data demonstrated a statistically significant (P < or =0.05) difference in the number of erectile events and percentage of volume change over baseline. With NEVA data, it was possible to distinguish arterial insufficiency from veno-occlusive dysfunction. CONCLUSIONS The present study demonstrates that electrobioimpedance volumetric assessment can be used in patients with ED. Compared with a reference population with no history of ED, the group with ED had fewer nocturnal erectile events that resulted in a smaller increase in penile blood volume change over baseline. Although the time dependence of the measured variables identifies the cause of ED, the application of NEVA to a larger population will allow further analysis of the dynamic information contained in the NEVA data.

Evaluation of Penile Ultrasonic Velocitometry Versus Penile Duplex Ultrasonography to Assess Penile Arterial Hemodynamics

OBJECTIVES A prospective study was performed comparing duplex ultrasonography (DU) and ultrasonic velocitometry (UV), using a new fixed-angle device, in assessing penile arterial hemodynamics. Cavernous arterial peak systolic and end-diastolic flow velocities were measured. METHODS Twenty-four consecutive patients (mean age 47 years) underwent DU (Ultramark 9 HDI System) and UV (Knoll/MIDUS system) at the same setting by the same technician. After preinjection scanning, all patients received 60 mg of papaverine intracavernosally. Repeat scanning was performed at 5, 10, 15, and 20 minutes. RESULTS The statistical significance between the two techniques was assessed by examining the correlation. For all patients (n = 24) and all velocity determinations in all patients (n = 554), the equation for the linear regression line is y = 0.952x + 1.453, r = 0.91 (r2 = 0.82) and P < 0.05. CONCLUSIONS UV is as accurate as DU in measuring peak flow velocities of the cavernous artery. This new fixed-angle device is capable of identifying a vessel without real time imaging. UV is a safe, office-based procedure and scanning is less operator-dependent and easier to learn.

Quantitative evaluation of clinical course in surgical ICU patients: the data conform to catastrophe theory

A response surface for critically ill patients is described. The coordinates of the three-dimensional response surface are two control variables, or state variables, related to aerobic and anaerobic metabolism, and a response variable, the A-VO2 difference. The data conform to a cusp catastrophe manifold. Cardiac insufficiency, adaptive response to stress, and sepsis may be distinguished by this model. The distinction between control and response variables is discussed.

Modeling inert pulmonary gas exchange using cellular automata

Intrapulmonary gas exchange is modeled with cellular automata. The use of cellular automata generates a new distribution function that can be used to estimate the partial pressure of oxygen in the blood of patients with asthma. It may be used also to aid in the classification of patients with respiratory failure and to define a criterion for optimization of ventilator support.