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Biomedical subjects

J I Gerson

Publications and source records attributed to J I Gerson.

8 recordsLinked to original sources
PubMed1991

Serum levels of Hyskon during hysteroscopic procedures.

Hyskon hysteroscopy fluid is used with the hysteroscope as an aid in distending the uterine cavity and in visualizing its surfaces. We correlated the amount of Hyskon used during hysteroscopy with both the instillation pressures generated within the uterine cavity and with serum levels of Hyskon in 11 healthy subjects. Serum levels in excess of 1000 mg% were measured at 30 min when an amount of Hyskon greater than 300 mL was used. Intrauterine Hyskon absorption and/or injection during hysteroscopy were found even after volumes of Hyskon as small as 50-100 mL were used. Serum levels were significantly higher with the larger amounts of Hyskon used in ablative procedures (P less than 0.01), as compared with serum levels seen with the smaller amounts of Hyskon used for diagnostic procedures. The injection pressures should be low to minimize the amount of intravascular injection. In cases in which extensive ablative procedures are necessary, we suggest that a two-stage procedure be considered. Because of the hypertonicity of Hyskon, intravascular volume expansion that may be larger than that seen during transurethral prostatectomy occurs.

Absorption↗
PubMed1979

Decrease in arterial pressure following heparin injection prior to cardiopulmonary bypass.

Evidence exists in the literature that heparin has vasodilating properties. We recorded arterial blood pressure changes that occur after administration of 300 units/kg of beef-lung heparin prior to cardiopulmonary bypass. In 37 out of 43 patients there was a significant decrease in arterial pressure following administration of beef-lung sodium heparin. Systolic blood pressure fell approximately 10 mmHg (1.3 kPa) and diastolic blood pressure fell about 5 mmHg (0.65 kPa). Heart rates remained unchanged. In 7 of the 43 patients in whom pulmonary artery catheters were placed, cardiac output was determined and systemic vascular resistance was calculated. On the basis of these calculations, it seems that a decrease in systemic vascular resistance is responsible for the decrease in arterial blood pressure noted following sodium heparin.

Blood Pressure↗
PubMedDate not supplied

Echocardiographic analysis of human left ventricular diastolic volume and cardiac performance during halothane anesthesia.

Using M-mode echocardiography we found that 0.5, 1.0, and 1.5% end-tidal halothane induced dose-related increases in left ventricular volume and decreases in left ventricular performance in seven normal unpremedicated subjects. During controlled respiration with normocarbia, the diastolic minor axis of the heart, which is related to the cube root of left ventricular volume, increased to a maximum of 107. 7 +/- 1.9 (% +/- SE of control) at 1.5% end-tidal halothane from a control value of 43.5 +/- 1.3 (mm +/- SE). Two ejection-phase performance variables, percentage shortening and mean velocity of circumferential shortening decreased to 60.1 +/- 6.1 (% +/- SE of control) and 62.4 +/- 6.5, (% +/- SE of control) at 1.5% halothane from respective control values of 29.7 +/- 2.61 (% +/- SE) and 0.94 +/- 0.08 (circumferences/second +/- SE). Surgical stimulation did not significantly affect these changes. Under these experimental conditions, we conclude that halothane dilates the heart, and that echocardiography can be used to monitor the depressant effect of halothane on the heart.

Adult↗
PubMedDate not supplied

Analysis of human epidural pressures.

BACKGROUND AND OBJECTIVES: During performance of epidural injection, entry into the epidural space has traditionally been determined by identification of negative pressure to the advancing needle by indirect means such as hanging drop; loss of resistance to air, saline, or water; or use of a MacIntosh balloon. Confusion in the literature regarding entry pressures versus postentry (baseline) pressures and zero reference pressure was noted. METHODS: Baseline epidural pressure changes were examined using a closed system zeroed to the dorsal spine during and after injection of local anesthetics in 39 patients referred to the Pain Treatment Center, located at SUNY Health Science Center, Syracuse, New York, for epidural injections. The course of epidural pressure changes after injection and the temporal relation of epidural pressure waves to the arterial and venous wave forms were examined. RESULTS: In contrast to previous investigations, subatmospheric pressure was found in the epidural space in only one patient. Baseline pressure for all patients was 7.7 +/- 3.9 mmHg. There were significant differences in baseline pressure in patients who had undergone back surgery compared with patients who had not undergone such surgery: 11.8 +/- 3.4 as opposed to 7.0 +/- 3.5 mmHg, respectively (p less than 0.005). Three minutes after a 2-ml injection of local anesthetic into the epidural space, the pressure returned to baseline. This contrasted to the effects of a 6-ml injection, which resulted in the pressure remaining above baseline after 3 minutes. The epidural pressure wave forms more closely paralleled the radial artery wave form than the central venous pressure. CONCLUSION: Lumbar epidural pressure is greater than atmospheric pressure when referenced to zero at the dorsal spine level.

Adult↗