Increased intravascular coagulation associated with pregnancy.

Based on an increased turnover of the hemostatic system, it is believed that pregnancy is associated with "hypercoagulability." However, this hypothesis is based primarily on the measurement of specific coagulation factors or functional tests reflecting hemostatic activity in vitro. Using recent technological advances, we determined the effect of pregnancy on hemostasis in vivo by measuring 11 specific hemostatic indices simultaneously in 28 healthy pregnant women and in 24 nonpregnant female controls. Significant increases were found in fibrinopeptide A (P less than .01), beta thromboglobulin (P less than .001), platelet factor 4 (P less than .02), and fibrin(ogen) degradation products (P less than .001), suggesting increased platelet turnover, clotting, and fibrinolysis. This state of compensated, accelerated intravascular coagulation may be necessary for maintenance of the uterine-placental interface and preparation for the hemostatic challenge of delivery.

Hemostasis and diagnosis of preeclampsia.

The diagnosis of preeclampsia, with all of its consequences, is at times difficult to establish, especially when the patient has underlying chronic hypertension and is not known from prior prenatal care visits. Many screening tests have been proposed. These should be sensitive, relatively specific, easy to perform, of low cost, and have a reasonable interval from prediction to disease onset. Laboratory assays would obviously be useful. We evaluated hemostasis tests for the diagnosis of preeclampsia, and compared fibronectin, antithrombin III and alpha 2-antiplasmin in 48 preeclamptics and 86 control nulliparas. Receive operator characteristic (ROC) curve analysis suggested that fibronectin is the most effective of these tests. A similar analysis comparing the results of previous studies using serum iron, angiotensin infusion, urinary calcium/creatinine ratio, the rollover test and uric acid suggested a possible role for fibronectin in the diagnosis of preeclampsia. While not ideal, there seems to be, at present, no other, easy to perform laboratory test that outperforms fibronectin in predicting preeclampsia.

On-line interactive evaluation in course and clinical instruction.

Student evaluations incorporated into feedback for instruction modification are an important aspect of any educational program. It is particularly important for healthcare programs in which teaching processes are continually dynamic. An interactive evaluation was designed and implemented on-line for students. Confidentiality was assured and privacy protected through a unique coding system. Our experience with the interactive, automated system proved particularly successful with respondents and faculty expectations have improved since its integration into course and clinical objectives.

Certification: past, present and future implications. Report of the National Commission on Nurse Anesthesia Education.

In 1942, the National Association of Nurse Anesthetists established a voluntary certification program to safeguard the interests of surgeons, hospitals and the public. Prerequisites for certification included minimum training standards, a valid nursing license and successful completion of a national certification examination. In 1975, the Council on Certification of Nurse Anesthetists was established as an autonomous decision-making body. Certification for nurse anesthetists is now recognized in two-thirds of the states and required by most employers--a factor that makes it vital to establish the job-relatedness of the examination. An innovative and responsible certification process will continue to be needed to address health care issues and advances in testing.

Postoperative nausea and vomiting: a comparison of propofol infusion versus isoflurane inhalational technique for laparoscopic patients.

Gynecologic laparoscopic procedures frequently precipitate postoperative nausea and/or vomiting. The use of specific anesthetic agents and premedicants may decrease the incidence. This study determined the occurrence of postoperative nausea/retching/vomiting (N/R/V) when propofol was used for anesthesia maintenance compared with isoflurane when both groups of patients received metoclopramide and ranitidine preoperatively and were induced with propofol. Sixty American Society of Anesthesiologists (ASA) physical status I or II patients (age 19 to 50 years, weighing 50 to 90 kilograms) who were having elective laparoscopies were evaluated for postoperative N/R/V. No significant difference in the incidence of N/R/V was demonstrated between the propofol and isoflurane groups (P < 0.05). Sixty percent of the patients who received meperidine in the recovery room experienced nausea and/or vomiting. The use of propofol versus isoflurane for maintenance of anesthesia had no effect on the incidence of postoperative N/R/V when patients were premedicated with metoclopramide and ranitidine.

The effect of flumazenil on patient recovery and discharge following ambulatory surgery.

Midazolam is a short-acting agent used for preoperative and conscious sedation. Despite a relatively short half-life, midazolam sedation contributes to postoperative sedation, delays in discharge, and increased costs. Administration of flumazenil, a benzodiazepine antagonist, can reverse the centrally mediated effects of midazolam and facilitate patient recovery and discharge, thereby reducing costs. The purpose of this multicenter study was to determine whether flumazenil antagonism of midazolam decreased the length of postoperative stay following intravenous sedation during local and selected regional procedures. A prospective, double-blinded, and randomized convenience sample of 110 adult patients who underwent procedures lasting 90 minutes or less was used. After receiving institutional review board approval and informed consent, patients received up to 150 micrograms of fentanyl and unlimited midazolam titrated intravenously to effect. Flumazenil or a placebo was administered at the conclusion of the surgical procedure. Cognitive scores were assessed by using the Digital Symbol Substitution Test and picture recall, while sedation scores were assessed by using the Observer's Assessment of Alertness/Sedation Scale. The time between the end of the surgical procedure until the patient met discharge criteria in phases I and II was recorded. Statistical analyses revealed no significant difference in age, height, weight, sex, ASA physical status, amount of midazolam and fentanyl received, time for each group to achieve phase I and phase II discharge criteria, or postoperative congnitive scores. The flumazenil group exhibited less amnesia and sedation than the placebo group on initial arrival in the postanesthesia care unit. Discharge times between the groups were not significantly different. Factors such as staffing and institutional discharge policies were identified as determinants of discharge times.

Changes in hemostasis activity during delivery and the immediate postpartum period.

Postpartum deep vein thrombosis is believed to be related to increased activation of the hemostasis system at the time of delivery. To date, studies designed to test this hypothesis have had relatively small sample sizes or used the measurement of specific coagulation factors and functional tests reflecting hemostasis activity in vitro. With the use of recent technologic advances we determined the effect of delivery on hemostasis in vivo by measuring 11 hemostatic indices simultaneously in 70 healthy pregnant women. Significant increases were found in fibrinopeptide A (p less than 0.001), beta-thromboglobulin (p less than 0.001), and platelet factor 4 (p less than 0.001), suggesting maximum platelet activation and fibrin formation at the time of delivery. In addition to continued clotting activity at 3 hours post partum, increased D-dimer, fibrin-fibrinogen degradation products, and decreased alpha 2-antiplasmin levels suggest maximum fibrinolysis. These changes reflect a peak in hemostatic activity at delivery and in the immediate postpartum period that may predispose the development of deep vein thrombosis.

Hemodynamic and hormonal changes during pneumoperitoneum and trendelenburg positioning for operative gynecologic laparoscopy surgery.

Objective: The number and types of surgical procedures being preformed using laparoscopic technique is increasing due to technological advances. Recent studies suggest the carbon dioxide pneumoperitoneum and patient positioning causes hemodynamic alterations, respiratory acidosis, and a release of stress hormones. However, to date, no studies have investigated the physiological effect of laparoscopic procedures lasting more than 60 minutes on the stress response and the effect of Trendelenburg positioning. The purpose of this study was to identify the physiological effect of pneumoperitoneum and positioning during prolonged laparoscopy on hemodynamic (cardiac index, mean arterial pressure, heart rate, systemic vascular resistance, and stroke volume), metabolic (arterial blood gases), and hormone (arginine vasopressin, aldosterone, and plasma renin activity) parameters. We hypothesized that pneumoperitoneum and patient positioning will alter the hemodynamic, hormone, and metabolic parameters.Methods: The study was longitudinal in design and sampled a total of 31 healthy subjects having a gynecologic oncologic laparoscopic procedure at Hurley Medical Center, Flint, Michigan. The subjects were randomly assigned one of three groups receiving an initial insufflation pressure of either 10, 15, or 18 mmHg. After obtaining informed consent hemodynamic, metabolic, and hormone measurements were obtained at the following times: 1) pre-induction, 2) post-induction, 3) post-insufflation, 4) post-Trendelenburg 5 minutes and at 30, 60, 90, and 120 minutes post-insufflation. The results were analyzed using multivariate analysis of variance for repeated measures with a P <.05. A power of 0.9 was obtained to identify changes over time.Results: During the time course of the study the hemodynamic, metabolic, and hormonal parameters showed significant alterations. The most dramatic hemodynamic changes occurred post-insufflation characterized by a decrease in cardiac index and stroke volume with a concurrent increase in systemic vascular resistance. The metabolic parameters showed a significant decrease in pH and corresponding increase in PaCO(2). However, the pH and PaCO(2) remained within normal limits through the study. As part of the study's protocol the investigators increased minute volume to control for a rise in PaCO(2) during the procedure. A significant increase was noted in aldosterone and arginine vasopressin at post-insufflation and Trendelenburg positioning. Plasma renin activity showed a dramatic increase following post-insufflation. None of the subjects developed any post anesthetic complications.Conclusion: Our study demonstrated that pneumoperitoneum and Trendelenburg positioning cause statistically significant elevations in the stress hormones and concurrently cause a decrease in hemodynamic parameters. A healthy patient may tolerate these changes but a patient with cardiovascular disease or pulmonary problems may not be able to compensate as efficiently.