Effect of insemination time of frozen semen on incidence of uterine fluid in mares.

Ninety five mares were inseminated with frozen semen either within 12 h before ovulation or within 8 h after ovulation. The effect of preovulatory versus postovulatory insemination (AI) on the subsequent detection of uterine fluid was studied. The overall pregnancy rate was 43% and this was not significantly influenced by preovulatory or postovulatory insemination. When mares were first examined 12 h after AI, 18 of 52 mares (35%) had accumulated uterine fluid. However, when mares were first examined 18 to 24 h after AI, only 6 of 43 mares (14%) had uterine fluid. Presence of intrauterine fluid significantly lowered pregnancy rates. Timing of insemination did not affect incidence of uterine fluid. Serum concentrations of estrogen and progesterone at time of insemination did not influence uterine clearance or pregnancy rates, but both hormones were higher at preovulatory than at postovulatory inseminations. We concluded that there was no evidence that postovulatory inseminations would predispose mares to persistence of uterine fluid after AI.

Deaths with acute cerebral lesion and heart-beating potential organ donors in the Veneto region.

BACKGROUND: The study was aimed at describing the clinical characteristics of dead patients with acute cerebral lesion and analyzing reasons of the shortage of heart-beating potential organ donors in the Intensive Care Units (ICUs) in the Veneto Region. METHODS: Data have been prospectively recorded in 23 ICUs over six months for deceased patients with acute cerebral lesion (clinical data, death diagnosis) and for any potential organ donor (medical suitability, family interview, organ retrieval). RESULTS: In the ICUs of the Veneto Region in 1998 deceased patients with acute cerebral lesion were 187 per million population (p.m.p.); 317 cases have been studied. Median age was 64 years (range 7-93). Heart-beating death was legally confirmed only in 98/317 cases (31%) against a clinical diagnosis of brain death in 203/317 (64%). Only 82/317 (26%) were considered eligible donors and 48/317 (15%) became real donors (22.8 p.m.p.). Among the remaining 235 cadavers, 105 were over 70 years old. In the group of 130 under 70 years absolute contraindications were present only in 30 and problematical clinical situations were reported in 100. CONCLUSIONS: The number of deaths with acute cerebral lesion represents a sensible index and a key factor for evaluating the potential organ donor pool in small regions and in the single intensive care unit. Collected data demonstrate that in the Veneto Region the efficiency of solid organ retrieval can be improved and that organ donor shortage may depend, beyond family refusal, on clinical and cultural factors that hamper stabilized heart-beating deaths. Most potential donors with age over 70 or problematical clinical situations are preventively excluded by ICUs physicians. To improve organ donation all the patients who die in spite of neuro-intensive treatment should be prevented from circulatory arrest to permit legal declaration of death. Thus more potential organ donors without absolute contraindications could be recovered and time would exist for discussing any problematical situation with experts in organ procurement, particularly in respect to existing urgencies in the waiting list.

Bioethical issues related to continuous renal replacement therapy in intensive care patients.

OBJECTIVE: To examine the ethical approach of intensivists and nephrologists to continuous renal replacement therapy (CRRT). DESIGN: A questionnaire. SETTING: The First International Course on Critical Care Nephrology. PARTICIPANTS: The participants in the course (around 500). RESULTS: Most participants think that establishing ethical criteria for managing CRRT is a medical task, as clinicians have adequate criteria for defining futility. However, many responders would grant the request of starting futile CRRT or would maintain it if requested by the family. Only 55% believe that informed consent is necessary for initiating CRRT; one out of four would start or maintain unwanted life-saving CRRT. In case of lack of equipment, the majority would select the patients, excluding the worst one or on a "first-come, first-served" basis. Withholding and withdrawing are regarded differently by most responders. Again, most think that every vital support should be withdrawn when futile, but practical and psychological aspects still influence the final decision. Responders think that ethics critical care committees can help in the management of ethical problems in ICU. CONCLUSIONS: Our results show that several ethical questions are still unsolved and that practical and psychological aspects of the treatment process can be stronger than bioethical principles.

Achievements and new directions in continuous renal replacement therapies.

The evolution of renal replacement therapy has permitted the treatment of critically ill patients with acute renal failure. In intensive care settings, continuous renal replacement therapies have been shown to be better tolerated and clinically useful. Continuous hemofiltration is now performed with blood pumps and double-lumen venous catheters, thus avoiding the complications found in previous arteriovenous treatments. The use of countercurrent dialysate flow has overcome problems related to low treatment efficiency. High clearances can now be obtained during continuous hemodialysis or hemodiafiltration, and adequate blood purification can be achieved even in severely catabolic patients. New replacement solutions allow for a more effective correction of acidosis and electrolyte imbalances. Finally, newly designed machines permit continuous therapies while minimizing staff workload. Continuous therapies are today moving toward newer indications and applications. The ability to remove proinflammatory substances by filtration and/or adsorption has opened a series of potential indications. The concept that renal support and protection take place during hemofiltration suggests that very early use of this technique is desirable, even before the onset of oliguria or azotemia.

Heart rate variability and severe brain damage: preliminary data.

Severe brain damage may cause alterations of cardiovascular function: heart rate, particularly, require the integrity of the vagal, sympathetic and central nervous systems. We studied brain-heart functional relation and neurovegetative modulation by spectral analysis of heart rate variability (HRV). This technique allows separate evaluation of the sympathetic and vagal components of heart rate modulation. In order to correlate changes in HRV with brain damage, we performed 45 recordings in 6 patients (5/1 M/F) by means of autoregressive analysis (AAR). All patients were admitted to the ICU for severe brain damage (anoxic, traumatic or vascular). In 4 patients clinical outcome was brain death, in 2 permanent vegetative status. Two different patterns were found: one in patients with brain death, the other in patients with vegetative status. The small number of patients does not allow definitive conclusions from collected data, but that application of spectral analysis of HRV seems to be a useful monitoring of brain damage subjects.

Acid base correction in bicarbonate CAPD patients.

Bicarbonate has been proposed as buffer in CAPD solutions in recent years instead of lactate and acetate. The present study is designed to evaluate peritoneal bicarbonate kinetics using bicarbonate solutions. Seventy kinetic studies have been performed in 7 patients treated with 2 CAPD solutions containing 35 mmol/l (A) and 27 mmol/l (B) of bicarbonate. The changes in dialysate bicarbonate concentration at different dwell times were correlated with bicarbonate blood levels. Furthermore after 2 hours of dwell time and at subsequent observations, no differences in dialysate bicarbonate concentration were found between A and B solutions at the same bicarbonatemia. Thus a feedback between bicarbonate absorption and bicarbonate blood concentration was observed. If the amount of bicarbonate transferred to the patient is over the metabolic acid production, bicarbonatemia will rise: consequently bicarbonate dialysate absorption will decrease. After a few days, an equilibrium point will be reached. In this condition the bicarbonate absorption is equal to metabolic acid production and, in stable clinical conditions, a stable acid base status will be maintained by the patient. Our studies empirically demonstrated that the equilibrium is reached when a difference of 5 mmols between blood and inlet dialysate bicarbonate concentration is observed. Consequently to achieve 25 mmol/l of bicarbonatemia, the bicarbonate concentration of CAPD solution should be about 30 mmol/l.