Active clinical trials for "Hypotension"

The purpose of this study is to compare the frequency of hypotension between hyperbaric anesthetics and isobaric anesthetics during cesarean section and determine whether continuous infusion of phenylephrine is effective in mothers who received hyperbaric anesthetics.

The purpose of the study is to determine if an intravenous bolus of phenylephrine is more effective compared to an intravenous bolus of norepinephrine associated with crystalloid loading for maintaining blood pressure during a spinal anesthetic for a cesarean delivery. Prevention of low blood pressure has been shown to decrease nausea and vomiting during and after cesarean delivery under spinal anesthesia. For elective cesarean delivery, all participants will receive spinal anesthesia with a local anesthetic and sufentanil. This study plans to enroll 120 pregnant women. Patients will be randomly assigned according to a computer generated system to be in one of two groups.

Maternal hypotension after spinal anesthesia in parturients undergoing cesarean section is a very common problem leading to several complications to both patients and their babies. It can cause maternal discomfort, lightheadedness, nausea and vomiting. The most important complication is the decreasing blood flow to babies; which may lead to fetal acidosis. Many interventions has been studied in order to prevent hypotension after spinal anesthesia in cesarean section e.g., fluid loading: colloid vs crystalloid, medications: ephedrine, phenylephrine, and metaraminol, etc. The recent study showed ondansetron (the antiemetic drug) can be effectively used to prevent hypotension after spinal anesthesia in normal patients or parturients. The action of ondansetron is believed to inhibit Bezold-Jarish reflex. This aim of this study is to compare the efficacy of ephedrine and ondansetron in the prevention of maternal hypotension after spinal anesthesia in cesarean section.

This is a pilot study to determine the hemodynamic effects when hydroxocobalamin vs methylene blue is administered during cardiopulmonary bypass in patients at risk of vasoplegia by measuring mean arterial pressure (MAP), systemic vascular resistance (SVR) and vasopressor requirement.

Spinal anaesthesia for caesarean section is the most commonly used anaesthetic choice in caesarean deliveries. This is usually associated with maternal hypotension and other adverse side effects. Prophylactic intravenous administration of ondansetron immediately and 5 minutes preoperatively have shown to provide a protective effect against hypotension while other studies have shown little effect on the incidence of blood pressure drop in healthy parturients. The investigators will study the effect of different doses and timing of intravenous ondansetron in full term obstetric patients undergoing elective lower segment caesarean section under spinal anaesthesia on the incidence and severity of hypotension and other adverse side effects in healthy parturients having the standard intrathecal plain bupivacaine and fentanyl.

Various regimens were used for prevention of hypotension; most of these regimens included the use of vasopressors. Ephedrine is commonly used vasopressor for management and prophylaxis of hypotension; however, ephedrine is usually associated with tachycardia which increases oxygen consumption; thus, it might be potentially harmful in this special group of patients. Phenylephrine (PE) is another vasopressor which is characterized by α agonistic activity. PE had been the preferred vasopressor for prophylaxis against post-spinal hypotension especially in obstetric population. it was reported that PE improved the intraoperative hemodynamic profile in elderly patients undergoing lower extremities orthopedic surgery under spinal anesthesia. PE (a pure α agonist) was reported to decrease cardiac output which limit its use in patients with compromised cardiac contractility; this fact makes the use of PE in elderly patients questionable. Norepinephrine (NE) is characterized by α agonistic and weak β agonistic activity; thus, NE is characterized by less cardiac depression compared to PE. NE was recently introduced for prophylaxis against post-spinal hypotension in obstetric anesthesia. In non-obstetric population, although, NE infusion effectively maintained patients hemodynamics during general anesthesia, its use during spinal anesthesia was not adequately evaluated in elderly population

Protamine remains the anticoagulant of choice for cardiopulmonary bypass (CPB). The process of protamine neutralization of heparin came with the side effects sometimes; it can be life threatening or fetal reaction. The adverse cardiopulmonary response of protamine has been observed during entire history of clinical cardiac surgery. The true mechanism reaction is difficult to defined and the complexity of the clinical situation The classification of protamine reaction has been divided in to main 3 types (transient systemic hypotension secondary to rapid administration, anaphylactic and anaphylactoid reaction and catastrophic pulmonary vasoconstriction. The reaction from pharmacologic histamine release is the most common type of reaction. Protamine was believed to induce hypotension by this mechanism, and it was demonstrated to release histamine by degranulation of isolated mast cells From the hypothesis that the systemic hypotension cause by the released of histamine. The investigators will measure the serum tryptase which is the enzyme that released from degranulation of human mast cell. Comparing the serum tryptase level of the patient at baseline, 30 min and 60 min after protamine was given. There for the hypothesis of this study is administrating of H1 and H2 blocker helps attenuate the drop in MAP after protamine is given.

Based on the data that DEX increases the TPR and may decrease the expression of serotonin the investigator conducted this study to test the hypothesis that the prophylactic intravenous infusion (IVI) of DEX can attenuate the hypotensive effect of spinal anesthesia in elderly population.

Complications are common during tracheal intubation of critically ill patients. Nearly one in five patients undergoing intubation in the intensive care unit experiences cardiovascular collapse, defined as severe hypotension, vasopressor administration, cardiac arrest or death. Cardiovascular collapse during intubation is associated with increased resource utilization and decreased survival. Administration of 500 mL of intravenous crystalloid solution beginning prior to induction may prevent cardiovascular collapse. The only prior trial examining fluid bolus administration during intubation found no effect on cardiovascular collapse or clinical outcomes overall, but a hypothesis-generating subgroup analysis suggested potential benefit to fluid bolus administration among patients receiving positive pressure ventilation between induction and laryngoscopy. Therefore, we propose a randomized trial comparing fluid bolus administration versus none with regard to cardiovascular collapse among critically adults undergoing intubation with positive pressure ventilation between induction and laryngoscopy.

The aim of this study was to examine the effect of keeping the patient in a sitting position for 1 minute after spinal anaesthesia in elective caesarean operations, primarily on the formation of hypotension and secondarily on nausea-vomiting, the need for ephedrine and the block characteristics.