Best practice & research. Clinical anaesthesiology
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Best Pract Res Clin Anaesthesiol · Mar 2017
ReviewSpinal-induced hypotension: Incidence, mechanisms, prophylaxis, and management: Summarizing 20 years of research.
Hypotension commonly occurs in parturients undergoing cesarean delivery under spinal anesthesia. This leads to maternal and neonatal adverse outcomes, including maternal nausea and vomiting and fetal acidosis, and might even lead to cardiovascular collapse if not treated. ⋯ Vasopressors are therefore the mainstay for the prophylaxis and treatment of spinal-induced hypotension. Phenylephrine is associated with improved neonatal acid-base status and a lower risk of maternal nausea and vomiting compared with ephedrine and is now considered the vasopressor of choice in obstetric patients. This review discusses the various strategies for managing spinal-induced hypotension with a particular emphasis on the optimal use of vasopressors.
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Best Pract Res Clin Anaesthesiol · Mar 2017
ReviewMaternal mortality and the role of the obstetric anesthesiologist.
Maternal mortality is increasing in the United States and remains unacceptably high in many parts of the world. Pre-existing conditions and social determinants of health frequently contribute to maternal death. ⋯ Although anesthesia is an exceedingly rare cause of maternal death, specific hazards remain, including airway management, high neuraxial block, and unintentional dural puncture. The review concludes with an overview of strategies to create an institutional culture of both safety and equity, including multidisciplinary team training, simulation, shared decision-making, family-centered care, and serious morbidity review.
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Best Pract Res Clin Anaesthesiol · Dec 2016
ReviewRed blood cell transfusion and its effect on microvascular dysfunction in shock states.
Among critically ill patients, red blood cell (RBC) transfusion is often prescribed for anemia in the absence of active or recent bleeding. The failure of RBC transfusion to improve physiological parameters and clinical outcomes in this setting may be explained by current understanding of the relationship between the RBCs and the microcirculation. It is now evident that the circulating RBCs contribute to microcirculatory hypoxic vasodilation by regulated nitric oxide (NO)-dependent vasodilation, thereby facilitating delivery of oxygen to oxygen-deprived tissue. ⋯ In recent years, there has been a significant focus on the dysfunctional interaction between stored RBCs and the microcirculation, with emphasis on understanding the mechanisms that drive erythrocyte NO-mediated vasodilation. The development of technology that allows noninvasive observation of the microcirculation in humans has allowed for direct observation of the microcirculation immediately before and after RBC transfusion. The current understanding of RBC NO-mediated vasodilation and the results of direct observation of the microcirculation in the setting of RBC transfusion are reviewed.
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Over the last decade, there has been an increased interest in the use of goal-directed therapy (GDT) in patients undergoing high-risk surgery, and various haemodynamic monitoring tools have been developed to guide perioperative care. Both the complexity of the patient and surgical procedure need to be considered when deciding whether GDT will be beneficial. ⋯ Although global haemodynamic parameters may be optimised with the use of GDT, microvascular impairment can still persist. This review will provide an overview of both haemodynamic optimisation and microvascular assessment in the perioperative period.
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Best Pract Res Clin Anaesthesiol · Dec 2016
ReviewEffect of non-adrenergic vasopressors on macro- and microvascular coupling in distributive shock.
The present review initially describes the rationale for the use of non-adrenergic vasopressors in the treatment of distributive shock and then provides an overview of the individual vasopressin-receptor agonists, namely arginine vasopressin, terlipressin, and selepressin. Following a brief summary of their current use in clinical practice, the present review focuses on the influence of vasopressin-receptor agonists on macro- and microvascular coupling, also referred to as hemodynamic coherence. ⋯ A higher selectivity for the V1a-receptor seems to be beneficial; however, future clinical trials are warranted to verify this assumption. Notably, the optimal treatment regime for non-adrenergic vasopressors with respect to compound, dose, and timing still needs to be defined.