Management of hypertensive emergencies: a practical approach

Hypertensive Emergency During Dialysis: A Paradoxical Physiologic Response

Most end-stage renal disease patients experience a reduction in blood pressure during their hemodialysis session compared to predialysis. Surprisingly, a small subset of patients will experience an unusual physiological response to dialysis that results in a paradoxical increase in blood pressure. We discuss a case that involved an exaggerated elevation in blood pressure, ultimately requiring immediate cessation of dialysis and admission to the intensive care unit for intravenous treatment of a hypertensive emergency. This case serves as a framework to introduce the infrequently discussed concept of intradialytic hypertension. The underlying pathogenesis is poorly understood with multiple theoretical etiologies including activation of the renin-angiotensin-aldosterone system, imbalances in circulating levels of endothelium-derived mediators, clearance of antihypertensive medications, increased cardiac output, and changes in arterial thickness. It is important to be cognizant of this phenomenon as emerging evidence suggests that patients with any elevation in blood pressure during hemodialysis have increased rates of both short-term and long-term mortality.

Management of the kidney transplant recipient in the intensive care unit

PURPOSE OF REVIEW

Kidney transplantation is the ideal treatment for patients with chronic kidney disease and end stage renal disease. While centers are performing more transplants every year, the need for organ transplantation outpaces the supply of organ donors. Due to a growing population of patients with advanced kidney disease and a scarcity of kidneys from deceased donors, patients face extended wait times. By the time patients approach transplantation they have multiple comorbidities, in particular cardiovascular complications. Their risk of complications is further compounded by exposure to immunosuppression post kidney transplantation. Kidney transplant recipients (KTRs) are medically complex and may require acute management in the intensive care unit (ICU), as a result of cardiovascular complications, infections, and/or respiratory compromise from lung infections and/or acute pulmonary edema. Acute complication of immunosuppression, such as thrombotic microangiopathy and posterior reversible encephalopathy syndrome may also warrant ICU admission. This review will cover assessment of high-risk complications and management strategies following kidney transplantation.

RECENT FINDINGS

For intensivists caring for KTRs, it is imperative to understand anatomical considerations of the transplanted kidney, unique infectious risks faced by this population, and appropriate modulation of immunosuppression.

SUMMARY

Recognizing potential complications and implementing appropriate management strategies for KTRs admitted to the ICU will improve kidney allograft and patient survival outcomes.

Hypertensive crisis: diagnosis, presentation, and treatment

PURPOSE OF REVIEW

Hypertensive crisis (HTN-C) is a condition of increasing prevalence. It carries significant morbidity and mortality, and prompt recognition and treatment are crucial. There is a paucity of controlled trials, so a working knowledge of the most recent literature in the area of HTN-C is helpful.

RECENT FINDINGS

Novel serological markers, including serum corin, have been found to aid in the early identification of end-organ damage from severely elevated blood pressure (BP). In the area of BP following thrombolysis for ischemic stroke, lower target BP (130-140 mmHg) is associated with some improved outcomes. Two large trials of lower BP following mechanical thrombectomy in stroke have failed to show improved outcomes; however, observed data show benefits at lower than currently recommended levels. Clevidipine, a calcium channel blocker marketed for unique use in HTN-C, was found to be noninferior to the generic less expensive nicardipine. Oral nifedipine was found to be the most effective agent for sustained BP reduction in preeclampsia.

SUMMARY

HTN-C remains an area with few prospective randomized trials, but there is active research on identifying lower goals for specific clinical scenarios. Ideal therapeutic agents should be tailored for specific end-organ damage.

The Management of Hypertensive Emergencies-Is There a "Magical" Prescription for All?

Hypertensive emergencies (HE) represent high cardiovascular risk situations defined by a severe increase in blood pressure (BP) associated with acute, hypertension mediated organ damage (A-HMOD) to the heart, brain, retina, kidneys, and large arteries. Blood pressure values alone do not accurately predict the presence of HE; therefore, the search for A-HMOD should be the first step in the management of acute severe hypertension. A rapid therapeutic intervention is mandatory in order to limit and promote regression of end-organ damage, minimize the risk of complications, and improve patient outcomes. Drug therapy for HE, target BP, and the speed of BP decrease are all dictated by the type of A-HMOD, specific drug pharmacokinetics, adverse drug effects, and comorbidities. Therefore, a tailored approach is warranted. However, there is currently a lack of solid evidence for the appropriate treatment strategies for most HE. This article reviews current pharmacological strategies while providing a stepwise, evidence based approach for the management of HE.

Modern Management of Hypertensive Emergencies

Acute increases of blood pressure values are common causes of patients' presentation to emergency departments, and their management represents a clinical challenge. They are usually described as 'hypertensive crises', 'hypertensive urgencies', terms that should be abandoned because they are misleading and inappropriate according to a recent task force of the European Society of Cardiology, which recommended to focus only on 'hypertensive emergencies'. The latter can be esasily identified by using the Brain, Arteries, Retina, Kidney, and/or Heart (BARKH) strategy as herein described. Although current guidelines recommendations/suggestions for treatment of these patients are not evidence-based, owing to the lack of randomized clinical trials, improved understanding of the underlying pathophysiology has changed the approach to management of the patients presenting with hypertensive emergencies in recent years. Starting from these premises and a systematic review of the available studies graded by their quality, using the AHA class of recommendation/level of evidence grading, whenever possible, we herein present a novel a streamlined symptoms- and evidence-based algorithm for the assessment and management of patients with hypertensive emergencies.