Minireviews Open Access
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Jun 16, 2015; 3(6): 510-513
Published online Jun 16, 2015. doi: 10.12998/wjcc.v3.i6.510
Clinical overview of hypertensive crisis in children
Wen-Chieh Yang, Chun-Yu Chen, Division of Emergency Medicine, Department of Pediatrics, Changhua Christian Hospital, Changhua 500, Taiwan
Wen-Chieh Yang, Chun-Yu Chen, School of Medicine, Chung Shan Medical University, Taichung 400, Taiwan
Mao-Jen Lin, Division of Cardiology, Department of Medicine, Taichung Tzuchi Hospital, the Buddhist Medical Foundation, Taichung 400, Taiwan
Mao-Jen Lin, Institute of Medicine, Chung Shan Medical University, Taichung 400, Taiwan
Mao-Jen Lin, Han-Ping Wu, Department of Medicine, School of Medicine, Tzu Chi University, Hualien 970, Taiwan
Han-Ping Wu, Department of Pediatrics, Taichung Tzuchi Hospital, the Buddhist Medical Foundation, Taichung 400, Taiwan
Author contributions: Yang WC and Lin MJ compared related studies, wrote the manuscript and contributed equally to this work; Chen CY coordinated, provided the collection of clinical images and wrote some parts of the manuscript; Wu HP designed the mini review.
Conflict-of-interest: There is no conflict of interest in the paper.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Han-Ping Wu, MD, PhD, Department of Pediatrics, Taichung Tzuchi Hospital, the Buddhist Medical Foundation, No.88, Sec. 1, Fongsing Rd., Taichung 42743, Taiwan. arthur1226@gmail.com
Telephone: +886-4-36060666Fax: +886-4-36021123
Received: June 24, 2014
Peer-review started: June 25, 2014
First decision: August 14, 2014
Revised: February 15, 2015
Accepted: March 16, 2015
Article in press: March 18 2015
Published online: June 16, 2015

Abstract

Hypertensive emergencies and hypertensive urgencies in children are uncommonly encountered in the pediatric emergency department and intensive care units, but the diseases are potentially a life-threatening medical emergency. In comparison with adults, hypertension in children is mostly asymptomatic and most have no history of hypertension. Additionally, measuring accurate blood pressure values in younger children is not easy. This article reviews current concepts in pediatric patients with severe hypertension.

Key Words: Hypertensive crisis, Hypertensive urgency, Hypertensive emergency, Blood pressure

Core tip: Hypertensive crisis in children is a disease easily mismanaged in the emergency department. The physician should carefully search for evidence of end organ injury to distinguish between hypertensive emergency and hypertensive urgency. Only patients with hypertensive emergency require immediate reduction in markedly elevated blood pressure to prevent and arrest progressive end organ damage. In all other patients, the elevated blood pressure can be lowered slowly using oral agents, i.e., esmolol, nicardipine, labetalol and fenoldopam. All young children should receive complete examinations to look for the underlying cause of secondary hypertension.



DEFINITIONS OF HYPERTENSION IN CHILDREN: HYPERTENSIVE CRISIS AND HYPERTENSIVE ENCEPHALOPATHY

Hypertension in children older than 12 mo was defined as blood pressure (BP) level > 140/90 mmHg, as in adults, until the updated definition of “The fourth report on the diagnosis, evaluation and treatment of high blood pressure in children and adolescents” in 2004[1]. Hypertension is identified when the systolic BP (SBP) or diastolic BP (DBP) is greater than or equal to the 95th percentile for gender, age and height: stage 1 hypertension is SBP or DBP within the range of the 95th percentile to the 99th percentile plus 5 mmHg; stage 2 hypertension is greater than the 99th percentile plus 5 mmHg. Height and gender revealed no statistical difference from the previous study[2-4].

Hypertensive crisis is defined as a severe elevation in BP, classified as hypertensive emergencies and hypertensive urgency[5]. Hypertensive encephalopathy is a hypertensive emergency and characterized by an abrupt or prolonged elevated BP that overcomes the autoregulatory capacity of the cerebral vasculature. It appears as severe hypertension associated with headache, altered mental status, seizure, visual disturbances or stroke, and the lesion may be revealed as reversible posterior leukoencephalopathy[6-11].

EPIDEMIOLOGY

Although the prevalence of hypertension tends to be increasing today, pediatric hypertension still accounts for about 0.5%-1% in children and its incidence is obviously less in younger children and infants[12,13]. Until now, data of the incidence of hypertensive crisis in children have not been analyzed enough to give a definite result, but in adults, approximately 1% of hypertensive individuals have been reported to have hypertensive crisis[14].

ETIOLOGY

Generally, primary hypertension is identifiable in children and adolescents, whereas secondary hypertension is more common in younger children. In primary hypertension, there is a strong association of high BP with being overweight and BMI should be calculated as part of physical examination, with the marked increase in the prevalence of overweight children.

In newborn infants with hypertension, the most likely definable causes are renal artery thrombosis or stenosis, congenital renal malformation, or coarctation of the aorta[15]. In children between infancy and 6 years of age, coarctation of the aorta, renal parenchymal diseases and renal artery stenosis are the three most common causes of secondary hypertension. In children older than 6 years, renal artery stenosis and renal parenchymal diseases are the leading causes of diastolic BP over 90-100 mmHg. Primary hypertension accounts for 90% of the causes of hypertension in patients aged over 15 years[16-19].

PATHOPHYSIOLOGY

In the long term in children, high BP levels could be associated with the early development of cardiovascular changes[20]. In the acute phase of hypertensive crisis, rapid increases in systemic vascular resistance could be precipitated as a result of increases in the circulating vasoconstrictor substances, including norepinephrine, angiotensin II, or anti-natriuretic hormone[21]. Arteriolar fibrinoid necrosis may induce a consequence of the severely elevated BP, precipitating endothelial damage with resultant end organ ischemia. Ischemia could trigger the further release of vasoactive substances, causing further vasoconstriction and myointimal proliferation[21]. This may appear to be an important part[22]. Activation of the renin-angiotensin system could also be highly involved[23-25].

CLINICAL MANIFESTATIONS

Compared to adults, the clinical presentations of hypertensive crisis in children are more likely asymptomatic[26]. Our previous study reported that no specific clinical manifestation correlated with the age factor[27]. Patients with hypertensive crisis in different age groups did not have specific different clinical presentations in this study[27]. In addition, the signs of end organ dysfunction are hypertensive encephalopathy, acute left ventricular failure and acute myocardial ischemia, papilledema, elevated liver function tests, etc. For children with complaints of any symptoms such as persistent headache, nausea/vomiting and altered mental status, hypertensive crisis should be ruled out immediately to prevent further damage. According to some clinical analyses, the related risk factors for hypertensive encephalopathy were male gender, stage 2 hypertension and some clinical symptoms. In pediatric patients with hypertensive crisis caused by essential hypertension, symptoms of chest tightness and no family history of hypertension may show a lower risk for hypertensive encephalopathy[27]. Moreover, the recurrence was 29.1%[27].

EVALUATION

Detailed medical history taking and complete physical examinations are both required in children presenting with suspected hypertensive crisis. In laboratory tests, serum electrolytes, complete blood counts, blood urea nitrogen, creatinine and urinalysis should be considered for children with suspected hypertensive crisis. Chest radiograph and electrocardiogram may be also performed in patients with chest pain and tachypnea. A brain computed tomography scan may be needed in hypertensive children with neurological signs[28].

MANAGEMENT

Pediatric patients with hypertensive crisis require immediate and appropriate reduction in BP levels, whereas patients with hypertensive urgency require a slower rate of reduction in BP levels over 24 to 48 h. However, rapidly decreasing BP levels may result in decreasing the blood flow of organs, causing ischemia and infarction[29-31]. In patients with hypertensive encephalopathy combined with chronic hypertension, it is important to reduce the mean arterial pressure gradually during the first hour[32]. Accordingly, patents with hypertensive emergency should be treated in an intensive care unit. The drugs of choice should depend on the end organs involved and the monitoring environment. Once the reductions in mean arterial pressure to less than 20% or to a DBP of 100 mmHg have been reached, oral maintenance therapy may be given instead of the intravenous agent. Another important part of BP control in hypertensive crisis is volume depletion. Adequate fluid replacement will restore organ perfusion.

The agent of choice should depend on the clinical presentation and the severity of the hypertensive crisis. The preferred agents include esmolol, labetalol, fenoldopam and nicardipine, but phentolamine and trimethaphan camsylate may be less commonly used today. Nevertheless, they appear to be useful in some particular situations, such as catecholamine-induced hypertensive crises, such as pheochromocytoma[33,34]. Sodium nitroprusside could be used in patients with acute pulmonary edema and/or severe left ventricular dysfunction and in patients with aortic dissection. However, this agent has some limitations for application in the pediatric ED because of the requirement of intra-arterial BP monitoring and protection from light[35]. Short-acting, immediate-release oral nifedipine and sublingual nifedipine have been used for effective reduction of severe elevated BP, but some studies cautioned against it as being potentially dangerous in patients with hypertensive crises. Clonidine and angiotensin-converting enzyme inhibitors are long acting and difficult to titrate, but these agents may be still useful in some clinical conditions[36].

CONCLUSION

Hypertensive crisis in children is a rare but important disease easily mismanaged in the ED. Pediatric patients with hypertensive emergencies need immediate reduction of BP levels to arrest further end organ damage. For patients with hypertensive urgency, BP may be lowered slowly.

Footnotes

P- Reviewer: Jiang B S- Editor: Ji FF L- Editor: Roemmele A E- Editor: Wu HL

References
1.  National High Blood Pressure Education Program Working Group on High Blood Pressure in Children and Adolescents. The fourth report on the diagnosis, evaluation, and treatment of high blood pressure in children and adolescents. Pediatrics. 2004;114:555-576.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 4058]  [Cited by in F6Publishing: 3781]  [Article Influence: 189.1]  [Reference Citation Analysis (0)]
2.  Kent AL, Kecskes Z, Shadbolt B, Falk MC. Blood pressure in the first year of life in healthy infants born at term. Pediatr Nephrol. 2007;22:1743-1749.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 77]  [Cited by in F6Publishing: 62]  [Article Influence: 3.6]  [Reference Citation Analysis (0)]
3.  de Swiet M, Fayers P, Shinebourne EA. Systolic blood pressure in a population of infants in the first year of life: the Brompton study. Pediatrics. 1980;65:1028-1035.  [PubMed]  [DOI]  [Cited in This Article: ]
4.  Levine RS, Hennekens CH, Jesse MJ. Blood pressure in prospective population based cohort of newborn and infant twins. BMJ. 1994;308:298-302.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 63]  [Cited by in F6Publishing: 65]  [Article Influence: 2.2]  [Reference Citation Analysis (0)]
5.  Koch-Weser J. Hypertensive emergencies. N Engl J Med. 1974;290:211-214.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 66]  [Cited by in F6Publishing: 66]  [Article Influence: 1.3]  [Reference Citation Analysis (0)]
6.  Oppenheimer BS, Fishberg AM. Hypertensive encephalopathy. Arch Intern Med. 1928;41:264-278.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 100]  [Cited by in F6Publishing: 102]  [Article Influence: 1.1]  [Reference Citation Analysis (0)]
7.  Pavlakis SG, Frank Y, Chusid R. Hypertensive encephalopathy, reversible occipitoparietal encephalopathy, or reversible posterior leukoencephalopathy: three names for an old syndrome. J Child Neurol. 1999;14:277-281.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 118]  [Cited by in F6Publishing: 117]  [Article Influence: 4.7]  [Reference Citation Analysis (0)]
8.  Hinchey J, Chaves C, Appignani B, Breen J, Pao L, Wang A, Pessin MS, Lamy C, Mas JL, Caplan LR. A reversible posterior leukoencephalopathy syndrome. N Engl J Med. 1996;334:494-500.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 2250]  [Cited by in F6Publishing: 2063]  [Article Influence: 73.7]  [Reference Citation Analysis (0)]
9.  Bakshi R, Bates VE, Mechtler LL, Kinkel PR, Kinkel WR. Occipital lobe seizures as the major clinical manifestation of reversible posterior leukoencephalopathy syndrome: magnetic resonance imaging findings. Epilepsia. 1998;39:295-299.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 72]  [Cited by in F6Publishing: 76]  [Article Influence: 2.9]  [Reference Citation Analysis (0)]
10.  Dinsdale HB. Hypertensive encephalopathy. Neurol Clin. 1983;1:3-16.  [PubMed]  [DOI]  [Cited in This Article: ]
11.  Stewart JN, McGillivray D, Sussman J, Foster B. The value of routine blood pressure measurement in children presenting to the emergency department with nonurgent problems. J Pediatr. 2008;153:478-483.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 13]  [Cited by in F6Publishing: 12]  [Article Influence: 0.8]  [Reference Citation Analysis (0)]
12.  Belsha CW. Pediatric hypertension in the emergency department. Ann Emerg Med. 2008;51:S21-S23.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 9]  [Cited by in F6Publishing: 9]  [Article Influence: 0.6]  [Reference Citation Analysis (0)]
13.  Lande MB, Kaczorowski JM, Auinger P, Schwartz GJ, Weitzman M. Elevated blood pressure and decreased cognitive function among school-age children and adolescents in the United States. J Pediatr. 2003;143:720-724.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 146]  [Cited by in F6Publishing: 111]  [Article Influence: 5.3]  [Reference Citation Analysis (0)]
14.  Martin JF, Higashiama E, Garcia E, Luizon MR, Cipullo JP. Hypertensive crisis profile. Prevalence and clinical presentation. Arq Bras Cardiol. 2004;83:131-116; 125-130.  [PubMed]  [DOI]  [Cited in This Article: ]
15.  Adelman RD Neonatal hypertension. En: Loggie JMH, Moran MJ, Gruskin AB, et al, editors. NHLBI Workshop on Juvenile Hypertension. New York: Biomedical Information Corp 1984; 267-282.  [PubMed]  [DOI]  [Cited in This Article: ]
16.  Flynn JT. Evaluation and management of hypertension in childhood. Prog Pediatr Cardiol. 2001;12:177-188.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 55]  [Cited by in F6Publishing: 58]  [Article Influence: 2.5]  [Reference Citation Analysis (0)]
17.  Seeman T, Dusek J, Vondrichová H, Kyncl M, John U, Misselwitz J, Janda J. Ambulatory blood pressure correlates with renal volume and number of renal cysts in children with autosomal dominant polycystic kidney disease. Blood Press Monit. 2003;8:107-110.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 57]  [Cited by in F6Publishing: 54]  [Article Influence: 2.7]  [Reference Citation Analysis (0)]
18.  Luma GB, Spiotta RT. Hypertension in children and adolescents. Am Fam Physician. 2006;73:1558-1568.  [PubMed]  [DOI]  [Cited in This Article: ]
19.  Reich A, Müller G, Gelbrich G, Deutscher K, Gödicke R, Kiess W. Obesity and blood pressure--results from the examination of 2365 schoolchildren in Germany. Int J Obes Relat Metab Disord. 2003;27:1459-1464.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 69]  [Cited by in F6Publishing: 71]  [Article Influence: 3.6]  [Reference Citation Analysis (0)]
20.  Sorof JM, Alexandrov AV, Cardwell G, Portman RJ. Carotid artery intimal-medial thickness and left ventricular hypertrophy in children with elevated blood pressure. Pediatrics. 2003;111:61-66.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 264]  [Cited by in F6Publishing: 264]  [Article Influence: 12.6]  [Reference Citation Analysis (0)]
21.  Sorof JM; Idem. Understnading milignant hyeprtension. Aust N Z J Med. 1981;11 Suppl I:64-68.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 22]  [Cited by in F6Publishing: 22]  [Article Influence: 1.4]  [Reference Citation Analysis (0)]
22.  Goldblatt H. Studies on experimental hypertension : vii. the production of the malignant phase of hypertension. J Exp Med. 1938;67:809-826.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 91]  [Cited by in F6Publishing: 100]  [Article Influence: 7.1]  [Reference Citation Analysis (0)]
23.  Laragh J. Laragh’s lessons in pathophysiology and clinical pearls for treating hypertension. Am J Hypertens. 2001;14:837-854.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 28]  [Cited by in F6Publishing: 30]  [Article Influence: 1.3]  [Reference Citation Analysis (0)]
24.  Kohno M, Yokokawa K, Yasunari K, Kano H, Minami M, Ueda M, Tatsumi Y, Yoshikawa J. Renoprotective effects of a combined endothelin type A/type B receptor antagonist in experimental malignant hypertension. Metabolism. 1997;46:1032-1038.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 5]  [Cited by in F6Publishing: 6]  [Article Influence: 0.2]  [Reference Citation Analysis (0)]
25.  Hiwatari M, Abrahams JM, Saito T, Johnston CI. Contribution of vasopressin to the maintenance of blood pressure in deoxycorticosterone-salt induced malignant hypertension in spontaneously hypertensive rats. Clin Sci (Lond). 1986;70:191-198.  [PubMed]  [DOI]  [Cited in This Article: ]
26.  Patel HP, Mitsnefes M. Advances in the pathogenesis and management of hypertensive crisis. Curr Opin Pediatr. 2005;17:210-214.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 65]  [Cited by in F6Publishing: 42]  [Article Influence: 2.2]  [Reference Citation Analysis (0)]
27.  Yang WC, Wu HP. Clinical analysis of hypertension in children admitted to the emergency department. Pediatr Neonatol. 2010;51:44-51.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 13]  [Cited by in F6Publishing: 16]  [Article Influence: 1.1]  [Reference Citation Analysis (0)]
28.  Garcia JY, Vidt DG. Current management of hypertensive emergencies. Drugs. 1987;34:263-278.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 35]  [Cited by in F6Publishing: 37]  [Article Influence: 1.0]  [Reference Citation Analysis (0)]
29.  Bannan LT, Beevers DG, Wright N. ABC of blood pressure reduction. Emergency reduction, hypertension in pregnancy, and hypertension in the elderly. Br Med J. 1980;281:1120-1122.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 16]  [Cited by in F6Publishing: 17]  [Article Influence: 0.4]  [Reference Citation Analysis (0)]
30.  Bertel O, Marx BE, Conen D. Effects of antihypertensive treatment on cerebral perfusion. Am J Med. 1987;82:29-36.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 45]  [Cited by in F6Publishing: 50]  [Article Influence: 1.4]  [Reference Citation Analysis (0)]
31.  Reed WG, Anderson RJ. Effects of rapid blood pressure reduction on cerebral blood flow. Am Heart J. 1986;111:226-228.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 21]  [Cited by in F6Publishing: 23]  [Article Influence: 0.6]  [Reference Citation Analysis (0)]
32.  Kosecoff J, Chassin MR, Fink A, Flynn MF, McCloskey L, Genovese BJ, Oken C, Solomon DH, Brook RH. Obtaining clinical data on the appropriateness of medical care in community practice. JAMA. 1987;258:2538-2542.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 23]  [Cited by in F6Publishing: 23]  [Article Influence: 0.6]  [Reference Citation Analysis (0)]
33.  Prisant LM, Carr AA, Hawkins DW. Treating hypertensive emergencies. Controlled reduction of blood pressure and protection of target organs. Postgrad Med. 1993;93:92-96, 101-104, 108-110.  [PubMed]  [DOI]  [Cited in This Article: ]
34.  Ziegler MG. Advances in the acute therapy of hypertension. Crit Care Med. 1992;20:1630-1631.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 9]  [Cited by in F6Publishing: 10]  [Article Influence: 0.3]  [Reference Citation Analysis (0)]
35.  Tumlin JA, Dunbar LM, Oparil S, Buckalew V, Ram CV, Mathur V, Ellis D, McGuire D, Fellmann J, Luther RR. Fenoldopam, a dopamine agonist, for hypertensive emergency: a multicenter randomized trial. Fenoldopam Study Group. Acad Emerg Med. 2000;7:653-662.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 58]  [Cited by in F6Publishing: 63]  [Article Influence: 2.6]  [Reference Citation Analysis (0)]
36.  Strauss R, Gavras I, Vlahakos D, Gavras H. Enalaprilat in hypertensive emergencies. J Clin Pharmacol. 1986;26:39-43.  [PubMed]  [DOI]  [Cited in This Article: ]  [Cited by in Crossref: 36]  [Cited by in F6Publishing: 37]  [Article Influence: 1.0]  [Reference Citation Analysis (0)]