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					Hypertensive Emergencies

    Amy Staples, MD, MPH
  UNM Department of Pediatrics
                   Outline
•   Measuring BP
•   Definition of Hypertension
•   Etiology of hypertension in kids
•   When to treat
•   How to treat
               Clinical Quiz
1. 11 yo girl with a       HTN   Treat
   sinusitis, HA and BP    ___   ___
   124/83
2. 5 yo boy with rash,
   abd pain, joint pain,
   tea colored urine       ___   ___
   and BP 117/81
3. 16 yo athletic boy in
   clinic for sports PE    ___   ___
   BP 132/84
               Clinical Quiz
4. 3 yo girl with NF, alert   HTN   Treat
   and playful; BP 125/77
                              ___    ___
5. 2 yo girl with nephrotic
   syndrome admitted for
   albumin/lasix due to
   anarsca, with severe HA
                              ___    ___
   and seizure, BP 119/76;
   on admit 93/52
                   Outline
•   Measuring BP
•   Definition of Hypertension
•   Etiology of hypertension in kids
•   When to treat
•   How to treat
    Measuring accurate BP’s
• Cuff too small → high reading
• Cuff too big → OK reading or no reading
  (usually not falsely low)
• Lower extremities - Normally, BP is 10 to
  20 mmHg higher in the legs than the arms
  – Prefer arm if at all possible
  – Right arm for comparison with standards
                             Cuff Size
 • Bladder width > 40% of
   mid-arm circumference.
 • Bladder length 80-100%
   of arm circumference.




A. Ideal arm circumference
B. Range of acceptable arm
  circumferences
C. Bladder length
D. Midline of bladder
E. Bladder width
F. Cuff width
  Oscillometric Devices

Measure mean arterial pressure (MAP) and
 calculates SBP and DBP
  – The algorithms used are proprietary and NOT
    standardized
  – Results can vary widely and they do not
    always closely match BP values obtained by
    auscultation
  – These machines must be calibrated regularly
       Manual vs. Automatic
• Manual is the gold standard
• Oscillometric measurements preferred in
  infants and ICU settings ONLY
• All high readings should be confirmed with
  a manual
       Confirming High BP’s
• Repeat BP in both arms and one leg (both
  not usually necessary)
• Repeat 3 times to assure accurate
• Dx of HTN requires elevated BP’s on 3
  separate occasions
 Disappearance of ―HTN‖ with
   Repeated Measurement

100%
         17%
80%
                      52%
60%                               80%       HTN
40%      83%                                Normal
20%                   48%
                                  20%
 0%
       1st Screen   2d Screen   3d Screen
        (N=2460)     (N=323)     (N=87)
                   Outline
•   Measuring BP
•   Definition of Hypertension
•   Etiology of hypertension in kids
•   When to treat
•   How to treat
          New BP Normals
• 4th report on the diagnosis, evaluation and
  treatment of high blood pressure in
  children and adolescents
  – Correlates with the JNC 7
  – Uses new growth parameter data from
    NHANES
                  Definitions
Normotensive
• Average SBP and DBP <90th % for age, sex and
  height
Pre-hypertension
• Average SBP or DBP >90th but <95th percentile
  (OR >120/80)
Hypertension
• Average SBP and/or DBP >95th percentile for
  age, sex and height on 3 separate occasions
  – Stage 1: 95th-99th percentile + 5 mmHg
  – Stage 2: >99th percentile + 5 mm Hg
       How to use the tables
• Need:
  – Age, gender, height percentage
  – BP charts
   7 yo boy
   Ht 75%tile


   50% 99/58
   90% 113/73
   95% 119/80
   99% 127/88




http://www.cc.nih.gov/ccc/pedweb/pedsstaff/bptable1.PDF
                       BP tables for Infants




*Task Force on Blood Pressure Control in Children. Report of the Second Task Force on Blood Pressure Control in Children—
1987.Pediatrics.1987;79:1–25(PR)
           Urgency vs. Emergency
• Urgency – severely elevated BP with no
  current evidence of secondary organ
  damage, although if left untreated, target
  organ injury may result imminently
   → Decrease BP Soon
• Emergency – severely elevated BP with
  evidence of target organ injury
   → Decrease BP Immediately
• Target organs – CNS, heart, kidney, eye
Constantine and Linakis, Pediatric Emergency Care, 2005
             Severe Hypertension

   ―Hypertension that represents a threat to
     life or to the function of vital organs‖
                     OR
   Severe hypertension is when your blood
     pressure goes up too!



Adelman, et al. Pediatric Nephrology, 2000
                   Outline
•   Measuring BP
•   Definition of Hypertension
•   Etiology of hypertension in kids
•   When to treat
•   How to treat
           Etiology of Hypertension
      Newborn           Early Childhood          School Age     Adolescence
                         (Infant-6 yo)            (6-12 yo)

•Renal vein           •Renal                 •Renal           •Essential
thrombosis            parenchymal            parenchymal      hypertension
•Coarctation          disease                disease          •Renal
•Renal artery         •Renovascular          •Renovascular    parenchymal
stenosis              disease                disease          disease
•Congenital renal     •Coarctation           •Essential       •Renovascular
anomalies                                    hypertension     disease




Constantine and Linakis, Pediatric Emergency Care, 2005
         Miscellaneous Causes
• Endocrine
    – Hyperthyroid
    – Pheochromocytoma
•   Elevated ICP/CNS disease
•   Drug use (cocaine, ecstasy)
•   Medication (abrupt withdrawal)
•   Exercise
•   Traction
•   Hypovolemia
                Overall
• 15-20% Essential Hypertension
• 80-85% Secondary Hypertension
  – 60-80% Renal
  – 8-10% Renovascular
  – 2% Coarctation
                   Outline
•   Measuring BP
•   Definition of Hypertension
•   Etiology of hypertension in kids
•   When to treat
•   How to treat
Which hypertensive patients need
     immediate treatment?
1. Severe HTN
  •   Malignant HTN - >30% above 95%
  •   Moderate – Severe HTN - >99% with target
      organ damage
2. Symptomatic HTN
3. Target Organ Damage
      Complications of Severe HTN
         Retinopathy                27%
         Encephalopathy             25%
         LVH                        13%
         Facial palsy               12%
         Visual changes             9%
         Hemiplegia                 8%


Deal, et al. Arch Dis Child, 1992
Clinical Signs of Malignant HTN
• Eyes
  – Retinal hemorrhages, exudates and papilledema

• Malignant Nephrosclerosis
  – ARF, Hematuria, Proteinuria

• Hypertensive Encephalopathy
  – Headache, nausea, vomiting
  – Restlessness, confusion  seizures, coma
  – MRI (T2-weighted images) ;
     • Edema of the white matter of the parieto-occipital regions: posterior
       leukoencephalopathy
                 Eyes




Papilledema, blurred optic disk, hemorrhages
     Hypertensive Encephalopathy
 • Failure of autoregulation


                                      Shifted
                                      baseline




Flynn, Ped Neph 2009; 24, 1101-1112
 Hypertensive Encephalopathy
• Headache, nausea, vomiting
• Restlessness, confusion → seizures,
  coma
• Posterior Leukoencephalopathy
Posterior Leukoencephalopathy
T1 weighted
images – normal
appearing

T2 weighted
images – occipital
hyperintensity
                   Outline
•   Measuring BP
•   Definition of Hypertension
•   Etiology of hypertension in kids
•   When to treat
•   How to treat
       Severe Hypertension
• Treatment Goals
  – Prevent adverse events
  – Reduce BP in controlled manner
  – Preserve target organ function
  – Minimize complications of therapy
       Severe Hypertension
• Treatment Risks
  – Rapid reduction of BP can lead to
    complications
    • Risk of hypoperfusion (ischemia) secondary to
      autoregulation
    • Medication side effects may have adverse effects
      depending on cause of hypertension (e.g. ACEi)
        How Much
        Just Enough




Depends on Acute vs. Chronic
              How Much
• Reduce by 25% of the planned reduction
  over 8-12 hrs
• Another 25% over the next 8-12 hrs
• Final 50% over the next 24 hrs
• Planned reduction – goal is to the 95-99%
  for age and height

If Unsure, slower is safer
             What to do 1st
• Monitor, Monitor, Monitor
• Need cardiopulmonary monitoring
• Need continual BP monitoring (frequently
  cycling cuff vs. arterial line)
• Decide oral vs. IV
  – Oral OK if asymptomatic
  – IV necessary if acute target organ damage is
    present or imminent
               Oral vs. IV
IV Medication          PO Medication
• Rapid Action         • Don’t need an IV
• Titratable           • Harder to control
• Easy to adjust the     effects
  dose                 • Absorption variable
• Requires IV access   • Slower kinetics can
                         make titrating more
                         difficult
              What to choose
First Line           Second Line
• PO                 • PO
   – Isradipine        – Clonidine
   – Nifedipine      • IV
• IV                   – Hydralazine
   – Nicardipine       – Enalaprilat
   – Nitroprusside     – Fenoldopam
   – Labetalol
                       Isradipine
• Ca channel blocker (Inhibit Ca++ entry into
  smooth muscle cells → vasodilitation)
• Onset of action 30-60 minutes
• Side Effects: peripherial edema, flushing,
  nausea, headache, tachycardia

• 0.05-0.1 mg/kg/dose q 4-6 hrs
• 2.5 mg and 5 mg tab, 1mg/1ml suspension
     Nifedipine – 0.1-0.25 mg/kg q 4-6 hours (10 mg tab available)
                       Onset of action 15-30 min
   A note on Short acting Ca Channel Blockers

   • In adults with severe elevations in BP, Nifedipine
     has been associated with*:
        – Cerebral ischemia
        – Myocardial ischemia
        – Symptomatic hypotension
         Preexisting MI, CAD, and hypovolemia predispose to these
          events.


   • In children Nifedipine / Isradapine have not been
     associated with cerebral or myocardial events. †

*Grossman E, JAMA 1996;276:1328-31
†Sinaiko AR, NEJM 1997;336:1675
              Nicardipine
• Ca channel blocker
• Onset of action within minutes
• Side Effects: same as isradipine

• 1-3 mcg/kg/min continuous infusion
              Nitroprusside
• Direct arteriolar/venous dilator (via nitric
  oxide donation)
• Onset of action within seconds
• Side Effects: cyanide/thiocyanate toxicity

• 0.5-1 mcg/kg/ min initially, titrate to max
  10 mcg/kg/min
• Must monitor cyanide levels if used for >24
  hrs
               Labetalol
• Mixed alpha/beta blocker
• Onset of action 5-10 min
• Side Effects: bronchospasm,
  contraindicated in asthma, cardiogenic
  shock, pulmonary edema, or heart block

• 0.2-0.3 mg/kg/dose q 10-20 min (max
  dose 20mg) can be converted into a drip
               Enalaprilat
• ACE inhibitor (prevents the vaso-
  constrictive and Na retaining effects of the
  RAS)
• Onset of action 15 min, long duration of
  action
• Side Effects: risk of decreased GFR

• 0.005-0.01 mg/kg/dose
• Use in cases of severe renin mediated
  HTN
             Hydralazine
• Direct arteriolar vasodilator
• Side Effects: may cause Lupus-like
  syndrome
• Can be given PO, IV, IM

• 0.1 - 0.5 mg/kg q 4-6 hr (max 20 mg/dose)
                 Case # 1
11 yo girl with a sinusitis, HA and BP 124/83

Ht 75th%
Blood Pressures
50% -105/62     95% -122/80       99% -128/87
Diagnosis
Pain, repeat when well, no treatment
                  Case # 2
5 yo boy with rash, abd pain, joint pain, tea
   colored urine and BP 117/81
Ht 25th%
Blood Pressures
50% - 93/52      95% - 110/71       99% - 118/79
Diagnosis
GN, treat with medication, likely Ca channel
    blocker
                 Case # 3
16 yo athletic boy in clinic for sports PE
BP 132/84
Ht 90th%
Blood Pressures
50% - 119/67    95% - 137/86    99% - 144/94
Diagnosis
Possibly Pre HTN, need repeat measurements
  and TLC
                 Case # 4
3 yo girl with NF, alert and playful
BP 125/77
Ht 25%
Blood Pressures
50% - 88/48      95% - 105/66      99% - 113/74
Diagnosis
NF (possible associated renal artery stenosis),
  Stage 2 HTN, treat with medication, renal
  vascular imaging
                  Case # 5
2 yo girl with nephrotic syndrome admitted for
  albumin/lasix due to anarsca, with severe HA
  and seizure BP 119/76; on admit 93/52
Ht – 75th%
Blood Pressures
50% - 89/46       95% - 107/64      99% - 114/71
Diagnosis
Acute HTN with end organ involvement, stop
  albumin, give lasix, consider IV therapy if sz
  continues
Flynn, Ped Neph 2009; 24, 1101-1112

				
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