Transcript HYPERTENSION IN ICU

HYPERTENSION IN ICU
Common causes include:
pain
agitation
cold, shivering
hypoxia, hypercarbia
increased ICP
transducer height etc.
Urinary retension
Positional discomfort
Omission of pre_admission anti hypertensives
(esp.B blockers)
withdrawal
Hypertension in the ICU
Dr Danie Babypaul
Worthing Anaesthetic Department
HYPERTENSION IN ICU
Underlying hypertension
Essential or primary
Secondary
Phaechromocytoma
Aortic stenosis
Renal artery stenosis
Cushing’s syndrome
PIH
Pain
Adequate analgesia
Opioid analgesics
Simple analgesics
NSAIDS
Dexmeditomedine &tramadol – novel agents
Local anaesthetic agents
Volatiles
Ketamine
Supplemental –
acupuncture,acupressure,massage,TENS
Sedation
Primarily in ventilated patients
 Benzodiazepines –midazolam,diazepam
 Anaesthetic agents- propofol,thiopentone
 Butyrophenones- haloperidol
 Phenothiazines- chlorpromazine
 Volatiles
 Opioids
 Dexmeditomedine
Cold , Shivering
Passive –warm environment,warm blanket
Active ,external- warmed pads,blankets,Bair Hugger
Active, core humidified inspired gases
 warm intravenous fluids
 Body cavity lavage-gastric,pleural,peritoneal
 Extra corporeal methods-hemodialysis, Bypass
Other therapies
Hypoxia- oxygen
therapy(masks,cpap,bipap,ventilator)
Hypercarbiabronchodilators,steroids,CPT,NIV,ventilator
Maneuvers to reduce ICP- medications,ventilator
Adjust transducer height
Urinary retension-catheterize,definitive treatment
Comfortable position for the patients
Reintroduction of pre admission antihypertensives
Psychological support- trust with staff
Look for possible secondary causes-eg:renal artery
stenosis
Antihypertensives
&vasodilators
Mechanisms
 Diuretics – bendrofluothiazide, frusemide
 α antagonistslabetalol,phentolamine,phenoxybenzamine,prazosin,
carvedilol,haloperidol,chlorpromazine
 β antagonists-propranolol,metoprolol,atenolol,esmolol
 CCB- nifedipine,nimodepine,verapamil,diltiazem,magnesium
 Direct vasodilators-SNP,GTN,isosorbide,hydralazine,diazoxide
 ACE inhibitors-captopril,enalapril,lisinopril
 Angiotensin receptor blockers- losartan,irbesartan,eprosartan
 Centrally acting-clonidine,methyl dopa,trimetaphan
α antagonists
Act by alpha adrenergic blockade
Phentolamine-nonselective-1-10mg I.v. boluses,530mg/hr
Phenoxybenzamine-nonselective-1mg/kg/day
Labetolol-α1, α2,β1- 20-80mg I.v boluses,0.54mg/min infusion
Prazosin- α1—2-10mg/day,8th hourly
Carvedilol –oral preparation
Side effects
Can cause tachycardia, idiosyncratic hypotension
CCBs
Acts by blocking voltage gated calcium channels
Nifedipine– 5-10mg po/sl
Nimodepine- mostly used in SAH
Amlodepine- 5-10mgpo b.d.
Magnesium- physiological calcium antagonist
40-60mg/kg loading, 2-4 gm/hr infusion
Side effects: hypotension, tachycardia,peripheral
oedema
β blockers
Widely used now,acts by β blockade,
inhibit release of renin from juxtaglomerular cells
Prejunctional inhibition of nor epinephrine
Atenolol- 1-10 mg iv boluses,25-100mg pob.d
Metoprolol-same doses
Esmolol-loading 0.5mg/kg,50-200mic/min
Side effects :
Bradycardia
Bronchospasm
Hyperkalemia,masking response to hypoglycemia
Dirct vasodilators
Sodium Nitro Prusside
44% cyanide by weight- cyanide toxicity
Nonselective vasodilator
50mg/250ml 5%D
3-40ml/hr
Glyceryl trinitrate
30mg/100ml5%D
2-25ml/hr
Hydralazine
10-20mg I.v. bolus, 20-40 mg 6-8 hrly
Diazoxide
50-100mg I.v. boluses, 15-30mg/min infusion
ACE inhibitors
Captopril-6.25-50mg QDS ,in acute hypertension
12.5-25sl
Enalapril-5-20mg QDS
Enalaprilat –0.625-5mg boluses(parenteral)
Caution in renal impairment, hypotension
Losartan – 25-100mg daily
Caution in renal failure
Diuretics
Salt &water excretion
Inhibition of aldosterone
Direct vasodilatory effects
Eg: frusemide, thiazides
Caution in hypovolemia,renal dysfunction
Acute treatment
In hypertensive encephalopathy
Heart failure
Eclampsia
Acute dissecting aortic aneurysm
In c/c hypertension or a/c neurological events
A precipitate reduction- worsens CPP-further
deterioration
Target CPP>70mm Hg
Hypertensive crisis
Symptomatic
Increased
drowsiness,seizures,papilloedema,retinopathy
In presence of elevated systemic pressures
Diastolic BP>120-130 mm Hg
Mean BP>140-150 mm Hg
Encephalopathy can occur at lower pressures
Principles of management
Adequate monitoring-invasive BP,ECG,CVP,CO,U/O
Consider pain,hypovolemia,hypothermia,agitation
Consider specific treatment-phaeo,thyroid
crisis,dissection
Slow iv infusion-GTN,SNP,others
Aim to reduce to mildly hypertensive levels
Longer term treatment –started at low doses
Drug doses
GTN
0.5-20mg/hr
SNP
0.5-1.5mic/kg/min0.58mic/kg/min
Labetolol
50mg iv over 1 min repeated
every
5min to max 200mg
Esmolol
50-200 mic/min
Hydralazine
5-10mg slow I.v. followed by
50-150mic/min
Thank you