Orthostatic Hypotension

These slides prepared by Dr.A.K.Mallik under supervision of Dr.L. Nilachandra deptt. of pmr rims Imphal; Manipur, India.

1. Dr AMIT KUMAR MALLIK DEPT. OF PHYSICAL MEDICINE AND REHABILITATION RIMS,IMPHAL ORTHOSTATIC HYPOTENSION

2. Definition BLOOD PRESSURE The pressure exerted by flowing column of blood on arterial wall. Normal BP- Systolic 100-140 mm Hg Diastolic 60-90 mm Hg

3. Orthostatic hypotension Decrease in systolic BP≥20 mm Hg or decrease in diastolic BP≥10 mm Hg within 3 minutes of standing when compared with BP from sitting or supine position or Similar drop in BP within 3 minutes in a head up position on tilt table test at angle ≥60°

4. Normal mechanism of BP regulation There are two basic mechanisms for regulating blood pressure: (1) short-term mechanisms (2) long-term mechanisms Blood Pressure = cardiac output x peripheral resistance

5. Location of Baroreceptor and Chemoreceptor

6. Control of Blood pressure I. Nervous system II. Chemoreceptor

7. I. Nervous System Control BP by changing blood distribution in the body and by changing blood vessel diameter . Sympathetic & Parasympathetic activity The vasomotor center – medulla It sends efferent motor fibers that innervate smooth muscle of blood vessels

8. Regulation of Rising Blood Pressure

9. Baroreceptors The best known of nervous mechanisms for arterial pressure control(baroreceptor reflex) Baroreceptor are stretch receptors found in the carotid sinus ,aortic sinus Respond more to a rapidly changing pressure than stationary

10. Baroreceptors

11. Effect of Baroreceptors EFFECT VASODILATATION OF THE VEINS AND ARTERIOLES DECREASED HEART RATE AND STRENGTH OF HEART CONTRACTION Therefore, excitation of baroreceptors by high pressure in the arteries reflexly causes arterial pressure to decrease (as decrease in PR and CO)

12. Increased Parasympathetic Activity Reduction of heart rate Lower cardiac output Lower blood pressure

13. Regulation of Falling Blood Pressure Baroreceptors inhibited Decreased impulses to the brain Decreased parasympathetic activity, increased sympathetic activity Effects Heart increased heart rate and increased contractility Vessels increased vasoconstriction Adrenal gland release of epinephrine and norepinephrine which enhance heart rate Contractility and vasoconstriction Increased blood pressure

14. II. Chemoreceptor

15. Chemoreceptor Chemosensitive cells that respond to changes in pCO 2 and pO 2 and pH levels (Hydrogen ion). pCO 2  pO 2 and pH  Stimulation of vasomotor center CO  HR  vasoconstriction  BP (speeding return of blood to the heart and lungs)

16. Chemoreceptor

17. Any interruption in the body's natural process of counteracting low blood pressure

18. Causes of Postural Hypotension Neurogenic causes Primary causes- A utonomic failure due to idiopathic central and peripheral neurodegenerative diseases—the “ synucleinopathies ” Parkinson’s disease Lewy body dementia Pure autonomic failure Multiple system atrophy (Shy- Drager syndrome )

19. Secondary causes 1.Spinal cord injury 2.Secondary autonomic failure Diabetes Hereditary amyloidosis (familial amyloid polyneuropathy ) Primary amyloidosis (AL amyloidosis; immunoglobulin light chain associated )

20. Idiopathic immune-mediated autonomic neuropathy Autoimmune autonomic ganglionopathy HIV neuropathy

21. Non-neurogenic Causes of Orthostatic Hypotension Age related Cardiac pump failure Myocardial infarction Myocarditis Constrictive pericarditis Aortic stenosis Tachy -arrhythmias Brady-arrhythmias

22. Reduced intravascular volume Dehydration Diarrhea, emesis Hemorrhage Burns

23. Metabolic Adrenocortical insufficiency Hypo- aldosteronism Pheo-chromocytoma Severe potassium depletion

24. Venous pooling Postprandial dilation of splanchnic vessel beds Vigorous exercise with dilation of skeletal vessel beds Heat: hot environment, hot showers and baths, fever Prolonged recumbency or standing

25. Medications Antihypertensives Diuretics Vasodilators: nitrates , hydralazine Alpha- and beta-blocking agents CNS sedatives: barbiturates,opiates Tricyclic antidepressants Phenothiazines

26. Symptoms Characteristic symptoms are Light-headedness Dizziness Presyncope (near-faintness) However , symptoms may be absent or nonspecific like G eneralized weakness Fatigue C ognitive slowing H eadache.

27. Visual blurring Neck pain—typically in - suboccipital -posterior cervical -shoulder region ( “coat- hanger headache”)

28. Patients may report orthostatic dyspnea Symptoms may be exacerbated by exertion , prolonged standing, increased ambient temperature , or meals Syncope is usually preceded by warning symptoms, but may occur suddenly, suggesting the possibility of a seizure or cardiac cause

29. Percentage wise symptoms Lightheadedness (dizziness) 88% Weakness or tiredness 72% Cognitive difficulty (thinking/concentrating) 47% Blurred vision 47% Tremulousness 38% Vertigo 37% Pallor 31% Anxiety 29% Palpitations 26% Clammy feeling 19% Nausea 18%

30. Diagnosis By taking BP in supine and standing By comparing both BP

31. Management Non pharmacological Patient education: mechanisms and stressors of OH Compression garments

32. The head of the bed of a patient with orthostatic hypotension should be elevated by 10 to 20 degrees or 4 inches (10 cm)

33. Move legs while standing Get up slowly Avoid bending at waist FES Exercise-Calf muscle exercise, when getting out of bed, sit on edge of bed for a minute before standing

34. High-salt diet ( 1 g/d) QID High-fluid intake (2 l/d) Learn physical counter-maneuvers Correct anemia

35. Medicines(pharmacological) Fludrocortisone L-dopa-to treat hypotension a/w Parkinson ds. Midodrine or Ephedrine Erythropoitin Pyridostigmine

36. Thank You