Autonomic Nervous System

1. Autonomic Nervous System Chapter 17,18, 19, 20

2. Central Nervous System or CNS • Brain and spinal cord: receives and processes incoming sensory information and responds by sending out signals that initiate or modify a process.

3. Peripheral Nervous System • Includes all the neurons and ganglia found outside the CNS • Includes the • Sympathetic receptors (adrenergic) • Parasympathetic receptors (cholinergic)

4. Sympathetic Nervous System • Helps the body cope with external stimuli and functions during stress (triggers the flight or fight response) • Vasoconstriction – increase in blood pressure • Increased heart rate • Increased respiratory rate • Cold, sweaty palms • Pupil dilation

5. Parasympathetic Nervous System • Works to save energy, aids in digestion, and supports restorative, resting body functions. • Decrease in heart rate • Increased gastro intestinal tract tone and peristalsis • Urinary sphincter relaxation • Vasodilation – decrease in blood pressure

6. The Race Horse and the Cow Sympathetic Nervous System Parasympathetic

7. Norepinephrine and epinephrine • Both always present in the blood. • Norepinephrine varies according to the amount of stress present and will cause transient changes in heart rate and systemic arteries and veins. • Epinephrine is a constant in regulating heart rate, vasoconstriction in systemic arteries and veins and vasodilation of muscles and liver.

8. Adrenergic Receptors • Norepinephrine produces its effects by combining with adrenergic receptors • Alpha • Beta

9. Adrenergic Receptors • Found in: • Cardiovascular • Endocrine • Gastrointestinal • Genitourinary • Respiratory • Ocular

10. Alpha Receptors • Alpha 1: adrenergic receptors located on postsynaptic effector cells. • Smooth muscles of blood vessels: Constriction • Bladder sphincter • Penis • Uterus • Pupillary muscles of iris

11. Adrenergic Receptor • Alpha 1 • Therapeutic Uses • Control topical superficial bleeding • Treat nasal congestion • Elevate blood pressure • Delay absorption of local anesthesia • Decrease intraocular pressure (pressure in eye)

12. Alpha 2 • Same as the Alpha 1 but are located in the presynaptic nerve terminals.

13. Adrenergic Receptor • Beta 1 • Cardiovascular • Cardiac muscle: increased contractility • Atrioventricular node: increased heart rate • Sinoatrial node: increase in heart rate • Endocrine • Pancreas

14. Beta 1 Drugs • Predominately works on vascular smooth muscle of the heart.

15. Adrenergic Receptor • Beta 2 • Cardiovascular • Dilation of blood vessels • Endocrine • Uterine relaxation • Respiratory: dilation of bronchial muscles

16. Beta 2 Drugs • Used in Asthma to relieve bronchocontriction. • Used to delay pre-term labor by relaxing the uterus.

17. Dopamine • Adrenergic neurotransmitter – essential for normal brain function. • Studies focus on connection between dopamine malfunction in schizophrenia and Parkinson’s Disease. • Role of dopamine: stimulants and depressants.

18. Body Responses – “fight or flight” • Increase in blood pressure and cardiac output. • Increase blood flow to brain, heart and skeletal muscles. • Decrease blood flow to skin and organs not needed for “flight”. • Increase in glycogen for energy, mental activity, muscle strength, blood coagulation, respiratory rate, pupil dilation to aid vision, and increase in sweating.

19. Fight of Flight Response • Can be a problem if the body stay in the “fight or flight” mode. • Type A personalities? • High stress environment? • Medications may be needed reduce the physiologic body responses.

20. Parasympathetic Nervous System Rest and Digest Save energy Decreased heart rate

21. Sympathetic Nervous System • Protective mechanisms designed to help person cope with the stress or get away from it.

22. Body Responses – “rest and digest” • Dilation of blood vessels in skin • Decrease heart rate (bradycardia) • Increase secretion of digestive enzymes • Constriction of smooth muscle of bronchi • Increase in sweat glands - cooling • Contraction of smooth muscles of urinary bladder • Contraction of smooth muscle of skeletal system

23. Adrenergic Drugs • What do they do? • Stimulation of the sympathetic nervous system.

24. Indications • Respiratory conditions • Topical nasal congestion • Ophthalmic conditions • Cardiovascular

25. Lungs Asthma and COPD (Chronic Obstructive Pulmonary Disease): Beta 2 drugs or bronchodilators are used to relieve broncho-constriction and broncho-spasm. Action: dilation of bronchioles

26. Asthma

27. OTC Adrenergic Drugs • Common cold: anti-histamines • Allergy: nasal or oral to relieve nasal congestion

28. Heart • Direct stimulation of receptors • Alpha 1 – • Vasoconstriction of blood vessels which increases blood pressure • Pressor or vasopressor effect to maintain blood pressure • Beta 1 • Increased force of myocardial contraction • Increased speed of electrical conduction in the heart.

29. Heart: SA Node

30. Ophthalmic Conditions • Used to reduce intraocular pressure in treatment of glaucoma.

31. Glaucoma

32. Contraindications • Only contraindications to use of adrenergic drugs are: • Drug allergy • Severe hypertension

33. Adrenergic Drugs • Epinephrine • Pseudoephedrine – Sudafed • Isoproterenol (Isuprel) • Phenylephrine (Neo-Synephrine) • Clonidine (antihypertensive)

34. pseudoephedrine • Trade names: Sudafed, Afrin nose spray • Therapeutic classification: allergy, cold and cough remedies, nasal drying agents / decongestants • Action: stimulates alpha and beta adrenergic receptors

36. Forms and Dosage • How supplied: tabs, chew tabs, extended release tabs, liquid or drops • Dosing: 30 to 60 mg / dose q 6-8 hours PO • Maximum dose 240 mg/24 hours • Sustained release: 120 mg PO q 12 hours

37. Contraindications • Severe Hypertension • Severe coronary artery disease (CAD) • Use with caution in pregnancy, breast feeding and renal failure

38. Side Effects • Dizziness, nervousness, restlessness, insomnia and arrhythmias • Seizures • Cardiovascular collapse

39. Additional Information • Primarily excreted renally – adjust in patients with renal impairment • May cause false-positive for amphetamines – athletes • Currently need to ask pharmacist for Sudafed – OTC has been limited due to abuse

40. Nursing Implications • Assess for congestion • Monitor pulse and blood pressure before beginning therapy • Assess lung sound for signs of bronchial secretions

41. Allergies

42. Anaphylactic Shock

43. Epinephrine • Epinephrine would be the drug of choice • Classification: adrenergic • Action: affects both the beta 1 (cardiac) and beta 2 (pulmonary) receptors • produces bronchodilation • inhibits hypersensitivity reaction of mast cells.

44. Epinephrine • Therapeutic Effects: • Bronchodilation • Maintenance of heart rate and blood pressure • Adverse Side Effects: • Nervousness, restlessness, tremors, angina, arrhythmias, hypertension, tachycardia

45. How it is given? • Sub-Q or IV or inhaled • Epi-pen is given to clients with severe allergy reactions • Not given by mouth because drug is inactivated by gastric juices • Can be inhaled in asthma attack

48. Check dose, concentration, and route of administration fatalities have occurred from medication errors use TB syringe for subcutaneous administration Inhaled provided as metered dose inhaler 160 to 250 mcg – can have 3 treatments 5 minutes apart. IV would be 0.1 to 0.25 mg (cardiopulmonary resuscitation) CAUTION!

49. Calculation • The order is for 0.25 mg of epinephrine. • How much would you need to draw up from the vial: • Epinephrine 1 mg / 1 ml

50. Precautions with Use • Tachyarrhythmia's (fast irregular heart rate), headache, nausea, and palpitations • Short acting so more definitive treatment needs to be initiated • Need cardio-respiratory monitoring • Pulse oximetry • Cardiac monitor