Chapter 24

1. Chapter 24 Vital Signs

2. Vital Signs • Temperature • Pulse • Respiration • Blood Pressure • Pain

3. Temperature • Heat Production • Heat Loss

4. Temperature • Core Temperature • Surface Temperature

5. Variations in Body Temperature • Factors Affecting Body Temperature • Circadian Rhythms • Age and Sex • Environmental Temperature • Hypothermia – low body temperature • Hyperthermia – high body temperature

6. Normal Body Temperature • Varies 0.3 to 0.6 degrees C (0.5-1.0 degrees F). • Afebrile – a person with a normal body temperature

7. Increased Body Temperature • Pyrexia (fever) –Febrile – a person with an increased body temperature. • Hyperpyrexia – a high fever, usually above 41 degrees C (105.8 degrees F). • Hyperthermia- differs from pyrexia – hypothalamic set point is not changed, but in extreme heat exposure or excessive heat production, the mechanisms that control body temp are ineffective. • Neurogenic fever – result of damage to the hypothalamus from intracranial trauma, intracranial bleeding, or increased intracranial pressure.

8. Physical Effects of Increased Body Temperature • Loss of appetite, headache, hot, dry skin, flushed face, thirst, and general malaise. • Young children may experience delirium or seizures • Assess for potentially dangerous manifestations of a fever, such as dehydration, decreased urinary output, and rapid heart rate. • Methods of reducing

9. Decreased Body Temperature • Hypothermia – body temp below the lower limit of normal. • Death may occur when temp falls below 34 degrees C (93.2 degrees F).

10. Assessing Temperature • Equipment • Electronic and Digital Thermometers • Tympanic Membrane Thermometer • Glass thermometer • Disposable Single-Use Thermometers • Temporal Artery Thermometer • Automated Monitoring Devices

11. Temperature • Routes • Oral most common • Rectal • Axillary • Tympanic • Always record site when recording temperature.

12. Pulse • Throbbing sensation that can be palpated over a peripheral artery or auscultated (listened to ) over the apex of the heart. • Results as a wave of blood is pumped into the arterial circulation by the contraction of the left ventricle.

13. Pulse Physiology • Pulse regulated by the ANS through the cardiac SA node (pacemaker). • Parasympathetic stimulation via the vagus nerve decreases the HR, and sympathetic stimulation increased the HR and force of contraction. • Pulse rate is the number of pulsations felt over a peripheral artery or heard over the apex of the heart in 1 minute.

14. Variations in Pulse Rate • Pulse Rate • Normal range 60 – 100 • Increased to 100 – 180 Tachycardia • Decreased below 60 Bradycardia

15. Variations in Pulse Amplitude and Quality • Pulse Amplitude and Quality • Quality of pulse in terms of its fullness and reflects the strength of left ventricular contraction. • Assessed by the feel of the blood flow through the vessel. • Amplitude is normally strong in areas where an artery can be palpated. • Absent (0), Thready (1+), Weak (2+), Normal (3+), Bounding (4+)

16. Variations in Pulse Rhythm • Pulse Rhythm • The pattern of the pulsations and the pauses between them. • Normally regular • Irregular pattern of heartbeats - dysrhythmia

17. Assessing the Pulse • Palpating peripheral arteries or by auscultating the apical pulse with a stethoscope. • Equipment • Stethoscope

18. Sites and Methodsof Assessing the Pulse • Peripheral Arterial Pulses – place the middle three fingers over the artery and lightly compress the artery so pulsations can by felt and counted. • Temporal • Carotid – during emergency situations • Brachial – used for infants who have had a cardiac arrest • Radial – most commonly used in children and adults • Femoral • Popliteal • Posterior tibial • Dorsalis pedis

19. Pulse • Apical Pulse • Apical-Radial Pulse

20. Respirations • Pulmonary ventilation (or breathing) is movement of air in and out of the lungs; inspiration (or inhalation) is the act of breathing in, and expiration ( or exhalation) is the act of breathing out. • External respiration is the exchange of oxygen and carbon dioxide between the alveoli of the lungs and the circulating blood through diffusion. • Internal respiration is the exchange of oxygen and carbon dioxide between the circulating blood and tissue cells.

21. Respiration Physiology • Rate and depth of breathing can change in response to body demands. • Increase in carbon dioxide is the most powerful respiratory stimulant, causing an increase in respiratory depth and rate. • The cerebral cortex of the brain allows voluntary control of breathing.

22. Variations in Respiratory Rate and Depth • Normally smooth, effortless, and without conscious effort. • Factors Affecting Respiration • Respiratory Rate (12 to 20 times each minute) • Normal – eupnea (1 resp to 4 heartbeats) • Increased – tachypnea – occurs inresponse to the increased metabolic rate during fever (pyrexia). • Decreased – bradypnea – occurs in some pathologic conditions.

23. Respiratory Depth and Rhythm • Normally from shallow to deep. • Apnea – no breathing • If lasts longer than 4 to 6 minutes, brain damage and death might occur. • Dyspnea – difficult or labored breathing

24. Assessing Respirations • Rate, Depth, and Rhythm by inspection (observing and listening) or by listening with the stethoscope. • Monitoring arterial blood gas results and using a pulse oximeter to determine oxygenation of blood. • Depth – assessed by observing the degree of excursion or movement in the chest wall. • Rhythm

25. Alterations in Respirations • Bradypnea - <10 rate reg but abn slow. • Tachypnea - > 24 rate reg but abn rapid. • Hyperpnea – resp labored, increase in depth, increase in rate > 20 (occurs normal in exercise). • Apnea – respirations cease for several second. Persistent cessation results in respiratory arrest.

26. Alterations in Respirations • Hyperventilation – increased rate and depth • Hypoventilation – decreased rate and depth; irregular • Cheyne-Stokes Respirations – Alternating periods of deep, rapid breathing followed by periods of apnea. • Kussmauls’s Respirations – abnormally deep; regular and increase in rate. • Biolt’s Respirations – varying depth and rate of breathing, followed by periods of apnea.

27. Oxygen Saturation • Measures diffusion and perfusion. • 95% - 100% - % of hemoglobin that is bound with oxygen in the arteries is the % of saturation of hemoglobin (SaO2). • Pulse oximeter – indirect measurement • Interferance with Light Transmission

28. Reduction of Arterial Pulsations • PVD • Hypothermia • Pharmocological vasoconstrictors • Decreased Cardiac Output and Hypotension • Peripheral Edema • Tight Probe

29. Blood Pressure • The force of the blood against arterial walls. • Maximum blood pressure is exerted on the walls of arteries when the left ventricle of the heart pushes blood through the aortic valve into the aorta at the beginning of systole. • Pressure rises as the ventricle contracts and falls as the heart relaxes. • This continuous contraction and relaxation of the left ventricle creates a pressure wave that is transmitted through the arterial system.

30. Blood Pressure • Systolic pressure (numerator) – the highest pressure • Diastolic pressure (denominator) – the lowest pressure • Pulse pressure – the difference between Systolic and Diastolic pressure. • Measured in millimeters of mercury (mm Hg) and recorded as a fraction. (Example 120/80 – systolic 120, diastolic 80, pulse pressure 40)

31. Compliance • Arteries have a considerable quantity of elastic tissue that allows them to stretch and distend. • Constant state of pressure in arteries which offers the resistance. • Elasticity of walls + resistance of the arterioles = maintain normal blood pressure. • With age, walls of arterioles less elastic, decreased ability to stretch and dilate. Ultimately limits adequate blood flow and contributes to rising pressure.

32. Neural and Humoral Mechanisms • ANS mediates control mechanisms that function to maintain short-term regulation of BP • Hormones and humoral mechanisms regulate BP • Renin-angiotensin-aldosterone system controls vasoconstriction to increase peripheral vascular resistance and also increases sodium and water retention bythe kidneys to increase circulatory fluid volume – increased BP • ADH 0 Antidiuretic hormone – vasopressin- is release from the posterior pituitary when stimulated by decreased blood volume and blood pressure, or by an increased osmolarity of the blood – water is retained to increase circulatory fluid volume - increase BP

33. Cardiac Output • Stroke Volume – quantity of blood forced out of the left ventricle with each contraction • Cardiac Output is the amount of blood pumped per minute, and averages from 3.5L to 8.0 L/min in a healthy adult. • CO = SV X HR • Increases during exercise, decreases during sleep. • Varies depending on body size and metabolic needs. • Increased CO – arteries distend more, increased BP. • Decreased CO – BP falls

34. Variations in Blood Pressure • Factors Affection BP • Age • Circadian rhythm • Sex • Food Intake • Exercise • Weight • Emotional state • Body position • Race • Drugs/Medications

35. Increased Blood Pressure • Hypertension – BP is above normal for a sustained period • Most common health problems in adults and the leading cause of cardiovascular disorders. • Primary or essential HTN – without know cause. • Secondary HTN – with know pathology. • Major risk factor for heart disease, and most imp risk factor for stroke. • “Silent Killer” • Few symptoms beyond the HTN; 22 million don’t know

36. Risk Factors for HTN • Family history • Sedentary lifestyle • Obesity • Continual stress

37. HIGH RISK FACTORS • Cigarette smoking • Alcohol consumption • High salt intake • High-fat, high-calorie diet • Twice as common in African Americans as in Americans of European descent.

38. Treatment of HTN • Medications • Antihypertensive medication • Diuretics – to decrease fluid volume. • Beta-adrenergic blockers – to block sympathetic stimulation and decrease cardiac output. • Vasodilators and calcium channel blockers – to relax smooth muscles of arterioles and decrease peripheral vascular resistance. • ACE inhibitors – to prevent vasoconstriction by angiotensin II and decrease circulatory fluid volume by reducing aldosterone production.

39. Lifestyle Changes • Low-calorie, low-fat diet • Losing excess weight and maintaining weight loss • Limiting alcohol intake • Eliminating smoking • Reducing salt intake • Regular physical activity

40. Decreased Blood Pressure • Hypotension – below-normal BP • Orthostatic hypotension (Postural Hypotension) – low BP

41. Assessing Blood Pressure • Equipment • Sphygmonmanometer • Noninvasive BP monitors • Doppler Ultrasound • Direct Electronic Measurement

42. Assessment Sites and Methods • Korotkoff Sounds • Assessing a Brachial Artery BP • Assessing a Popliteal Artery BP • Palpating the BP

43. Blood Pressure Assessment Errors and Contributing Causes • See Table 24-11 on page 554.