Chapter 24 Vital Signs. Copyright 2011 Wolters Kluwer Health Lippincott Williams & Wilkins

Transcription

1 Chapter 24 Vital Signs

2 Vital Signs Temperature Pulse Respiration Blood pressure

3 When to Assess Vital Signs Upon admission to any healthcare agency Based on agency institutional policy and procedures Anytime there is a change in the patient s condition Before and after surgical or invasive diagnostic procedures Before and after activity that may increase risk Before administering medications that affect cardiovascular or respiratory functioning

4 Maintenance of Body Temperature Thermoregulatory center in the hypothalamus regulates temperature Center receives messages from cold and warm thermal receptors in the body Center initiates responses to produce or conserve body heat or increase heat loss

5 Range of Human Body Temperature Measured Orally

6 Heat Production Primary source is metabolism Hormones, muscle movements, and exercise increase metabolism Epinephrine and norepinephrine are released and alter metabolism Energy production decreases and heat production increases

7 Sources of Heat Loss Skin (primary source) Evaporation of sweat Warming and humidifying inspired air Eliminating urine and feces

8 Transfer of Body Heat to External Environment Radiation Convection Evaporation Conduction

9 Question What is the term for the heat that is lost when a person goes out in the cold without a hat? A. Convection B. Radiation C. Evaporation D. Conduction

10 Answer Answer: B. Radiation Rationale: Radiation is the diffusion or dissemination of heat by electromagnetic waves, such as occurs with an uncovered head. Convection is the dissemination of heat by motion between areas of unequal density. Evaporation is the conversion of a liquid to a vapor. Conduction is the transfer of heat to another object during direct contact.

11 Pulse Physiology Regulated by the autonomic nervous system through cardiac sinoatrial node Parasympathetic stimulation decreases heart rate Sympathetic stimulation increases heart rate Pulse rate = number of contractions over a peripheral artery in 1 minute

12 Question Tell whether the following statement is true or false. The normal pulse rate for adolescents and adults ranges from 60 to 100 beats/min. A. True B. False

13 Answer Answer: A. True The normal pulse rate for adolescents and adults ranges from 60 to 100 beats/min. Normal for newborn is Normal for 1-3 year old Normal 6-8 year old Normal 10 year old

14 Respirations Pulmonary ventilation movement of air in and out of lungs Inhalation: breathing in Exhalation: breathing out

15 Question Tell whether the following statement is true or false. Changes in the rate and depth of inhalation and exhalation are brought about by the inhibition or stimulation of the respiratory muscles by respiratory centers in the medulla and pons. A. True B. False

16 Answer Answer: A. True Changes in the rate and depth of inhalation and exhalation are brought about by the inhibition or stimulation of the respiratory muscles by respiratory centers in the medulla and pons.

17 Rate and Depth of Breathing Changes in response to tissue demands Controlled by respiratory centers in the medulla and pons Activated by impulses from chemoreceptors in the aortic arch and carotid arteries Increase in carbon dioxide is the most powerful respiratory stimulant

18 Factors affecting Respirations Age: resp rate decreases with age: Newborn 30 60, adult Exercise: increases rate Acid-base: acidosis increased rate and depth of resp Brain lesions: can cause change in rate and depth Cheyne-stokes resp: waxing and waning of resp rate and depth with periods of apnea Increased altitude Respiratory disease

19 Resp con t Anemia Anxiety Medications Acute pain

20 Respiratory terminology Tachypnea Bradypnea Apnea Dyspnea Orthopnea

21 Physiology of Blood Pressure Force of the blood against arterial walls Controlled by a variety of mechanisms to maintain adequate tissue perfusion Pressure rises as ventricle contracts and falls as heart relaxes Highest pressure is systolic Lowest pressure is diastolic

22 Short term regulation of BP Mechanisms correct temporary changes in pressure. These mechanisms are primarily neural and humoral (pertaining to body fluid) Neural centers in lower pons and medulla called the cardiovascular center transmit parasympathetic impulses to the heart via vagus nerve. Sympathetic to heart and blood vessels via the spinal cord and peripheral sympathetic nerves Pressure sensitive receptors called Baroreceptors located in heart and walls of arteries at aortic arch and carotid. They are stimulated by changes in stretch of blood vessels and send impulses to the cardiovascular center

23 Regulation of BP: humoral and hormone The adrenal glands release epinephrine, a sympathetic neurotransmitter increases heart rate and contractility increasing cardiac output Renin-angiotensin-aldosterone system causes vasoconstriction in the arterioles causes increased peripheral vascular resistance and increases sodium and water retention ADH is released from the posterior pituitary when stimulated by decreased blood volume and blood pressure or by increased osmolality of body fluids. Has direct vasoconstricting effect on blood vessels

24 Question What is the cardiac output of an adult with a stroke volume of 70 ml and a heart rate of 80 beats/min? A. 5.6 L/min B L/min C L/min D L/min

25 Answer Answer: A. 5.6 L/min Rationale: Cardiac output = stroke volume heart rate. It is the amount of blood pumped per minute and averages from 3.5 L/min to 8.0 L/min in a healthy adult (Porth, 2007).

26 Factors Affecting Body Temperature Circadian rhythms Age and gender Environmental temperatures

27 Pulse Variations Increased or decreased pulse rate Pulse amplitude and quality Regular or irregular pulse rhythm

28 Factors Affecting Blood Pressure Age, gender, race Circadian rhythm Food intake Exercise Weight Emotional state Body position Drugs/medications

29 Orthostatic hypotension When systolic BP falls 20mm Hg or diastolic falls 10 mm Hg within 3 minutes of standing Result of peripheral vasodilation without compensatory rise in cardiac output People at risk: older adults, patients on prolong bed rest, patients dehydrated or with blood loss and patients on certain medications.

30 Equipment for Assessing Temperature Electronic and digital thermometer Tympanic membrane thermometer Disposable single-use thermometer Temporal artery thermometer Automated monitoring devices

31 Equipment for Assessing Blood Pressure Stethoscope and sphygmomanometer Doppler ultrasound Electronic or automated devices

32 Sites for Assessing Temperature Tympanic membrane Oral Anal Axillary

33 Sites for Assessing Pulse Palpating peripheral arteries Auscultating apical pulse with stethoscope Assessing apical-radial pulse

34 Question Which one of the following pulse sites is located on the inside of the elbow? A. Temporal B. Radial C. Femoral D. Brachial

35 Answer Answer: D. Brachial Rationale: The brachial pulse site is located on the inner elbow. The temporal site is located on the side of the head, the radial site is on the wrist, and the femoral site is located on the groin.

36 Sites for Assessing Pulse by Palpation

37 Assessing Respirations Inspection Listening with stethoscope Monitoring arterial blood gas results Using a pulse oximeter

38 Assessing Blood Pressure Listening for Korotkoff sounds with stethoscope First sound is systolic pressure Change or cessation of sounds occurs diastolic pressure The brachial artery and popliteal artery are commonly used

39 Parts of a Sphygmomanometer 3 Sizes of Cuffs See table 24-8 on page 535

40 Normal Temperatures for Healthy Adults Oral 37.0 C, 98.6 F Rectal 37.5 C, 99.5 F Axillary 36.5 C, 97.7 F Tympanic 37.5ºC, 99.5 F Forehead 34.4 C, 94.0 F

41 Normal Ranges for Vital Signs for Healthy Adults Oral temperature 37.0 C, 98.6 F Pulse rate 60 to 100 (80 average) Respirations 12 to 20 breaths/min Blood pressure 120/80