Stressors that Affect Oxygen Needs NUR101 FALL 2008 K. BURGER, MSEd, MSN, RN, CNE LECTURE #19 PPP by Sharon Niggemeier RN, MSN Revised October 2005 by K. Burger

Oxygenation Ventilation- air moves in & out of lungs External respiration-exchange of O2 & CO2 between alveoli and blood Gas Transport- blood transports O2 & CO2 to body cells Internal respiration- exchange of O2 & CO2 between blood and cells. Internal- exchange of O2 and CO2

Checkpoint T / F The pulmonary artery carries oxygenated blood away from the lungs. The pulmonary ARTERY carries un-oxygenated blood from the heart (R Ventricle) to the lungs The pulmonary VEIN carries oxygenated blood away from the lungs WHERE does it go???? L Atrium and L Ventricle and then AORTA to body FALSE

Factors Affecting Respiration Integrity of the airway system (ventilation) Functioning cardiovascular system (perfusion) Functioning alveoli (diffusion) Functioning medulla & chemoreceptors Ventilation- Physical movement of gases into and out of lungs Perfusion- passage of blood through the pulmonary circulation. Amount of blood flowing thru lungs effects amount of O2 & CO2 exchanged. Diffusion- passage of gases thru the resp. membrane from the alveolar sac to the capillaries and back. Medulla- brain stem: stimulated by Inc. CO2 will cause an inc. ht. Rate to blow off CO2 and this inc. O2 levels Chemoreceptors- sensitive to inc. CO2 in arterial blood gas level activates medulla.

Pulmonary Ventilation Inspiration- air flows into lungs Expiration-gases flow out of lungs According to pressure gradiant – Boyle Intrapulmonic or intra-alveolar pressure- pressure within alveoli (fluctuates: Inspiration 759mm Hg Expiration 761mm Hg) Intrapleural pressure-pressure within the intrapleural space (always negative) (756 mm Hg) Note: Atmospheric Pressure = 760 mm Hg Respiration depends on volume changes within the thoracic cavity. A change in the volume of air leads to a change in the air pressure, since gases always flow along a pressure gradient , a change in pressure results gases flowing into or out of lungs to equalize pressure. BOYLES LAW – volume of gas at a constant temperature varies inversely with the pressure FLOW from higher pressure to lower pressure INSPIRATION – diaphragm (aided by accessory external intercostal muscles) contracts, pulling downward ABOUT 3-5 CM lengthening thoracic cavity – creates negative intra-alveolar pressure EXPIRATION – diaphragm relaxes, decreasing thoracic volume- creates positive intra-alveolar pressure ( greater than atmospheric air 760 mm Hg) INTRAPULMONIC OR INTRA ALVEOLAR PRESSURE – fluctuates with respiration Inspiration = 759 mm Hg, Expiration = 761 mm Hg INTRAPLEURAL PRESSURE – pressure in the space between 2 pleural linings. ALWAYS negative 756 mm Hg Exerts pulling pressure on alveoli to keep them inflated. TERMED a transmural pressure gradient PLEURISY = inflammation of pleural linings causes friction and pain. Fluid accumulation can decrease pressure resulting in reduced alveoli expansion

Factors Affecting Ventilation Lung elasticity / compliance (ability to stretch and recoil) Airway obstruction Musculature condition Neurological controls ELASTICITY – TWO ELEMENTS: Elastic Recoil- ability of lungs to return to normal after stretching Compliance – how difficult it is to stretch the lungs Decreased RECOIL = Especially in EMPHYSEMA; difficulty fully expiring air Decreased COMPLIANCE = normal aging and/or pulmonary fibrosis OBSTRUCTION – narrowing of airways NOTE: chronic obstruction ADDS to decreased recoil COPD Chronic Brochitis/ long-term inflammation leads to edematous linings and excessive mucous production Asthma/ thickening of airways and/or constriction of airways from histamine induced edema Emphysema / collapse of smaller airways and alveoli d/t destructive trypsin enzymes released by macrophages as defense mechanism in response to chronic inhaled cigarette smoke MUSCULATURE CONDITION Respiration controlled by medulla with messages sent to diaphragm. When respiratory center is depressed – decreased messages to diaphragm to contract If diaphragm or supplying nerve network is damaged – no contraction If overall condition of patient is extremely debilitated – decrease accessory muscle use

Checkpoint What is the name of the nerve that supplies the diaphragm? PHRENIC NERVE

Alveoli Gas Exchange Air reaches alveoli Oxygen from alveoli space moves into pulmonary capillary (oxygen uptake) via diffusion Oxygen diffuses across alveoli membranes moving from high concentration (alveoli) to lower concentration (pulmonary capillary) Partial Pressure Gradiants Partial pressure = individual pressure exerted by a particular gas in a mixture of gases Atmospheric Air 760 mm Hg 02 = 160 mm Hg ….. 21% N2 Nitrogen = 600 mm Hg….79% Arterial Blood PO2 = 100 mm Hg PCO2 = 40 mm Hg Represented by Pgas Ex: PO2

Alveoli Gas Exchange Surfactant- secreted by alveoli cells, keeps surfaces moist and prevents atelectasis Atelectasis- incomplete lung expansion or collapse of alveoli Lung Compliance- elasticity of lung tissue and flexibility of rib cage Lung recoil- ability of lungs to recoil Surfactant – A mixture of lipids and proteins secreted by Type II alveolar cells Interspersed among the water molecules in the liquid film that surrounds each alveoli Water molecules great greater surface tension – keeps alveoli stretched and maintains recoil Surfactant creates reduced surface tension: increases pulmonary compliance – reducing the work of inflation reduces the lungs tendency to recoil – alveoli do not collapse as readily Newborn respiratory distress syndrome – premature birth, not enough surfactant, greater effort to inspire Also adjacent alveoli exert outward pressure on each other – aiding the maintenance of inflation Lung compliance – normally very compliant and it takes less than 3% of our total energy expenditure to maintain quiet breathing In lung disease energy may be as high as 30% Recoil- lungs recoil after being stretched. In COPD there is decreased lung recoil leading to impaired respirations.

Other Factors Affecting Gas Exchange Surface area Thickness of tissue Fick’s Law of Diffusion: Rate of a diffusion of gas is dependent on surface area and thickness of the membrane FICKS Laws of diffusion Rate of a gas through a sheet of tissue depends on surface area and thickness of the membrane During heavy exercise and increased cardiac output many previously closed pulmonary capillaries are forced open. This increases the surface area of blood available for exchange Increased thickness can occur with pulmonary edema – buildup of excess interstitial fluid pneumonia – buildup of excess mucous and fluid

Perfusion Transport of O2 & CO2 via blood to tissue Volume of blood flowing through lungs affects amount of oxygen and gases exchanged Adequate blood supply and cardiovascular functioning are needed Oxyhemoglobin HbO2 (or SaO2) Need the circulatory system to assist respiratory processes Perfusion is dependent on having enough blood and functioning circulatory system to do the exchange Oxygen is poorly soluble in body fluids so it must be bound to hemoglobin for transport. The PO2 of the blood is not a measure of the total content of oxygen in the blood but only the dissolved portion Only 1.5% of oxygen is dissolved in blood Remaining 98.5 % carried on hemoglobin as Oxyhemoglobin HbO2 or SaO2 Inversely proportional ANEMIC HYPOXIA – reduced O2 carrying capacity CIRCULATORY HYPOXIA – blockage or shock HYPOXIC HYPOXIA – reduced atmospheric O2 ( high altitudes, suffocation) HISTOTOXIC HYPOXIA – HbO2 is OK but cells cannot use the oxygen supplied to them (cyanide poisoning)

Checkpoint The majority of CARBON DIOXIDE molecules are transported in the blood as: ??? BICARBONATE HCO3 60% = HCO3 30% on hemoglobin 10% dissolved in blood

Perfusion Rate of O2 transport depends on: Cardiac output Activity level CO2 transport Cardiac output- Stroke volume x heart rate= 5L/min of blood needed to circulate FACTORS THAT PROMOTE THE UNLOADING OF O2 FROM HEMOGLOBIN during increased cardiac output Exercise ( increased cardiac output) produces: Heat - metabolizing cell gives off heat and enhances O2 release from Hb Increased CO2 in the blood ( attaches to hemoglobin and decreases O2 affinity) aids unloading of O2 Increased acid in blood does same thing as CO2

Neurologic/Chemical Controls of Respiration Peripheral Chemoreceptors Central Chemoreceptors Medullary respiratory center Spinal cord Phrenic nerve Diaphragm Peripheral chemoreceptors located in CAROTIDs and AORTIC ARCH Sense the PCO2 levels in blood HYPERCAPNIA = increased CO2 levels in blood Central chemoreceptors located in medulla close to the respiratory center Increased CO2 in the blood cause release of H The central chemoreceptors then…. Sense the H concentration in brain extracellular fluid (NOT the CO2 level) to trigger respiration

Factors Affecting Oxygenation Environment Emotions Exercise Health Age Life style Medications Respiratory History Environment- work place, air pollution, smoke, clean chimneys, Sandblasting, Toxic fumes Emotions- upset trigger attack asthma/ stress cause dyspnea which increases stress… Exercise uses more O2, if resp. system not functioning to capacity increased exercise will cause inability to get enough O2 Health- Fluid overload ( renal and cardiac patients), severe and chronic illness-muscle wasting, anemia, skeletal abnormalities ( kyphosis, pectus carinatum, pectus excavatum, scoliosis ) and of course Respiratory Disorders Lifestyle- smokers/ second hand smoke. Medications- Depressant effect of narcotics. FYI O2 is considered a medication – need MD order Age – premature infant ( lack of surfactant) VERSUS elderly ( loss of lung tissue elasticity, decreased muscle tone)

Checkpoint What is the normal respiratory rate of a newborn? 30-60 breaths/min Vital Signs lecture notes SAY 40-60 Average adult = 16-20 They go down as we age

Assessing Respiratory Functioning Difficulty breathing? SOB? Chest pain? Coughing? Sputum production? Nocturnal diaphoresis Fatigue Sleep with 2 or more pillows?

Assessing Respiratory Functioning Respiratory Hx includes: Allergies Medications Medical Hx Smoking Lifestyle / Activity Level Stressors Recent exposures Developmental level Allergies to cats/ dogs/ meds/food environment Meds- take to tx resp problems…inhalers/ cough suppressant/ decongestant Hx- asthma, TB, bronchitis, lung Ca COPD Cardio vascular disorders/ chronic illnesses Smoking PPD? Lifestyle-active, couch potatoes, can climb stairs without being SOB? Stress –what brings on stress….effects breathing…Take a deep breath….i.e. at the dentist “breathe” Exposure post 9/11 air particles/ Iraq sand/dust Fireplace foe 2 weeks at the ski lodge Dev.- infants prone to specific resp problems differ from elderly COPD

Assessing Respiratory Functioning Patient states difficulty breathing: you can assess by using PQRST P- provokes Q- quality R- region/radiation S- severity scale T- timing P- when I’m near the cat Q- I get SOB and wheeze R-Tightness in my upper chest S-7-8 on scale of 1-10 (worse) T- it lasts till I take my inhaler

Assessing Respiratory Functioning Respiratory Rate: Tachypnea R>24 Bradypnea R<10 Apnea Respiratory Depth: Deep - diaphragmatic Shallow normal easy respirations 12-20 Tachy = respirations greater than 24/min rapid and shallow FYI: Hyperventilation = increase in both rate and depth ( extreme exertion or anxiety ) _ Brady = respirations of 10 or less/min decreased but regular FYI: Hypoventilation = decrease in both rate and depth ( shallower than brady ) = overdose of narcotics Apnea – no respirations

Assessing Respiratory Functioning Respiratory Rhythm: Regular – “even and symmetrical” Cheyne-Stokes Kussmauls Biot’s (ataxic – without rhythm) Apneustic breathing (gasping) Normal even and unlabored C/S= shallow then increases then decrease and stop then shallow… related to decreased neuro response to CO2 K- deep rapid – metabolic Acidosis B – like Cheyne stokes except regular rhythm interspersed with periods of apnea Also called ATAXIC A- sustained inspiration effort with strained expiration – gasping

Assessing Respiratory Functioning Respiratory Quality: No difficulty- Eupneic/ Unlabored Dyspnea Orthopnea Retractions Use of accessory muscles Auscultation: Vesicular Bronchial Bronchovesicular D- difficulty O- leaning forward support by overbed table, tripod position R intercostals muscles between ribs pull in Accessory muscles = abdominal, scalene, sternocleidomastoid, trapezius, pectoralis Vesicular- heard over most of lung field I>E Bronchial- heard over trachea and larynx I<E Broncovesicular Bronchi I=E

Assessing Respiratory Functioning Adventitious Sounds: Crackles: fine,medium,coarse Wheeze: sibilant,sonorous Stridor Stertor Pleural friction rub Cough: Nonproductive Productive Sputum Hemoptysis ADVENTITIOUS SOUNDS AUDIBLE VS AUSCULATATED Sputum Yellow/Green = bacterial infection may also be blood streaked Mucoid = viral infection Slight but persistant blood streaking = carcinoma Larger amts of blood and purulence = TB Fine crackles (hairs between fingers)- end of inspiration/ not cleared by coughing Medium crackles – lower and moister sounding midstage of inspiration/ not cleared by coughing Course crackles – loud and bubbly, during inspiration/ not cleared by coughing Wheeze Sibilant = squeaky on inspiration and expiration/ louder on expiration Sonorous ( Rhonchi) = snore like on inspiration and expiration / may clear with cough Stridor- high pitched sound croup = acute airway obstruction Stertor- snoring noise Pleural Friction Rub = dry, grating/ inflammation of pleura/ inspiration and/or expiration/ heard laterally Breath sounds

Respiratory Assessment Review Oxygen delivery method correctly applied Obtain a pulse oximetry reading (norm is >95%) Check Vital Signs ?T ?P ?R Auscultate the pt’s lungs Note changes in skin and mucosa color Assess capillary refill

Checkpoint What are some other elements of a respiratory assessment not yet mentioned? Neurological state Color + tactile fremitus Voice sounds Decreased diaphragmatic excursion Nail clubbing AP vs Transverse Diameter Barrel Chest?

Assessing Respiratory Functioning Diagnostic tests: Sputum Nose/throat cultures CBC (complete blood count) ABG (arterial blood gases) CXR (chest x ray) PFT (pulmonary function tests) Pulse Oximetry http://www.oximeter.org/pulseox/principles.htm Other: Scopes, CT, MRI, PET SPUTUM- cells expelled from the lungs tested for: Cytology OR Culture Best obtained in AM, no saliva, Sterile cup with cytology liquid ( 50% alcohol) Nose/Throat Cultures- determine if pathogen is present & antimicrobial that it is sensitive to to destroy it: Strep/MRSA CBC- determines RBC/ Hbg etc effects oxygenation ABG: provide physiological functioning of respirations… PaO2-partial pressure of O2 in arterial blood. Decreased levels indicate insufficient Norm = 100mmHg PaCO2 partial pressure of CO2 Norm = 40 mm Hg CxR- lungs examined via x-ray PFT- measures volume of air in lungs used to Dx and Tx & monitor resp system/ inspiratory and expiratory volumes Pulse Ox- light waves measure SaO@ noninvasive . SaO2 % or Sp02 = saturated O2 on Hgb in arterial blood 95-100% Less than 85 severe hypoxia Based on the red and infrared light absorption characteristics of oxygenated and deoxygenated hemoglobin. Oxygenated hemoglobin absorbs more infrared light and allows more red light to pass through. Deoxygenated (or reduced) hemoglobin absorbs more red light and allows more infrared light to pass through. Caution with anemic patient – lo Hgb but all saturated CLICK ON WEBSITE http://www.oximeter.org/pulseox/principles.htm Bronchoscopy- scope used to visualize inside the lungs. Direct visualization CT/MRI/PET –scans imaging used to Dx resp. disorders/pathology Indirect visualization

Alterations:Respiratory Functioning Hypoxia Hypoxemia Hyperventilation Hypercapnia Obstructed airway Foreign body obstruction (FBO) Hypoxia- prolonged oxygen deprivation Hypoxemia- decreased blood oxygen concentration Hypervet- deep rapid respirations Hypercapnia- CO2 retention O/A- airway partially blocked diminished airflow, tongue/ edema/ FBO- meat/ toys/ coins food

Nursing Interventions Independent Airway maintenance Positioning Deep breathing & coughing Pursed-lip breathing Abdominal/diaphragmatic breathing Hydration Teaching of health habits ABC’s always maintain open airway to promote oxygenation… Hyperextension of neck ( unless otherwise contraindicated) Artificial airway if necessary: Oropharangeal keeps tongue from obstructing airway – post op Nasopharangeal- used for frequent suctioning without nares trauma Endotracheal-inserted via nose or mouth into trachea Tracheostomy- surgical procedure to open airway via trachea Positioning- allow for increased expansion of thoracic cavity…high fowlers/ orthopneic DB&C raises sputum to maintain airway ..take deep breath thru the nose ( warms /filters air) and cough with force…may have to splint abd…. DB done alone to increase more efficient respirations Pursed-lip- slowly inhale thru the nose exhale thru lips close together. This maintains positive pressure in lungs, prevents atelectasis and promotes fuller exhalation phase A/D breathing- helps decrease resp. rate and increase volume. Place hands on abd/diaphragm, inhale slowly thru nose , inflating abd. As much as possible, exhale thru pursed lips while hands press on abd. Hydration- need fluids to thin secretions so they are more easily expelled. Habits- Teaching life style changes, no smoking, control asthma, monitor environment.etc..

Nursing Interventions Collaborative/Dependent Incentive spirometry Percussion/postural drainage Suctioning Oxygen therapy Medications I/S-allows for sustained maximum inspiration. More air in greater the oxygenation. Exhale, insert mouthpiece, inhale deeply to make ball rise in chamber, remove mouth piece exhale thru pursed lips. Perc/PD- promotes drainage of secretions, Perc.- cupped hands beat firmly on chest. PD –Place client in various positions to promote lung drainage ( also known as chest physiotherapy.) Most often performed by Resp Therapy Suctioning- clears secretions from airway. Using a device secretions are removed . Catheter placed in mouth, nose or lungs and secretions are sucked out. PLEASE REVIEW THE PROCEDURAL OUTLINE ( OROPHARYNGEAL/NASOPHARYNGEAL SUCTIONING, ADMINISTERING OXYGEN) IN YOUR TEXTBOOKS PRIOR TO LAB SESSION OT –provides supplemental oxygen (will discuss further) Meds- various meds can assist pt. To breath easier thereby increasing their oxygenation (will discuss further) IE: bronchodilators, antihistamines, mucolytics, corticosteroids

Nursing Interventions Collaborative/Dependent Oxygen Therapy Indications Sources- wall outlet or portable tank Monitor pulse oximetry Methods- cannula, mask, venturi mask, tent/isolette,BiPAP, CPAP Will discuss in lab. Sources- wall outlet, or portable tank. O2 is released under pressure and a regulator is needed to achieve the desired amount of O2 Measured in L/min or % depending upon the type of delivery system. Often attached to humidification Methods- LOW FLOW – provides only part of the patients total inspired air Nasal Cannula- convenient/pt can talk and eat/causes nares to dry ( 2-3L ) Simple Mask – short time period ( 12 hrs or less ) / higher delivery ( must be 5L or more to avoid CO2 retention) Re-breathers– collects some of expired air increasing overall O2 delivery HIGH FLOW- provides total inspired air and consistent oxygen delivery Venturi – Large tube narrows as it enters the mask creating air to be sucked into side ports ( keep unobstructed). Delivers a more precise volume of O2 Mask problems: claustrophobic, moist air and skin breakdown Tent- plastic tent / w/ children doesn’t provide accurate concentration. CAUTION IN COPD PATIENTS!! Normally the stimulus to breathe is excessive CO2 levels in blood but in COPD the chemoreceptors become de-sensitized to the excess CO2 and these patients respond to HYPOXIA ( low O2 levels ) for stimulus to breathe. If O2 therapy is administered too high this stimulus is removed and pt may stop breathing. Usually no more than 2L

Administering Oxygen Therapy Flow rate Humidification Hydration Positioning Safety precautions Document MD order required O2 is a drug must be prescribed Flow rate- prescribed by MD L/min or % ( % = the Fraction Inspired Oxygen or FiO2) Humidification- keeps mucus membranes moist Hydration is important because O2 is very drying to the mucus membranes, nares is using N/C, mouth masks Positioning, using semi to high fowlers Safety precautions discuss next. Document in nurses note or flow sheet, pt. Respiratory status, amount O2/min , how administered, any problems,

Oxygen Safety Precautions Signs: “No smoking. Oxygen in use.”  Remove matches, lighters and cigarettes.  Remove and store electrical equipment to avoid sparks. Ground electrical equipment.  Avoid materials that generate static electricity  Avoid use of volatile, flammable materials, such as alcohol. Know location & use of fire extinguishers & alarms.

Nursing Interventions Medications Nebulizer Tx Cough suppressants Mucolytic: expectorants Bronchodilators Corticosteroids Tx- apparatus produces fines spray/mist of medications administered directly into the lungs bronchodilators open the airway to provide better oxygenation Cough suppressants- stops coughs can be liquids/ lozenges/drops/ etc. Coughing can prevent pt. From sleeping, can cause further respiratory distress Expectorants- thin secretions making it easier to expel Bronchodilators- open narrow passage ways Corticosteroids – reduce inflammation

Documentation Routine Nurses Note Date Time LOC Rate Depth Rhythm Breath sounds (auscultated) Quality Color 1/5/05 10:23pm A & O x 3 Respirations 14 deep,even & unlabored, vesicular breath sounds clear, bilaterally, no cyanosis.

Nursing Diagnosis Ineffective airway clearance Risk for aspiration Ineffective breathing pattern Impaired gas exchange Risk for suffocation Ineffective tissue perfusion; cardiopulmonary Impaired spontaneous ventilation Dysfunctional ventilatory weaning response

Ineffective airway clearance Checkpoint Select a priority nursing diagnosis for the following scenario: 88 y.o. female with pneumonia who has a non-productive cough, R= 24, course crackles upon auscultation. She is weak, undernourished and fatigued. Ineffective airway clearance

Checkpoint Select a priority nursing diagnosis for the following scenario: A patient with hx of emphysema with decreased PO2, increased CO2 levels who is dyspneic and restless. Impaired Gas Exchange

Ineffective Tissue Perfusion; Cardiopulmonary Checkpoint Select a priority nursing diagnosis for the following scenario: A patient admitted to the ER post MVA with notable blood loss, BP= 80/50, P=120, R=22 Ineffective Tissue Perfusion; Cardiopulmonary

Summary: Oxygenation Oxygenation based on ventilation/perfusion/diffusion of oxygen Various factors effect oxygenation Assessment includes respiratory Hx, clinical exam, diagnostic tests Interventions include airway maintenance /proper breathing/ oxygen therapy/meds