-
Lab Levels
- PaO2- 80-100 normal (if norm)
- Rule of pH 7.40
- < 7.40 acidios
- > 7.40 Alkalosis
- pH 7.35-7.45
- < 7.35 acidios
- > 7.45 Alkalosis
- PaCo2- 35-45
- < 35 alkalosis
- < 45 acidios
- HCo3- 22-26
- < 22 acidios
- > 26 alkalosis
-
Ventilation
- Process of moving air in and out of the lungs
- affected by
- - compliance- elasticity/expandability- seen in elders- stiffens
- - surface tension- surfactant (alveoli gas xchx)
- - muscular efforts- inspiration
- ventilation facilitates the process of respiration, without ventilation- no respiration
- lining of alveoli- surfactant outer lining. macrophage- WBC helps to fight infection
-
respiration
is the process of xchanging gases, mainly oxygen and carbon dioxide
-
respiration controlled by
- CNS- medulla and pons responds to:
- - respiratory rate and depth (air moving in and out, problem here cause shallow breathing, retaining co2)
- - O2 and CO2 in the blood
- Determines- inc/dec the rate/depth of resp
- Musculoskeletal structures- influences respiration
- - intercostal/thoracic mus
- - diaphragm
- reflex control
-
Gas Exchange
- when a gas is exposed to liquid-dissolves in liquid until equilibrium is reached
- the dissolved gas also exerts a partial pressure
- O2 diffuses in the bld, until the the pp of O2 in the bld is the same as in alveoli- 104mm Hg
- In lung, Co2 diffuses out of venous bld to alveolar gas. in equilibrium both pp of Co2 in the bld/alveolar has is same 40mm Hg
-
Oxyhemoglobin dissociation curve
- 97% of o2 is bound to Hgb in ferrous iron-oxyhemoglobin
- 5 shaped curve
- as slope steepens chanes in PaO2 causes changes in O2 stat
-
oxyhemoglobin dissociation curve
- right and left shift
- Right shift
- "lets go"
- adequate oxygenation
- - acidosis
- - hypercapnia
- - hyperthermia
- - Anemia
- - Chronic hypoxia
- (helps release o2 to tissue, move o2 from blood to tissue)
- Left Shift
- "holds on"
- tissue hypoxia
- - alkalosis
- - hypocapnia
- - hypothermia
- - Co poisoning
- ( holding on to O2 and not moving tissues)
- this one is bad- ABG
- - pull PaO2 to negative
- - < 80
- think of being stingy
-
ventilation/perfusion ratios
- adequate gas exchange depends on adequate ventilation perfusion- VQ ratio
- Dead space- ventilation exceeds perfusion
- - Alveoli lacks adequate blood supply for gas exchange: PE
- Shunt- perfusion exceeds ventilation, shunt exists
- - bld bypass alveoli without gas exchange, pne, atcleectasis
-
response to injury
- injury to lung barrier increases vascular permeability and causes pulmonary edema
- inflammatory cells (neutrophils) arrive, macrophages inc
- lung repairs itself by lymphatic drainage, phagocytotic removal
- with more severe disease, type II cells are generated to differentiate into Type I
- the lung's ability to regenerate determines ability to return to normal function
-
Changes with age
- alveoli less elastic
- cilia slow in movement- inc risk for infection
- chest wall stiffens
- respiratory muscle weakens
- co- morbidities
- age, sex is very important
- - htn
- - dm
- - hyperlidemia
- - copd
-
Resp assessment
- chief compliant
- dyspnea- very commons subjective/objective
- cough- onset, duration, frequency, character
- sputum- color, odor, quality, quantity
- wheezing
- stridor- ** respiratory distress
-
respiratory assessment
- symptoms
- Chest Pain CP
- pleuritic CP sharp, stabbing, inc w/deep breaths,dec w/sitting and leaning forward, does not radiate
- associated symptoms- chills, fever, night sweats, anorexia, wt loss, fatigue, hoarseness
- PMH- childhood and infectious diseases
- - immunization (tdap)
- - meds, allergies
-
resp assessment
- fam hx, psycho hx
- Fam Hx- genetic, infectious, smokers
- psychosocial hx
- - occupation/enviromental factors- dust, asbestos
- - geographic location, travel
- - environment- crowding
- - habbits
- - excerise
- - nutrition
-
resp assessment
- inspection
- color condition of skin (pay attention to pt color)
- level of comfort, dyspnea, accessory muscles
- AP diameter- kyposcoliosis- "hunchback"
- - barrel chest- AP transverse diameter
- - pigeon chest- sternum juts forward
- - funnel chest- sternum
-
respiratory assessment
- inspection 2
- respirations- rate, rhythm, depth, pattern, retractions
- fingers/toes- color cap refill, clubbing
-
Resp assessment
- palpation
- trachea- masses, crepitus, deviation
- chest- creptitus, tenderness, edema
- tactile fremitus- vibration with voice
- - pne- this would be abnormal
-
resp assessment
- percussion
- resonant- low pitched, hollow normal
- hyperresonant- incr air-pneumothorax
- dull- dense lung tissue
- flat- airless tissue
- tympanic- air filled
-
respiratory assess
- auscultation
- normal, vesicular, bronchial, bronchovesicular
- - crackles- wet- lasix
- - rhonchi
- - wheeze- albuterol steriods
- - stridor
- - pleutal friction rub
- - voice sounds- brochophony, egophony, whispered pectriloquy
-
Diagnostic test
- PFT
- Pulse oximetry
- PFT- pulmonary function test
- - measure lung volumes
- - peak flow meters
- - no smoking or bronchodialators 6hrs before
- Pulse oximetry
- - should not be tape tightly- affects circulation
- - less accurate with thick, artificial nails, dark skin color, anemia and dec perfusion ** check the patient first
- - inaccurate with CO poisoning
-
Peak flow meters
- Pt should know their best peak flow- should be > 80% (80-100) green
- yellow- 80-60
- Go to the ER if peak flow < 50% of best peak flow
- if symptoms are worsening- meds not working
- measure forced expiration
- inhales deep in lips around meter, exhales hard and fast
- explain how to clean, why it is important to know your personal best
-
diagnostic test
- capnography
- measure exhale co2
- capnography waveform/co2 values- useful in determining pt ventilatory status
- co2 inc pay attention to pt breathing
- rate/depth- this helps to get rid of co2
-
diagnostic test
- Acid-base balance ABGs
- an arterial blood gas test measures the acidity ph and the levels of O2 and Co2 in the blood from an artery. this test is used to check how well the lunges are able to move O2 in the blood and remove Co2 from the blood
- arterial- radial, brachial, femoral, A-line
- pressure to site- 5-10 minutes after
-
PaO2- hypoxemia
- abnormal low partial pressure o2 in the arterial blood
- - norm 80-100
- - mild hypoxemia < 80 on RA
- - moderate hypoxemia < 60 on RA
- - severe hypoxemia < 40 RA
-
pH
- the pH is a measurement of the acidity or alkalinity of the blood
- normal pH 7.35-7.45
- in order for normal metabolism to take place the body must maintain this narrow range at all times
- - < 7.35 acidosis
- - > 7.45 alkalosis
- body regulates acid-base balance to maintain normal pH through buffer mechanism b/w respiratory and renal systems. - monitors pH keeps the body balance
-
ABG's- respiratory lungs buffer response
- a normal by product of cellular metabolism is CO2. Co2 is carried in the bld to the lunds where excess Co2 combines with H2o to form cabonic acid (H2CO3)
- the bld ph will change according to the lebel of carbonic acid present. this triggers the lungs to either inc or dec the rate/depth of ventilation until the appropriate amount of Co2 has been re-estab.
- lung activation- 1 to 3 mins
- too much co2 brain triggers- tells thoracic cavity to deep breath to let Co2 go
-
ABG metabolic buffer response
- in an effect to maintain ph in a norm range in the blood the kidneys excrete bicarbonate HCO3)
- as the ph dec the kidneys compensate by retaining HCO3. as the ph rises the kidnets releases HCO3
- this is great way to balance this out. it could take hours or days to correct imbalance
- when the resp and renal system are working together they are able to keep the ph blood balance by maintaining 1 part acid to 20 part base
-
key concepts
- the only 2 ways an acidotic state can exist is from either too much pCO2 or too little HCO3
- the only 2 ways alkalotic state exist is from either too little pCO2 or too much HCO3
-
acid-base disorders- respiratory acidosis
- defined ph < 7.35 and pCO2 > 45
- acidosis- caused by accumulation of Co2 which combines with the water in the body to produce carbonic acid thus lowering the ph in the blood
- any condition that results in Hypoventilaiton can cause respiratory
- acidosis
- condition include:
- - CNS depression, d/t head injury, meds, narcotics, sedatives
- - pulmonary disorders: atelectasis, pne, pul edema,
- - hypoventilation d/t pain
- CO2 too high- co2 narcosis- drowiness/unresponsive
-
ABG respiratory alkalosis
- defined as Ph > 7.45, pCo2 < 35
- hyperventilation
- these condition-
- - anxiety or fear
- - pain
- - meds- respiratory stimulants
- - cns lesions
- tx of this centers around resolving underlining problems
- incr work with breathing and must be monitored closely for resp muscle fatigue
- when the respiratory muscle become exhausted acute resp failure may ensue
-
ABg's metabolic acidosis
- defined as
- Ph < 7.35 and HCO3 < 22
- caused by a deficit of base in the bloodstream or excessive acid other than co2. diarrehea and intestinal fistula may cause dec levels of base
- Causes of inc acids include:
- - renal failure, diabetic ketoacidosis, anaerbic metabolism, starvation
- s/s:
- - neuro- h/a, confusion, restlessness, lethargy, stupor, or coma
- - cardiovascular- dysrhythmia, warm flushed skin
- - pulmonary- Kussmaul's respirations
- - gi- n/v
-
ABG metabolic alkalosis
- defined by Ph > 7.45 and HCO3> 26
- excessive base or loss of acid in the body
- excessive base occurs of ingestion of antacids, excess use of bicarbontate or use of lactate in dialysis
- loss of acid can be secondary to vomiting or gastric suctioning
- s/s:
- - resp depression, dizziness, lethargic, disorientation, seizures coma, weakness, muscle twitching, muscle cramps, n/v
- rx
- bicarbonate excretion through the kidneys can be stimulated with diamox or IV acids- severe cases
-
ABG- compensation
- explanation
- when a pt develops an acid-base imbalance, the body attempts to compensate. remember lungs and kidneys are the primary buffer
- the body tries to overcome either the resp or metabolic dysfunction in an attempt to return ph to normal range
- a pt can be compensated or uncompensated
-
ABG- compensation ***
- ** When both the PCO2 and HCO3 are abnormal indicates the compensation is occuring- ph is normal- this will give you direction
- ** when an acid-base disorder is uncompensated the ph remains outside the normal range 7.35-7.45
-
ABG compensation 2
- in compensated states the ph has returned to normal range, although the other values may still be abnormal. be aware that neither system has the ability to overcompensate
- attention:
- - if both the pCO2 and the HCO3 are abnormal but the ph is normal range, instead of using the norm range, use the single value of 7.40 as the normal so if ph < 7.4 is acidosis and ph > 7.4 is alkalosis
-
ABG uncompensated resp acidosis
- there is no compensation when the secondary organ system is still with in normal range
- Ph 7.16
- CO2- 78
- HCO3 25- normal this is the secondary organ system it would compensate for the repiratory acidosis by releasing more bicarbonate to lessen the acidosis. the kidneys have not yet compensated. uncompensated respiratory acidosis
|
|