What is the physiological mechanisms that keep the hydrogen ion concentration (H+) of blood and body fluids compatible with life?
- Acid-base balance
The body generates __________________ _ so there must be a regulation that occurs to keep the balance.
hydrogen ions
___________________ _ are positively charged ions.
cations
___________________ are negatively charged ions.
anions
What must we have a equal mix of to have a balance?
- Equal mix of cations and anions. Think of them canceling each other out.
What is the Bronsted-Lowry theory say about:
Acid:
Base:
- Acid: any substance that donates a proton to aqueous solution
- Base: any substance that accepts a proton removing it from solution
If body fluids are acidic, they have abnormally high____________________ _.
H + concentration
What are increased H+ ions in the blood called______________________ .
acidemia
What is characterized by the accumulation of H+ in body fluids__________________ .
acidosis
What is the opposite of acidic______________________ .
alkaline
The term ________________ __ is synonymous with base.
alkali
What are body fluids that have abnormally high amounts of base or contain low amounts of H+_____________________________ _
alkaline or basic
The concentration of H+ in body fluids are extremely small. Equal to _________________________________ .
40 billionths of 1 mol per liter
Prefix nano refers to billionths, how would it be written_________________________ .
(We use pH rather than 40 nmol/L)
40nmol/l
Who developed the concept of pH?
He came up with a way to simplify the way pH was expressed.
Danish Chemist in 1909 (Sorenson)
What does the pH scale ranges from________________
0-14
What does chemists and professionals believe the p refers to _ ____________.
power
What is the pH defined as?
Negative logarithm or exponent of the H+
pH is the ______________________ , a ____________ _ in pH indicates an _ __ _______________________.
negative logarithm of H+
decrease
increase in H+
A chemically neutral solution has a pH of __ _____.
7.0
(In this case ONLY) A pH of anything less than 7.0 is considered____________ _ and a pH of anything higher is __ ___ __________.
acidic
alkaline
Hydrogen ions formed in the body arise from____ _ or __ .
volatile
fixed acids
The only volatile acid of significance is _______________________ .
carbonic acid (H2CO3)
What are fixed acids?
Sulfuric and phosphoric acids
What does anaerobic metabolism produce?
Lactic acid (also fixed acid)
How do we balance all of this?
Buffers
What is defined as resisting change in pH when acids or bases are added to it.
Buffer
What is one of the most important blood buffers?
Solution of carbonic acid and its conjugate base HCO3-.
What is a conjugate base?
Remaining anion portion of the acid molecule
Blood buffers are classified as either______________________ or ______________ buffer systems.
bicarbonate
non bicarbonate
What does the bicarbonate system contain?
Carbonic acid (H2CO3) and its conjugate base bicarbonate ions
Why is the bicarbonate buffer system considered an open system?
It is readily removed by ventilation
Nonbicarbonate buffer systems are closed. True or false
true
It is because all components remain in the system
How do we excrete the acid we make and rid ourselves of it?
2 primary organs:
2 primary organs: lungs and kidneys
If what did not happen the buffer systems would eventually be exhausted and pH levels would drop to life threatening levels?
Excrete the acid we make and rid ourselves of it through the lungs and kidneys
What is capable of excreting large amounts of acids within minutes?
lungs
What excrete fixed acids at a much lower speed. From hours to days compared to minutes.
kidneys
The kidneys excrete ________________ __of fixed acids per day.
less than 100mEq
These _______________ __ work together and can compensate when one organ fails.
organs
Normal pH is not affected by______ _ or _______ _.
age
gender
pH=___ _ ________
PaCO2=__________ _
PaO2=________________ _
SaO2%=_ ___________
HCO3-=__ _______
7.35-7.45
35-45 mmHg
80-100 mmHg
95-98%
22-26 mEq/L
What is defined as a blood pH> 7.45?
Alkalemia
What is defined as a blood pH < 7.35?
Acidemia
What is defined by a PaCO2 <35 mmHg
Hyperventilation
What is defined by a PaCO2 >45 mmHg
hypoventilation
What changes the arterial pH in a non respiratory way.
Primary metabolic disturbances
Non respiratory processes that cause acidemia/alkalosis produce______________ _.
What would be the compensatory organ.
metabolic acidosis or alkalosis
lungs
What can change the arterial pH as well causing a respiratory acidosis or alkalosis.
Primary respiratory disturbances
What happens when there is a acid base defect that occurs?
Organ system NOT responsible immediately initiates a compensatory process to counteract the defect.
If reduced ventilation is _______________________ _the kidneys will work to restore the pH to normal by retaining bicarb.
primary defect (respiratory acidosis)
It is important to know what issues that you could see in patients with_____________ and how to treat them to return to normal ________________ _ so they are not at risk for life threatening pH levels.
abnormal ABGs
pH range
What is abnormal low pH?
<7.0 will induce a comatose state or death.
What is abnormal high pH?
<7.80 cause convulsions, tetany, and death
What is specific to CVT pH?
- pH values around 7.10 will result in ventricular arrhythmias and reduce heart contractility.
What does tetany mean?
state of sustained muscle contraction/ spasm
What is step one of classification:
Classify the pH
- Acidosis (lower than 7.35)
- Normal
- Alkalosis (higher than 7.45)
What is step two of classification:
Inspect the PaCO2 (ask if the observed PaCO2 by itself can cause the pH abnormalities)
- Can you explain the pH?
What is step three of classification:
Inspect the bicarb (bicarb is logical factor of non respiratory involvement in acid base disturbances)
- Can you explain the pH
What is step four of classification:
Check for compensation(once identified if you have respiratory or metabolic abnormalities)
- Did the correct organ (lungs, kidneys) system respond? Or at least start to respond?
_____________________ has occurred when the pH has restored to normal.
Full compensation
Compensation can be considered __________ _ if pH is outside of the normal but the non causative component is also abnormal in a way that brings the pH back to normal range.
partial
What does it mean when there has not been enough time to correct the pH but it is moving toward the normal range.
Partial compensation
(PaCO2, HCO3 values high but pH is acidic)
What is the acid base disturbance is so recent that the compensation has not been started.
Uncompensated (pH abnormal, PaCO2 or HCO3 abnormal)
Even with the body’s compensation methods, we still need to treat the _______________________ .
underlying cause of defect
Compensation _____________ __ and ______________________ _ the pH to the normal range but if this is not a chronic condition it will only be a temporary fix.
corrects
restores
Always remember that monitors are to be used as _____________________ , never solely relied on!
adjuncts to assessment
Make sure you have:
- Adequate lighting
- Correct equipment
- Correct patient position
- Enough time
- A way to monitor time
- Complete objectivity
- Be understanding and sensitive to cultural diversity
Symptoms of pulmonary disease can also indicate _____________________ _.
other diseases
More critically ill patients are harder to assess, due to:
- Presence of multiple disease states
- Positioning of the patient
- Critical care environment
- Increased amount of equipment
- Equipment use obscuring physical signs of the disease or or patient’s present state
What is a cough?
- Sensation of irritation in the pulmonary system.
- Stimuli arising in any part of the airways from the pharynx to terminal bronchi
What is Productive vs. nonproductive
- Is there sputum produced?
- Elderly ↓ in productive coughs
- COPD pts.
Sputum evaluation:
Should be from _____________: not from _____________ or __________________
lungs
saliva or postnasal
- Clear
- odorless
- watery
Sputum eval:
- Volume
- Color
- Consistency
- Odor
Sputum examples:
Smokers and COPD:
- Copus
- thick
- mucoid
- grayish
Sputum examples:
Bacterial infections:
- Purulent
- foul smelling
- yellow-brown or green mucoid color
Sputum examples:
Pneumonia
Rusty or golden yellow color
Sputum examples:
Asthma
Clear/white mucoid
Sputum examples:
Hemoptysis:
- Lung Tumors
- Chronic bronchitis
- Pulmonary emboli
- TB
- Sputum is grossly bloody, blood streaked or w/ small pink clots
Sputum examples:
Cardiogenic pulmonary edema
- Pink , sometimes peach in color
- Frothy
- Pressure of ruptured capillaries
What is Dyspnea
- Act of breathing becoming difficult, needing conscious effort
- Appears as SOB
CNS mechanisms of dyspnea
Work of breathing and adequate muscle contraction
Emotional mechanisms of Dyspnea
Hysterical hyperventilation
Max breathing capacity Dyspnea
- 200L/min
- Minute ventilatory requirements
-
↑ exercise and ↓ COPD and
weaning off ventilators
Abnormal blood gases Dyspnea
- Hypoxemia
- hypercapnia
Dyspnea Caused by:
Inflow limitations
- Obstructive disorders ( Asthma, Chronic bronchitis)
Reduction in pulmonary
compliance (
ARDS,
Atelectasis)
Resistance to lung expansion
Pneumothorax
Pleural effusions
Pleural thickening
Inflammation
Increases in dead space
Pulmonary embolism
Respiratory muscle fatigue
Underlying disease
Obstructive conditions
Chest wall trauma
Ask patient:
When and how it started
Does anything help alleviate it?
You will be able to witness physical indications
Mouth breathing
Distressed or anxious
Rhythm of breathing
Flaring of nostrils and accessory muscle use (
Respiratory distress)
Rhythm of pt speech (Can they speak?)
Gasping
Test:
Ask pt to breathe in and on exhalation count to 10:
If they can’t get past 5 or get to 10
Extreme risk of respiratory collapse
Chest pain: Pulmonary
Upper retrosternal pain
Acute tracheitis
Chest pain: Pulmonary
Retrosternal pain (similar to chest pain (angina)
- Acute mediastinitis
- Pneumomediastinum
- Radiate to arms and neck
- Not related to exertion
- Differential EKG and cardiac enzymes
Chest pain: Pulmonary
Pleurtic pain > Stretching of inflamed parietal pleura
- Pleurisy
- Pulmonary embolism
- Sharp an stabbing > pericarditis similar (EKG, echo)
- Aggravated by exertion, deep inspiration or cough
Chest pain: Pulmonary
Musculoskeletal:
Chest wall deformities or injury
Signs of pulmonary disease
LOC: Level of consciousness
Alteration of cerebral function
Changes perception of reality as well
May require detailed questioning
Blood gas evaluation commonly
required
Hypoxemia > PaO2 < 60 mmHg
Hypoxia= reduction of blood supply to
tissues
Hypoxemia= reduction of oxygen in blood
Usually coexist
Can appear similar to signs and
symptoms of alcohol intoxication
Signs of cerebral hypoxia can be variable
Restlessness
Agitation
Confusion
Inappropriate sense of well being
Outbursts of hilarity
Paranoia
Irritability
Combativeness
Uncooperativeness
Loss of muscle coordination
Loss of visual acuity
CNS suppression
Stupor, Coma or seizures
Other clinical signs of hypoxia:
Tachycardia
Tachypnea
Dyspnea (possibly)
Ectopic arrhythmias
Atach
PACs
PVCs
Bradycardia is a very late and ominous
sign
Aggressive oxygen and airway treatment
Hypercapnia
PaCO2 > 45 mmHg
Resemble CNS depression
Anesthetics
Lethargy
Confusion
Slurred speech
Poor coordination
Somnolence
Stupor
Coma
Headache: cerebral vasodilation
Tachypnea
Respiratory acidosis
Vasoconstriction
Systemic vasodilation (severe)
Hypotension
Combined with hypoxemia
Signs of pulmonary
Respirations:
Rate, Rhythm and
character
Frequency: 12-20 breaths
per min.
Increase w/ fever, sepsis,
hypercapnia, hypoxemia,
acidemia, Emotional
stimuli, CNS lesion, pain
and pulmonary emboli
Dyspnea ≠ Tachypnea
RR > 28 Bpm= significant
respiratory distress
RR 28-34 Bpm= need for
intubation
Warnings of
cardiopulmonary collapse:
Warnings of
cardiopulmonary collapse:
RR> 30 Bpm
Neurologic deterioration
Restlessness, lethargy or
confusion
RR < 8 Bpm
RR low for underlying
conditions
Counting RR:
Auscultating each breath
By chest rise
(visualization):
Does not measure actual
breathing
Could be just effort
Count # of breaths in one
minute
Abnormal Breathing Patterns:
Kussmal’s breathing:
Rapid and deep
Infarction to midbrain
metabolic acidosis (DKA)
Cheyne-stokes: Decreased
rate and depth:
Brain damage
Severe cardiogenic shock
Drug induced respiratory
depression
Biot: long periods of
apnea:
Brainstem dysfunction
Agonal: irregular gasping
Occurs just before death
Depth of breathing:
Normal breathing= barely visible
Visible breathing= Min ventilation has at least doubled
Excessive deep breathing may indicate:
Brain damage
Head injury
Stroke
Symmetry of breathing:
Both sides of chest should move together normally
Lay pt. supine, chest exposed
Look @ infraclavicular, mid chest, lower ribs and abdomen.
Observations difficult in: May require palpation
Obese
Edema
Thoracic or abdominal dressings
Asymmetrical movement:
Pleural effusion
Obstruction of a major bronchus or loss of lobe (surgery)
Neuromuscular abnormalities (GB or MG)
Right main bronchus intubation:
Ventilates right lobe only
Left has diminished breath sounds
Requires chest X-ray evaluation