Pulmonary Flashcards
What is a normal minute ventilation and how is it calculated? What does it mean if you increase your minute ventilation?
Normal 5-8L/minute
Tidal volume x RR
Increase work of breathing
What is the clinical indicator of ventilation? How do you know your patient is ventilating normally?
The PaCO2
What is the primary muscle of ventilation? What conditions affect this muscle?
Diaphragm
Deconditioning, hypoxemia, acidosis, hypophosphatemia
What is alveolar dead space? What condition increases it?
Alveolar dead space is pathologic and is the area of non-perfused alveoli
PE increases alveolar dead space- no blood flow past the alveoli in the area of the pulmonary circulation
What is pulmonary perfusion? What conditions affect perfusion?
It’s a movement of blood through the pulmonary capillaries.
PE, low cardiac output- any decrease in blood flow past the alveoli will affect the ventilation/perfusion ratio and gas exchange.
What is a normal Ventilation/ Perfusion (VQ) ratio?
4L ventilation/min/ 5L perfusion/min
Ideal lung unit =0.8
A patient is experiencing a large right lung PNA. What side should the patient lay on to prevent hypoxia?
“You want the GOOD lung down”
Turn pt to left side
What is V/Q mismatch? What causes it and how do you treat a V/Q mistmatch?
Is when there is excessive blood flow in relation to ventilation OR ventilation with decreased perfusion
Causes: ARDS( shunting), PNA,mucus plugging
Treatment: give O2 and identify and treat the underlying cause
With shunting even providing 100%FiO2 will not correct the hypoxemia
What are the effects of PEEP?
- prevents expiratory pressure from returning to zero by keeping the expiratory pressure positive
- decreases surface tension of thr alveoli (preventing atelectasis)
- increases alveolar recruitment
- increases driving pressure- extending the time of gas transfer, allows for a decrease in FiO2
What is the PaO2? What is the normal?
Arterial oxygen. Normal 80 - 100mmHg on RA.
Less than 80 = hypoxemia
What is the SaO2, normal and relevance?
Saturation of arterial oxygen
95- 99% on RA
Direct relationship with PaO2: amount of hemoglobin combined with O2
What is an SvO2, normal, relevance?
Mixed venous o2 saturation
60-75%
Most sensitive indicator of oxygenation at the cellular level
What is CaO2, normal and relevance?
Oxygen content
15-20ml/100 ml blood
Severe anemia may result in hypoxia
What is DO2, normal, relevance?
Oxygen delivery
900 to 1,100 ml/min
Pump problem ❤ will decrease the DO2
What is the alveolar arterial gradient (A-a)?
<10mmHg
Calculates the difference between the alveolar oxygen and the arterial oxygen. Indicates whether the gas transfer is normal and if not how bad the VQ mismatch or shunt is
According the oxyhemoglobin dissociation curve, what clinical conditions shift the curve to the left?
“Left is aLkaLosis, coLd, Low Bad for patients; SaO2 is high but the O2 is stuck to the Hgb”
Alkalosis
Low PaCO2
Hypothermia
Low 2,3 DPG
According the oxyhemoglobin dissociation curve, what clinical conditions shift the curve to the right?
” Good for tissues; SaO2 is low but the O2 is easily released to the tissues”
Acidosis
High PaCO2
Fever
High 2,3 DPG
What clinical conditions causes a decreased affinity of 2,3 DPG?
Multiple blood transfusions of banked blood
Low phosphate
Hypothyroidism
Results in less O2 available to tissues
What clinical conditions causes an increased affinity of 2,3 DPG
Chronic hypoxemia ( prolonged time spent at high altitudes, chronic CHF)
Anemia
Hyperthyroidism
Results in more O2 availability to tissues
A patient is experiencing carbon monoxide poisoning, their carboxyhemoglobin (COHb) level is approx. 50%. They are losing consciousness along with Cheyne stokes respiration. What nursing intervention are required for this patient?
100% FiO2 until symptoms resolve and COHb levels are less than 10%
Hyperbaric o2 chamber is available
What is static compliance?
Measurement of elastic properties of the LUNG
increase in plateau pressures will decrease compliance
Tidal volume ÷ plateau pressures (minus PEEP)
Normal 45 to 50
What is dynamic compliance?
Measurement of elastic properties if the AIRWAY
Tidal volume ÷ peak inspiratory pressure
An increase in PIP will decrease compliance
Normal 45 to 50
What are problems that can lead to metabolic acidosis/increase the anion gap?
M ethanol P ropylene glycol
U remia. I soniazid
D ka. L actic acidosis(shock,hypoxemia)
E thylene glycol
S alicylates
What are clinical symptoms of hypoxemic respiratory failure?
Tachypnea, adventitious breath sounds,use of accessory muscles, cyanosis ( central- lips and ear lobes)
What are signs of hypercapnic respiratory failure?
Shallow breathing, bradypnea, lungs may be clear or adventitious
Neuro- progressive LOC
What is the treatment for acute respiratory failure?
- Maintain airway and improve ventilation (bronchodilators if wheezing, positioning, ABGs)
- Optimize O2 (Decrease FIO2 to 50 or less)
- Optimize cardiac output and circulation (manage hypotension and arrhythmias)
- identify cause
- Provide emotional support
What are contraindications for NIV?
- Hemodynamic instability
- Copious secretions
- High risk for aspiration
- Impaired mental status
- Suspected pneumothorax
- Life threatening refractory hypoxemia (PaO2<60 with FIO2 at 100%)
A patient complaining of worsening dyspnea, sputum production and hypoxemia comes in. It appears as though they are experiencing a COPD exacerbation. What line of treatment is indicated for the patient? Are they a candidate for NIV?
A. Yes, provide O2 and sit them up
B. No d/t increasing sputum production
C. No. Titration O2 to PaO2 > 60, bronchodilators, corticosteroids and abx if indicated
D. No. Titration O2 until reach SaO2 of 100% give bronchodilators and corticosteroids
C ( bronchodilators - inhaled short acting beta agonists ie albuterol, inhaled anticholinergic)
Do not over correct the hypoxemia as it will decrease their respiratory drive
A patient presents with chest tightness, wheezing bilaterally, elevated WBC, eosinophils, and pulsus paradoxus (greater than 15mmHg) and CXR reveals a flatten diaphragm. What is the diagnosis for this patient and how do you manage them?
Status Asthmatics
Bronchodilators ( short acting beta 2 agonist albuterol)
Anticholinergic(atrovent)
Corticosteroids (systemic)
Hydration to prevent thickened secretions
When should you intubate a patient with status asthmaticus?
Ominous signs- respiratory acidosis, severe hypoxemia, silent chest, change in LOC
Your patient with a hx of status asthmaticus is intubated, they are causing a high pressure alarm on the vent and are dysynchronous with the ventilator. Should you paralyze the pt to aid in ventilator synchrony? What is causing thr high pressure alarm?
No paralytics! Because paralytics combined with steroids increase the incidence of neuropathy.
The high pressure alarm indicates- water or kink in the tube or secretions
What settings are recommended for an incubated patient with status asthmaticus?
Low rate to increase exhalation time
Low Tidal volume to prevent auto peep
Increase IE ratio ( inhalation/ exhalation) 1:3-4 to allow time for optimal exhalation and prevent auto peep
What are signs and symptoms of a PE?
Dyspnea, tachypnea Tachycardia, chest pain Right sided S3 or S4 heart sound Cough, hemoptysis, crackles Petechiae (fat embolism) Low grade fever Respiratory alkalosis
What are S/S of a massive PE?
Hypoxia
Hypotension
EKG changes - RBBB, Tall peaked P waves in lead II, ST elevation in V1 and V2
Cardiopulmonary arrest
What is the treatment and diagnosis of a PE?
Gold standard- pulmonary angiography
Treatment:
- maintain airway, ventilation and oxygenation
-fluids
-anticoags( heparin and Coumadin on first day treatment if able)
- fibrinolytic therapy for pt with low risk for bleeding
- maintain CO ( inotropes and fluids)
- pain management
Pulmonary HTN
Mean pulmonary artery pressure, PAOP, signs and symptoms
Mean PAP > 25mmHg
PAOP less than 16 mmHg at rest with secondary right heart failure
S/S:
exertions dyspnea
lethargy and fatigue due to an inability to increase cardiac output with activity
syncope with exertion,
hepatic congestion causing anorexia and abd pain
Increased intensity of pulmonary component of s2 heart sound
RV hypertrophy
Ortner’s syndrome ( cough, hemoptysis, hoarseness)
Treatment for Pulmonary HTN
Treat underlying cause
All regimens should consider: diuretics, O2, AC, digoxin and exercise training
Use dilators: Ca channel blockers and phosphodiesterase-5 inhibitors ( viagra, cialis, remodulin)
What are 4 factors that need to be evaluated to diagnose ARDS?
- Acute onset with precipitating factors
- Bilateral infiltrates consistent with pulmonary edema
- PaO2/FiO2 less than or equal to 200mmHg regardless of the level of PEEP
- PAOP less than or equal to 18 mmHg
P/F ratios - PaO2/FiO2
Examples:
Pt is receiving 50% fio2 and pao2 is 90
90 ÷ .5= 180
Pt is on 100% fio2 and pao2 is 95
95 ÷ 1= 95
What is the treatment for ARDS?
- *pulmonary stabilization
- PEEP 15 or greater but monitor for barotrauma and decrease in CO- limit plateau pressure to 30cm H2O or less
- low Tidal volume 5-6 ml/kg prevent volutrauma
- Cardiovascular stabilization
- support BP with fluids and pressure
- monitor for arrhythmias - Prone
- Prevent and identify organ failure
What are the ventilator guidelines for a pt with ARDS?
Plateau (static) pressure <30cm Low Tidal volume (5-6 ml/kg) High PEEP (15-20 cm)
Criteria for weaning from a ventilator
Resting minute ventilation (ideally <10L/min)
Spontaneous Tidal volume >5ml/kg
NIF > -25 cm H2O
Rapid shallow breathing index (RR/Vt) <105 breaths/min/L
Vital capacity ( above 10ml/kg body weight)
ABG/oxygenation acceptable with FiO2 50% or less
