PCTH - ACPE/CPAP Flashcards
What is acute cardiogenic pulmonary edema?
Fluid in the lungs (pulmonary edema) caused by increased pulmonary venous pressure leading to increased capillary hydrostatic pressure (which then pushes the fluid into the interstitium and alveolar spaces). This is due to pressures in your heart not being being adequate enough to pump blood out to the rest of the body, thus causing fluid to backup.
Acute Cardiogenic Pulmonary Edema Medical Directive
Indications
Conditions
Contraindications
Indications: moderate to severe respiratory distress AND suspected acute cardiogenic pulmonary edema (ACPE)
Conditions: for nitroglycerin
- Age: ≥18 y.o.
- LOA: n/a (because often these patients are hypoxic therefore may be altered) + you’re more relying on ax findings than hx
- HR: 60-159 bpm
- RR: N/A
- SBP: normotension
- Other: n/a
Contraindications:
- allergy or sensitivity to nitrates
- phosphodiesterase inhibitor use within the previous 48 hrs
- SBP drops by 1/3 or more of its initial value after nitroglycerin is administered
Acute Cardiogenic Pulmonary Edema Medical Directive
Treatment
Clinical Considerations
Treatment: see attached screenshot
- 1) Consider nitroglyerin
- 2) Consider 12-lead acquisition and interpretation
Clinical Considerations: IV condition applies only to PCPs authorized for PCP Autonomous IV
True or False. For a patient with ACPE, a maximum of 6 doses of nitro can be administered regardless of any previous administrations.
True
On arrival, how would you determine if a patient was having ACPE?
1) medical history
2) incident history
3) medications
4) Signs and symptoms
What sort of medical history are you looking for in a patient with suspected ACPE?
- CHF (right and left sided heart failure)
- some form of MI/CAD
- HTN
- High cholesterol
- A-fib
What sort of incident history would cause you to suspect ACPE?
- SOB that has worsened; may be getting worse with minimal exertion
- If on home O2, the O2 is not relieving the SOB
- coughing up print frothy sputum (later stages) - tell tale signs
- scene awareness - lived in area (food, garbage around) where they’re not moving from one location/can’t lay flat because it gets worse & they’re not moving around
What sort of medications would a patient be on that would cause you to suspect ACPE?
- HTN meds (ACE inhibitors)
- Beta blockers (-olol)
- CCB (-dipine) - amlodipine, diltiazem
- Lasix (diuretic)
- Nitro
Signs and symptoms of ACPE
- RHF: peripheral pitting edema, JVD (Due to backing up of blood; area that is accepting the blood is dysfunctional)
-
LHF: coarse crackles, pink frothy sputum (because blood not getting circulated from pulmonary circuit)
- crackles are bilateral and tend to start at the bottom, work their way up (if unilateral, may be pneumonia instead)
For a patient with suspected ACPE, do you have to do a 12 lead before giving nitro?
No. It’s not a requirement because RVIs typically do not present with ACPE however do get a 12 lead/15 lead when possible/practical to do so.
Also advised that if they’re also experiencing chest pain and pulmonary edema, do a 12 lead before giving nitro use.
If BP was initially ≥140mmHg and was receiving 0.8mg of nitro but then drops outside of parameters (now 120mmHg), are you still allowed to give nitro?
Yes. If BP is still within range, then you can switch from 0.8mg to 0.4mg doses.
Should a patient present with crackles receive Salbutamol? Why or why not?
NO. Salbutamol is a bronchodilator which means that it will drop the pressure in the lungs and make it easier for fluids to flow into the lungs causing worsened pulmonary edema. Additionally, since it works on beta receptors, it will also increase the patient’s HR but patient already has a shit pump to start with so salbutamol would just make things worse
There are times when wheezes could be an early sign of crackles. How do you then distinguish between a patient who is have an asthma exacerbations vs ACPE?
medical history (pt with CHF may likely be on home O2 and meds that point to heart-related while a pt who has asthma will likely have prescribed puffers)
Describe what physiologically occurs during inspiration
- diaphragm contracts (pushes downwards to increase thoracic space)
- Intercostal muscles contract (ribs go up and out to increase thoracic space)
- Creates negative pressure in the lungs (alveoli) compared to the atmosphere
- So atm air rushes in to fill the space
- Gas exchange then occurs by diffusion at the alveolocapillary membrane
The lungs exchange respiratory gases across a very large SA at the alveolo-capillary membrane, around ______ m2.
70
What is the Ventilation-perfusion ratio (V/Q)?
V/Q aka respiratory quotient - the relationship between ventilation and perfusion expressed as a ratio (explains the effectiveness of gas exchange i.e. how much oxygen and CO2 trade places) - IDEALLY 1:1 exchange but
normal is 0.8 meaning that under normal conditions, not all the air we get from ventilation is is 100% perfused (due to anatomical deadspace)
___ in every 100 Canadians suffer from CHF.
___% of all deaths in Canada are related to CHF.
1 in every 100
9%
The avg length of stay for someone hospitalized due to CHF (non-intubated) is ______.
Patients who do get intubated have a ____x higher mortality rate
7 day (length of stay)
4x
What is heart failure? Congestive Heart Failure?
Heart failure: a condition in which the heart cannot pump sufficient blood to meet the metabolic needs of the body
CHF: refers to heart failure with fluid in tissues
What kinds of patients would you use CPAP for?
COPD exacerbations
CHF
S/S of heart failure
- dyspnes
- HTN
- crackles, rarely wheezing
- anxiety, confusion, restlessness (due to hypoxia)
- fatigue, generalized weakness
- tachypnea
- Tachycardiac
- Diaphoresis
- Paroxysmal nocturnal dyspnea (SOB that happens at night)
- Orthopnea (SOB when lying down)
- Persistent cough (pink frothy sputum)
- Cyanosis (late finding)
__________ people are diagnosed with COPD yearly in Canada.
COPD is the ____ leading cause of death.
_______ dollars are spent every year dealingw ith COPD in emergency situations.
750 000 people
4th leading cause of death
1.67 billion dollars spent
What is COPD?
- lung disease characterized by obstruction of air flow: emphysema, bronchitis
- Characterized by:
- progressive, irreversible airway obstruction
- increasing severity of exacerbations
What physiological changes occur with COPD?
- Terminal bronchioles becomes increasingly compliant and collapse before emptying (results in gas trapping)
- Bronchiolar walls become edematous, surrounding smooth muscle become hyperreactive and ciliary dysfunction lead to clogging
- All this leads to lungs becoming progressively hyperinflated
S/S of COPD
- Dyspnea (common presentation) - dyspnea on mild exertion is 50% loss of lung capacity
- Wheezy
- Chest tightness/pain
- Cough/sputum production
- fatigue, depression, insomnia, confusion
- Smoking*
What is goal of prehospital CPAP?
It provides an effective way to treat CHF/COPD by:
- increasing Functional Residual Capacity (FRC): volume of gas remaining in lungs at end-expiration
- Distending alveoli preventing collapse on expiration & providing a greater SA improving gas exchange
What benefits are there for using CPAP for COPD patients?
Maintaining a constant level of pressure throughout the respiratory cycle:
- splints airways open, increasing the potential for gas exchange
- increase SA of alveoli, increasing the potential for gas exchange
True or False. CHF patients are euvolemic (normal fluid/blood volume).
True
What benefits are there for using CPAP for CHF?
- CPAP causes positive intra-thoracic pressure (So be cautious that there are not other indicators of chest trauma)
- Reduces R-sided cardiac output
- Fluid ceases to build up and may be reabsorbed
Would you use CPAP for asthma attacks? Why or why not?
No because in asthma attacks there is impaired inspiration and expiration leading to air trapping and increased intrathoracic pressure
Adding more pressure in via CPAP would hyperexpand the thorax and position the respiratory muscles to not be at optimal functioning (at a mechanical disadvantage)
What are the two available CPAP systems?
1) Boussignac CPAP System (MACS CPAP unit)
2) O2 CPAP
Components of the O2 CPAP system
Continuous Positive Airway Pressure (CPAP) Medical Directive
Indications
Conditions
Contraindications
Indication: Severe respiratory distress AND S/S of acute pulmonary edema or COPD
Conditions:
- Age: ≥18 y.o.
- LOA: n/a
- HR: n/a
- RR: tachypnea
- SBP: normotension
- Other: SpO2 <90% of accessory muscle use
Contraindications:
- asthma exacerbation
- suspected pneumothorax
- unprotected or unstable airway
- major trauma or burns to head/torso
- tracheostomy - because you won’t be able to get a seal
- inability to sit upright
- unable to cooperate - CPAP is aggressive tx so pt should be on board with this
Continuous Positive Airway Pressure (CPAP) Medical Directive
Treatment
Clinical Considerations
Treatment: see screenshot
- 1) Consider CPAP
- 2) Consider increasing FiO2 (if available)
- 3) Confirm CPAP pressure by manometer (if available)
Clinical Considerations: n/a
Advantanges of CPAP
- flexibility in initiating, interrupting, and discontinuing mechanical ventilation
- easy to use
- decrease need for ICU admission and hospital costs
- Improves patient comfort immediate relief
- psychological advantage to the patient
- preserves speech and swallowing, allow patient to communicate with family and staff
Common complications of CPAP
- discomfort and pressure sores (with long use)
- gastric distension (usually with pressures >10cm H2O)
- pulmonary barotrauma (rate of 0.5%) - increased pressure can cause alveolar rupture
- reduced cardiac output
- hypoventilation (results in CO2 retention)
- claustrophobic and noisy
- requires coaching and support
Flow rates for CPAP using the O2 system setup
