Week 1- Respiratory Flashcards
(50 cards)
Physiology - Compliance
This is an indication of how well the chest wall and lungs can expand and collapse. If the patient has decreased compliance, it is more difficult to inflate the lungs
Physiology - Resistance
This relates to the size of the airway. The resistance of the airway increases when the diameter of the airway decreases.
Physiology- V/Q mismatch
When there are issues with ventilation and perfusion, the diffusion of gases is altered. This is called a V/Q mismatch.
Acute Pulmonary Oedema (APO)
Acute Pulmonary Oedema (APO) is a life threatening condition, caused by excess fluid in the lungs. It can be a complication observed in deteriorating patients who have a history of heart failure. That said, there are also other acute causes of APO.
Our lungs are usually kept dry by a combination of the following normal processes and forces, such as:
Lymphatic drainage involves various pressures, including hydrostatic, capillary oncotic, capillary permeability, and the presence of surfactants. These pressures help push fluid out of vessels, maintain capillary permeability, and prevent large molecules from entering alveoli.
Cardiogenic APO
one type of APO and can have heart failure as one of its causes. As the pressures in the heart increase cardiac output (CO) is decreased, as the ventricle must pump against an increased systemic vascular resistance (SVR).
Cardiogenic APO occurs when
Blood entering the left atrium from the lungs exceeds that leaving the left ventricle, causing increased pulmonary vein pressure and pulmonary capillary hydrostatic pressure. This leads to net filtration of fluid into interstitial spaces and alveoli.
Summary pathophysiology of APO
- Abnormal accumulation of fluid in the lung tissue, the alveolar space, or both
- Impaired gas exchange and decreased lung compliance
- Sudden onset of symptoms
- Requires immediate emergency management
Cardiac (cardiogenic) APO common causes:
- Heart disease/left ventricular dysfunction
- AMI (Acute Myocardial Infarction/ heart attack)
- Acute dysrhythmia (any abnormality of physiologic rhythm, either atrial or ventricular)
- Valvular insufficiency (cardiac disease characterised by the failure of the cardiac valves to close perfectly, resulting in blood flowing in the opposite direction; thereby, causing regurgitation or leakage)
Non-cardiac (non-cardiogenic) APO common causes:
- Capillary injury
- Obstruction of lymphatic system
- Blood transfusion/fluid overload
- Acute lung injury
- High altitude
Clinical Manifestions
- Sudden onset of extreme breathlessness
- Hypertension (because of hyper-adrenergic state)
- Tachypnoea
- Hypotension = severe LVF and cardiogenic shock
- Chest auscultation – crackles
- Diaphoresis
- Cough
- Raised JVP
- Pink frothy sputum present if alveoli injured
- Anxiety and agitation
- Cyanosis (late sign)
- Confusion
- Tachycardia
APO think
Why would the patient develop tachycardia? Well, the patient who is experiencing cardiogenic APO has a failing left ventricle. The left ventricle is unable to pump effectively and eject blood forwards (into the aorta). This means the patient has a reduction in their cardiac output (CO). If you think back to the equation cardiac output = stroke volume x heart rate (CO = SV x HR), then you can see that the heart rate needs to increase in order to maintain the cardiac output. This is one of the ways the body can compensate for a drop in cardiac output and explains why tachycardia occurs in cardiogenic APO.
APO Assessment & Management: airway
Partial obstruction of the lower airway (frothy sputum), Cough, Words/ short sentences. Resulting in need for suction
APO Assessment & Management: breathing
Shortness of breath, Tachypnoea, Increased work of breathing (WOB), Hypoxia, Adventitious breath sounds (crackles). Resulting in need to apply oxygen and postion patient upright
APO Assessment & Management: circulation
Hypertensive, Hypotension (cardiogenic shock), Tachycardia, Arrhythmia (cause), Pallor, cool and clammy skin. Check vital signs frequently, assess pain, IVC, pathology (VBG), ECG & cardiac monitoring
APO Assessment & Management: disability
Altered conscious state, confusion, Restless, anxious. Check GCS frequently, BSL, IDC and provide reassurance
APO Management
- Continuous reassessment: ABCD
- Respiratory: manage hypoxia
- Oxygen: maintain saturations
>94% (88-92% in COPD) - Ventilatory support: Non-Invasive
Positive Pressure Ventilation
(NIPPV)
- Oxygen: maintain saturations
- Cardiac: reduce preload and afterload
- Nitrates (GTN): Sublingually or
intravenous infusion - Diuretics (Furosemide):
Controversial. IV rather than oral - Morphine: Lack of good evidence
to support efficacy
- Nitrates (GTN): Sublingually or
- Aetiology: Treat underlying cause
NIPPV
- Ventilatory support for a spontaneously breathing patient
- Improves lung compliance
- Reduces V/Q mismatch
- Lowers intubation rates and reduces mortality rate
- Less expensive than intubation
- Fewer complications than invasive mechanical ventilation
Indications for NIPPV
- APO (cardiogenic)
- COPD acute exacerbation
- Moderate to severe respiratory distress
- Pneumonia
- Atelectasis
- Dyspnoea
- Accessory muscle use
- SpO2 less than 90%
- Increased respiratory rate (>24 for COPD)
- Respiratory acidosis (pH < 7.35, PaCO2 > than 45 mmHg)
Contraindications for NIPPV
- Uncooperative/ extreme anxiety/ depressed level of consciousness
- Unable to protect airway/ risk of aspiration (impaired swallowing or cough)
- Poor respiratory drive (Head injury)
- Haemodynamic instability
- Myocardial ischaemia/ unstable angina
- Copious respiratory secretions
- Difficulty fitting mask (Facial Trauma/ burns/ abnormalities)
- Pneumothorax
Complications of NIPPV
- Hypotension (↑ intrathoracic pressure, ↓ venous return, ↓ CO)
- Myocardial Ischaemia (↑ intrathoracic pressure, ↓ coronary perfusion)
- Altered conscious state (↓ CO, ↓ Cerebral perfusion)
- Risk of aspiration (vomiting)
- Gastric distension (swallowing air)
- Barotrauma
- Pneumothorax (↑ positive pressure)
- Pressure sores (mask)
Nursing Management of NIPPV
Response
- Monitor GCS for decrease Airway
- Monitor for patency
- Observe for secretions
- Check equipment including suction
- Aspiration risk
Nursing Management of NIPPV
Breathing
- Monitor RR / WOB / SaO2 / ABGs
- Assess speech pattern
- Talking in sentences / words / nil
- Auscultate chest
- Nurse in Fowlers position
- Repeated focussed respiratory assessment
- Monitor NIPPV delivery settings
- FiO2, PEEP, IPAP, flow rate
Nursing Management of NIPPV
Circulation
- Monitor HR
- Monitor BP
- Cardiac monitor
- ECG
- Monitor urine output
