Respiratory Failure Flashcards
(29 cards)
Define respiratory failure
Syndrome of inadequate gas exchange due to dysfunction of one or more components of the respiratory system
Which areas are most affected by respiratory disease?
North America and North Europe
What is the biggest risk factor for chronic resp disease in men vs women?
Men = smoking
Women = Household air pollution from sold fuels
Why is there limited data on Acute Respiratory Distress Syndrome (ARDS)?
Hetrogenous diseasae presentation
What are some of the reasons for ARDS? (5)
Pneumonia COPD Infective Exacerbation Worsening pulmonary hypertension CF
What 2 factors are associated with an increased ARDS mortality?
Advanced age and severity
What does the Berlin definition of ARDS classification consider?
Timing - within 1 week of known clinical insult or new or worsening respiratory symptoms
Chest Imaging - bilateral opacities not fully explained by effusion, lobar/lung collapse, nodules
Origin of oedema - resp failure not fully explained by cardiac failure or fluid overload
Need objective assesment to exclude hydrostatic oedema if no risk factor present
Oxygenation - mild -> severe based on PF ratio, when pts on positive end expiratory pressure of 5+
What causes acute respiratory failure?
Pulmonary: Infection, aspiration, primary graft dysfunction following lung Tx
Extra-pulmonary: trauma, sepsis, pancreatitis
Neuro-muscular: myasthenic crisis, Guillain-Barre Syndrome (GBS)
What causes chronic respiratory failure?
Pulmonary/airways: COPD, CF, lung fibrosis, lobectomy
Musculoskeletal: muscular dystrophy
What causes acute on chronic respiratory failure?
Infective exacerbation of chronic diseases -> COPD, CF
Myasthenic crises
Post operative with underlying resp disease
Define type I respiratory failure
Hypoxaemic, PaO2 < 60 at sea lvl: Failure of oxygen exchange Increased shunt fraction Due to alveolar flooding Hypoxaemia refractory to supplemental O2
What are some causes of type I resp failure? (6)
Collapse Aspiration Fibrosis Pulmonary hypertension Pulmonary oedema Pulmonary embolism
CAFHOE
Define type II respiratory failure
Hypercapnic,PaCO2 > 45 at sea lvl:
Failure to exchange or remove CO2
Decreased alveolar minute ventilation (VA)
Dead space ventilation
What are some of the causes of type II respiratory failure? (5)
Nervous system Neuromuscular Airway obstruction Muscle failure Chest wall deformity (e.g. following trauma, ageing)
Define type III respiratory failure
Perioperative respiratory failure
Increased atelectasis due to low functional residual capacity
Hypoxaemia or hypercapnoea
Frequently down to abdominal wall mechanics limiting the amount chest can open up
How can we prevent type III respiratory failure? (5)
Anaesthetic or operative technique
Incentive spirometry
Good postural positioning during extubation
Make sure muscle relaxant paralysis fully reversed
Analgesia -> stop tensing abdo muscles
-> attempts to lower intra-abdominal pressure
Define type IV respiratory failure
Shock - patients who are intubated and ventilated during shock
Poor perfusion of the lung - vasoplegic presentation -> pooling of blood -> reduced central return
What are the ventilatory effects on the right and left heart?
Reduced afterload - good for LV, stress across heart muscle reduced
Increased pre-load - bad for RV, increased thoracic pressure affects contractility
How do you treat type IV respiratory failure?
Optimise ventilation to improve gas exchange and to unload the respiratory muscles
-> lowering oxygen consumption
What are the chronic risk factors for resp failure? (6)
COPD Pollution Recurrent pneumonia CF Pulmonary fibrosis Neuro-muscular diseases
What are the acute risk factors of ARDS? (4)
Infection (virus, bacterial, both) -> superinfection with gram positive, toxin producing organisms
Aspiration
Pancreatitis
Transfusion
What can people with servere and progressive ARDS present with?
Infection with 2 different types of organisms
How can aspiration induce ARDS?
Acid causes trauma-induced inflammatory response
What are some common origins of shortness of breath? (5)
Lower respiratory tract infection Aspiration Trauma (transfusion) Pulmonary vascular disease Extrapulmonary
