respiratory failure Flashcards
what is the key sign/symptom of resp failure
shortness of breath - due to inadequate gas exchange
what is resp failure
syndrome of inadequate gas exchange due to dysfunction of one/more components of resp system
what components is the respiratory system broken down into
nervous system
respiratory muscle
pulmonary
what parts of the nervous system are involved in resp failure
cns,brainstem - resp centre found in ventrolateral medulla
neuromuscular junctions
what muscles are involved in resp failure
diaphragm and thoracic muscles
extra - thoracic muscles
pulmonary components of resp failure
alveolar - capillary
circulation
any airway disease e.g copd,fibrosis
what is the 3rd leading cause of death globally (2017)
chronic respiratory disease
what is the biggest risk factor for chronic respiratory disease in men
smoking
what is the biggest risk factor for chronic respiratory disease in women
household air pollution from solid fuels
what is the criteria used to classify ards
berlin definition: timing imaging origin of oedema oxygenation
what stats tell us its mild disease
200 mmHg 5cm h2O
what stats tell us its moderate disease
100mmHg 5cm H2O
what stats tell us severe disease
PaO2/FiO2 <100 mmHg with PEEP >5cm H2O
how can we classify acute respiratory failure/disease
pulmonary - infection,aspiration, primary graft dysfunction
extrapulmonary - trauma, pancreatitis,sepsis
neuro muscular - myasthenia/gbs
how can we classify chronic resp disease
pulmonary/airways:
copd, lung fibrosis,cf,lobectomy
musculoskeletal: muscular dystrophy
how can we classify acute on chronic resp disease
infective exacerbation of: copd/fibrosis
myasthenic crises
post operative
what is type 1 resp failure
hypoxemic - failure of oxygen exchange
pao2<60
what are some causes of type 1 failure
collapse aspiration pulmonary oedema fibrosis pulmonary embolism pulmonary hypertension = causes alveolar flooding
what is the response to supplemental oxygen in type 1 failure
refractory (stubborn/unmanageable)
what is type 2 resp failure
hypercapnic - failure to exchange/remove co2
paco2 >45
what causes hypercapnea
decreased alveolar minute ventilation dead space ventilation due to nervous system neuromuscular muscle failure airway obstruction chest wall deformity
what is type 3 respiratory failure
perioperative respiratory failure
increased atelactasis (collapse of airway) due to low functional residual capacity with abnormal wall mechanics
hypoxemia/hypercapnoea
how can we prevent type 3 resp failure
anaesthetics, operative technique posture incentive spirometry analgesia attempts to lower intra abdominal pressure
what is type 4 resp failure
patients who are intubated and ventilated during shock (septic,cardiogenic,neurologic)
what are some risk factors for chronic resp failure
copd pollution recurrent oneumonia cystic fibrosis pulmonary fibrosis neuromuscular disease
what are some risk factors for acute resp failure
infection - viral,bacterial aspiration trauma pancreatitis transfusion
whats the first thing to look at in patients with acute resp failure
origin of shortness of breath
causes of acute resp failure
lower resp infection aspiration trauma pulmonary vascular disease extra pulmonary - pancreatitis, new meds
what causes acute lung injury
damage to interstitum causes:
alveolar macrophages release cytokines: il6,il8, tnf alpha and type1 and 2 cells
in response to inflammation- = alveolar fluid build up, protein rich oedema
leads to degradation of surfactant
migration of leukocytes e.g neutrophils into interstitium
causes more oedema
therefore greater distance between alveolar and blood supply
what damps are released during lung injury
hmgb1
rage
therapies that have been tried for resp failure
steroids salbutamol surfactant n acetylcysteine neutrophil esterase inhibitor gm-csf statins
what is proning
rolling patient onto tummy
useful indicators to look at for ards
platelet count
bilirubin
creatinine
crp
how can we treat underlying disease in resp failure
inhaled therapies - bronchodilators, pulmonary vasodilators
steroids
antibiotics
antivirals
drugs - pyridostigmine, plasma exchange, iViG, Rituximab
what type of respiratory support can be provided
physiotherapy oxygen nebulisers high flow oxygen non invasive ventilation mechanical ventilation extra corporeal support
what are some multi organ support that can be given
cardiovascular support - fluids, vasopressors,ionotropes,pulmonary vasodilators
renal support - haemofiltration
haemodialysis
immune therapies - plasma exchange ,convalescence
what takes place during ards
poor gas exchange - inadequate oxygenation poor perfusion hypercapnoea infection - sepsis inflammation systemic effects
ards specific intervention
resp support
intubation and ventilation
procedures to support ventilation
what are the types of ventilation
volume controlled
pressure controlled
assisted breathing modes
advanced ventilatory modes
what are some imaging techniques we can use for management of ards
lung us - to evaluate how well expanded lung is/ any fluid
lung ct
which guidelines used for escalation of therapy
use murray score pao2/flO2 on 100% oxygen cxr peep compliance
what does murray scores mean
0 = normal
1-2.5 - mild
2.5 - severe
3 - ecmo
inclusion criteria for ecmo treatment
severe resp failure
non cardia cause
pos pressure ventilation is not appropriate
exclusion criteria for ecmo
contraindication to continuation if treatment
significant co morbidity
significant life limiting co morbidity
what is ecmo
very invasive
large cannula passed through femoral vein into ivc
removal of co2 and input of oxygenated blood
issues with ecmo
time to access referral system - geographical inequity invasive costly clotting/bleeding
