Organ Failure Flashcards
What is the qSOFA score?
quick Sequential Organ Failure Assessment score
1 point = RR >22
1 point = GCS <15
1 point = SBP <100mmHG
Scores of 2-3 are associated with up to 14fold increase in mortality
Patients with these scores should always have infection considered as the underlying aetiology
What is the definition of SIRS, sepsis and septic shock?
Variable definitions and constantly changing, however basics as below
SIRS= Systemic inflammatory response syndrome with 2 or more of….
- altered temp (>38 or <36)
- Hr >90
- RR >20
- PaCO2 < 32
- WBC >12 or <4, >10% bands
Sepsis = SIRS + suspected infection
Septic shock = sepsis + end organ dysfunction and hypotension despite fluid resuscitation
What is the Berlin definition of ARDS?
Respiratory symptoms new or worsening within 1 week of insult
+
Bilateral opacities consistent with pulmonary oedema on imaging
+
The patients presentation must not be fully explained by cardiac failure or fluid overload
+
A moderate to severe impairment of oxygenation must be present (Pa02/Fi02)
How is the severity of ARDS classified?
Mild
- The Pa02/Fi02 is >200 but <300mmHg on ventilator settings with a PEEP/CPAP of 5 or more
Moderate
- The Pa02/Fi02 is >100 but <200mmHg on ventilator settings with a PEEP/CPAP of 5 or more
Severe
-The Pa02/Fi02 is <100 on ventilator settings with a PEEP/CPAP of 5 or more
ie if the Pa02 is 60mmHg and FiO2 is 0.80 then the PaO2/FiO2 ratio is 75mmHg (severe)
What are the main lung ventilation strategies to help with ARDS?
Low tidal volume ventilation
- 4-6ml/kg of predicted body weight
- Prevents alveolar overdistension (ie volutrauma)
- Aiming Pplateau <30cmH20
Open Lung Approach
- AKA airway pressure release ventilation or inverse ratio ventilation APRV and IRV
- Use 2 levels of PEEP with the higher level being 16cmH20
- Lungs essentially kept constantly inflated and ventilation happens when lungs let down
- Inspiratory time > expiratory time
- Improves 0xygenation but no proven mortality benefit and risk of hyperinflation
Permissive Hypercapnoea
- Very small tidal volumes as above approach, but targeting CO2 40-60
- Thought now that benefit is from the low tidal volumes and not the higher CO2
What are the differentials for bilateral infiltrates?
ARDS
APO
Bilateral pneumonia
Diffuse alveolar haemorrhage
Acute eosinophilic pneumonia
- autoimmune pneumonitis
Pulmonary vasculitis
Acute Interstitial Pneumonitis
- AKA Hamman-Rich syndrome
- essentially idiopathic ARDS
Disseminated malignancy
Acute exacerbation of idiopathic pulmonary fibrosis (AEIPF)
- need pre-existing fibrosis
What are the indications for ECMO?
Acute, severe reversible cardiac or respiratory disease
P:F ratio <100
Shunt fraction >30%
Poor gas exchange
Compliance <0.5ml/cmH20/kg
ECMO CPR
What are the contraindications to ECMO?
Absolute
- Non-recoverable cardiac disease and not a transplant candidate
- non-recoverable respiratory disease (irrespective of transplant status)
- Chronic severe pulmonary HTN
- Advanced malignancy
- Graft vs Host disease
- Morbid obesity >120kg
- Unwitnessed cardiac arrest
Relative
- Age >75
- Multi trauma
- CPR >60mins
- Multiple organ failure
- Significant CNS injury
What is the difference between VV and VA ecmo?
VV
- Most common
- Support for resp failure only
- Venous drainage and return to large central veins
- Pulsatile arterial blood flow
- Oxygenated lung blood
- Native cardiac output must be good to high
- Good 02 flow to coronaries
VA
- Cardiac + resp failure
- Venous and arterial cannulas
- Contraindicated in severe AR (LV massive distention and aortic dissection)
- Better perfusion to lower body
- higher risk limb ischaemia
- Relative lung ischaemia
- Higher 02 tension than VV
- Non-pulsatile blood flow
- Poorer perfusion to coronary and cerebral vessels
- Risk of lung overventilation
What is the ventilation strategy in ECMO?
- Don’t need to ventilate at normal level
- Need to maintain alveolar volume and some oxygenation
- RR 8-10, PEEP 15, TV 3-4ml/kg, PIP <30, FiO2 0.4
What are the indications and contraindications to ECLS aka ECMO CPR?
Indications
- Persistent arrest despite standard efforts
Contraindications
- Initial rhythm asystole
- No CPR within 10mins of arrest
- EMS transport time >10mins
- Total arrest time >60mins
- Suspicion of sepsis or haemorrhage as the cause
- Pre-existing severe neurological disease
What is the APACHE score for ICU mortality?
Calculated for all patients going to ICU, helps predict prognosis and can be used for family discussions
- Age
- pH
- Febrile?
- Recent surgery and type
- End organ failure
- Immunocompromised
- MAP and obs
- Electrolytes (Na+, K+)
- Acute renal failure?
- Haematocrit
- WCC count
- GCS
- Fi02 < or > 50%
What patient factors affect suitability for going onto ECMO?
What disease/clinical state factors affect suitability for ECMO?
