Critical Care Medicine - Triage and ICU care Flashcards
Functions of the ICU
Monitoring of unstable patients
Provide intensive therapy and organ support, with intensive monitoring
Supportive treatment of organ failure before irreverisble EOD, buy time for recovery: e.g.
- Respiration: mechanical ventilation
- Cardiovascular: inotropes / vasopressors / aortic balloon pump
- Renal: renal replacement therapy- Liver failure: MARS
Triage logic for ICU admission
Patients referred are assessed early as to need and suitability
Highest priority given to patients suffering from (potentially) reversible organ failures, commonly hypoxia and shock
Factors for consideration:
- Reversibility of active medical problem
- Clinical condition/ critical illness?
- Premorbid state: QoL, ADLs, Exercise tolerances
- Co-morbidities: malignant or non-malignant terminal diseases?
- Age
Define the ICU priority scale
Priority I
Critically ill with organ failure(s) requiring support
e.g. Respiratory failure need Ventilation; Shock need Inotropes and vasopressors
Priority II
Same as priority Ill, but not requiring organ support
e.g. Respiratory failure need Oxygen supplementation; Shock need Fluid challenge
Priority III
Critically ill, with poor prognosis
e.g. Terminal illness, end-stage chronic disease, acute irreversible disease, very poor functional status
Options for CVS support
Aim: Maintain adequate blood pressure for organ perfusion, Provide adequate cardiac output for the delivery of oxygen
Options:
- inotropes: dopamine, dobutamine, adrenaline, ephedrine
- chronotropes
- vasopressors: noradrenaline, pheylephrine, vasopressin
- pacemaker
- Intra-aortic balloon counterpulsation (IABP)
- Extracorporeal membrane oxygenation
Options for renal support
Renal monitoring
Renal support:
* Haemodialysis, peritoneal dialysis
* Continuous renal replacement therapy/ Haemofiltration
* Fluid management
* Remove renal toxins
* Treat perfusion or outflow obstruction
Monitoring:
Clinical:
* Uraemic symptoms
* Urine output, fluid balance
* Urine microscopy
Biochemical:
* Acid base status, electrolytes, urea & creatinine
* Creatinine clearance
Indications include ARF, severe metabolic acidosis, hyperkalaemia, some poisonings
Terms for withdrawal of treatment in the ICU
Forms of withdrawal
Terms:
* On-going futile treatment is undesirable from both ethical and economic points of view
* Withdrawal of treatment allows the natural process of death to occur unimpeded by artificial organ support
* All treating physicians must be unanimous in agreement that this is an appropriate step
* Family members must be counseled until the family understand the concept and do not object
Forms of withdrawal:
* Withdrawal of Inotropes / Vasopressors
* Limiting blood products
* Limitation of Ventilator settings
* Stopping Renal Replacement Therapy
General monitoring of ICU patients
- Posture/ appearance/ movement
- Neuromonitoring: GCS, EEG, Transcranial doppler, ICP
- Respiration: RR, breathing pattern, breath sounds
- Cardiac: BP, ECG, Arterial BP, CVP, Pulmonary artery catheter
- CVS: Fluid IO, Pulse oximeter, perfusion, peripheries
Fluid monitoring in ICU
Metrics
Fluid IN:
* Volume
* Composition (determines distribution in the body)
* Rate
* Route of infusion
* Fluid intake and food intake
Fluid OUT:
* Urine
* Faeces. other GIT losses
* Insensible loss through respiration and skin
* Bleeding
ECMO
- Types
- Function
2 forms of ECMO: veno-arterial (VA) and veno-venous (VV)
In both modalities, blood drained from the venous system is oxygenated outside of the body
- In VA ECMO, this blood is returned to the arterial system
- In VV ECMO the blood is returned to the venous system & no cardiac support is provided
Anticoagulants (heparin) are given to prevent blood clotting
Pulse oximeter
- Function
- MoA
- Factors that affect accuracy
MoA:
- Pulse oximetry uses a light emitter with red and infrared LEDs that shines through a reasonably translucent site with good blood flow.
- Typical sites: finger, toe, pinna or lobe of the ear.
- Opposite the emitter is a photodetector that receives the light that passes through the measuring site.
Function: Measure SpO2 = (oxygenated Hb/ oxy + deoxy Hb) x 100
Inaccuracy:
- high concentration of metHb or carboxyHb, there will be a falsely high oxyHb estimate (SpO2).
- Hypotension
- Anaemia: Accurate down to Hb>3g/dl
- Skin pigmentation: False reduction with very dark skin & patient with hyperbilirubinaemia
- Nail polish: False reduction with blue or black colour
Define type 1 and type 2 respiratory failure mechanisms
Type I Failure: Hypoxaemic Failure, Low PaO2
5 Mechanisms
* Hypoxia
* Hypoventilation
* Alveolo-Capillary Block
* Ventilation Perfusion Mismatch
* Shunting
Type II Failure: Hypercapneic Failure, High PaCO2
2 Major Mechanisms
- Hypoventilation: Muscular Weakness, Sedation/Hypnotics, Central Apnoea, Respiratory Muscles Fatigue
- Dead Space: COPD, obstructive lung diseases
Triage
Function
Triage categories in A&E
Primary assessment in A&E
Secondary assessment in A&E
Common triage interventions
