Critical Care Flashcards
Sepsis Pathophsyiology
life threatening - results from dysregulated inflammatory response to infection
causes widespread inflammatory response with systemic vasodilation and increased vascular permeability
- results in reduced BP
- inflammatory markers enter the tissues
Can lead to septic shock - blood pressure low, dangerous levels, requires medication to regulate it
Can cause death
Sepsis Diagnostic Criteria
2 or more - deranged respiratory function profound hypotension deranged kidney function reduced platelet count deranged liver function altered mental function
Sepsis Bedside Criteria
RR > 22
altered cognition and mental status
SBP < 100
Acute Respiratory Distress Syndrome
diffuse, inflammatory lung injury results of local or distant insult
- systemic inflammation
- causes increased vascular permeability
- fluid enters lung tissues and air spaces
- interferes with surfactant production - increased surface tension
- lungs becomes less compliant
- as fluid fills lungs, increase in weight, become even less compliant
- requires more pressure to keep airways open
- reduced aerated tissue and increased physiological deadspace
- over time lungs become thickened and fibrotic, thickening of the alveolar wall and capillary wall
- results in shunting - where blood flows to poorly ventilated areas of the lungs and where gas exchange cannot occur = hypoxaemia
CXR - looks like pulmonary oedema with bilateral infiltrates from the lung tissues
ARDs Risk Factors
Direct
- pneumonia
- aspiration gastric contents
- lung contusion
- fat embolism
- near drowning
- inhalation/reperfusion injury
Indirect
- non-pulmonary sepsis
- multiple trauma
- massive transfusion
- pancreatitis
- cardiopulmonary bypass
Medical Management
Controlled ventilation
Prone positioning - air into non-dependent lung, prone makes posterior lung non-dependent, greater surface area in posterior lung, increases amount of tissue being ventilated = improved VQ ratio
Pharmacology
Treat underlying causes and complications
ICU Acquired Weakness
Critically ill patients experience respiratory and peripheral muscle wasting and weakness
- due to immobility and disuse atrophy
Pathophysiological Mechanisms
- circulatory inflammatory mediators and intracellular inflammatory mediators
- causes reaction within the muscle
- results in catabolism and dysfunction
- results in muscle weakness
Physiological Adaptations Bed Rest - Healthy Individuals
muscle atrophy 1-1.5% loss per day VO2 max decreases by 0.9% per day bone demineralisation 2% of bone mass per month increased HR decreased SV
Prevention and Treatment ICU AW
wean from mechanical ventilation where possible
minimise exposure to corticosteroids and neuromuscular blocking agents
control gylcaemia with insulin therapy
maintain nutrition
maintain electrolyte haemostasis
minimise immobility
minimise delirium
Implications for Physio
Pulmonary Complications - atelactasis - secretion retention - respiratory muscle weakness Circulatory Complications - venous stasis - prevents DVTs - orthostatic hypotension Musc and Neuro Complications - disuse atropy - contractures and increased tone - ICU acquired weakness
Clinical Implications
pain reduced lung volumes impaired airway clearance impaired gas exchange abnormal breathing pattern dyspnoea musculoskeletal dysfunction respiratory muscle dysfunction reduced exercise tolerance
Subjective Assessment
same as any other patient
from patient, nursing staff, family and friends
Objective Assessment
CNS function respiratory function CVS GI Renal musculoskeletal bloods medication attachments ICU specific function
Respiratory Physio ICU - Aims
facilitate airway clearance
optimise lung volumes
enhance gas exchange
reduce work of breathing
Passive techniques Respiratory Physio
positioning manual hyperinflation ventilator hyperinflation percussion vibration suctioning respiratory muscle training weaning from mechanical ventilation non-invasive ventilation
Manual Hyperinflation (MHI)
for patients mechanically ventilated and unable to take a breath on their own
- disconnected from ventilator and reconnected to reservoir bag with O2 source
- squeeze and release bag to provide different inspiratory and expiratory pressure
- provides inspiration pressure greater than tidal volume
assists with airway clearance, lung re-expansion, improves lung compliance
Complications MHI
technique varies
have to disconnect from ventilator - lose PEEP and potential for small airway collapse
when reconnect to ventilator - sudden increase in PEEP, increased risk of barotrauma
lose monitoring and alarm systems - can’t be sure what tidal volume you are giving them
haemodynamic instability - compresses the IVC, reduced venous return and cardiac output - causes reduced BP
Ventilator Hyperinflation
Alter ventilator settings to temporarily increase inspiratory pressure
improves tidal volumes
facilitates airway clearance and lung volumes
Avoids complications of MHI
- don’t have to disconnect from the ventilator
- able to continue monitoring of lung volumes
Weaning
process of gradually decreasing the amount of support the patient receives from the mechanical ventilator
considered as soon as they are put on the ventilator
Criteria to begin weaning
Central respiratory drive
- need intact CNS
- minimal sedatives
- not on any paralysing agents
Respiratory muscle capacity
- impacted by respiratory muscle dysfunction
- poor cardiac function
- malnutrition
- general deconditioning
Demands on the respiratory pump
- unresolved primary illness
- ongoing increased metabolic demand
Signs of weaning failure
accessory muscle use asynchronous breathing pattern with the ventilator anxiety diaphoresis tachypnoea subcostal and intercostal retractions impaired gas exchange
Physio Role Weaning
early rehab - stronger they are, more capable of tolerating weaning process
improve muscle strength
improve ventilation
secretion mobilisation and removal
ensure adequate rest - fatigue impairs weaning process
Early Rehab - benefits
reduced ICU and hospital length of stay shorter duration of delirium improved weaning reduced muscle atrophy improved strength and functional independence attenuates complications of bed rest addresses sequelae of ICU-AW reduces overall resource utilisation
Importance of being upright
encourages basal lung expansion and increased FRC psychological improvements increased muscle strength increased exercise tolerance improved trunk stability addresses postural hypotension improves bowel and bladder function weight bearing
Exercise Prescription
every patient different daily activity schedules complements weaning program strengthening and endurance exercise support psychosocial needs needs to be tolerable consider FITT principles consider SMART goals include MDT
Exercise Contraindictations
In and out of bed exercise NOT for patients with prone positioning receiving intravenous therapy for HTN bradycardia requiring pharmacological management very agitated and combative uncontrolled seizures known uncontrolled active bleeding active management of ICP
Potential Complications Respiratory Management ICU
barotrauma raised ICP haemodynamic instability deterioration in gas exchange airway trauma from suctioning patient discomfort
What OMs could you use in this setting?
Chelsea Critical Care Physical Assessment Tool
Physical Function ICU Test
Medical Research Council Scoring System
