Respiratory failure and Intubation (1B) Flashcards
Why would somebody go to ICU?
- Haemodynamic/respiratory/neurological monitoring
- Support of normal body functions (Intubation and mechanical ventilation. Cardiovascular support eg inotropes)
- Stabilisation of life threatening injuries
- Treatment of multi organ failure
What is the definition of respiratory failure?
When the patient loses the ability to ventilate adequately (CO2) or to provide sufficient oxygen to the blood and systemic organs
What is hypoxaemic respiratory failure?
Long, o2 gas movement, regional ventilation)
PaO2 < 60 mm Hg
PaCO2 < 42 mm Hg
- Lung disease is severe enough to interfere with O2 exchange
What is hypercapnic respiratory failure?
Pump, CO2 gas movement, effective minute ventilation, overall ventilation
PaCO2 > 50 mm Hg
The respiratory system pump is inadequate and cannot maintain ventilation to eliminate the CO2 produced by metabolism
What is acute respiratory failure?
Rapid onset, short course and pronounced symptoms
What is chronic respiratory failure?
Long duration of poor ABG values with (metabolic) compensation
VE =
minute ventilation
RR x VT (tidal volume)
Vd =
dead space (non gas exchange area -> upper airways)
VD=
dead space ventilation
= RR x Vd
VA=
alveolar ventilation
= (VT - Vd) x rr
= VE- VD
Normal male Vd = VT = RR VE = VA= CO2 =
Vd = 100mL VT =500 mL RR = 12 VE = 61/min VA= 4.81/min CO2 = normal
Post abdominal surgery Vd = VT = RR VE = VA= CO2 =
Vd = 100 mL VT = 250 mL RR = 24 VE = 61/min VA= 3.61/min CO2 = increased
DBE with physiotherapist Vd = VT = RR= VE = VA= CO2 =
Vd = 100 mL VT = 750 mL RR= 8 VE = 61/min VA= 5.21/min CO2 = decreased.
PE 2 weeks post discharge Vd = VT = RR= VE = VA= CO2 =
Vd = 200 mL VT = 500 mL RR= 12 VE = 61/min VA= 3.61/min CO2 = increase
Mechanisms & causes
• Hypoxaemic respiratory failure
– Reduced gas going to areas with perfusion
• Low lung volume (O2 movement problem)
– No gas going to areas with perfusion
• Acute lobar collapse (O2 movement problem)
– Diffusion impairment
Mechanisms & causes
• Hypercapnic respiratory failure
Mechanisms & causes • Hypercapnic respiratory failure (CO2 movement problem) – Depressed drive • Opiate overdose – Impaired neuromuscular function • Cervical spinal cord injury • Guillain Barré syndrome • Respiratory muscle dysfunction – Weakness – Fatigue
Mechanisms & causes
– Increased respiratory load
– Increased respiratory load • Increased airway resistance – asthma • altered chest wall compliance – kyphoscoliosis – # ribs • Decreased lung compliance
Clinical manifestations
• Hypoxaemia
– Decreased mental acuity (PaO2 < 40‐50 mm Hg)
– Agitation followed by somnolence
– Dyspnoea
– Increased RR, change in pattern of breathing
– (Organ failure – renal failure, brain injury)
Clinical manifestations
• Hypercapnia
– Depends on rate of rise of CO2 and metabolic
compensation
– Dyspnoea
– Increased RR, change in pattern of breathing
• COPD – accessory muscle use, paradoxical breathing,
intercostal space or rib indrawing, pursed lips breathing
– Agitation, tremor
– Confusion to coma
– Increased ICP, headache
Implications respiratory failure for physiotherapy
• Watch for signs & symptoms of respiratory failure • Review medical assessment & management • Determine type of respiratory failure – hypoxaemic, hypercapnic • Determine cause of respiratory failure – problem list in terms of impairments • Choose appropriate treatment interventions
Reasons for intubation
• Maintain patent upper airway • (suffocation) • Protect lower respiratory tract • (aspiration) • Enable adequate tracheobronchial toilet • (suctioning) • Allow ventilatory support – Mechanical ventilation • during paralysis & sedation • rest respiratory muscles – Oxygen therapy/CPAP/PEEP
What is a Tracheostomy?
• A tracheostomy is an artificial airway that is shorter
than an endotracheal tube
• Inserted surgically or percutaneously through the
neck into the trachea between 2nd and 3rd tracheal
rings
• Bypasses the upper airway and all air intake occurs
via the tracheostomy tube when cuff is inflated
• Can be temporary or permanent
Why is an ETT not done long term?
unstable, pressure on tracheal wall
Indications for Tracheostomy
• The same as for endotracheal intubation but……
• When intubation will be required for a longer period
– As the ETT passes through the vocal cords these can be
damaged
• Voice problems
• Swallowing problems (aspiration)
• Prolonged mechanical ventilation (> 10‐14 days)
• To facilitate weaning from mechanical ventilation
• Tracheomalacia, tracheal stenosis
• Compared to an ETT a tracheostomy:
– reduces dead space compared to an ETT, easier to wean
from mechanical ventilation
– allows reduction in level of sedation as it is more
comfortable (less gag stimulation)
– patient can communicate more easily ‐ mouth words, or
specialised tubes may allow use of a speaking valve
Tracheostomy management
• Will vary between facilities • Multidisciplinary teams • Physiotherapist – Checking patency – Tube changes – Decannulation (removal)
