CP 2013 Vivia

• - alleviate hypoxaemia- give O2- treat this first as it kills faster
• - alleviate hypercapnia- increase MV= RR + TV
• - treat cause
• - intubation and mechanical ventilation

- mechanical support of the respiratory function

• - BiPAP
• - CPAP

• - intensive care
• - high dependency
• - emergency departments
• - OT
• - retrieval (when a team goes out and picks up someone from another hospital and brings them back)

• - airway management
• - respiratory failure- type 1 and 2

• - RR> 35bpm
• - TV < 5ml/kg
• - VC< 10ml/kg
• - negative inspiratory force (MIP) < 25cmH2O
• - MV < 10L/min
• - rise in PaCO2> 10mmHg (eg 52)
• - A-a gradient > 450
• - PaO2 with supplemental O2 < 5mmHg

• - negative pressure ones
• - sucks the ribs out to bring air in- 1950s/60s

- through the use of positive pressure

• - modes of ventilation
• - PEEP
• - gas mixing
• - flow patterns
• - humidification
• - alarms
• - assessing adequacy of ventilation
• - weaning
• - physiological effects
• - physiotherapy management

• - MV= RR x TV
• - machine breaths
• - spontaneous breaths- breaths initiated by pt and supported by ventilation
• - triggering- ventilator senses something happening with a pt like a breath and gives a breath
• - circuit- how everything is connected between pt and machine

- a volume or pressure

• - passive
• - expired gas goes back into the machine

• - controlled mandatory ventilation (CMV)
• - intermittent mandatory ventilation (IMV)
• - Synchronised intermittent mandatory ventilation  (SIMV)
• - pressure support (PS)

• - machine reports what it does and what the pt does
• - FiO2 (lowest 21%)
• - TV- needs to be 8-10ml/kg
• - Pi- inspiratory pressure
• - RR
• - PS- pressure support (25)
• - PEEP

• - pt needs to be paralysed 
• - inspiration is terminated when a set volume, pressure or time is reached
• - if pt wakes up it wouldnt 
• - only used in theatre now
• - certain TV and RR set
• eg RR= 12, Vt (TV)- 500ml. So every 5 sec pt gets 500ml

• - not used anymore- uncomfy and can result in breath stacking
• - developed in the 80s
• - pt initiated breaths allowed
• - set IMV rate is superimposed on pts own efforts and delivered at regular intervals

• - form of positive pressure ventilation
• - synchronised intermittent mandatory ventilation
• - works with pts efforts
• - still makes sure pt receives a certain number of breaths/ min
• - used even with non- breathing patients

• - more comfortable
• - less sedation
• - faster weaning
• Note used in combination with other modes

• - Pressure control 
• - Volume control (PSV)
• Both work generally the same, will differ with different pathology

- used when barotrauma/ volutrauma is a possibility eg poorly compliant lungs eg ARDS

• - similar to PSV
• - pt breaths on their own
• - fully pt controlled
• - every breath gets a bit of pressure 
• - pt triggers a breath and the machine provides a flow of gas at a pressure for the pt to breath in- augments inspiration 
• - the machine terminated the inspiratory pressure once the flow rate drops (end of inspiration)

10-20cmH2O

- positive end expiratory pressure

- it increases the amount of alveolar pressure above atmospheric pressure at the end of expiratory imposed by the machine

- to help keep the alveoli open

• - helps the pt overcome the resistance in the machine circuit
• - increase FRC
• - helps recruit collapsed lung
• - improves oxygenation
• - may redistribute lung water from the alveoli to the interstitium (eg pulmonary odema)

• - haemodynamic instability
• - lung damage
• - ? effect on ICP
• - ? may worsen oxygenation in focal lung pathology
• - heart has to push harder against pressure as there is an increase pressure in the lungs

• - CPAP
• - BiPAP
• - NIPPV

• - close fit mask over the nose ormouth
• - increase MV
• - gas blown through mask at high flow rates, expiratroy PEEP valve provides expiratory pressure
• - decrease WOB

• - splint open airways
• - increase lung volumes
• - increase alveolar ventilation
• - reduce WOB

• 
• 

- Continuous positive airway pressure

- can be both invasive and non invasive

• - increase FRC
• - maintenance of continuous positive airway pressure throughout the respiratory cycle
• - increase ventilation
• - spontaneous mode of ventilation
• - decrease WOB

5-20cmH2O

• - PCV
• - <40 best
• - poor compliant lungs

- bi- level (biphasic) positive airway pressure

• - like CPAP but allows different inspiratory and expiratory pressures
• - spontaneous mode of ventilation
• - allows pt to be more supported in inspiration that CPAP