Critical Care Flashcards
What is mechanical ventilation?
MV replaces the function of the inspiratory muscles by delivering gas under positive pressure to the lungs.
Either the ventilator or the patient “triggers” inspiration. If the patient triggers it, the ventilator delivers the breath as soon it senses the beginning of the patients inspiration
What is lung compliance?
The ability of the alveoli and lung tissue to expand on inspiration. Compliance varies depending on the elasticity and surface tension of the lungs . The stiffer the lung the less compliant. Poorly complaint Kung so are harder to mechanically ventilate.
What are the indications to ventilate?
Respiratory failure Prolonged post op recovery Altered conscious level Inability to protect the airway Inadequate gas exchange as reflected in ABGS
What are the two types of respiratory failure?
Hypoxaemia- failed oxygenation due to failure of the gas exchanging function of the respiratory system
Hypoxaemia and hypercapnia (increased o2) failed ventilation, raised co2 is caused by failure of the respiratory pump
What does PEEP stand for?
Positive End Expiratory Pressure.
It is pressure maintained in the alveoli at the end of expiration to prevent alveolar and airway collapse
What is volume controlled ventilation?
Ventilator delivers a pre set tidal volume, pre set inspiratory time, pre set pause time and a pre set respiratory rate. Airway pressure rises slowly as the ventilator reaches the desired volume
What is pressure controlled ventilation?
Flow is delivered to a pre set target pressure limit during inspiration, pre set respiratory rate, pre set inspiratory time, pressure is constant and set so the volume can change from breath to breath depending on lung compliance. Better lung compliance leads to larger lung volume. Poorer lung compliance leads to smaller volumes.
The main advantage is that pressure can be controlled reducing the risk of barotrauma (injury sustained because of changes in barometric air pressure) in patients with stiff lungs.
What is CPAP and what does it do?
CPAP stands for continuous positive airway pressure. It provides positive pressure but with no mandatory breathes so the patient has to breath spontaneously. It increases FRC improving gas exchange by splinting open the alveoli. It delivers the same flow of gas through inspiration and expiration. It is likened to putting your head out of the window of a speeding car.
Some key messages about mechanical ventilation
Invasive mechanical ventilation can be
1.controlled by pressure
2.controlled by volume
Or a combination of both
Ventilation can be fully controlled by the machine CMV or can allow for some synchronisation with the patients effort SIMV.
Spontaneous modes like PS, ASB and CPAP need the patient to be able to indicate a breath or they won’t provide and support for ventilation.
PEEP is required to hold the alveoli open at the end of expiration otherwise they would collapse
What is heart rate and rhythm affected by?
Physiotherapy Hypoxia Electrolyte imbalance Myocardial ischaemia Anxiety
What complications can occur during a line in one of the major arteries such as the femoral artery?
If the patient sits up and puts pressure on the legs before 12 hours has passed, the line in could burst.
An ischaemia can occur if it occludes or bleeding could occur if it becomes dislodged
What is the role of physiotherapists on critical care?
Maintenance and improvement of cardio respiratory status.
Maintenance of MSK function
Optimisation of neurological status
To work as part of the wider critical care MDT.
Weaning/liberating patients from mechanical ventilation.
Extubating/decannulation
What information gathering should you do for a patient on the intensive care ward?
Subjective
- ask about emotional status, symptoms
, fatigue, SOB, specific problems, ask nursing staff how the patient is, what has happened since the last PT treatment, are there any limitations to movement/handling.
What to look at in a general observation for an ICU patient?
Face/colour/expression Position/posture/comfort Equipment/ attachments/drips/ drains Skin/wounds Peripheries/oedema/cyanosis
What to assess in the respiratory system for someone on the ICU ward?
Mode of ventilation 1 or 2 or both? Method of delivery (ETT/tracheostomy/face ask) ventilator settings Oxygen delivered/mode of delivery RR ABGS and Pulse oximetry CXR Previous Pulmonary function test Auscultation Chest wall shape and expansion Palpation Cough/sputum/suctioning Breathlessness/cyanosis/ work and pattern of breathing
What to look at in the cardiovascular system for patients in the ICU ward?
Heart rate Rhythm BP and MAP CVP Temperature Invasive cardiac monitoring Ensure vigilance for signs of deterioration/loss of stability
What to look at in the CNS
Levels of consciousness AVPU and GCS- common causes of unconsciousness include hypoxia, hypercapnia, cerebral hypo perfusion or recent administration of sedatives or analgesics. If sedated look for a sedation scores. Pain score and route of analgesia- oral or IV.
Tone/patterning
What other information regarding bloods do you take from a patient in ICU?
CRP- C-reactive protein
What are some common abnormalities associated with prolonged ICU stay?
Deconditioning Muscle weakness Dyspnoea Depression and anxiety Reduced health related quality of life
What are the 3 main areas physios are involved in when practicing in critical care?
Management of respiratory problems including intubation avoidance and weaning from ventilation
Emotional problems and communication
Deconditioning and related complications
Early physical activity, mobilisation and rehabilitation within critical care is considered safe and feasible after initial cardiovascular or neurological stabilisation
What are the goals of respiratory physiotherapy?
Optimise oxygen transport Improve ventilation/perfusion Improves lung volumes Reduce work of breathing Enhance mucocilliary clearance
What physical problems usually remain after an ICU stay?
Weakness Walking distance Fitness Lack of stamina Sob Aches and pain
What is a joint mobilisation?
Manual therapy technique used to modulate pain and treat joint dysfunction that limits range of movement. It can be done by specifically addressing the altered mechanics of the joint.
What are mobilisations of secretions?
The movement of respiratory secretions from distal to more proximal airways
What does mobilisation enhance for a patient?
Ventilation Circulation Muscle metabolism Central and peripheral perfusion Alertness
What are the various steps in the oxygen transport pathway?
Ventilation of the alveoli Diffusion of oxygen across the alveolar capillary membrane Perfusion of the lungs Biochemical reaction of oxygen with the blood Affinity of oxygen with haemoglobin Cardiac output Integrity of the peripheral circulation Oxygen extraction at tissue level
What is the difference between exercise, mobilisation and rehabilitation ?
Exercise- describes aspects of our management such as bed exercises, walking on the spot
Mobilisation- describes aspects of our management such as walking, sitting out
Rehabilitation- includes physical, functional, communication, social, spiritual, nutritional and psychological aspects
Why would you want to mobilise the critically ill?
Pain and discomfort
Tethered/restricted
Immobile because of their illness and the environment
Atrophy of postural muscles resulting in the inability to sit/stand independently
Risk of contracture
Antigravity muscles of the back, knee extensors, quads and calf muscles are more affected than upper limbs
What are some strategies and interventions available for rehabilitation of ICU?
Passive range of movement to assess joint range and for patient comfort and use of accessory mobilisations if appropriate p.
Positioning-passive, active assisted and active turning eg rolling/side lying
Active assisted/ active movements and bed exercises
Strengthening and resisted exercises
Sit out in multi function chair
Lie to sit transfers, sit on edge of bed. Sitting balance and practice. Once independent sitting balance is achieved, patients may tolerate sitting in a ward chair
Sit to stand assessment and practice via standing hoist
Work in standing to assess and manage balance, posture, endurance, ability to transfer weight
Stepping practice and gait re education
Progress mobility to reduce aids and increase exercise tolerance. Consider therapeutic touch and massage for anxiety at any time.
Mechanical ventilation
On mechanical ventilation peep, don’t remove patient from ventilator if the setting is at 15 as patient won’t have enough peep to keep their airways open
What is mechanical ventilation
It replaces the function of the inspiratory muscles by delivering gas under positive pressure to the lungs.
You can get patient triggered ventilation or ventilation triggered ventilation,
There needs to be good lung compliance which refers to the ability of the lungs to expand on inspiration. This depends on the elasticity and surface tension of the lungs.
What are the indications to ventilate?
Respiratory failure
Prolonged post op recovery
Altered conscious level
Inability to protect the airway
What are the two types of respiratory failure?
Type 1- hypoxaemia- failed oxygenation decrease oxygen
Type 2- hypoxaemia and hypercapnia - failed ventilation decreased oxygen and increased co2
What is PEEP
Positive end expiratory pressure - pressure maintained in the alveoli at the end of expiration to prevent alveolar and airway collapse
Do pursed lip breathing
Peep can be set on a ventilator to stop collapse of a patient
What are the different types of ventilation
Volume controlled ventilation - airway pressure rises slowly as the ventilator reaches the desired volume
Pressure controlled ventilation - pressure is constant and set so the volume can change from breath to breath depending on lung compliance.
Some ventilators can combine the 2 in an attempt to avoid barotrauma ( lung explodes basically) but maintain good lung volumes - delivers a pre set volume with the lowest possible pressure
