Critical care and ventilation

Question 1

what is mechanical ventilation

Answer 1

mechanical ventilation replaces the function of the inspiratory muscles by delivering gas under positive pressure to the lungs. this substitutes for the respiratory pump. respiratory pump= the abdominal and thoracic structures that contribute to the expansion and contraction of the lungs, if patient triggered- the ventilator delivers the breath as soon as it senses the beginning of the patient inspiration

Question 2

compliance

Answer 2

compliance- reflects ability to change the shape of a structure when mechanical load applied, so lung compliance is the ability of the alveoli and lung tissue to expand on inspirations. Compliance varies depending on the elasticity and surface tension of lungs (stiffer lungs= less compliant= lungs are harder to mechanically ventilate)

Question 3

indications to ventilate

Answer 3

respiratory failure (COPD), prolonged post op recovery (heart ,head, abdominal), altered conscious level (cannot maintain airway), inability to protect airway, respiratory failure- inadequate gas exchange as reflected in ABGs

Question 4

What is PEEP

Answer 4

positive end expiratory pressure, pressure maintained in the alveoli at the end of expiration to prevent alveolar and airway collapse

Question 5

volume controlled ventilation

Answer 5

ventilator delivers a pre set TV, pre set inspiratory time, pre set pause time, airway pressure tissues slowly as the ventilator reaches the desired volume

Question 6

how does peak airway pressure vary

Answer 6

it varies from breath to breath as this mode is volume controlled and the ventilator will deliver its set volume irrespective of how hard that might be because of variations in lung compliance and resistance to flow

Question 7

pressure controlled ventilation

Answer 7

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 volumes and vice versa)

Question 8

main advantage of pressure controlled ventilation q

Answer 8

pressure can be controlled reduce the risk of baraotruma in patients with stiff lungs

Question 9

dual control ventilator

Answer 9

combines volume control and pressure control, delvers a pre set volume with the lowest possible pressure, if the volume falls below the pre set value the pressure level rises but only to a point, if the upper pressure limit is reached before the ventilator can deliver the appropriate amount of volume that has been set, the volume will alarm,

Question 10

pressure support (PS) or AKA assisted spontaneous breath (ASB)

Answer 10

a spontaneous mode- so the patient must trigger the machine or there will be no breath given, provides a pre set pressure boost to each breath

Question 11

volume support

Answer 11

spontaneous mode, a set TV is delivered with different pressure support from the ventilator depending on the patients effort/activity

Question 12

biphasic positive airway pressure

Answer 12

pressure controlled mode giving the patient unrestricted opportunities for spontaneous breathing at pre set high and low pressure levels. uses 2 shifting pressure levels- IPAP and EPAP

Question 13

automode

Answer 13

interactive mode, allow patient to receive a supported breath if triggered or a mandatory breath if not. allows for weaning

Question 14

CPAP

Answer 14

provides positive pressure but with no mandatory breaths so the patient has to breathe spontaneously. it increases FRC improving gas exchange by splinting open alveoli. it delivers the same flow of gas through inspiration as expiration. can be delivered non invasively via a face mask

Question 15

examples of spontaneous modes

Answer 15

such as PS, ASB, CPAP

Question 16

ventilator alarms

Answer 16

if the ventilator alarms- do not panic, ask for help, you can press alarm silence but find out why the vent has alarmed before you press reset, the vent will alarm when you suction if you have not pressed alarm since, ask for help if necessary

Question 17

assessment in critical care/ICU

Answer 17

establish if the patient has got a physio related problem, determine if the patient is stable enough for selected treatment, identify any deterioration and ensure appropriate action

Question 18

special considerations for critical care

Answer 18

basic components of assessment remain the same, use a logical process to establish the main physio problems, consider patient anxiety, consider relatives and confidentiality, consider expectations of both patient and yourself, not any equipment

Question 19

systematic approach

Answer 19

A- airway, B- breathing, C- circulation, D-disability, E- exposure,
looks at- respiratory system, cardiovascular system, central nervous system (AVPU), renal system, MSK, bloods

Question 20

information gathering

Answer 20

clinical history from the medical notes, staff, nursing record, ICU char, carers/relatives
look for- PC/HPC/PMH/SH/DH, subjective - emotional status, symptoms pain, fatigue, SOB, specific problems
change since last PT treatment, any limitations to movement/handling, are the patient if they are rousable

Question 21

observations- general

Answer 21

face/colour/expression, position/posture/ comfort, equipment/attachments/drip/drains, skin/wounds, peripheries/oedema/ cyanosis

Question 22

systematic approach- A and B

Answer 22

respiratory system- airway and breathing
mode of ventilation, method of delivery (ETT/Tracheostomy/facemask)/ ventilator settings, oxygen delivered/mode of delivery, RR, ABGS & pulse oximetry, CXR, previous PFT, auscultation, chest wall shape and expansion, palpation, cough/sputum/suctioning, breathlessness/cyanosis/ work and pattern of breathing

Question 23

systematic approach- C

Answer 23

cardiovascular system- circulation
HR, Rhythm, BP and MAP, CVP (central venous pressure- should be <5), temperature, invasive cardiac monitoring, ensure vigilance for signs of deterioration/ loss of stability

Question 24

systematic approach- D

Answer 24

disability- central nervous system= common causes of unconsciousness included profound hypoxia, hypercapnia, cerebral hypo perfusion, or the recent administration of sedatives or analgesic drugs, if sedated look for sedation score, pain score and route of analgesics, ICP, tone

Question 25

renal system

Answer 25

fluid input- infusions, fluid output- NGTube/drains/urine, renal results e.g. urea and creatine levels in the blood
kidneys maintain the blood creatine and urea levels within a normal range
urea and creatine are good indicators of a normal functioning kidney and an increase in the blood are indications of kidney dysfunction
negative balance- too little fluid= more has come out, positive=too much fluid, can lead to pulmonary oedema

Question 26

systematic approach- E

Answer 26

exposure- MSK system
muscle charting/grading, bony injury/fixation, be mindful of skin conditions, ex tolerance and any limitations, baseline=any PMH that may result in functional limitations/use of aids

Question 27

bloods

Answer 27

any other relevant blood tests e.g. C-reactive protein (CRP) and WCC for signs of inflammation or infection, CRP is an acute phase reactant, a protein made by the liver that is released into the blood within a few hours after tissue injury, the start of an infection or other inflammation, liver function, clotting- e.g. platelet level and clotting times