A B C

Question 1

how can you assess a patients airway?

Answer 1

if conscious and speaking in full sentences = reassuring
if unconscious - get down to level of mouth listen for breath sounds, feel for breath on your cheeks and view chest for any movement.

Question 2

what are the features suggestive of a:

a) completely obstructed airway
b) partly obstructed airway

Answer 2

a) silent chest, unable to talk, cough or breathe

b) stridor - partial obstruction at the level of or above larynx
wheeze - partial obstruction of lower airways
gurgling - vomit, blood or secretions.

other features:
reduced level of consciousness, respiratory distress , make look distress e.g. if choking

Question 3

what are the signs of respiratory distress?

Answer 3

tachypnoea
use of accessory muscles - intercostal recession, tracheal tugging, sea saw pattern of chest wall and abdomen. 
cyanosis 
grunting
apnoea 
tachycardia

Question 4

what can airway obstruction lead to?

Answer 4

cardiac arrest.

complete obstruction leads to rapid cardiac arrest
partial obstruction leads to pulmonary oedema, cerebral oedema, hypoxia, exhaustion, apnoea and eventually cardiac arrest.

Question 5

give examples of causes of airway obstruction

Answer 5

reduced conscious level (head injury, intoxication, hypoglycaemia) - loss of protective reflexes so tongue and epiglottis can occlude upper airway.

foreign body - more common in children

secretions - (blood, vomit) - e.g. intoxication and reduced level of consciousness can result in aspiration

swellings:
anaphylaxis - oedema of larynx and upper airways
infection - tonsillitis, quinsy, epiglottitis, supraglottitis
external compression - goitre, tumour, haematoma (after thyroid surgery)

other laryngospasm, bronchospasm, blocked tracheostomy

Question 6

what manoeuvres are available to secure an airway?

Answer 6

head tilt chin lift - assuming no c spine injury

jaw thrust - when C spine injury suspected

Question 7

what different adjuvants can be used to help maintain an airway. briefly compare the use of each one

Answer 7

Oropharyngeal (Guedel)

nasopharyngeal - can be better tolerated in semi conscious patients (therefore if cant tolerate guedel use this instead)

laryngeal mask / I gel - needs to be fully unconscious to be tolerate. more secure than the above two. reduces risk of gastric inflation and thus aspiration.

endotracheal tube - the most secure airway, needs skilled anaesthetist to set up, needs to be fully unconscious to be tolerated. reduces risk of gastric inflation/aspiration

Question 8

how is the size of oropharyngeal airway measured?

Answer 8

from midpoint of incisor to angle of jaw

Question 9

how is the size of the nasopharyngeal airway measured?

Answer 9

from nose to tragus.

Question 10

when should a nasopharyngeal airway be avoided?

Answer 10

basal skull injury

Question 11

what happens if a nasopharyngeal airway is too big?

Answer 11

bleeding, gagging, vomitting

Question 12

what size of laryngeal airway is used for most men/women?

Answer 12

most men - size 5

most women - size 4

Question 13

how do laryngeal airways and I gels differ?

Answer 13

laryngeal mask airways - require inflation of cuff when in larynx

I gel is covered in jelly and thus no inflation is required. - easier to use in CPR

Question 14

what is bag valve mask ventilation?

Answer 14

allows us to manually ventilate patients who are either fully unconscious or have a reduced respiratory drive.

2 person technique: the mask is held tightly over the mouth and the other person squeezes the bag to deliver air.

if someone has 0 respirations then give one breath every 5 seconds = 12 breaths/ min
if someone has a reduced respiratory rate e.g. of 6, then give a breath in between each of their own.

can be used along side adjuvants:

• laryngeal airways and endotracheal can actually be attached to the bag and the mask bit can be removed
• if no adjuvant is present then whilst holding the mask over the face, a head tilt chin lift/ jaw thrust needs to be maintained.

high flow oxygen can be attached to reservoir bag (gives around 85% oxygenation)

Question 15

what should be considered if there is resistance against ventilation by bag valve mask ?

Answer 15

airway obstruction e.g. foreign body

Question 16

what is a risk of mechanical ventilation? what contributes to this problem?

Answer 16

over inflation and gastric inflation.
gastric inflation can lead to aspiration of stomach contents

this occurs if breaths are being given too quickly and not enough time for adequate expiration.
also can occur if there is airway obstruction
also partly due to relaxed oesophageal sphincter in those who are unconscious

the risk is reduced in laryngeal / endotracheal airway is used.

Question 17

how can the airway be additionally protected in those who are at risk of aspirating?

Answer 17

recovery position
suction if gurgling heard
consider NGT to empty stomach contents.

Question 18

what are the signs of choking?

Answer 18

occurs during eating and patient will suddenly grab their neck and become distressed.

mild: they can speak but struggling, coughing
severe: unable to speak or cough, quickly turns blue

Question 19

how is a choking patient managed?

Answer 19

if mild - encourage coughing

if severe:

• give 5 blows to back whilst patient is leant forward (use blade of hand and give sharp blows between scapula).
• if not successful give 5 abdominal thrusts (wrap arms around patient and make a fist below xiphisternum and pull sharply inwards and upwards) .
  - continue to alternate between these two manoeuvres
  - if still not successful, get resuscitation team and someone with skills to use a laryngoscope and Magills foreceps to remove obstructed foreign body.

Question 20

where is the pharynx positioned and what parts does it consist of?

Answer 20

pharynx extends from cranial base to the inferior border of cricoid cartilage (anteriorly) and inferior border of C6 (posteriorly)

consists of nasopharynx, oropharynx and laryngopharynx

Question 21

what is included in a breathing assessment?

Answer 21

look: deformity, wounds, cyanosis, chest expansion, resp rate
feel: chest expansion, tracheal, surgical emphysema, percuss
listen
extras: oxygen sats, ABG, CXR

Question 22

what is respiratory failure and how can it be categorised?

Answer 22

respiratory failure is the failure of adequate gas exchange which results in hypoxia. defined as a pO2 <8kpa and can be divided into:

type 1: PCO2 normal or low
type 2: PCO2 >6kpa

Question 23

list the causes of type 1 respiratory failure

Answer 23

COPD, asthma, pulmonary fibrosis, pulmonary HTN, pneumonia, ARDS, pneumothorax, P.E, pulmonary oedema, bronchiectasis

Question 24

list the causes of type 2 respiratory failure

Answer 24

pulmonary disease: severe COPD/ asthma, pneumonia, end stage fibrosis, obstructive sleep apnoea

reduced respiratory drive: head injury, brain tumour, CNS depressants, hypothyroidism

neuromuscular: MS, myasthenia, guillian barre, cord lesion

chest wall: kyphoscoliosis, flail chest

Question 25

how can a fractured rib result in respiratory failure? (assume no pneumothorax)

Answer 25

pain - reduced breathing and coughing eventually exhaustion from breathing results in depressed respiratory drive overall.

Question 26

what are the signs of symptoms of respiratory failure?

Answer 26

hypoxia: reduced sats, dyspnoea, tachycardia/ arrhythmia, confusion, agitation, central cyanosis (late sign) hypercapnia: peripheral vasodilation, bounding pulse, tachycardia, flapping tremor, headache, papilledema, confusion, drowsiness, coma others: tachypnoea (>25) - useful and simple indicator signs and symptoms relating to specific cause

Question 27

what are the consequences of long standing hypoxaemia?

Answer 27

polycythemia pulmonary HTN cor pulmonale

Question 28

what are the complications of respiratory failure?

Answer 28

``` arrhythmias GI bleed stress ulceration (duodenal) organ failure (due to lack of O2) - AKI and can lead to cardiac arrest neurological damage from hypoxia complications of mechanical ventilation ```

Question 29

why is acute respiratory failure so dangerous?

Answer 29

no time for compensatory mechanisms (renal bicarb, polycythaemia ) to develop. So become quickly acidotic and unwell.

Question 30

what is the normal respiratory rate?

Answer 30

12 - 20 breaths / min

Question 31

what are the causes of tachypnoea?

Answer 31

exertion, anxiety, pain pneumothorax, P.E, pleural effusion , pneumonia, asthma sepsis, DKA,

Question 32

what are the causes of bradypnoea?

Answer 32

raised ICP, intoxication (opiate overdose), obstructive sleep apnoea, exhaustion after airway obstruction, sedation, hypothyroid.

Question 33

what are the different types of hypoxaemia ?

Answer 33

hypoxemia is defined as low arterial oxygenation (can be measured by oxygen saturations. ischaemia hypoxaemia - thrombus/ embolus/ shock hypoxic hypoxaemia - poor oxygenation at lungs i.e. any cause of respiratory failure. also CO poisoning due to binding to Hb more tightly than O2 anaemic hypoxaemia - not enough Hb cellular hypoxaemia - e.g. cyanide poisoning blocks oxidative phosphorylation

Question 34

how can we investigate hypoxaemia?

Answer 34

``` O2 sats FBC - anaemia, polycythemia BP - shock (ischaemic hypoxaemia) CXR - respiratory cause other tests : TFT (hypothyroid), U&E (electrolytes can disturb respiratory muscles and heart) ``` more specific tests: spirometry, ECHO, ECG, Ddimer/CTPA, toxological screen , CT head (trauma)

Question 35

how is acute respiratory failure managed?

Answer 35

A TO E airways - secure it? treat obstruction e.g. nebulisers breathing - assess and treat - high flow oxygen (unless CO2 retainer) , may require non invasive ventilation (if exhausted)/ mechanical ventilation/ ECMO if severe. check if on morphine (may need naloxone and alternative pain management if resp rate low) Circulation - fluid resus if BP low to improve tissue oxygenation D - look for other causes of respiratory failure e.g. signs of head trauma. E - any wounds to chest etc treat underlying cause e.g. salbutamol nebuliser, EpiPen, Abx for pneumonia

Question 36

what is ECMO?

Answer 36

extracorporeal membrane oxygenation

Question 37

list the differentials for respiratory acidosis?

Answer 37

respiratory centre depression (decreased resp rate): drugs, raised ICP, encephalitis, stroke, central apnoea, excess o2 in CO2 retainer neuromuscular disorders (decreased vital capacity): Myasthenia gravis, guillian barre, polio, ALS, muscular dystrophy parenchymal disease: COPD, pulmonary oedema, pneumothorax, pneumonia, interstitial lung disease, ARDS airway obstruction - COPD, Asthma, foreign body inadequate mechanical ventilation

Question 38

list the differentials for respiratory alkalosis?

Answer 38

hypoxaemia: leads to hyperventilation and lowers CO2 (better diffusion than O2). e.g. severe anaemia, heart failure, high altitude, type 1 resp failure resp centre stimulation: CNS disorder, hepatic failure, gram negative sepsis, anxiety, pregnany, pain, drugs (catecholamines, theophylline) excess mechanical ventilation

Question 39

what is the cause of respiratory acidosis? respiratory alkalosis?

Answer 39

acidosis: raised CO2 secondary to poor ventilation/ gas exchange alkalosis: low CO2 due to hyperventilation

Question 40

how can the effectiveness of oxygenation/ ventilation be assessed?

Answer 40

O2 sats - should respond to oxygen | ABG

Question 41

when is ABG indicated as well as O2 pulse oximetry ?

Answer 41

ABG indicated in any CO2 retainers (and repeat in 30 mins) critically ill patients (although O2 sats may be fine may have high CO2) anyone with sats below 92

Question 42

what may it indicate if pulse oximetry not pick up a value?

Answer 42

shock - poor peripheral perfusion and thus no sats measured.

Question 43

what situations is pulse oximetry unreliable?

Answer 43

``` shock hypothermia (vasoconstriction) methamoglobinaemia CO poisoning sickle cell disease surgical dye (methylene blue) - falsely low sats nail varnish ``` (not affected by jaundice or anaemia)

Question 44

what oxygen saturations should we aim for?

Answer 44

non CO2 retainer - 94-98% | CO2 retainer - 88-92%

Question 45

what should you ensure before mechanical ventilation of a patient?

Answer 45

no tension pneumothorax

Question 46

when is high flow/ concentration of oxygen via non-rebreathe mask used?

Answer 46

critically ill patient / hypoxic - that isn't a long term CO2 retainer. type 1 respiratory failure? after return of spontaneous circulation after arrest

Question 47

what % oxygen does: a) high flow oxygen via non-rebreathe mask? b) nasal cannulae? c) Hudson mask? d) venturi mask?

Answer 47

a) 85% to 100% b) 24-30% oxygen delivery (flow rate 1-4 L / min) c) 24-60% (flow rate 5-10L) d) venturi: blue - 24% (2-4L/min) white - 28% (4-6 L/min) yellow - 35% (8-10L/min) red - 40% (10-12 L/min) green - 60% (12-15 L/ min

Question 48

why should we not keep high flow oxygen on for a long period? (oxygen delivery)

Answer 48

need to aim for sats of 94-98%. | there is evidence that high blood oxygenation after cardiac arrest/ MI can be harmful

Question 49

when is a simple face mask used? (oxygen delivery)

Answer 49

mild hypoxia without chronic lung disease | could also use nasal cannulae here

Question 50

how is safe oxygen delivery achieved in to those with long standing CO2 retention or acute type II respiratory failure?

Answer 50

any CO2 retention - acute or long standing need to give 24% venture mask and aim for sats of 88-92% keep reassessing ABG and alter % O2 accordingly

Question 51

what things should be documented when prescribing oxygen?

Answer 51

oxygen mask type flow rate target sats

Question 52

what are the different types of mechanical ventilation?

Answer 52

positive pressure - increases airway pressure to deliver oxygen. Negative pressure - reduces pressure in alveoli to create sub atmospheric pressure in chest and draw air in (not used anymore) controlled vs patient initiated: - controlled initiates ventilation automatically. patient sensored initiates when it senses patients effort and then adds to this to aid ventilation. invasive vs non invasive: - invasive: endotracheal tube and tracheostomy - non invasive: nose mask or full face mask (CPAP/ BiPAP)

Question 53

when is invasive ventilation used over non-invasive?

Answer 53

generally intubate people with GCS = 8 i.e. invasive ventilation used. (endotracheal tube) however if the cause of respiratory depression is unknown then intubate at GCS 9 too. for non invasive ventilation patient should have patent protective airway reflexes and be alert/responsive

Question 54

how deep is an endotracheal tube inserted in men and women?

Answer 54

23cm in men 21 cm in women. CXR to confirm correct placement need to monitor endotracheal cuff pressure periodically to prevent its migration

Question 55

give examples of ventilation associated trauma?

Answer 55

pneumothorax pneumomediastinum subcutaneous emphysema alveolar wall stress

Question 56

compare CPAP and BiPAP?

Answer 56

CPAP - continuous positive airway pressure - high pressure oxygen with tight fitted mask - continuous positive pressure to help keep aiways open - good for acute pulmonary oedema and sleep apnoea BiPAP - bilevel positive airway pressure - high positive pressure on inspiration and lower level positive pressure on expiration - good for COPD and ARDS

Question 57

what is the modified WELLS score?

Answer 57

clinical signs and symptoms of DVT - 3 points alternative diagnosis less likely - 3 point HR >100 - 1.5 points immbolisation (>3 days)/ surgery in last 4 weeks - 1.5 previous history of VTE - 1.5 haemoptysis - 1 point active cancer in last 6 months - 1 point low risk <2 moderate risk 2-6 high risk >6

Question 58

how can we identify circulation failure/ shock?

Answer 58

arterial hypotension - systolic BP <90 or MAP <65 - tachycardia poor perfusion: - long cap refil, cold, pale, clammy, mottling - oliguria (<0.5ml/kg/hr)/ anuria - neurological - syncope , low GCS hyperlactataemia: - high lactate due to anaerobic respiration - tachypnoea (due to acidosis)

Question 59

what is circulation failure/ shock?

Answer 59

failure of the circulatory system to provide adequate delivery of oxygen and nutrients to tissues (inadequate organ perfusion

Question 60

what are the causes of shock?

Answer 60

hypovolaemic shock - blood loss - AAA, GI bleed, trauma, splenic rupture, ectopic pregnancy - fluid loss - pancreatitis, diarrhoea/ vomiting, burns cardiogenic shock: - primary - arrhythmia, MI, valve problems, myocarditis - secondary - tension pneumothorax, tamponade, P.E distributive shock - anaphylaxis/ sepsis - neurogenic shock - reduced vascular resistance.

Question 61

what are the ways to differentiate distributive, cardiogenic and hypovolaemic shock?

Answer 61

hypovolaemic - cold, clammy, low JVP cardiogenic - cold clammy, raised JVP distributive - warm, well perfused, bounding pulse, low JVP

Question 62

what are the causes of ventricular fibrillation?

Answer 62

``` MI/ ACS hypertensive heart disease valve disease acidosis hyper K, Mg or Ca hypothermia long QT drugs - antiarrhythmics, TCA, digoxin electrocution ```

Question 63

what is the most common cause of cardiac arrest?

Answer 63

arrhythmia post MI

Question 64

how is shock managed?

Answer 64

A to E - airways, oxygenation - raise foot of bed - IV access (2 wide bore cannulas) - take bloods from these - ECG - 500ml 0.9% saline STAT (unless cardiogenic cause and be cautious if AAA is the cause) treat specific cause of shock

Question 65

what are the causes of tachycardia?

Answer 65

sinus tachycardia - pain, anxiety, sepsis, shock, hyperthyroid, drugs, anaemia , P.E atrial flutter, AF, re-entry loop tachycardia, junctional tachycardia, VF, VT

Question 66

what are the causes of bradycardia?

Answer 66

sinus brady - high resting vasal tone in athletes drugs - B blockers, amiodarone, verapamil, CaCB hypothyroid, hypothermia, hypoxia cushings reflex/ triad sick sinus syndrome, heart block, inferior MI

Question 67

what are the causes of oliguria?

Answer 67

``` dehydration vascular collapse/ shock nephritic syndrome AKI / acute tubular necrosis post renal obstruction - tumour, stone, catheter ```

Question 68

what are the causes of hypotension?

Answer 68

shock acutely may be neurogenic e.g. epidural;/ drugs orthostatic hypotension - aortic stenosis, arrhythmias, diabetes, dumping syndrome, vasovagal faints, parkinsons.

Question 69

what are the causes of electrolyte imbalance?

Answer 69

diuretics, AKI, SiADH, dehydration , vomiting, diarrhoea, iatrogenic from incorrect fluids.

Question 70

what is bleeding diathesis?

Answer 70

the susceptibility to bleed mostly due to hypercoagulability

Question 71

what are the causes of bleeding diathesis?

Answer 71

vascular defects - connective tissue disorder e.g. ehlers danlos, berry aneurysms in PCKD1 platelet disorders - poor production - aplastic anaemia, marrow suppression (cytotoxic drugs, cancer infiltration, radiation) - destruction - splenic sequestration (hypersplenism), immune (immunothrombocytopenic purpura and SLE), DIC - defective - NSAIDs, increased urea, myeloproliferative disease coagulation defects - congenital - haemophilia (A/B) - acquired - liver disease, vit K deficiency, warfarin, DIC

Question 72

how does bleeding diathesis present?

Answer 72

petechial rash - non blanching, non palpable, red pin point due to capillary inflammation and haemorrhage ecchymosis (bruise) - collection of blood under skin due to extravastion (leakage) of nearby vessel. bleeding gums, epistaxis, menorrhagia prolonged bleeding after injury haematoma massive haemorrhage - GI, stroke

Question 73

what investigations should be ordered if someone presents with bleeding diathesis?

Answer 73

prothrombin time (PT) - tests for abnormalities in factor I, II, V, VII and X. can be converted to INR. altered with warfarin, liver disease, DIC, vit K deficiency activated partial thromboplastin time (APTT) - looks at factors I, II, V, VIII, IX, X, XI, XII. normally 35-45s. prolonged by heparin, haemophilia, DIC and liver disease thrombin time - measures how well fibrinogen is working. normally 10-15s. prolonged by heparin/ DIC other things: - platelet levels - if low could be due to chemotherapy or massive blood transfusion , coeliacs, leukaemia - factor V assay - low in liver disease, DIC - fibrinogen levels - If low may suggest haemorrhage, fibrinolysis or placental abruption

Question 74

how is bleeding diathesis managed?

Answer 74

if shocked - resuscitate with fluids discuss need for FFP and platelets or specific factor replacement e.g. prothrombin complex concentrate treat cause of coagulopathy e.g. ITP - steroid and Ig stop anticoagulation and reverse effects - e.g. vit K

Question 75

how is the drip rate of an infusion calculated?

Answer 75

20 x ml in the bag divided by time to run in minutes use a clock and count the drips to make sure it is correct rate e.g. count drips over 10 seconds and times by 6

Question 76

how can we clinically assess cardiac output?

Answer 76

CO = HR x SV SV can be assessed with ECHO and LVOT however easier way = pulse pressure x1.75 is an estimate of SV. otherwise cardiac output can be assessed based on clinical signs: perfusion of peripheries, strength of pulse, urine output. barely palpable central pulse suggests low CO

Question 77

how is epistaxis managed?

Answer 77

if haemodynamically unstable: A+E, resuscitate, use first aid measures to control bleed in meantime. if patient is stable: first aid measures: - get the patient to lean forward and open their mouth. (leaning forward reduces blood flow through nasopharynx and minimises swallowing of blood) - pinch cartilaginous (soft part of nose) firmly and hold for 10-15 mins whilst they breathe through mouth - ice pack on bridge of nose if bleeding stops: - inspect nose with nasal canulae - consider applying topical antiseptic to reduce crusting and vestibulitis. Prescribe Naseptin (chlorhexidine and neomycin) cream for nostrils 4x daily for 10 days) if bleeding does not stop: - if bleeding from posterior area of nose suspected (bleeding profusely from both nostrils and cant identify source with speculum exam) - admit to hospital - consider nasal cautery (silver nitrate or electical wire used to cauterise the site of bleed) or nasal packing ( can add adrenaline too)

Question 78

when should secondary care for a nose bleed be considered?

Answer 78

haemodynamic instability <2 yrs old underlying reason e.g. haemophilia, leukaemia if there is comorbidity e.g. severe HTN, coronary artery disease.