Respiratory Trauma

Question 1

What are the 4 classifications of hypoxia?

Answer 1

Hypoxic hypoxia (low O2 supply)
Anaemic hypoxia (low Hb function)
Stagnant hypoxia (inadequate circulation)
Histotoxic hypoxia (impaired cellular O2 metabolism)

Question 2

What happens to CO2 &O2 in type 1&2 respiratory failure? How is it diagnosed?

Answer 2

1: HYPOXIA
pCO2= normal, ↓pO2 <8 on air
2: HYPOXIA W/HYERCAPNIA
pCO2↑ , ↓pO2 <8 on air
Diagnosed: ABG, CXR

Question 3

What is the pathophysiology & cause of type 1 respiratory failure?

Answer 3

V/Q mismatch
Alveolus perfused (receiving venous blood from RV) but not oxygenated (alveolus malfunctioning- filled w/fluid in pneumonia/HF)
Blood remains deoxygenated & mixes w/oxygenated blood from other alveoli.
Multiple alveoli affected proportion of blood entering LA deoxygenated enough to dilute blood= hypoxic

CAUSE: V/Q mismatch, Upper airway obstruction, low O2 in inspired air
Low= Obstruction, mucus plug in asthma/COPD, airway collapse in emphysema
High= Block in blood flow, PE

Question 4

What is the cause of type 2 respiratory failure?

Answer 4

Damage to lungs= inc alveolar resistance (structural/ inc secretions). Amount of air entering alveoli is limited w/added ineffective gas exchange. Air enters alveoli but nothing happens

CAUSES:
Hypoventilation- Drug OD, weakness
Increased dead space: COPD, restrictive lung disease, dec resp drive, NM disease, thoracic wall disease

Question 5

What is the calculation for the delivery of oxygen?

Answer 5

DO2= 10 x CO x Conc of O2 in the blood

Question 6

Define obstructive lung disease

How can it occur?

Answer 6

Narrowing of pulmonary airways hinder a person’s ability to completely expel air from the lungs
Affect the bronchi and bronchioles, usually in a diffuse pattern across the whole lung
E.g: COPD, Asthma, Bronchiectasis, CF

Question 7

Define restrictive lung disease

How can it occur?

Answer 7

Cannot fully fill their lungs with air.
Stiffness & reduced compliance in the lungs, chest wall, weak muscles, or damaged nerves may cause the restriction in lung expansion
Increase in the amount of tissue in the interstitium of the lung
E.g: Interstitial lung disease (pulmonary fibrosis), Sarcoidosis, Obesity, Muscular atrophy & ALS

Question 8

What is the pattern seen in obstructive lung disease?

Answer 8

Reduced peak flow
Reduced FEV1:FVC ratio <70%
Reduced FVC <80% of normal

Question 9

What is the pattern seen in restrictive lung disease?

Answer 9

Reduced FVC
Reduced FEV1
Normal PEFR
Normal FEV1: FVC ratio

Question 10

What are the complications of invasive ventilation?

Answer 10

Complications: Upper airway trauma, local irritation, laryngospasm, aspiration

Question 11

What are the complications of non-invasive ventilation?

Answer 11

Complications: CPAP/BiPAP- gastric distension, dec CO, mucus plug, pneumothorax, hypT
Bag&mask- Aspiration, hypoventilation

Question 12

How is MAP calculated?

Answer 12

MAP= 2x D.BP + S.BP/3

Question 13

Define flail chest

Answer 13

> 2ribs fractured in >2 places

Question 14

What size ET tube is usually used for men & women?

Answer 14

M: 8
W: 7

Question 15

What are the 4 checks used to make sure an ET tube is in the correct position?

Answer 15

Chest rise & fall
Tube has gone past the cords
CO2/ misting of the mask / O2 sats holding
Audible/auscultate breath sounds

Question 16

Who is CPAP used for?

Answer 16

High pressure air/oxygen with a tight fitting mask.
Positive pressure between 4-25cm H2O during inspiration AND expiration
Improves: FRC, V/Q match
Decreases: Atelectasis, leakage of fluid into lung

USE:
Acute hypoxic respiratory failure (TYPE 1)
Acute pulmonary oedema
Fluid overload (HF)
Atelectasis
Chest infection
Sleep apnoea
Assist weaning from invasive ventilation

Question 17

Who is BiPAP used for?

Answer 17

high positive pressure on inspiration and lower positive pressure on expiration.
Increases minute vol by increasing tidal vol
Type 2 respiratory failure
Hypercapnoeic COPD exacerbations
MSK conditions w/resp failure
Obesity hyperventilation syndrome

Question 18

In a trauma patient, when is intubation a definite?

Answer 18

GCS <8

Question 19

What are the contraindications for CPAP/BiPAP?

Answer 19

MUST BE ABLE TO: Maintain own airway, cough, make own respiratory effort
Undrained pneumothorax
Severe epistaxis
Vomiting
Apnoea
Severe agitation
Unable to tolerate or fit mask
Low GCS
Asthma or pneumonia (unless not for intubation)

Question 20

What investigations should be done for breathlessness?

Answer 20

Bloods
ABG
CXR
ECG
CTPA or V/Q scan

Question 21

What is IPPV?

Answer 21

Intermittent 
Positive
 Pressure 
Ventilation
Ventilator creates positive pressure in ET tube driving air into lungs
Can be set to specifics: breaths/min, O2 conc, tidal vol
Optimises patients oxygenation & ventilation

Question 22

What are the problems with CPAP?

Answer 22

hypoT
Expand pneumothoraces
Difficult to apply if facial injuries

Question 23

What is the mechanism of hypercapnoea in COPD?

Answer 23

Combination of muscle fatigue & worsening lung mechanisms
Inc bronchial constriction, narrowing, oedema
Disordered central ventilatory drive

Question 24

What are the problems with IPPV?

Answer 24

Requires ET tube
Sedation
HypoT
Gastroparesis
Immobility
Vascular access
Inc risk of pneumonia
ICU requirement