Miscellaneous Flashcards
What are the diagnostic criteria for ARDS?
An acute lung injury - within one week of the insult
Bilateral infiltrates on a chest x-ray, not explained by other lung pathology
Respiratory failure not explained by fluid overload
A Decreased PaO2/FiO2 ratio
A patient with COPD has saturations of 95% OA and MRC score of 1. They want to know if they need further investigations before they fly
No. No HCT required . Not meeting criteria for in flight oxygen
A patient with COPD has saturations of 95% OA and MRC score of 3. They want to know if they need further investigations before they fly
Yes , given MRC 3 , guidelines recommend 6MWT or SWT and if sats <84% review if hx of hypercapnia. If yes then need HCT, if no then inflight O2 @ 2l/min.
If sats on 6MWT/ SWT are > 84% then no need for HCT/ in flight O2
A patient with COPD has saturations of 91% OA and not on LTOT. They want to know if they need further investigations before they fly
Yes. Is there a history of hypercapnia ? If Yes then need HCT, if no then in flight O2 @ 2l/min
A patient with COPD has saturations of 91% on 1L LTOT. They want to know if they need further investigations before they fly
If known T1RF - no , just increase LTOT by 2l/min
If known T2RF - yes , needs HCT
Who needs a hypoxic challenge test for flying ?
- those with sats ≤ 95% , not usually on LTOT and at risk of hypercapnia OR sats < 84% on 6MWT or SWT with concerns re hypercapnia
- severe asthma with persistent symptoms or frequent exacerbations despite optimal treatment regardless of SpO2 at sea level
- ILD patients with sats <95% on exercise and resting sea level PaO2 ≤9.42 or TLCO ≤ 50%
- Severe chest wall deformity / severe resp muscle weakness FVC <1L
- Those with existing or previous hypercapnia and those at risk of T2RF already on LTOT
What HCT results indicate need for in flight O2 ?
PaO2 < 6.6 or Sats <85%
Patient with IPF wants to know if they need in flight O2 . There sats are 96% following 6MWT
No , HCT not req and in flight O2 not required
Patient with IPF wants to know if they need in flight O2 . There sats are 92% following 6MWT and they are not on LTOT
Need ABG:
- if PaO2 < 9.42 on room air then need to review TLCO. If TLCO < 50% predicted then need in flight O2 at 2l/min
- if PaO2 > 9.42 then still review TLCO . If <50% predicted then should have HCT. If more then doesn’t require HCT
Patient with IPF on LTOT wants to know if they need in flight O2 .
Yes , 2L greater than usual prescription
What are recommendations for CF patients when flying ?
Review spirometry if FEV1 <50% should have HCT . If sats <90% will need in flight O2
What is the advice following thoracic surgery and air travel?
Four weeks for non essential travel , 2 weeks for essential
What is the advice for air travel following TBB/TBNA/EBUS/Endobronchial valve insertion?
Those with no PTX on X ray should wait 1 week
What is the advice for flying with PTX?
Can’t fly with untreated PTX
Can fly 1 week after resolution of PTX
Be aware those high risk of recurrence
What is the advice for patients who develop sinus barotrauma after flying ?
Topical / oral decongestants and appropriate analgesia.
If allergic component intranasal steroids for 1 week prior to travel and /or oral corticosteroids
Symptoms and signs of barotrauma should have resolved prior to flying
What is the advice for air travel following otitis media ?
Advised not to fly for 2 weeks
What are the viral infections you are advised not to fly with?
Measles , chicken pox , mumps , SARs, MERS, COVID
When can patients with TB fly?
Smear positive patients must not fly until there are two consecutive smear negative samples on treatment
Those starting TB treatment when all info not available should not fly for at least 2 weeks
For those who are smear negative treatment should render them non infectious in 2 weeks
For MDR/XDR TB this is prohibited until 2 negative samples produced and clinical evidence of improvement
Extra pulmonary TB no restrictions
When can patients with Pneumonia fly?
Air travel should be postponed for 7 days in those with sats < 94%
What is the advice for those with OSA/OHS re air travel?
Daytime flights where posssible and take CPAP in hand luggage
Avoid EtOH/sedation
If night flight should use CPAP, if day avoid falling asleep
What is the advice for muscle wall weakness for air travel
FVC < 1L then HCT
If can’t tolerate spiro then consider 6MWT /SWT
What is the advice we provide to avoid VTE with air travel?
Ensure hydrated , avoid alcohol , keep mobile , compression stockings , for high risk patients LMWH ie 40mg Enox /DOAC for long haul (6-8 hr) flight
Low risk - all
Mod risk- over 60, preggo , minor surgery , extensive varicose veins
High risk- precious VTE (and not on anticoag) , thrombophilia , 6/52 major surgery , malignancy
How long should air travel be delayed after acute PE/DVT?
2 weeks
For pulmonary HTN what NYHA category are patients advised to have in flight O2 ?
NYHA III or IV
Should patients with lung cancer / mesothelioma fly if on chemo?
No, high risk of infection and side effects
What are the contraindications to air travel?
Untreated respiratory failure
PTX (unresolved)
Active infection (TB, COVID, MERS, SARS)
Bronchogenic cysts - cerebral air embolism following rupture risk
How do they perform a HCT?
Patient inspires gas mixture containing 15% oxygen
What type of drug is Tacrolimus?
Calcineurin Inhibitor
What type of drug is Ciclosporin?
Calcineurin Inhibitor
What type of drug is Azathioprine?
Purine synthase inhibitor
What type of drug is MMF?
Purine synthase inhibitor
What type of drug is Sirolimus inhibitor?
An mTOR inhibitor
(mTOR is the mammalian target of Rapamycin)
What type of drug is Everolimus inhibitor?
An mTOR inhibitor
(mTOR is the mammalian target of Rapamycin)
Who may be harmed by unecessary high O2?
CO2 retainers
MI (may increase infarct size)
Paraquat poisoning or Bleomycin lung injury
What FiO2 and flow rate is the blue Venturi ?
24% (2-3l/min)
What FiO2 and flow rate is the white Venturi ?
28% (4-6L/min)
What FiO2 and flow rate is the yellow Venturi ?
35% (8-12l/min)
What FiO2 and flow rate is the red Venturi ?
40% (10-15 l/min)
What FiO2 and flow rate is the green Venturi ?
60% (12-15l/min)
How often should O2 saturations be measured in hospital?
4 hourly
What do we do with target sats in COPD?
ABG, if normal then for normal targets UNLESS hx of previous hypercapnia
What can happen with sudden cessation of oxygen?
Rebound hypoxia with rapid fall in O2 sats
Above what BMI should we lower target saturations?
40
What are the equivalent sats of pO2 <7
<85%
Patient on immunosuppressant medications should avoid what vaccines ?
Need to avoid live vaccines :
Measles
Mumps
Rubella
BCG
Yellow Fever
Oral Polio
Oral Typhoid
Patients on immunosuppressive medication who have never had varicella zoster and are exposed should have ?
Immunoglobulin therapy
Patients on immunosuppressive medication who have never had measles and and are exposed should have ?
Immunoglobulin
What should be checked prior to starting and during AZT treatment ?
Prior to starting : FBC, LFT, TPMT
During treatment : FBC ever 2/52 for 3/12 and then monthly , monthly LFTs
At what parameters should AZT /MTX be held ?
WCC <3
PLT < 100
ALP / transaminases > x3
What % of patients have no TPMT activity and should therefore should avoid AZT ?
0.3%
What is Azathioprine ?
Pro-drug of 6-mecaptopurine
What are the side effects of AZT?
Sore mouth, mouth ulcers , nausea , vomiting , diarrhoea , skin rash , alopecia , incr risk of skin cancer
What should be checked prior to starting and during treatment with MTX?
FBC/ U&E/LFT
CXR
Folic Acid
Pregnancy
Avoid if significant hepatic or renal impairment or if ascites / pleural effusion as can accumulate
During :
Bloods every 2/52 for 3/52 and then monitoring
What are the side effects of MTX?
Mouth Ulcers, Skin rashes, nausea , macrocytosis , myelosuppression , pneumonitis
What should be checked prior to starting and during cyclophosphamide treatment ?
FBC /U&E/LFT
Urine Dip
Semen store
Pregnancy check - avoid & if BF (and for 6/12 after for both M & F)
Should have bloods weekly for 1 month then every 2 months
How long does cyclophosphamide take to work?
12-14/7 hence why usually combined with high dose steroids
What are the side effects of cyclophosphamide ?
Haemorrhagic cystitis , bladder cancer , nausea and vomiting , hair thinning , alopecia , cervical cancer
What should be checked prior to starting and during Rituximab treatment ?
FBC/U&E/LFT
Hep B and C
ECG
CXR
First week check FBC/ U&E/LFT and then weekly
Alternative to cyclophosphamide
Side effects of Rituximab
Abdominal pain; acne; alopecia; anaemia; anxiety; appetite decreased; arthralgia; asthenia; asthma; conjunctivitis; constipation; cough; cytokine release syndrome; depression; diarrhoea; dysphagia; ear pain; epistaxis; fever; gastrooesophageal reflux disease; headache; increased risk of infection; influenza like illness; infusion related reaction; leucopenia; lymphadenopathy; malaise; muscle complaints; muscle weakness; myocardial infarction; neutropenia; pain; pancytopenia; peripheral oedema; sensation abnormal; skin papilloma; stomatitis; sweat changes; throat irritation; thrombocytopenia; tremor; vomiting; weight decreased
What is the empey index?
The ratio of FEV1 (in ml) to PEFR (in L)
Useful in predicting if someone has upper airway obstruction , normal result is <10 and if >10 should prompt further evaluation
The PEFR is clipped first by the presence of upper airflow obstruction relative to the FEV2
Where are perfusion and ventilation greatest in the lungs ?
At the bases
What causes an increased DLCO?
Pulmonary haemorrhage
Polycythemia
Obesity
High altitude
Hyperthyroidism
AV malformations
What causes a decreased DLCO?
ILD
Emphysema
Severe anaemia
PE
Increased carboxyhaemoglobin
Hypothyroidism
CCF
Pneumonectomy
What is DLCO ?
The diffusing capacity for carbon monoxide and is the same as transfer factor for carbon monoxide. It is a measure of gas transfer from inspired air to the red blood cells . diseases that decrease blood flow to the lung or damage alveoli cause less efficient gas exchange resulting in lower DLCO
If the PaCO2 is normal the PaO2 for different FiO2 can be estimated how ?
FiO2 (%) x 0.75
In CPET what are indicators of a maximal test ?
- Respiratory Exchange Ratio (RER) > 1.1 (switch from aerobic to anaerobic)
- Low HRR (ie close to maximal HR)
- Rise in lactate
- Anaerobic threshold reached (if given as graph it’s where VCO2 raises faster than VO2)
What are the lung function changes seen in pregnancy?
Expiratory reserve volume decreased , FRC decreased , minute ventilation increased , TLC no change , arterial pCO2 decreased
What are the contraindications to CPET?
- Known history of exercise induced syncope or pre-syncope
- MSK problem limiting exercise
- ACS/MI within 7 days
- Unstable angina
- Poorly controlled HF
- Aortic dissection / Aneurysm
- Acute exacerbation of COPD/Asthma
- Severe Pulmonary HTN
- Resp failure pO2<8
- Acute PE
- Recent DVT
- Frailty
- Hx of seizures / syncope
Most common adverse event during CPET?
Vasovagal / dizzyness
What should VO2 max be in normal individuals in CPET?
> 80% predicted
If > 80% predicted very unlikely that the individual has any significant pathology of heart or lungs (slight caveat with athletes but for purposes of exam)
What should HR be in normal individuals in CPET?
≥ 80% predicted maximal HR
(NB Maximal HR is 220 - age)
What should VE (minute ventilation) be in normal individuals in CPET?
Should not reach 80% of predicted during exercise (as should have ventilatory reserve, NB can be super maximal in athletes)
What is an abnormal fall of O2 sats in CPET?
A fall >4% from resting value is abnormal and implies lung issue, PVD or opening of R to L shunt
What is oxygen pulse ?
A non invasive CPET given idea of CO
What should oxygen pulse be in normal individuals in CPET?
> 10ml/beat at peak exercise
What should AT (anaerobic threshold) be in normal individuals in CPET?
> 40% of predicted VO max (NB predicted, not achieved)
If VO2 max is >80% predicted , how would you interpret the CPET?
Normal
If VO2 max is <80% predicted, max HR <80% predicted and VE max <80% predicted how would you interpret the CPET?
Submaximal effort
If VO2 max is <80% predicted, max HR <80% predicted and VE max >80% predicted how would you interpret the CPET
Lung disease
If VO2 max is <80% predicted, max HR >80% predicted and fall in O2 says >4% how would you interpret the CPET
Pulmonary vascular disease