PULMONARY HTN-GROUP 2 & 3 TX

SUMMARY

GROUP 2: NO TX AVAILABLE!
1. Vasodilation of precapillary arterioles with fixed elevated post capillary pressure
2. Worsening of pressure gradient over alveolar bed precipitating pulmonary oedema

GROUP 3: NO TX AVAILABLE!
1. Very tight automatic control V/Q matching
2. More blood flow to well ventilated lung; less blood flow through poorly ventilated lung (blood diverted away from damaged lung)
3. Pulmonary vasodilator drugs disturb this autoregulation –shunting of blood to poorly ventilated lung with more hypoxaemia

NB: limited role for vasodilator therapies in post capillary PH (PCWP >15mmhg) and PH secondary to lung disease, i.e. groups 2 & 5

Reference(s)

Wilkinson, I., Furmedge, D. and Sinharay, R. (2017). Oxford handbook of clinical medicine. Oxford: Oxford University Press. Get it on Amazon.
Feather, A., Randall, D. and Waterhouse, M. (2020). Kumar And Clark’s Clinical Medicine. 10th ed. S.L.: Elsevier Health Sciences. Get it on Amazon.
Hannaman, R. A., Bullock, L., Hatchell, C. A., & Yoffe, M. (2016). Internal medicine review core curriculum, 2017-2018. CO Springs, CO: MedStudy.
Therapeutic Guidelines. Melbourne: Therapeutic Guidelines Limited. https://www.tg.org.au [Accessed 2021].