Pulmonary hypertension:

 

Normal values

PASP

<25 or <20mmHg (??)

Wedge

<12mmHg

PVR

<3 Wood units

TPG

<12mmHg

DPG

<7mmHg

 

Causes of PHTN:

·         Left heart failure

·         Lung disease

·         Chronic venous thromboembolism

·         Systemic inflammatory disease

·         Primary pulmonary hypertension

 

Severity:

NYHA style

1.    No limitation

2.    SOB with decent activity

3.    SOB with minimal activity

4.    SOB at rest

By mPAP

·      Mild: 20-40

·      Moderate: 40-55

·      Severe: >55

 

Anaesthetic goals: PHTN with RV dysfx

Perfuse the coronaries

·      Maintain arterial pressure (fluid + pressor)

·      Avoid tachycardia

Support the RV

·      Maintain preload (fluid)

·      Minimise afterload (↓PIP and PEEP)

Minimise PVR

Physiology:

·      Normal O2

·      Low-normal CO2

·      Normal pH

·      Normal temp

·      Normal lung volume

Pharmacology:

·      General anaesthetic drugs

·      Nitric oxide donors (GTN, NTP)

·      Nitric oxide itself

·      Prostanoids

·      Endothelin receptor antagonists

 

Anaesthetic management:

Monitoring

·      Sat probe

·      Arterial BP

·      5 lead ECG

Access

·      Big IV

·      Arterial line

Induction plan

·      IV fluid 5mL/kg bolus

·      Metaraminol infusion 5mg/h

·      Fentanyl 5mcg/kg

·      Propofol 1mg/kg slow bolus

·      Rocuronium 1.2mg/kg