Preoperative Physiology/ Procedural Consideration

Question 1

Perioperative Phsyiology

* Primary intraoperative goal is maintaining optimal “______ ______” btw the RV + pulmonary circulation to promote adequate left-sided filling and systemic perfusion
* Any intervention that may affect ____ , ____ , ___ , _______ needs to be considered

Answer 1

• mechanical coupling
  *RV preload, inotropy, afterload, and oxygen supply/demand

Question 2

Perioperative Phsyiology

What added perioperative complexities can have potentially serious consequences? (7)

Answer 2

HoTN ,, mechanical ventilation ,, hypercarbia ,, bubbles in IV ,, Trendelenburg ,, Pneumoperitoneum ,, single-lung ventilation

Question 3

Periop :: RV Afterload

• Increased RV afterload leads to? (3)
• Interaction bw RV + pulm circulation is ____ + _____ and involves the compliance of the pulm vessels
• How does ventilator management effect RV afterload? (5)

Answer 3

• RV dilation, increased wall stress, and RV hypertrophy
• pulsatile + dynamic
• PEEP , hypoventilation , hypercarbia , acidosis , atelectasis

Question 4

Periop :: Myocardial Supply + Demand

• RV is thinner walled which leads to greater wall tension and can cause increased _____ _____ ____
• In PAH, elevated RV pressures cause increased ______ __ which makes RV vulnerable to ____ ____ and worsens the O2 supply/demand mismatch
• HTN + RV ischemia/afterload causes the “LETHAL COMBINATION” which consists of what factors?

Answer 4

• myocardial oxygen demand
• coronary flow
• systemic htn
• RV dilatation, insufficient LV filling, reduced stroke volume, and further systemic hypotension

Question 5

Procedural Considerations

• Ortho : Increase M+M with PH + what 2 surgeries?
• Laparoscopy : combination of what 3 things affects RV pressures?
• Thoracic : involve _____ and ____ of operative lung
• What are the 3 features of lung collapse?

Answer 5

• Hip + Knee
• pneumoperitoneum (insufflation) ,, head-down position ,, increased inspiratory pressure
• nonventilation + atelectasis
• (1) pressurize the chest to induce atelectasis&raquo_space; increase pressure on pulm
  o (2) potential for systemic hypoxia
  o (3) hypoxic pulmonary vasoconstriction (HPV)&raquo_space; increase RV afterload