Robert

Question 1

Why did Robert need to be on a ventilator for so long after his accident?

Answer 1

• When he inhaled the water (into his lungs), it dissolved the surfactant that prevents atelectasis from occurring
• Less surfactant = worse O2 saturation

Question 2

How could have the exercise Robert was doing before he fell in the lake have helped him survive?

Answer 2

• When physically active, his body temp would have been slightly elevated and he would have had high RR, so he may have had mild alkalosis too
• When he fell, the acid that accumulated because of insufficient oxygen perfusion may have been slightly offset

Question 3

What happened to Robert when he went into acidosis under the water?

Answer 3

• Due to Bohr effect, (inc acidity = inc Hb offload) so it would have been possible to offload 2 oxygen molecules from each Hb

Question 4

The cold/hypothermia contributed significantly to Robert’s survival. How?

Answer 4

• Hypothermia triggers SNS activation = peripheral vasoconstriction in periphery = stops cold from getting to core
• Cold makes metabolic processes slower therefore acidosis occurs at a slower rate
• Bradycardia so may have had a very weak/slow pulse that was undetectable

Question 5

What are some risks for Robert?

Answer 5

• Infection (pneumonia, etc.) = from bacteria in water he inhaled
• Hypoxia can lead to renal failure because of fixed acid generation = puts stress on heart

Question 6

Robert’s heart stopped while he was underwater. What primary physiological consequence resulted from this?

Answer 6

• Coagulation cascade begins when heart stops but since it was super cold, this process was happening slower