There are many caveats (e.g. regurgitant valves), but two basic points:
*Not all pts will have sx when PCWP>12 or RA>6.
*Those aren’t necessarily goals for diuresis either (“optimal” filling pressures change as ventricular function changes)
Within the pulmonary vascular bed:
I ▶️ Q = flow = cardiac output
V ▶️ delta-P ▶️ pressure difference across the bed ▶️ mPAP – PCWP
R ▶️ pulmonary vascular resistance = PVR
>Heuristic: a cognitive shortcut based on prior experience & pattern recognition
>Cognitive Bias: when a heuristic leads to misdiagnosis or inappropriate treatment
We need heuristics b/c reasoning every decision from 1st principles would take forever!
3/ Heuristic vs Bias
There is a fine line b/t a heuristic and a bias
For example: 80yoM w/ CAD p/w SOB, ankle edema, and alveolar filling on CXR. You start abx PNA
👍If he improves, PNA was a good call
👎If he gets worse because he has ♥️ failure, PNA was “premature closure”
It's time for #TwitterReport! Get out your illness scripts and problem representations.
Case: A 65yoM with metastatic melanoma goes to the ER with RLE edema: doppler shows a femoral DVT. He also says he's been getting more tired over the last 4wk.
What else do you want to know?
PMH: HTN, HL, T2DM (now diet controlled), metastatic melanoma
PSH: none
Meds: HCTZ, metoprolol, atorvastatin, pembrolizumab/ipilimumab (last cycle 2 weeks ago)
Social: lives with wife and dog at home. From a local rural area. Never smoker/alcohol. Former construction worker.
ER Triage Vitals:
-Temp 37*C
-HR 60
-BP 90/54
-RR 12
-SpO2 98% on room air
It’s time for #PhysioQuizzo! And today, we got a really trippy puzzle for you. [thread]
1/x You’re still working in the ICU (1 week to go!), and you take care of a pt who overdosed. He was revived in the ER. Urine was obtained before naloxone was given.
Quiz on post 3/x.
2/x His UDS is shown below. His outpatient med list is also shown.
You’ll note his UDS is positive for everything...
3/x
Here’s the Quiz:
—Which of the following is the least he could have plausibly taken given his UDS? (Assume he’s taken all his home meds that day)
A. Each and every drug on the UDS
B. Home meds, ethanol
C. Home meds, EtOH, oxycodone, valium
D. Home meds, cocaine, oxy, heroin
HPI:
-3 times in 1 month she’s gotten up from sitting and passed out. Darkened vision each time.
-First one witnessed by sister. She woke up w/in 1m. No confusion.
-Fatigue for the past 3-6mo
-No fevers or chills but she’s had a 10 lbs weight loss this year