#Nephrology #POCUS short story:
1/ Simple case, want to remind some pitfalls in routine practice.
There was a patient with orthostatic hypotension. Likely neurogenic secondary to amyloidosis.
Read the thread 🧵below:
#IMPOCUS #MedEd mini #tweetorial

2/ Physician A orders IV albumin q 6 hours and keeps continuing because:
1. 'Formal' echo from 4 days ago reported a RAP of 3 mmHg = not high
2. 'Documented' weight showed 3 kg drop since admission
Interestingly, documented cumulative fluid balance is +4 L!

3/ Physician B comes in and performs physical examination (#POCUS). Supine BP is relatively low (SBP ~103 mmHg) but nothing different compared to patient-reported figures at home. Pt feels OK, on midodrine.
Here is the IVC👇

1/How can #POCUS #echofirst help in the evaluation of #hyponatremia?
#Nephrology consulted for low sodium. Pt received diuretic for shortness of breath (which was possibly due to hiatal hernia as shown on CXR).
2 physicians FELT patient was EUVOLEMIC
Small 🧵below 👇 #MedEd

2/Based on the above labs, it does look like euvolemic hyponatremia (Urine Na is high, Uosm >100 but not too high, BUN not high). BP was 150s systolic.
That's it? Give some salt tablets or UreNa etc.?
No; perform PHYSICAL EXAM (= #POCUS)
IVC was small - doesn't tell much 😬

3/ Next step? Look at the heart, assess stoke volume.
Recent echo LVEF>50%
LV contraction looks good visually
We measured LVOT VTI (couldn't measure LVOT diameter due to chest deformity precluding good PLAX view but its not a problem; VTI is generally enough)
#POCUS

Time to discuss some rationale/evidence behind doing #VExUS #POCUS #Nephrology
A short #tweetorial #MedEd 👇
1/ Is fluid overload harmful?
of course yes. Here is a recent meta-analysis.

2/ Does fluid administration affect renal venous flow in asymptomatic but vulnerable patients (#heartfailure)?
#POCUS #VExUS

3/ In fact, elevated CVP is associated with reduced GFR.
This 👇is a study in outpatients undergoing right heart cath (N = 2557). In CVP values >6 mm Hg, a steep decrease in GFR was observed.

#POCUS #echofirst #MedEd case of the day.
Context: alcoholic liver cirrhosis with suspected #hepatorenal syndrome
Purpose: think about the underlying pathophysiology & seek expert input
1/ PLAX, PSAX, Apical views of the heart. Heart rate ~110-116 bpm
#VExUS images in 🧵

2/ overall, looks hyperdynamic. LA looks little enlarged on PLAX, visual TAPSE high on apical.
In cirrhosis, hyperdynamic circulation is expected because of splanchnic vasodilatation and 'relative' arterial under filling.
LV EF #POCUS obtained using @kosmosplatform 👇

3/ Lets calculate stroke volume using LVOT VTI #POCUS
It looks supra-normal

OK #VExUS #POCUS enthusiasts, time for another case discussion.
Somebody asked if I ever recommend IV fluid in a patient with #VExUS 3.
Here is one example where I did.
1/ First, let's see the #physicalexam (#IMPOCUS) findings, then will tell about the case. #MedEd #Nephrology

2/ So, hepatic shows D-only pattern👆
If we are doing #VExUS, IVC must be big. Here is the M-mode #POCUS 👇

3/ Renal parenchymal vein #VExUS #POCUS
It also demonstrates D-only pattern 👇

#POCUS quiz of the day:
Easy one. Identify 1, 2 and 3.
POLL in thread 👇 #IMPOCUS #MedEd

👆#POCUS
PE = pleural effusion
PER = pericardial effusion
Ao = aorta
IVC = inferior vena cava
Rt = right
Lt = left

Correct answer: option 2 -
1. left pleural effusion (note the appearance of collapsed lung; also u can see rib shadows/posterior chest wall = lung area)
2. Right pleural effusion (remember the Boomerang sign on subxiphoid view?)
3. IVC

Time for a #POCUS #tweetorial on optimization of Doppler. Very important for #VExUS enthusiasts. #MedEd
1/ Unlike greyscale imaging which depends on amplitude of the returned signal, Doppler depends on frequency information. This graphic explains why perpendicular angle is bad.

2/ other way of saying this, in relevance to color Doppler #POCUS
RBC moving away from the probe = Fr<Ft = negative Doppler shift = Blue color
RBC moving towards = Fr>Ft = positive Doppler shift = Red color

Rest of the images/videos from this excellent paper: pubs.rsna.org/doi/10.1148/rg…
3/ Anatomy (components) of a spectral Doppler waveform (carotid shown)👇
Above baseline is like red on color (towards probe), below = blue. As 0 degree angle is not always possible, <60 is considered OK.

@khaycock2 @ArgaizR @katiewiskar @ThinkingCC
Any comments on this portal vein pulsatility obtained from a pt with cirrhosis? (Why prox is more pulsatile?)
No cardiac issue that I know of; was reviewing rad-performed images 🤔

Splenic seems to be fine, looks more like that of distal portal.

Hepatics

1/ Thought of doing a quick #tweetorial on image acquisition for #POCUS friends starting to do #VExUS
It's kind of "how I do it" guide and not necessarily optimized for research.
1st: Look at the IVC in both long and short axes
If big, do further scans 👇 #MedEd #FOAMed

2/ Lateral approach works best to obtain a straight segment of the portal vein (straight = best Doppler shift) and a nice hepatic vein too.
Place transducer approximately in the anterior axillary line pointing towards sternal notch. Then fan antero-posteriorly.
#POCUS #VExUS

3/ Forgot what is fanning?
Its also called tilting or some people say, "look" in a particular direction from the same spot.
#POCUS

#Nephrology #POCUS case of the day:
What do you think is this anechoic structure adjacent to liver?
See thread 👇 for the answer and more images. #MedEd #IMPOCUS

Let's start with a poll before seeing other images: ☝️? #POCUS

The answer is right renal cyst. Note how the kidney appears with fanning the probe. #POCUS
Is rest of the kidney normal? doesn't appear to be...🤔

OK #VExUS #POCUS hemodynamicians, welcome back to the case. As promised, here are some follow up images:
@ArgaizR @ThinkingCC @khaycock2 @katiewiskar @Thind888 @MDBeni et al.
Hepatic v. 👇

Looks D-only but could this be S-wave? (or a delayed D? Pt has Afib and predisposed to having smaller S but wondering if there is some S-D fusion here)

Forgot, here is the IVC. Similar to previous.

Renal #POCUS in a #dialysis patient: Looks fine at first glance (thin parenchyma as expected) but fanning anteriorly reveals a large cyst, which would have been missed otherwise. Labeled images and notes in thread 👇
#Nephrology #MedEd #IMPOCUS

Labeled first image #POCUS
Note: peri-renal fat (usually prominent in ESRD patients) can be confused with free fluid.

Labeled second image #POCUS (obtained with phased array probe)
Note: EKG is not needed 😀

#Nephrology consult for worsening creatinine in the context of diuresis in a patient with #heartfailure
Documented weight 3 kg ⬇️ than the previous day. No accurate urine output. Pt feels OK (has some unrelated issue).
Question: over diuresis?
#POCUS #MedEd #VExUS see thread 👇

So, there is decreased LV systolic function and obviously diastolic dysfunction. Bi atrial enlargement. No significant pericardial effusion (there was trace on PLAX).
Next step in the hemodynamic circuit #POCUS assessment?
btw repeat weight was similar.

Next: IVC #POCUS assessment to assess right atrial pressure.
Here it is 👇
Big and plethoric (take it as 15 mmHg in a spontaneously breathing person - we get RVSP of ~41 mmHg based on the above tricuspid gradient)

Stimulated by the enthusiasm of #MedEd student and #nephrology fellow, did a small experiment to see how well #POCUS -determined blood flow in the continuous renal replacement therapy (CRRT) circuit correlates with the actual no.
1/ First, got a color #Doppler img. of the tube 👇

2/ How do you calculate flow? It is the same principle that we use to determine flow rate in an arteriovenous fistula 👇 #POCUS

3/ 2nd step: measured the diameter of the tube (double-lined structure) - 0.42 cm

#POCUS #IMPOCUS
Understanding #VExUS from scratch:
A mini #tweetorial on normal hepatic vein waveform genesis 👇 #MedEd #echofirst

1/ Understanding color and direction

2/ What is S wave? #POCUS

3/ V wave #POCUS

#POCUS Intra-renal vein Doppler waveform looking exactly like that of hepatic vein!
#VExUS obtained from a #nephrology clinic patient with pulmonary hypertension. #MedEd

Normal hepatic vein waveform #POCUS

Portal vein #POCUS in this patient - increased pulsatility.

@Thind888 @FH_Verbrugge @khaycock2 Dear hemodynamic masters, saw a cirrhotic pt with oliguria (relatively preserved Scr) & pulmonary congestion. Based on these findings, suggested norepinephrine (pressors). Agree? any educational input appreciated.

Basically I interpreted as high output cardiac failure with elevated filling pressures leading to pulmonary congestion.
This tracing I believe is right intra-renal 'arterial' with diminished diastolic flow. Correct me if I'm wrong.

Sorry, didn't realize that the scale dropped

1/ #Nephrology #POCUS case study:
Dr. X is rounding on an ESRD pt who initially presented with dyspnea after missing a dialysis (HD) session; underwent dialysis in the hospital. Pt asymptomatic at the time of exam and lung #ultrasound revealed 👇 Further story in thread #MedEd

2/ Based on the 2-zone lung #POCUS, Dr. X orders for another session of HD. Notably, pt says he is at his 'dry weight' and HD nurse says they could only get 1.5L off during first session. Dr. X doesn't change his/her mind.
Info on various lung scan zones👇

3/ Patient becomes hypotensive during HD and only ~500cc fluid could be removed.
Why can't we get more fluid out of a hypervolemic patient? Dr. X is perplexed and decides to more #POCUS Here is the IVC

#POCUS #echofirst The correct answer is dilated coronary sinus [48% got it right (of 229 votes)]. From #IMPOCUS standpoint, 2 main causes: persistent left superior vena cava and pulmonary HTN. This pt had the former. Normal anatomy of the coronary sinus (Read #thread)👇 #MedEd

https://twitter.com/NephroP/status/1272314795484643328

More anatomy: 3D CT angio
We need to understand the anatomy first to understand #pocus orientation

Original image shows the typical location of CS in PLAX view. Don't confuse with descending aorta. You can also see CS from the apical window. From apical 4C, tilt the transducer posterior (in the opposite direction as you would for the 5-chamber view) #POCUS

#POCUS teaching case: #Dialysis patient c/o sob, reports weight gain. BP low to begin with (~100-110 mmHg systolic) & drops further during ultrafiltration. Dr. X performs IVC #ultrasound at the bedside and sees this 👇 - probably volume depleted? See #thread
#MedEd #nephrology

2/ Dr. X orders to stop ultrafiltration. BP stabilized a little bit.
All done?
Wait, something doesn't make sense. Why did the patient gain weight? (usually #dialysis patients know their dry weight well). Why sob?
In the meanwhile, radiology tech performs chest #X-ray 👇

3/ That's not good. Diagnosis is apparent but lets get Dr. Y who does more than just IVC #POCUS
Subcostal view 👇
Significant pericardial effusion

Time for another #VExUS #POCUS case: A pt with known severe CHF presents with abdominal pain and receives fluids (~1L). Later develops AKI, hyper K.
NOTE: has trace edema; no c/o weight gain
Here is what #echofirst and venous #Doppler show. #MedEd #thread 👇
1/ Apical 4 chamber

2/ Note the smoke (spontaneous echo contrast) on the left. Also, LA is huge. Another one 👇

3/ PLAX view #POCUS
Note left pleural effusion (fluid posterior to descending aorta)