Contemplating medicine and the health care system
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This podcast represents the answer to the acid base case I posted yesterday. Please provide feedback on the answer and podcasting in general.
Solution to acid base case of 11/11/08
56 year old man with known COPD and pulmonary fibrosis was admitted a week ago for worsening respiratory status. He slowly improved (after a few days in the ICU.) Now he has the following ABGs:
Electrolyte panel
Na
Cl
BUN
K
4
HCO3
creat
Blood Sugar
ABG
pH
7.47
pCO2
49
pO2
77
calc HCO3
36
What is the acid-base disorder? What would you do?
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Anion Gap Acidosis
This represents the first in a series of 7 lectures that I plan for understanding acid-base problems. Please provide feedback and questions. I plan to collect questions over a few days and then prepare an audio addendum.
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Electrolyte panel
Na
141
Cl
112
BUN
18
K
4.3
HCO3
15
creat
0.7
Blood Sugar
105
ABG
pH
7.33
pCO2
25
pO2
103
calc HCO3
13
Today’s patient is well known to our service. She is 32 and has a long history of Crohn’s disease, with an ileostomy. Consider the differential diagnosis, and recommend tests to prove your hypothesis.
Additional information - albumin 5.7
Urine lytes = Na 10, K 47, Cl 72
Crohn’s patient explanation
Electrolyte panel
Na
141
Cl
112
BUN
18
K
4.3
HCO3
15
creat
0.7
Blood Sugar
105
ABG
pH
7.33
pCO2
25
pO2
103
calc HCO3
13
Today’s patient is well known to our service. She is 32 and has a long history of Crohn’s disease, with an ileostomy. Consider the differential diagnosis, and recommend tests to prove your hypothesis.
I have posted this case before. I am reposting because of all the positive feedback I received on the audio [...]
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I am trying an audio version of explanation for the case presented 4 days ago. I need your feedback - do you like this strategy, or should I type out the answer.
Acidosis discussion
49-year-old man, previously in good health, presents after a few weeks of progressive weakness and dizziness. He admits to polyuria. Your job is [...]
49-year-old man, previously in good health, presents after a few weeks of progressive weakness and dizziness. He admits to polyuria. Your job is to extensively discuss his lab tests.
Electrolyte panel
Na
147
Cl
104
BUN
28
K
4.7
HCO3
16
creat
1.3
Blood Sugar
678
ABG
pH
7.3
pCO2
33
pO2
68
calc HCO3
16
On sit down rounds yesterday morning, the team told me about a gentleman with severe achalasia. Because of the achalasia he had a G-tube in place for 15 years. As they told the story he came in for vomiting and was found to have a left lower lobe pneumonia. They worried that the patient had [...]
We have an interesting situation on our service this week. The patient is a 62 year old man with hepatocellular carcinoma. He has had significant hepatic encephalopathy. Lactulose does control his encephalopathy, but he tells us that the frequent stools that lactulose causes have a significant negative impact on his quality of life. Since he [...]
ABG
pH
7.35
pCO2
48
pO2
74
calc HCO3
25
50 year old man presents with chest pain and a recent abnormal stress test. He has a 30-40 pack year history.
This ABG was taken on room air.
Can you describe a set of circumstances that would give you these results?
I must congratulate the 2 responders, obviously astute diagnosticians. As they surmised, the liver tests did not support primary liver disease. The albumin was low but not what we would expect with cirrhosis. The other liver tests were remarkably normal.
We obtained an echocardiogram which showed severe pulmonary hypertension and pure right sided dilation and heart [...]
55 year old man admitted to our service for ascites and anasarca (massive scrotal and leg edema.) The patient had large volume paracentesis. The SAAG (serum ascites albumin gradient) was 1.8 - consistent with portal hypertension. He had no evidence for spontaneous bacterial peritonitis. His serum ammonia was normal.
Later that evening he becomes hypoxic and [...]
I am current at the ACP annual meeting, and this morning heard a brilliant grand rounds on hyponatremia - given by Juan Carlos Ayus. I have found an excellent article in the Southern Medical Journal that he co-authored on treatment of dysnatremias and also provide this Medscape link - Hospital-Acquired Hyponatremia — Why Are Hypotonic [...]
This interesting article describes a current Archives of Internal Medicine - Reasons Documented for Heart Failure Admissions
At least one identifiable precipitating factor was found in 61.3% of patients, the researchers said. In order of frequency, they were:
Pneumonia or respiratory processes at 15.3%.
Ischemia or acute coronary syndromes at 14.7%.
Arrhythmia at 13.5%.
Uncontrolled hypertension at 10.7%.
Nonadherence to medications [...]
The response to yesterday’s presentation was excellent. The key point here is the markedly elevated alk phos suggests biliary obstruction. The mildly elevated bilirubin suggests incomplete obstruction.
This patient needed a biliary evaluation. The patient had an unfortunate diagnosis - cholangiocarcinoma.
Please create a differential diagnosis for the following liver tests in an 80 year old woman:
Liver tests
Total protein
4.8
Albumin
2.2
Total Bili
6.5
Direct Bili
4.3
Indirect Bili
2.2
Alk Phos
973
AST
170
ALT
100
Yesterday’s numbers:
Electrolyte panel
Na
141
Cl
112
BUN
18
K
4.3
HCO3
15
creat
0.7
Blood Sugar
105
ABG
pH
7.33
pCO2
25
pO2
103
calc HCO3
13
Additional information:
1. She had increased ileal output.
2. Serum albumin was 5.7
3. Urine Na 10, urine K 47 and urine Cl 72
Her anion gap is 14, which is normal given her elevated albumin
Her urine anion gap is negative, consistent with sufficient ammonium (NH4+) in her urine
The urine anion gap results supports increased [...]
Started rounds today and had several interesting laboratory findings. I plan to post some patient quizzes for the next 3 days.
Electrolyte panel
Na
141
Cl
112
BUN
18
K
4.3
HCO3
15
creat
0.7
Blood Sugar
105
ABG
pH
7.33
pCO2
25
pO2
103
calc HCO3
13
Today’s patient is well known to our service. She is 32 and has a long history of Crohn’s disease, with an ileostomy. Consider the differential diagnosis, and recommend tests to prove your [...]
The new issue of the American Journal of Medicine has an addition to the world of CAP severity prediction - C-Reactive Protein Is an Independent Predictor of Severity in Community-acquired Pneumonia
CRP does a better job of predicting complicated pneumonia than the two standard models - CURB65 and Pneumonia Severity Index .
Both indices are better [...]
To remind you:
Exam reveals a markedly volume contracted 61 year old woman.
Electrolyte panel
Na
135
Cl
88
BUN
127
K
4.3
HCO3
14
creat
7.4
Blood Sugar
109
ABG
pH
7.3
pCO2
26
pO2
70
calc HCO3
13
Her serum albumin was 4.8. Her urine creatinine was 330 with a urine sodium of 14. Her PTH level was 138.
Resolution
This patient had remarkable volume contraction. She had both an increased anion gap acidosis as well as a metabolic [...]
Here is another puzzle for acid base aficionados.
The patient is a 61 year old woman admitted for severe nausea and vomiting. She states that she has had 6 days of severe nausea, vomiting and diarrhea. The diarrhea was watery.
Her past medical history included “CHF with normal EF”, gout, hypertension and a previous episode [...]
Congrats to the readers, most of you understood the point. Here is my analysis.
ABG
pH
7.46
pCO2
66
pO2
61
calc HCO3
46
1. The patient is alkalotic, therefore the patient clearly has a metabolic alkalosis.
2. I had to look up the compensation for metabolic alkalosis (I remember the Winter’s equation but not this equation). The predicted pCO2 = 0.7*HCO3 [...]
We made rounds on an 82 year old man today. Because his electrolyte panel revealed a bicarbonate level of 40, we order an ABG. The patient has known COPD and CHF. He was intubated until 2 days ago. He received aggressive diuresis for volume overload. Now his ABG reveals:
ABG
pH
7.46
pCO2
66
pO2
61
calc HCO3
46
Questions [...]
Readers know that I love teaching acid base and electrolytes. For years I (and many other educators) have difficulty explaining why edematous states can lead to hyponatremia. We always have talked about ineffective intravascular volume, although when you measure the intravascular volume it measures as increased. Thus, we had a difficult concept [...]
Today was my last day for this 2 week rotation. While there are clear personal advantages to a 2 week rotation, I still prefer doing a full month. My administrative circumstances make a full month very difficult, so I will probably have to compromise with shorter rotations.
The month was delightful. I had wonderful housestaff and [...]
Yesterday we reviewed stage III chronic kidney disease. So today I will review the main points I make as I discuss this condition.
Stage
GFR
Description
Treatment stage
1
90+
Normal kidney function but urine or other abnormalities point to kidney disease
Observation, control of blood pressure
2
60-89
Mildly reduced kidney function, urine or other abnormalities [...]
Yesterday I did something that I rarely do - I recommended bariatric surgery.
The patient has a BMI of 38.4 and is probably 100 pounds overweight. He has severe obstructive sleep apnea(OSA). At an earlier age he was very active, but he had “back surgery” and now he has little activity.
In our conversation, we discussed the [...]
Today we discussed a new patient with his first bout of hepatic encephalopathy. This gentleman has known hepatitis C. Unfortunately, he is not a good candidate for antiviral therapy.
His laboratory data suggest early cirrhosis (although we do not have biopsy confirmation.) His albumin is 3.5 and his INR is slightly higher than [...]
I have used this presentation for the past 30 years. It provides students a wonderful opportunity to consider the entire differential diagnosis of hypercalcemia. The answer is a surprise to many. In the presentation I fail to mention that the tachycardia persisted after volume expansion.
Today my team is admitting, so I made rounds in the afternoon. Our service is relatively quiet, so I took time to discuss a classic case from my residency. I previously did a podcast on this patient, but I suspended the podcast service and will have to write out the case now.
This case [...]
I forgot to include the calculated HCO3 in the acid base problem. I have editted the entry to now include that number.
My apologies to readers - I hope this number make the explanation more clear.
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