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
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 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 [...]
Was It the Drinking Binge?
Solution to "Was It the Drinking Binge?"
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 [...]
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 [...]
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.
One of my main teaching philosophies includes understanding how to teach basics and when to move to more advanced concepts. Solving yesterday’s problem requires some more advanced concepts.
The normal anion gap depends on the albumin level (albumin is the major component of the normal anion gap.) Therefore, when the albumin is decreased below [...]
60 yo male with strong alcohol history is admitted for cellulitis. On his second day in the hospital he develops delirium tremens and aspirates. In the ICU he requires sedation for his DTs.
He had the following laboratory values on the 3rd day of ICU care:
Electrolyte panel
Na
142
Cl
110
BUN
27
K
4.5
HCO3
17
creat
2.0
Blood Sugar
468
ABG
pH
7.24
pCO2
25
pO2
126
calc HCO3
10
His albumin is 3. His serum osms are [...]
Solution to "A 52-Year-Old Man With a Low Bicarbonate Level"
A 52-year-old Man With a Low Bicarbonate Level
Enjoy - the answer will be posted next week
To revisit our problem -
On room air - serum bicarbonate is 44
ABG
pH
7.52
pCO2
54
pO2
62
Clearly the patient has a metabolic alkalosis with respiratory compensation. The pO2 appears low, but …
Go to an A-a gradient calculator - and I calculate an A-a gradient of 20. While this was slightly elevated, I do not [...]
This ABG is quite deceiving. Calculate the A-a gradient - does that change your thought process?
The housestaff obtained this ABG on a patient presented yesterday at morning report.
Your task is to explain the acid-base disorder and the oxygen level.
On room air - serum bicarbonate is 44
ABG
pH
7.52
pCO2
54
pO2
62
I saw a similar patient 3 years ago. This case report is important - A case of valproate-induced hyperammonemic encephalopathy: look beyond the liver
The patient was admitted to hospital for further investigations and for monitoring with video electroencephalography. In the first 48 hours after admission, her level of consciousness fluctuated. Subsequent tests revealed an [...]
I am working on a handout for a workshop on acid-base and electrolyte disorders. This entry is my attempt to explain renal ammonia physiology. I hope a few readers will critique my attempt.
Each day the average American creates 1 mEq/kg of acid which needs buffering. Most of the acid comes from protein. [...]
Thanks to Dr. RW - Propylene glycol toxicity due to high dose lorazepam infusions
ADR Prevent-ERR: IV Lorazepam Infusion and Propylene Glycol Toxicity
A hospitalized patient with respiratory failure was sedated for intubation with a continuous infusion of lorazepam, initially running at 4 mg/hour but increased over the next several days to a maximum rate of [...]
Since that patient was not otherwise ill - normal vital signs, no fever - we decided to treat his nausea and vomiting as an extension of his previous GI dysfunction. We started metoclopramide, which worked well. We also wondered if his poorly functioning indwelling catheter may have contributed to his symptoms.
In terms of [...]
"For every complex problem, there is a solution that is simple, neat, and wrong." - HL Mencken
"I hear and I forget. I see and I remember. I do and I understand." - Confucius
"The good physician treats the disease; the great physician treats the patient who has the disease" - Sir William Osler
"Those are my principles, and if you don't like them - well, I have others." - Groucho Marx
"It is hard enough to remember my opinions, without also remembering my reasons for them" - Friedrich Nietzsche
"Anyone can make the simple complicated. Creativity is making the complicated simple." - Charles Mingus
"Not everything that can be counted counts, and not everything that counts can be counted." - Albert Einstein
"A foolish consistency is the hobgoblin of little minds, adored by little statesman and philosophers and divines. With consistency a great soul has simply nothing to do." - Ralph Waldo Emerson
"This ain't no party, this ain't no disco, this ain't no fooling around." - Talking Heads, Life During Wartime
"What is hateful to you, do not do to your neighbour. This is the whole Torah; all the rest is commentary. Go and learn it." - Hillel, Talmud, Shabbath 31a
"You will never understand bureaucracies until you understand that for bureaucrats procedure is everything and outcomes are nothing." - Thomas Sowell
"An idealist is one who, on noticing that a rose smells better than a cabbage, concludes that it will also make better soup." - HL Mencken
"If you only have a hammer, you tend to see every problem as a nail." - Abraham Maslow
"A great teacher is one who realizes that he himself is also a student and whose goal is not to dictate the answers, but to stimulate his students creativity enough so that they go out and find the answers themselves." - Herbie Hancock
"There are no facts, only interpretations." - Nietzsche
"An education isn't how much you have committed to memory, or even how much you know. It's being able to differentiate between what you do know and what you don't." - Anatole France
