Transcript Chairman Rounds

Chairman Rounds
Medicine I
Jesse Lester, Kannan Samy, Matt
Skomorowski, Dan Verrill
Patient Presentation
• 54 year old African American female
presents to the ED with vomiting and
depression on 12/3
• Vitals: BP 103/62, HR 119, RR 20, T 98F
• Her symptoms began four days ago.
• What else would you like to ask her?
History of Present Illness
• Patient reports a recent increase in her
alcohol intake and depressed mood.
• Her sister recently died and the patient is
having difficulty coping with the loss.
• What things would you suspect knowing
this information?
Past Medical History
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Non-insulin dependent diabetes mellitus
Alcoholic Hepatitis
Hypertension
s/p C-section
Medications:
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ASA 81mg
Nexium 40 mg
Januvia 100mg
Diovan 80 mg
Magnesium Oxide 400mg BID
Social History
• Current smoker
• Patient reports occasional alcohol
consumption. Daily alcohol use is approx.
1/4c gin.
• Not employed, single and lives alone
Review of Systems
• Patient denies fever, diarrhea, abdominal
pain, ill contacts, change in bowel
movements, problems with urination.
• Patient does report orthostatic
weakness/dizziness, and feels she cannot
eat and continues to vomit because of
emotional upset. Whatever she puts in
comes back up.
Physical Exam
• Gen: No acute distress, appears moderately ill,
alert and oriented
• ENT: Neck is supple, no adenopathy, sclerae
are non icteric
• Pulmonary: Unlabored respiration, good breath
sounds bilaterally
• CV: RRR, no murmors, normal S1S2
• Abd: soft, nontender, no organomegaly, normal
bowel sounds
• Psych: Flat affect, poor eye contact
Labs
• CBC: WBC 2.4, HGB 11.1, HCT 31.9,
MCV 116.5, Plt 81
• BMP: Glucose 74, BUN 14, Creatinine
1.20, Na 138, K 3.8, Cl 97, HCO3 8, Ca
7.3
• ABG: 7.12/21/98/7/95%
• Blood Osmolality 350
• Ethanol: 0.166
• Lactate: 4.4
Labs, continued
• Urinalysis: Nitrite negative, leukocyte
esterase trace, glucose negative
• Utox Panel: negative
Differential Diagnosis?
Step 1: Determine the primary insult
1) pH – acidosis or alkalosis?
- normal 7.4
Our patient: pH=7.12
pCO2=21
pO2=98
2) Metabolic or respiratory?
- Normal bicarbonate=24
>24=alkalosis
<24=acidosis
-Normal pCO2=40
>40 acidosis
<40 alkalosis
Bicarbonate=7
O2 sat=95%
Step 2: Compensation
1) Respiratory compensation for primary metabolic disorder
Acidosis:
Winter’s formula:
1.5 * HCO3 + 8 +/-2 = PCO2 (if compensated)
Another method:
1.2 *∆HCO3 +/-2 = ∆PCO2 (if compensated)
Alkalosis:
0.6 *∆HCO3 +/-2 = ∆PCO2 (if compensated)
Our patient:
1.5 * (7) + 8 +/- 2 = 16.5 <–> 20.5
Patient’s pCO2 = 21, therefore the metabolic acidosis is compensated
Step 2: Compensation
2) Metabolic compensation for primary respiratory disorder
Acidosis:
Acute:
0.1 * ∆PCO2 +/- 2= ∆HCO3
Chronic: 0.3 * ∆PCO2 +/- 2= ∆HCO3
Alkalosis:
Acute:
0.2 * ∆PCO2 +/- 2= ∆HCO3
Chronic:
0.4 * ∆PCO2 +/- 2= ∆HCO3
Step 3: Anion Gap
1) Only applicable with metabolic acidosis
2) Will be elevated if there is another serum anion creating the acid-base
disturbance
Normal AG = Na - (Cl+HCO3) = 12 +/- 2
(or 6-12 depending on who you are asking)
Our patient = 138 – (97+7) = 138 – 104 = 34
Therefore the patient has an elevated anion gap metabolic acidosis
Step 4: ∆/ ∆ Gap
1) Only applicable with an anion gap metabolic acidosis
2) Will be abnormal if a mixed disorder is present
In a sole AG metabolic acidosis ∆AG = ∆HCO3 should hold true
Our patient:
∆AG = 34 – 12 = 22
the predicted HCO3 = 24 – 22 (AG) = 2
Patient’s bicarb = 7, there is a base excess of 5
Therefore there is a coexisting metabolic alkalosis, possibly due to
her nausea/vomiting or contraction alkalosis.
Step 5: Osmolal Gap
1) Calculated when there is an anion gap metabolic acidosis
2) Will be abnormal if there is another electrolyte or ion present in serum
OG = 2 * Na + glucose/18 + BUN/2.8
The calculated number should be compared to the patient’s serum osmolality
- if the gap is greater than 10 it is abnormal
Our patient = 138 + 74/18 + 14/2.8 = 286.6
Serum osmolality (lab value) = 350
Therefore the patient has an elevated osmolal gap
Step 6: Urine Anion Gap
1) Can be used to differentiate between gastrointestinal or renal cause of
metabolic acidosis
2) Will be abnormal if there is another electrolyte or ion present in serum
UAG = (Na + K) – Cl
The normal urinary anion gap is near zero or positive.
A positive value indicates a renal insult, such that there is a problem with
acidification of urine.
A negative value indicates a gastrointestinal insult, such as the loss of
bicarbonate in diarrhea.
Differential Diagnosis
• Differential for anion gap metabolic acidosis:
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Methanol
Uremia
DKA
Paraldehyde
Infection, Iron, INH
Lactic Acidosis
Ethylene Glycol
Salicylates, Sepsis
Differential Diagnosis
• Differential Diagnosis for elevated osmolar
gap:
– Methanol
– Ethylene Glycol
– Ethanol
– Isopropyl Alcohol
What tests would you order to differentiate
these conditions?
Calcium oxalate crystals
Differential Diagnosis
• Differential diagnosis for non-anion gap
metabolic acidosis:
– Diarrhea
– Uremia
– RTA
– Addison’s Disease
– Acetazolamide
Differential Diagnosis
• Differential diagnosis for metabolic
alkalosis:
– Vomiting
– NG suction
– Contraction alkalosis
Differential Diagnosis
• Differential diagnosis for respiratory
acidosis:
– Hypoventilation or other conditions that
interfere with respiratory drive
– Obstructive and restrictive lung disorders
Differential Diagnosis
• Differential diagnosis for respiratory
alkalosis:
– Hypoxia leading to hyperventilation
– Primary hyperventilation