Slightly less insane about fluids and electrolytes than General Ripper

I'm gonna write a book.

Actually I'm going to rewrite an old book. The Fluid, Electrolyte and Acid-Base Companion was published in 2000 but went to the printer in 1999. This book on the physiology underlying common clinical electrolyte problems was written by two residents, one in internal medicine, one in Med-Peds.

Since 1999 I have:

Done a year of pediatric critical care as part of Riley Children's Hospital's Newborn transport team

Completed a 2 year fellowship in Nephrology at the U of Chicago

Written a textbook chapter in Intensive Care in Nephrology on calcium, phosphorous and magnesium

Written a chapter in Principles of Critical Care, Third Edition on electrolyte issues in critical care

Written a review article on magnesium

Worked as part of the faculty for St John Hospital's Nephrology Fellowship Program since 2003

So in the last nine years my knowledge and teaching sophistication on electrolytes has exploded. All this time I have been thinking about rewriting this book:

Fixing it

Adding an evidence based medicine perspective

Removing some of the esoteric chapters which add to the length without helping the student

Add resources to make it a better resource for teaching on rounds

Make it relevant in web based world (Think optimized for iPhone)

Complete revamp of Sodium with electrolyte free water

Finish the job we started by adding calcium, magnesium and phosphorous

So I'm going to write a book.
So it begins.

Lecture Schedule

March 21 Providence MS3: Acid-Base

February 28 Providence MS3: Sodium

January 24 Providence MS3: Body Water
January 3 St John Hospital Residency: Potassium

2014

December 12 St John Nephrology Fellowship: ASN Kidney Week: reviewed.
December 11 Mclaren Macomb: potassium and alkalosis
December 6 St John Hospital Residency: AKI
December 5 St John Nephrology Fellowship: NephSAP

November 26 Providence Hospital Internal Medicine: Potassium
November 22 Providence MS3: Acid-Base
November 13 Mclaren Macomb: Potassium
November 8 ASN Kidney Week, NephMadness
November 7 ASN Kidney Week, Introduce KDIGO Mobile App

October 24th St. John Hospital MS3: Acute renal failure
October 22nd: Providence Hospital Internal Medicine residency: Acute Kidney Injury
October 17th St John Nephrology Fellowship: Fellow level hyponatremia part 2
October 10th St John Nephrology Fellowship: Fellow level hyponatremia part 1
October 9th Mclaren Macomb: Acute Kidney Injury
October 3 St John Nephrology Fellowship: NephSAP Fluids and Electrolytes

September 27 ACP of Michigan: Uric Acic, Hypertension and Gout
September 17 Beaumont Hospital and Medical Center: Acid Base
September 11 Mclaren Macomb: Fluids and Electrolytes
September 12 Providence Hospital MS3: Acid-Base
September 6 St John Hospital Residency: Sodium

August 29 St John Nephrology Fellowship: Anemia
August 27 Oakland University Beaumont School of Medicine 2nd years: Potassium, alkalosis and secondary hypertension
August 27 Providence Hospital Internal Medicine residency: Acid-Base
August 19: Oakland University Beaumont School of Medicine 2nd years. Acid Base
August 15 Oakland University Beaumont School of Medicine 2nd years. Na and water TBL
August 3 Providence Hospital MS3: Sodium
August 2 St John Hospital Residency Acid Base

July St John Hospital Residency
July Providence Hospital

June 14 Providence Hospital MS3: Potassium
June 11 St. John Hospital MS3: Acid-Base

May 16 St. John Hospital MS3: Fluids and Electrolytes
May 13 William M. Davidson Medical Education Week: NephMadness recap
May 10 Providence Hospital MS3: IVF and sodium
May 8 Mclaren Macomb: NAGMA
May 3 St John Hospital internal medicine residents: Board review
May 2 Providence Hospital Grand Rounds: Social Media in Health Care

April 23 St John Hospital ID Fellowship: HIV and the Kidney
April 12 Providence Hospital MS3: Acid-Base
April 10 Mclaren Macomb: Acid-Base part 2
April 9 St John Hospital MS3: Acute Renal Failure
April 5 St John Hospital internal medicine residents: Metabolic alkalosis

March 22 Gift of Life Minority Organ and Tissue Transplant Education Program: Social Media in Transplant
March 15 Providence Hospital MS3: Potassium
March 14 St John Hospital internal medicine residents: How to give a Lecture Lecture
March 21 St. John Hospital MS3: Acid-Base
March 13 Mclaren Macomb: Acid-Base
March 1 St John Hospital internal medicine residents

February 15 18 Providence Hospital MS3: Fluids and Electrolytes
February 14 St. John Hospital MS3: Fluids and Electrolytes
February 13 Mclaren Macomb: Hyponatremia

January 18 Providence Hospital MS3: Acid-Base
January 17 St John Hospital MS3: Acute Renal Failure
January 9 Mclaren Macomb: IV Fluids
January 3 St John Hospital Nephrology Fellowship: NephSAP divalent ions part 2

2013

December 13 St John Hospital Nephrology Fellowship: NephSAP divalent ions part 1

December 11 St. John Hospital  MS3: Acid-Base
December 7 Providence Hospital MS3: Sodium and Water
December 6 St John Hospital Nephrology Fellowship: Renal Week Recap

November 27 St John Hospital and Medical Center Grand Rounds: Medicine and Social Media
November 13 St. John Hospital  MS3: Fluids and Electrolytes
November 9 Providence Hospital MS3: Potassium
November 9 St John Hospital internal medicine residents: Diabetic Nephropathy, A New Hope

October 24-28 Michigan State Medical Society: Diabetic Nephropathy, A New Hope
October 24 Providence Hospital MS3: Acid-Base
October 26 Providence Hospital MS3: Sodium and Water
October 9 St John Hospital MS3: Acute Renal Failure

September 11 St. John Hospital third year medical Students: Fluids and Electrolytes
September 7 St John Hospital internal medicine residents: Non-Anion Gap Metabolic Acidosis

August 31 Oakland University Beaumont School of Medicine 2nd years. PBL: Glomerular Disease
August 24 Oakland University Beaumont School of Medicine 2nd years. PBL: Acute and Chronic Kidney Disease
August 21 Oakland University Beaumont School of Medicine 2nd years, Acid-Base
August 20 Oakland University Beaumont School of Medicine 2nd years, Potassium Balance Disorders
August 17 Oakland University Beaumont School of Medicine 2nd years. PBL: Sodium and water

August 16 Providence Hospital 3rd year medical students: Potassium

August 3 St John Hospital internal medicine residents: Acute Kidney Injury
August 2 St John Hospital Nephrology Fellowship: Anemia and lack of placebo controlled trials
August 1 Providence Hospital internal medicine residents: Acute Kidney Injury

July 25 St Mary Hospital Grand Rounds: Acute Renal Failure, an update
July 24 St John Hospital internal medicine residents: Acid-Base
July 19 Providence Hospital 3rd year medical students: Sodium
July 17 Providence Hospital internal medicine residents: Water, IV Fluids, Sodium, Diuretics

July 13 Providence Hospital 3rd year medical students: Acid-Base

July 10 St John Hospital third year medical Students: Acute Renal Failure
July 3 St John Hospital internal medicine residents: Water, IV Fluids, Sodium, Diuretics

June 12 St John Hospital third year medical Students: Acute Renal Failure
June 8 Providence Hospital 3rd year medical students: Potassium

May 24 Providence Hospital 3rd year medical students: Sodium
May 15 St. John Hospital third year medical Students: Fluids and Electrolytes
May 4 St John Hospital internal medicine residents: Renal Anemia

April 19 Providence Hospital 3rd year medical students: Acid-Base
April 18 Providence Hospital Resident Reasearch Day: Judge
April 10 St John Hospital third year medical Students: Acute Renal Failure
April 6 St John Hospital internal medicine residents: HIV associated nephropathy

March 20 St. John Hospital third year medical Students: Fluids and Electrolytes
March 13 St. John Hospital third year medical Students: Acid-Base
March 2 St John Hospital internal medicine residents: board review

February 24 UIC/Advocate Christ Medical Center Residents: Non-Anion Gap Metabolic Acidosis
February 10 Providence Hospital 3rd year medical students: Potassium
February 9 Providence Hospital 3rd year medical students: Sodium and Water
February 3 St John Hospital internal medicine residents: Tolvaptan is effective in which patient and metabolic alkalosis
February 2 St John Hospital Nephrology Fellowship: Board Review NephSAP CKD and Progression part 2

January 19 St John Hospital Nephrology Fellowship Initiation of Dialysis
January 17 St John Hospital third year medical Students: Acute Renal Failure
January 12 Providence Hospital 3rd year medical students: Acid-Base
January 5 St John Hospital Nephrology Fellowship: Board Review NephSAP CKD and Progression part 1

2012

December 13 St. John Hospital third year medical Students: Acid-Base
December 8 St. Mary’s Hospital in Saginaw: Fructose, CKD and Hypertension
December 2 St John Hospital internal medicine residents: Severe lactic acidosis and electrolyte disorders of the drunk.

November 29 Providence Hospital 3rd year medical students: Potassium
November 17 Providence Hospital 3rd year medical students: Acid-Base
November 15 St John Hospital third year medical Students: Fluid and Electrolytes
November 15 St John Hospital and Medical Center Grand Rounds: Diabetic Nephropathy, an Update
November 11 U of C Alumni Reception. Marriott. 6:45pm
November 11 Blogger get together McGillins Olde Ale House. 8pm
November 11 AJKD Editorial Board Meeting Franklin 4 Room Marriott. 12:45-1:45
November 4 St John Hospital internal medicine residents: Non-anion gap

October 28 Providence Hospital 3rd year medical students: Sodium and Water

October 27 Providence Hospital Grand Rounds: Anemia and lack of placebo controlled trials

October 26 Michigan State Medical Society: Fructose, CKD and Hypertension
October 25 Providence Hospital Residency Program: What's New in Potassium
October 22 Lupus Alliance of America: Panel discussion
October 20 Providence Hospital 3rd year medical students: Acid-Base

October 12 St. Mary Mercy Hospital: Fructose, CKD and Hypertension

October 11 St John Hospital third year medical Students: Acute Renal Failure
October 6 St John Hospital Nephrology Fellowship: Dialysis Kinetics

September 30 Providence Hospital 3rd year medical students: Acid-Base
September 22 St John Hospital Nephrology Fellowship: Physiology of Sodium and Water Handling
September 20 Royal Oak Beaumont Internal medicine residency: Acid-Base Disorders
September 13 St John Hospital third year medical Students: Acute Renal Failure
September 2 St John Hospital internal medicine residents: Potassium

August 30th Providence Hospital Residency Program: Potassium

August 26th Providence Hospital 3rd year medical students: Acid-Base

August 9th St John Hospital third year medical Students: Fluid and Electrolytes
August 5 St John Hospital internal medicine residents: Acid Base

July 26th St John Hospital third year medical Students: Acid-Base
July 22nd Providence Hospital 3rd year medical students: Fluids and Electrolytes
July 22nd St John Hospital internal medicine residents: Acute renal failure
July 21st Beaumont Family Practice Residency: Acute renal failure
July 21st St John Hospital Nephrology Fellowship: Anemia and lack of placebo controlled trials
July 19th Providence Hospital Residency Program: Body water, IV fluids and diuretics
July 1st St John Hospital internal medicine residents: Body water, IV fluids, diuretics and dysnatremia

June 14th St John Hospital third year medical Students: Acid-Base
June 9th: Abbott pharmaceuticals secondary Hyperparathyroidism: FGF-23
June 8th: St John Hospital and Medical Center: Update in CKD: Anemia
June 3rd: St John Hospital internal medicine residents: a case of Milk-Alkali syndrome and Fructose, Hypertension and Uric Acid
June 2nd: St John Hospital Nephrology Fellowship Program: NephSAP Fluids and Electrolytes
June 1st: Grand Rounds Beaumont Hospital: Fructose, Hypertension and Uric Acid

May 26th St John Hospital Nephrology Fellowship Program: Hyponatremia
May 17th St John Hospital third year medical Students: IVF and Hyponatremia
May 6th St John Hospital internal medicine residents: Nephrology board review
May 2nd: Michigan CRN meeting: Fructose, Hypertension and Uric Acid

April 29th: Providence Hospital third year medical students: Sodium in the morning, potassium at 11
April 20th: Providence Hospital third year medical students: Acid-Base
April 18th: St John Hospital cardiology fellows: Cardiorenal Syndrome
April 14th: Beaumont Gross Point family practice residents: IVF and Sodium Part 1
April 12th: St John Hospital third year medical Students: Acute Renal Failure
April 8th: St John Hospital internal medicine residents: How to give a lecture: Keynote Tutorial

March 29th: Providence Hospital internal medicine residents: hypernatremia and hypercalcemia
March 17th: St John Hospital third year medical Students: Acid-Base
March 4th: St John Hospital internal medicine residents: Cardiorenal Syndrome

Feburary 18th: Providence Hospital third year medical students: Potassium

Feburary 16th: Providence Hospital third year medical students: IVF and Na

Feburary 11th: Providence Hospital third year medical students: Acid Base
Feburary 8th: Providence Hospital internal medicine residents: Hyponatremia, hypokalemia

January 18th: St John Hospital Grand Rounds: Dialysis for the internist, an update

2011

Polyuria, polydipsia

The set up

Patient is the ICU, you receive a consult for hypernatremia resistant to therapy for three days.

Na 174

Cl 128

BUN 38

K 3.2

HCO3 27

Cr 1.6

glucose 128

urine lytes:

Na 56

K 12

Body weight 45 kg

urine output 2,800

Step one

Calculate the fluid deficit:

We assume the increase in sodium is entirely due to loss of water. If the patient is hypotensive, tachycardic orthostatic or has other clues that he maybe volume depleted, the situation is more complex. We calculate the percentage that the sodium is elevated above an imagined "ideal sodium." Many equations use 140 as the idealized sodium, I tend to use 145. The percentage the sodium is above the ideal is identical to the percentage of the total body water that is needed to lower the sodium to the target level.

174-145 / 145 = 0.2 (the sodium is 20% above 145)

Multiple that by the estimated total body water (weight x % body water) = 5.4 liters

I used 60% for estimated total body water. The patient looks like a young boy. Rose suggests lowering the estimated % body water by 10% so 50% would be okay also. In the elderly and obese this number can go below 50%. 

Step two

Going from 174 to 154 is too much change in 24 hours. The speed limit is 12 mmol/L/day so we will target a change from 174 to 162.

I use a modified water deficit formula. I divide 12 (the change in sodium we are looking for) by the target sodium (current sodium minus 12):

12/(174-12) = 0.08 x total body water = 2.0 liters or just over 80 mL/hour

Step three

Calculate the electrolyte free water clearance. The reason the ICU team repeatedly failed to correct the sodium is that they corrected the deficit without accounting for the ongoing water losses. In this case it is renal losses. If you just add the urine volume to the water deficit you will over estimate the amount of water needed because the urine contains sodium and potassium. To account for the electrolyte content of the urine we calculate the free water clearance.

Urine Na + K divided by the serum Na will give the ratio of urinary electrolytes to serum solute. 

56 + 12 / 174 = 39%
The urine has 39% electrolyte content of plasma, another way of thinking about this is that 39% of the urine volume is isotonic and the remainder (61%) is pure water. The 61% is what we are interested in; multiply the urne output by 61% this is the volume of water we need to give the patient to account for his ongoing renal losses. 

Then multiply this by the urine output (2,800) to get the electrolyte free water clearance, 1705 ml. This is another 71 mL/hour

Wrap up

Final fluid orders: 154 mL/hour of water, this can be given as D5W in the IV or preferably oral flushes. This calculation does not insensible losses.