the bicarbonate ”rules of thumb“also known as Winters’ rules

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 1 / 20

Outline

1 history

2 casesglycole intoxicationa 27 year old diabetic

3 more formulae

4 good byeconflicts of interest

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 2 / 20

Outline

1 history

2 casesglycole intoxicationa 27 year old diabetic

3 more formulae

4 good byeconflicts of interest

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 2 / 20

Outline

1 history

2 casesglycole intoxicationa 27 year old diabetic

3 more formulae

4 good byeconflicts of interest

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 2 / 20

Outline

1 history

2 casesglycole intoxicationa 27 year old diabetic

3 more formulae

4 good byeconflicts of interest

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 2 / 20

history

background 0

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 3 / 20

The bicarbonate rules of thumb, often called ”Winters’ rules“, inAustralia also known as ”Worthley’s rules“, after L.I.G. Worthley, are a

set of rules relating PCO2 and bicarbonate levels to each other.

They are popular as part of the ”bicarbonate approach“ to acid-baseanalysis popular in North America, as opposed to the”base excess approach“ that dominates in Europe.

history

background 1

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 4 / 20

Their origin can be traced to a study published in 1967 by Albert et alii.

Quantitative Displacement of Acid-Base Equilibrium in Metabolic AcidosisMorris S. Albert, M.D., Ralph B. Dell, M.D., and Robert W. Winters, M.D

Annals of Internal Medicine, Volume 66, No. 2, February 1967from the Department of Pediatrics, Columbia Univeraity, College of Physicians and Surgeons,

and the Babies Hospital, Columbia-Presbyterian Medical Center, New York, N. Y.

history

background 2

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 5 / 20

The rules describe the normal physiological reactions of the humanbody to one isolated acid-base perturbance - the classical example

being the hyperventilatory compensation in an otherwise healthypatient with diabetic ketoacidosis.

Theoretically speaking, there is no reason why these rules ought tobelong to one or another of the different schools of acid-base teaching!

history

background 3

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 6 / 20

The resulting formula was slightly simplified to:PCO2 (in mmHg) = 1.5*[HCO3

–] (in mmol/l) + 8 ± 2

cases glycole intoxication

Outline

1 history

2 casesglycole intoxicationa 27 year old diabetic

3 more formulae

4 good byeconflicts of interest

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 7 / 20

cases glycole intoxication

glycole intoxication 0

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 8 / 20

measured values:pH 7.17PCO2 1.4 [kPa]Na+ 150 [mmol/l]K+ 5.0 [mmol/l]Cl– 108 [mmol/l]phosphate 1.3 [mmol/l]albumin 50 [g/l]

calculated values:SBE -22 [mEq/l]HCO3

– 4 [mmol/l]

cases glycole intoxication

glycole intoxication 1

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 9 / 20

an almost pure case of unknown anion metabolic acidosis

glycole intoxication, 12h hours after ingestion(we did not routinely measure lactate at the time)

expected PCO2 = 1.5*[HCO3–] (in mmol/l) + 8 ± 2

14 mmHg or 1.84 kPa

versus measured PCO2 1.4 kPa

cases glycole intoxication

glycole intoxication 2

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 10 / 20

If you use the analysis module on acidbase.org, you get this kind ofoutput.

cases glycole intoxication

glycole intoxication 3

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 11 / 20

If you use the analysis module on acidbase.org, you get this kind ofoutput.

cases a 27 year old diabetic

Outline

1 history

2 casesglycole intoxicationa 27 year old diabetic

3 more formulae

4 good byeconflicts of interest

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 12 / 20

cases a 27 year old diabetic

a 27 year old diabetic 0

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 13 / 20

at admission to ICU

measured values:pH 6.93PCO2 1.75 [kPa]Na+ 130 [mmol/l]K+ 5.3 [mmol/l]Cl– 101 [mmol/l]albumin 32 [g/l]

calculated values:SBE -27 [mEq/l]HCO3

– 2.8 [mmol/l]

cases a 27 year old diabetic

a 27 year old diabetic 1

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 14 / 20

at admission to ICU

a severe case of diabetic ketoacidosis in a young adult with knowntype 1 diabetes mellitus and impulsive behaviour, who in an angry fit

just ignores her insulin needs

expected PCO2 = 1.5*[HCO3–] (in mmol/l) + 8 ± 2

12 mmHg or 1.6 kPa

versus measured PCO2 1.75 kPa

cases a 27 year old diabetic

a 27 year old diabetic 2

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 15 / 20

9 hous later

measured values:pH 7.014PCO2 3.42 [kPa]Na+ 140 [mmol/l]Cl– 114 [mmol/l]

calculated values:SBE -22 [mEq/l]HCO3

– 6.9 [mmol/l]

cases a 27 year old diabetic

a 27 year old diabetic 3

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 16 / 20

9 hous later

a severe case of diabetic ketoacidosis in a young adult with knowntype 1 diabetes mellitus and impulsive behaviour, who in an angry fit

just ignores her insulin needs

expected PCO2 = 1.5*[HCO3–] (in mmol/l) + 8 ± 2

18 mmHg or 2.4 kPa

versus measured PCO2 3.4 kPa

cases a 27 year old diabetic

a 27 year old diabetic 4

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 17 / 20

10 hous later

slow resolution of the ketoacidotic derangementno resolution of the hyperchloraemic component

increasingly inadequate respiratory response10 hours after admission to ICU severe vomiting, aspiration,

respiratory and cardiac arrestsevere persistent central nervous damage inspite of CPR in an ICU

environment

cases a 27 year old diabetic

a 27 year old diabetic 4

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 17 / 20

10 hous later

slow resolution of the ketoacidotic derangementno resolution of the hyperchloraemic component

increasingly inadequate respiratory response10 hours after admission to ICU severe vomiting, aspiration,

respiratory and cardiac arrestsevere persistent central nervous damage inspite of CPR in an ICU

environment

more formulae

more formulae

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 18 / 20

a complete set of formulae

1- metabolic acidosis as the primary disturbance, PCO2 (in mmHg) in relation to [HCO3–]

∆PCO2/∆HCO3− = 1.2mmHg per mEq/l

2- metabolic alkalosis as the primary disturbance, PCO2 (in mmHg) in relation to HCO3–

∆PCO2/∆HCO3− = 0.7mmHg per mEq/l

3- respiratory acidosis as the primary disturbance, HCO3– in relation to PCO2 (in mmHg)

3a- acute compensation:∆HCO3

−/∆PCO2 = 0.1mEq/l per mmHg3b- chronic compensation:

∆HCO3−/∆PCO2 = 0.3mEq/l per mmHg

4- respiratory alkalosis as the primary disturbance, HCO3– in relation to PCO2 (in mmHg)

4a- acute compensation:∆HCO3

−/∆PCO2 = 0.2mEq/l per mmHg4b- chronic compensation:

∆HCO3−/∆PCO2 = 0.4mEq/l per mmHg

Assessing acid-base disorders Adrogue HJ, Gennari FJ, Galla JH, Madias NEKidney Int 2009 Dec;76(12):1239-47

http://www.acidbase.org/phpscripts6/glossary.php

more formulae

more formulae

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 18 / 20

a complete set of formulae

1- metabolic acidosis as the primary disturbance, PCO2 (in mmHg) in relation to [HCO3–]

∆PCO2/∆HCO3− = 1.2mmHg per mEq/l

2- metabolic alkalosis as the primary disturbance, PCO2 (in mmHg) in relation to HCO3–

∆PCO2/∆HCO3− = 0.7mmHg per mEq/l

3- respiratory acidosis as the primary disturbance, HCO3– in relation to PCO2 (in mmHg)

3a- acute compensation:∆HCO3

−/∆PCO2 = 0.1mEq/l per mmHg3b- chronic compensation:

∆HCO3−/∆PCO2 = 0.3mEq/l per mmHg

4- respiratory alkalosis as the primary disturbance, HCO3– in relation to PCO2 (in mmHg)

4a- acute compensation:∆HCO3

−/∆PCO2 = 0.2mEq/l per mmHg4b- chronic compensation:

∆HCO3−/∆PCO2 = 0.4mEq/l per mmHg

Assessing acid-base disorders Adrogue HJ, Gennari FJ, Galla JH, Madias NEKidney Int 2009 Dec;76(12):1239-47

http://www.acidbase.org/phpscripts6/glossary.php

more formulae

more formulae

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 18 / 20

a complete set of formulae

1- metabolic acidosis as the primary disturbance, PCO2 (in mmHg) in relation to [HCO3–]

∆PCO2/∆HCO3− = 1.2mmHg per mEq/l

2- metabolic alkalosis as the primary disturbance, PCO2 (in mmHg) in relation to HCO3–

∆PCO2/∆HCO3− = 0.7mmHg per mEq/l

3- respiratory acidosis as the primary disturbance, HCO3– in relation to PCO2 (in mmHg)

3a- acute compensation:∆HCO3

−/∆PCO2 = 0.1mEq/l per mmHg3b- chronic compensation:

∆HCO3−/∆PCO2 = 0.3mEq/l per mmHg

4- respiratory alkalosis as the primary disturbance, HCO3– in relation to PCO2 (in mmHg)

4a- acute compensation:∆HCO3

−/∆PCO2 = 0.2mEq/l per mmHg4b- chronic compensation:

∆HCO3−/∆PCO2 = 0.4mEq/l per mmHg

Assessing acid-base disorders Adrogue HJ, Gennari FJ, Galla JH, Madias NEKidney Int 2009 Dec;76(12):1239-47

http://www.acidbase.org/phpscripts6/glossary.php

good bye conflicts of interest

Outline

1 history

2 casesglycole intoxicationa 27 year old diabetic

3 more formulae

4 good byeconflicts of interest

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 19 / 20

good bye conflicts of interest

conflicts of interest

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 20 / 20

my two conflicts of interest!

http://www.acidbase.org/presentations/

good bye conflicts of interest

conflicts of interest

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 20 / 20

my two conflicts of interest!

http://www.acidbase.org/presentations/

good bye conflicts of interest

conflicts of interest

(ICU, Herlev Hospital, Copenhagen) Winters’ rules ”Fem Minutter“ uge 14 2016 20 / 20

my two conflicts of interest!

http://www.acidbase.org/presentations/