hypokalaemia and hyponatraemia acute mx

Managing My Salts

A guide to ED management of Hypo-K and Hypo-Na.

Dr Kyle KophamelCME 10 Dec 2015

DisclaimerSimple ED specific approachIn light of NEATSome areas will be Charlies specificFeel free to challenge my conclusions

AimHypo – K

Emergent treatmentDosing, Timing, Central vs Venous

Hypo - NaEmergent treatment of Severe, Symptomatic

Hyponatremia. An easy, evidence based ‘How to’ of super - salt

What to look out forHelpful Labs at presentation.What not to do.

Hypo-K – Let’s define it. QuicklyMild: 3.0 – 3.5 mmol/LModerate: 2.5 – 3.0 mmol/LSevere < 2.5

Broadly speaking:ECG changes <2.7 mmols/L

ECG ChangesFlat T’sU WavesProlonged Qt (QU)Broad QRSArrythmias (PAC’s, PVC’s, SVT, VT, TdP)

SymptomsWeaknessFatigueMuscle crampsParalysis and RhabdomyolysisRespiratory DifficultyConstipation/Paralytic IleusLeg cramps

LabsVBG

NaKClCreatinineGlucoseBicarb

Mg Level

CorrectionMinimize LossesGive K.

Aim 4-4.5mmomls/L

Give Mg. Aim >1 mmol/L

CorrectionIV vs OralPeripheral vs CentralCardiac Arrest

10 mmols IV over 5 mins peripherally

CorrectionOral

Multiple marketed brands Controlled release formulations Oral electrolytes list on AMH Aim 40-100mmols/day In practice

Usually 2-3 tablets, 2-3 x daily for 2-3 days then review response.

If you’re interested 1mmol/L defecit is approximately 200mmol whole

body defecit

CorrectionIV

Peripheral <40 mmols/L concentration <20mmols/hr Minibags (10mmols KCl in 100mls 0.29% NaCl) are

isotonic and can be administered peripherally.Central

>40mmols/L concentration >10mmols/Hr

Hyponatremia - Let’s Define it. Quickly!

Sodium < 135 mmol/L Mild: 125 -134 Moderate: 120 – 124 Severe: < 120

True vs Factitious Hypotonic (Losing Sodium or Holding Water)

Hypovolaemic, Euvolaemic, Hypervolaemic Isotonic (Psuedohyponatremia) Hypertonic (Glucose, Mannitol)

SymptomsAsymptomaticAltered Mental StateComaSiezureNeurological Defecit

CausesLots.

Drugs, Drugs, Drugs Prescribed and Street

Water overloadSIADHBeerEndocrineOrgan FailuresThird space lossesFacticious

The Simple ED Stepwise ApproachStep 1

VBG – DiagnosisU+ESerum OsmolalityUric Acid

• Urine• Electrolytes• Uric acid• Osmolality• Creatinine

• Endocrine Suspected• TSH/Cortisol

LABS

Step 2Treat CNS Symptoms

Aim to raise Na by 2-6 mmol/L 100mls 3% NaCL over 10 mins

Simple way to make-up to follow Wait 10mins Repeat x 1ORRule of 3’s3mls/kg 3% NaCl over 30 mins and stop if mental state improves

If not worked after 3x, Recheck Na and look for alternate cause. CT Head

Step 3Don’t do anything.Sit tight.Forget the formulas.

Or, just don’t look them up.

Be conservativeFluid RestrictWhy

Osmotic Demyelination AKA Cental Pontine Myelinolysis

Step 4If you couldn’t follow step 3Na jump >10mmols

DDAvp 1-2 microgram dose IV Synthetic ADH, creates concentrate urine

Get help.Friendly NephrologistConsider 3-6mls/kg D5W over 1 hour (decreases Na

by 2mmols)

A Just about 3% Salt solutionCharlies ED

Vials of 20% NaCl in 10mls availableAim to give approx 100mls over 10mins

My suggestion: Inject 10ml 20% NaCl into 100mls 0.9% Saline

Concentration of 2.63% Give over 10mins

Case 1Would you make the diagnosis?32 Female

Walks into emergency Dept with familyComplaining of Nausea, Vomiting and headacheAt triage becomes edgy and agitatedAt Assessment is swimming in the bedAt Resus is lashing out, disorientated and not

coherantly respondingShe scored a tube.

Case 1VBG

pH:7.47PCO2: 29Bicarb: 21BE: -3Na: 126K:3.7Lact:2.1

Case 1Differential

EncephalitisPsych Intracranial Pathology

Bleed, Tumour Illicit DrugsHyponatremia

Case 1Collateral

Playing touch rugby all morning (and previous day)40 degree dayDrank several liters of water

Case 2Blue form anyone?89 year old, from home.Found by family in bed, unresponsiveTriage: ‘Neurological – Altered Mental State. Hit by

car low speed – now GCS 5Vitals normal, unremarkable physical examination

Case 2Na 99K 2.0Not tubed.2 x 10ml 20% NaCl pushes.

GCS 9 in 1 hour

Admitted HDU5 days later, Na 127Discharged Day 10 zipping around on her zimmer frame.

SummarySend the labs

Catheterise earlyTreat CNS Symptoms

100mls 3% NaCl (raises by 2mmols each time)

Sit tight. Fluid Restrict.Rescue remedies if you didn’t sit tight

dDAVPFriendly Nephrologist

References Lifeinthefastlane

http://lifeinthefastlane.com/investigations/hyponatraemia/interpretation/

EMCrit http://emcrit.org/podcasts/hyponatremia/

Australian Medicines Handbook https

://amhonline-amh-net-au.qelibresources.health.wa.gov.au/chapters/chap-07/tables/electrolytes-oral.tb

Therapeutic Guidelines http://online.tg.org.au.qelibresources.health.wa.gov.au/ip/desktop/index.htm

• http://www.health.wa.gov.au/circularsnew/circular.cfm?Circ_ID=12986• Western Australian Policy for Use of Intravenous Potassium Chloride