The pathology lab calls on a Friday night to advise a patient has

hyperkalaemia?

What next….

Dr Chris Arden

GP, Chandlers Ford

GPSI Cardiology, Southampton

Issues & Answers in Issues & Answers in Cardiovascular DiseaseCardiovascular Disease

1717thth November 2012 November 2012

WarwickWarwick

G e o rg e

7 2 y e a r o ld re tire d s a le s m an

PH - LVSD HTN Typ e 2 DM O A

Rx - Ena la p ril 1 0 m g o d Bis o p ro lo l 5 m g o d Sp iro no la c to ne 2 5 m g o d Nap ro x e n 2 5 0 m g i-ii bd Co -Co dam o l 8 /5 0 0 p rn

It’s Friday 6.15pm, the phone rings…

K 6.1K 6.1Na 1 3 2Ur 1 4. 6Cr 1 5 2

July 2 0 1 2 ;

K 5 . 1Na 1 3 4Ur 1 1 . 9Cr 1 2 7

it’s the lab…

‘ ’we ’v e g o t s o m e re s ults fo r y o u, c am e thro ug h fro m this m o rning … ’ ’

Po ta s s ium p a tho phys io lo g y

No rm a l ra ng e - 3 . 5 -5 . 0 m m o l/l

Hyp e rka la e m ia - > 5 . 5 m m o l/l

Hyp e rka la e m ia is a p o te ntia lly life -thre a te ning m e ta bo lic p ro ble m c a us e d by ;

•inability of the kidneys to excrete potassium•impairment of the mechanisms facilitating potassium movement from circulation into cells•or a combination of these factors

Co m m o n c a us e s o f hyp e rka la e m ia

Incre a s e d inta ke

• + Po ta s s ium s up p le m e nts

• d ie ta ry e x c e s s

• s a lt s ubs titute s

Incre a s e d p ro duc tio n

• ha e m o ly s is• tra um a• inte ns e phys ic a l a c tiv ity• e x te ns ive burns

Co m m o n c a us e s o f hyp e rka la e m ia

Im pa ire d e x c re tio n

• re duc e d G FR (a cute o r ESRF)

• Drug s• ACE-I• potassium sparing diuretics• NSAID’s• cyclosporin

• d e fe c t in tubula r s e c re tio n (e . g . re na l tubula r a c id o s is )

Co m m o n c a us e s o f hyp e rka la e m ia

Re d is tributio n

‘shift from intracellular to extracellular fluid’

•a c id o s is (m e ta bo lic o r re s p ira to ry )

•ins ulin d e fic ie nc y

•Drug s• Digoxin• Beta blockers• Scoline (suxamethonium)

Co m m o n c a us e s o f hyp e rka la e m ia

Ps e udo hyp e rka la e m ia

• ha e m o ly s is (in la b tube !) most common• thro m bo c y to s is

• ve ne p unc ture te chniq ue• (e . g . p ro lo ng e d to uniq ue t a p p lic a tio n)

Sig ns & Sym p to m s o f hyp e rka la e m ia

• Clinic a l fe a ture s o fte n non-specific• Lethargy• Confusion• Weakness• Palpitations

• G e ne ra lis e d m us c le we a kne s s

• Pa ra e s the s ia o f ha nds & fe e t

ECG cha ng e s o f hyp e rka la e m ia

The ECG is one of the most important diagnostic tools in detecting hyperkalaemia

Predicted ECG changes associated with hyperkalaemia include

Serum Potassium (m m o l/l)

5.5-6.56.5-7.57.5-8.5

> 8.5

ECG changes

Tall tented T wavesLoss of P waveWidening QRSQRS widening, to sine wave

ECG cha ng e s o f hyp e rka la e m ia

ECG cha ng e s o f hyp e rka la e m ia

e a rly ECG cha ng e s s ho wing p e a ke d T wa ve s (Po ta s s ium 7 . 1 )

You’re on duty, the clock’s ticking, wha t d o y o u d o ne x t… ?

•phone patient..•assess symptoms

• a cute• s y s te m ic a lly unwe ll• Rx c o m p lia nc e ? O TC• inte r-c urre nt illne s s

•review previous results – trend ? ARF•vulnerable/alone?•options include;

• admit• d/w medics• No thing• none of the above…• Or…?