generally unwell (part 2)…

For those joining the story for the first time, you can catch up here….

My interpretation of the ECG;

Sinus rhythm with 1st degree HB, an ‘odd’ axis. Wide complex QRS (~140-160ms) with symmetrical tall T-waves.
? Hyperkalaemia. Needs urgent bloods….

The nurse returns…

No one can place an IV or take bloods from her. So off you go, USS in tow to the bedside.

IV placed; bloods taken; urgent VBG to the iStat…..

Transfer to Resus & treated with….

• Calcium Gluconate 2x 10mLs
• Sodium Bicarbonate
• Insulin + Dextrose
• Salbutamol
• Resonium
• the kitchen sink….

The Review:

CRITICAL HYPERKALAEMIA

The causes:

• Factitious hyperkalaemia (most common, secondary to haemolysed sample) –>; urgent recheck.
• Increased K+ intake (meds, supplements, stored blood) Rare !
• Transcellular shifts (acidosis, hypertonicity, beta blockers, digoxin toxicity, exercise)
• Cellular injury (crush injury, burns, rhabdomyolysis, DIC, tumour-lysis syndrome).
• Impaired excretion

• Acute Renal Failure (Pre, intra & Post-renal causes)
• Tubular defects
• Hypoaldosteronism
• Addison’s Disease
• Drugs (NSAIDS, ACEi, potassium-sparing diuretics)

The ECG:

• Mild Elevation (5.5 – 6.5 mmol/L)
  • Tall symmetrical, peak T-waves
• Moderate Elevation (6.5 – 8.0 mmol/L)
  • P-wave amplitude decreases –>; loss of P-wave
  • PR interval increases
  • QRS widens
• Severe Elevation (>; 8.0 mmol/L)
  • Intraventricular, fascicular or bundle-branch blocks
  • QRS widens further –>; progression to ‘Sine wave’.
  • VF –>; Asystole.

The Management:

Divided into three phases;

1. Membrane stabilisation
2. Intracellular shift of K+
3. Removal / Excretion of K+

Drug options:

• Calcium Gluconate (10mL = ~ 2.2mmol Ca2+) / Chloride (10mL = ~ 6.8mmol Ca2+)
  • Onset 1-3 mins / Duration 30-50 mins.
• Sodium Bicarbonate (50-100mL 8.4% solution)
  • Onset 5-10 mins / Duration 1-2 hours.
• Insulin / Dextrose (~ 5-10 units insulin + 25g glucose)
  • Onset 30 mins / Duration 4-6 hours.
• Beta-agonists (5-20mg Salbutamol nebulised)
  • Onset 15-30 mins / Duration 2-4 hours.
• Frusemide (~40mg, only if passing urine)
• Exchange Resins (15-30 grams, PR or PO)
  • Onset 1-2 hours / Duration 4-6 hours.
• Dialysis
  • Indications include pulmonary oedema & fluid overload, profound acidosis, hyperkalaemia (esp with associated rhabdomyolysis), uraemia and altered mental status.

As always –>; correct & treat the underlying pathology or precipitating cause !

SO…. what happened to our lady ???

ECG post treatment:

• An IDC is placed & only 10mL of clear urine is aspirated (urinalysis unremarkable).
• Bedside USS shows at least moderate hydronephrosis –>; CT (non-contrast) booked

• She is taken to ICU for urgent haemodialysis… Overnight she is anuric.
• The following morning she heads to the operating room…

• Her very thin left ureter is stented. The dilated right ureter is obstructed distally & unable to get stented.
• She receives a percutaneous nephrostomy a few hours later.
• Within 48 hours her renal function has returned to baseline…..

The Diagnosis: Acute Renal Failure secondary to obstructive uropathy from a previously undiagnosed pelvic malignancy…

Finally an ECG to reinforce the notion that not all patients behave the same at the same K+ levels….
Here is one I dug up from the collection with a K+ of only 7.8

I know the topic this week is a little pedestrian, but it is so common that I felt a refresher would be helpful to keep some of this stuff in active memory….

I also think its a good example of how diligent and thorough we need to be throughout our entire shift in the ED, no matter how hectic the environment becomes !

Hope you found it useful,

CHRIS.

REFERENCES.

Chris Partyka

Dr Chris Partyka MBBS, BMedSci, MD. Staff Specialist in Emergency Medicine, Royal North Shore Hospital. Prehospital and Retrieval Specialist, NSW Ambulance. Clinical Lecturer, University of Sydney