Interesting Case - Severe acidosis

Todd Fraser on 13-10-2013

Here's another interesting case sent in this week.

A 65 year old woman was brought in by ambulance to emergency, grossly obtunded with abdominal pain and vomiting.  She was a diabetic controlled on metformin.

Her blood pressure was 135/80, heart rate 110 and saturations 98% on 6L/min oxygen.  She was grossly confused, had no focal neurology and her abdomen was soft.

Her initial blood gas showed a pH of 6.5, a lactate of 17mmol/L, a potassium of 8.9mmol/L, sodium 125mmol/L, unrecordable bicarbonate and a base deficit of -26mmol/L.  Her oxygenation was adequate and a CO2 was 10mmHg.  The creatinine on the gas is recorded as >1000

A CT of her abdomen was performed that was reported as normal by a radiologist, other than fairly small looking kidneys

After fluids, inotropes, 10mmol calcium, 50ml of 9.8% bicarbonate, lines and intubation, she was admitted to the ICU for further management.

The question our member asks is : What is the best mode of renal replacement therapy?


How would you proceed?


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Aleem from India wrote 10-13-2013 11:06:07 pm
Check the cvp give fluids stop metformin , if output is not maintained and lactate and bicarb
does not improve pt. NEEDS DIALYSIS

Ashpa from India wrote 10-15-2013 09:15:52 pm
Blood glucose level on admission?
are we dealing with DKA?
need to find cause of DKA.
Needs fluid replacement.
Recheck ABG if no improvement in base deficit will need rrt.

Ashpa from India wrote 10-15-2013 09:22:49 pm
Rhabdomyolysis needs to be ruled out.fluid resus,sodabicarb till urine pH >7.

Todd Fraser from Australia wrote 10-17-2013 11:58:46 am
Great comments, thanks.

Blood sugar was within normal range on presentation, as was CK. Ketones were not elevated on urine or blood analysis. Following volume resuscitation, there was no improvement in the acid-base balance.

What CRRT strategy would you employ?

Ashpa from India wrote 10-17-2013 04:18:45 pm
CVVHD is preferable .

Sarah from Australia wrote 10-19-2013 03:10:32 pm
This lady needs urgent RRT - severe acidaemia and life-threatening hyperkalaemia.

Although initial BP is satifactory I would give CRRT rather than IHD - either CVVH or CVVHDF (whichever is available). She is clearly sick.

The renal failure is likely to have a chronic element (Creat >1000 unusual in AKI alone, small kidneys on CT) so it would be worth looking at previous renal chemistry. How high is her urea? What other drugs is she taking?

Metformin obviously needs stopping. As do any other nephrotoxins.

Does she have dead tissue somewhere (e.g.gut) - abdominal pain, lacatate 17 although I note abdomen soft and CT unremarkable. Currently too sick for theatre but might have to be considered.

Georgia from Australia wrote 10-21-2013 09:22:31 am
My understanding is that electrolytes / acid-base is most rapidly corrected using haemodialysis. Its possible in many places to get a formal dialysis machine set up on an ICU patient, and in some parts of the world this is essentially all they use (eg US).

However, it seems from the case that the patient is not stable enough for this, so CVVHD seems the best. Not sure that filtration will significantly add benefit.

The other question is what type of dialyse / filtration replacement fluid you use. Using a bicarbonate buffer is probably best, and must avoid lactate. Fluids with a relatively high citrate concentration can also cause alkalosis, so might be the best, though this can limit the blood flows you can use, depending on your machine.

John from Australia wrote 10-21-2013 12:56:19 pm
If the patient's liver is cactus, then the citrate might not get metabolised, causing toxicity. This might also be impaired by the metformin - it somehow blocks lactate metabolism so is there a chance that it could do the same to citrate?

I'd be inclined to steer clear of citrate and use bicarb buffered fluids. You can always pour more bicarb into the patient as well...

OSAMA from Saudi Arabia wrote 10-23-2013 04:40:36 am
this patient has severe lactic acidosis with creatinine more than 1000 ,small kidney on CT ,patient old and had abdominal ,patient may had acute renal failure on top of chronic may we need to know the past medical and drug history ,also may we have to think about intestinal ischemia or pancreatits ,we need serum amylase ,and mesentric CT ANGIO ,WE NEED ALSO to check liver function test ,and CRP or procalcitonin and septic work up,for dialysis I THINK NO difference between both method of dialysis what ever CRRT or IHD patient is haemodynmaically stable .

Vishvesh from India wrote 10-28-2013 05:10:20 am
Question is specific;CRRT with CVVHD,bicarbonate buffer,heparine(if no contraindication) or citrate anticoagulation.

BE -26 is not explained by elevated lactate,must have additional cause for metabolic acidosis..R/O toxic ingestion/ RTA.

Todd Fraser from Australia wrote 10-29-2013 02:48:15 pm
I just completed a podcast with Dr John Kellum, whose research career involves plenty of acid-base and renal replacement work. I asked him this very question - what mode of RRT is best in patients with severe acidosis.

You can hear what he has to say in the full podcast, coming soon!

J Doyle wrote 11-09-2013 03:30:31 pm
There are a number of interesting responses here advocating a rapid resolution of acidaemia and hyperkalaemia generally with CVVHD(F). Can I ask does anyone have much experience with the occurrence of dysequilibrium syndrome with such rapid correction? There are general guidelines of rate of urea correction which might suggest a slower approach to this situation??

Todd Fraser from Australia wrote 12-02-2013 07:38:35 pm
I've just posted a podcast with John Kellum, Professor of Intensive Care Medicine at University of Pittsburgh on this topic - check it out here -

ICU fellow from Canada wrote 03-10-2014 05:27:24 am
Todd,,, I could not view the podcast! Do I need to become a member to do so? Thank you

Todd Fraser from Australia wrote 03-10-2014 08:15:31 am
Hi ICU fellow, yes, that's right. There's a heap of great quality educational material on our site, with over 70 podcasts, 50 vodcasts, modules, exam preparation material, our echo learning centre and our journal club.

Hope to see you inside soon!

ICU fellow from Canada wrote 03-10-2014 08:19:03 am
Thanks Todd, I will subscribe now

Naveed from Pakistan wrote 03-10-2014 04:38:31 pm
As a member i wont be able to get access to the podcasts..???let me know

Drzubbasith from Saudi Arabia wrote 03-17-2014 02:40:09 am
For me it looks metformin associated lactic acidosis as her creatinine is abnormal and also she is still normoteensive despite of such a high lactate.I would prefer SLED as it is a hybrid form of renal replacement therapy though the role of RRT in lactic acidosis is not clear.

Taniab from Italy wrote 03-30-2014 10:47:55 pm
I agree with the prevoius comment. It looks like metformin associated lactic acidosis, maybe developed in a chronic renal failure. I think therapy should be: support treatments, CVVHDF and thiam

Alan from New Zealand wrote 04-02-2014 09:53:13 am
Airway and Breathing Maintained on 6l 02 good sats
Circulation- Life threatening Hyperkalaemia secondary acute renal faliure with unknown cause Normal Blood glucose , Normotensive, mildly tacchycardic, with Gross Acidemia, lactatemia,
D- Confused?
E abdo soft non tender Ct scanned - small kidneys?

I am ICU Nurse but I love learning more about the A and P and treatment so I guess main issues are..
firstly treating Life threatening Hyperkalaemia

My suggestions to treating doctor:
Is patient able to consent and maintain airway and breathing for Vascath insertion?
If yes give salbutamol 5mg neb
Iv Line for volume resus NaCl 0.9% 1l slowly (as PL148 contains 5mmol KCl )
Give 6.8mmol CaCl2
10units Actrapid in 50mls 50% dextrose whilst colleague is inserting lines
Could give 100mls of 8.4% bIcarbonate?

Catheterise patient and check urinalysis esp for blood?

Bloods for fbc, U and E, LFT, coag and toxicology, ?
A-Line (Work as a team!! someone taking any history of foods ingested etc to guide diagnosis whilst treatment plans to treat the hyperkalaemia)

Have cvvhdf set up (by nurse) likely pre- dilution to increase solute removal using Accusol (Bicarbonate) with No Kcl. Heparin infusion for filter using ACT or APTT to guide as per protocol.

Update patient and family throughout. Explain kidney faliure and what treatment plan is and that the team is working to confirm a diagnosis

Alan from New Zealand wrote 04-02-2014 09:56:36 am
sorry forgot to put in the A section- If not able to maintain airway explain procedure, Sedate, intubate and ventilate be careful with Suxemethonium though!




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