Thread by @jfdwolff

A question that junior doctors ask themselves every day: in this septic patient with hypotension, how much fluid should I give, and how much would be too much? #fluidchallenges @acutemedicine

@acutemedicine The first question is always what the physiological impact of the low blood pressure is. Ultimately it is a bunch of numbers; some people with advanced heart failure have an SBP of 80 on a good day and they tolerate that remarkably well.

Assessment should consist of the level of consciousness, peripheral perfusion (hot or cold, up to which part of the arm), urine output (and creatinine if recent values available), and fluid balance if already in hospital for a few days.

Most hypotension in hospital is multifactorial. I am saying this because we are taught about the different Weil & Shubin shock states (est 1972), but in practice there is usually soo much more going on.
link.springer.com/chapter/10.100…

The sepsis is causing vasodilation and myocardial depression, but the LV was already stiff from 30 years of hypertension, and the patient takes amlodipine (a vasodilator), ramipril (effectively a vasodilator) and bendroflumethiazide (a diuretic). See how tricky this gets?

Look, the sepsisologists have updated the Surviving Sepsis recommendations again!
journals.lww.com/ccmjournal/Ful…

"5. For patients with sepsis induced hypoperfusion or septic shock we suggest that at least 30 mL/kg of IV crystalloid fluid should be given within the first 3 hr of resuscitation. Weak, low quality of evidence. DOWNGRADE from Strong , low quality of evidence." Ouch.

"We recommend that in the initial resuscitation from sepsis-induced hypoperfusion, at least 30 mL/kg of IV crystalloid fluid be given within the first 3 hr".

So in a 70kg adult presenting afresh with sepsis, hypotension and/or a raised lactate, 2.1L within 3h.

Things get even messier on the ward, where you have genuinely no way of reasonably determining how much fluid is going to make your patient better (if at all), and how much is too much. Wet lungs bad, wet skin bad, wet kidneys bad too.

Wait, can you make the kidney too wet? Oh yes, you bet! Renal venous hypertension, swollen kidney, encapsulated organ, perfusion drops (just some guesses).
link.springer.com/article/10.100…

NICE clinical guideline 174 (2013), for all its failings, does contain some useful guidance on unstable patients who may require fluid challenges. nice.org.uk/guidance/cg174

Unless the patient is "in extremis", strongly consider performing the "passive leg raise" manoeuvre. You will need a helper for the patient's other leg, unless they are very thin indeed. @LITFLblog
litfl.com/passive-leg-ra…

This is pretty well validated, especially of course in those with continuous cardiac output monitoring. But that would be on ITU and you're on the medical ward at 3:25 AM.

Here is an article on fluid responsiveness from PLR gurus from France. ncbi.nlm.nih.gov/pmc/articles/P…

I cannot repeat this often enough: a fluid challenge is as much a diagnostic test as it is an intervention. You are measuring the response to volume expansion to demonstrate actual hypovolaemia and fluid responsiveness. #fluidchallenges

Once again for those at the back looking at their smartphones: a fluid challenge is as much a diagnostic test as it is an intervention. You are measuring the response to volume expansion to demonstrate actual hypovolaemia and fluid responsiveness. #fluidchallenges

What is your preferred fluid challenge volume?

Conventional teaching (e.g. NICE, ALS, IMPACT course etc) is that 500 ml is reasonable fluid challenge in someone who has no major cardiopulmonary comorbidity. Those who do are better off with smaller volumes, but this may obscure the response. Decide what your endpoints are!

You really should be remaining on the ward to determine the outcome of the fluid challenge. The change in BP, HR etc should be measurable in minutes, possibly even shorter. The results will be determining your next step: further challenges or ringing your boss.

Things to do in the meantime:
1. Withhold blood pressure lowering drugs
2. Is this worsening sepsis and do antibiotics need escalating? Aminoglycosides help in Gram negative sepsis with bacteraemias
3. Find the missed steroids and consider IV hydrocortisone

Urinary catheters are not mandatory in unwell patients with labile blood pressure, even if they have AKI, but they must urinate in a bottle/bedpan, and if there is any doubt (or possible retention): really consider that Foley.

Another thing to consider while the fluids run: is the diagnosis correct? Could the "LRTI" actually be a pulmonary embolism that has decided to go massive on your watch? What are the chances this is cardiogenic shock?

Yeah, an ECG is never a bad idea in a deteriorating patient.

NICE CG174 stipulates that 2L of fluid challenges are about the maximum a patient should be getting without a senior review. This is a pretty good rule of thumb, because lack of response does indicate escalation of care may indeed be needed.

Back in the previous decade I quite enjoyed the ProCESS study, which was one of three to overturn EGDT/Rivers. It used clinician judgement and the "shock index" (HR/SBP) rather than other measurements to determine circulatory management. nejm.org/doi/full/10.10… @NEJM

This was pretty "real world". Those started on inotropes received them after approximately 3L of fluid had been given. The remainder did not need inotropes. I have taken this on board as a rule of thumb: 3L should make you consider vasopressor infusions.

We are quite spoilt locally: in our medically run HDU we can give single vasopressor infusions. In most other hospitals you'll be talking to ITU to achieve that. Most of the time they will tell you to give more fluid first. @dr_shai

I hope this was in any way useful, dear readers. I hope you were not expecting a "one size fits all" figure on fluid challenges, because the answer is always "it depends". It is an opportunity to use your clinical acumen and fine-tune it further.

Feedback please. Feel free to claim CPD points but I can't issue certificates...