IV fluids

IV fluids

May 1, 2019 0
critical care,Emergency Medicine,geriatrics

In this podcast, James chats to John Myburgh about IV fluids. IV fluids are an integral part of therapy for patients in the hospital but come with some adverse effects, toxicities and potential complications.

Script Writer:  Sam Orton

Interviewee:  John Myburgh

Summary Writer:  Lise Kempler

Reviewer:  John Myburgh and Luke Collett

About John Myburgh

Professor John Myburgh is Professor of Critical Care at the Faculty of Medicine, University of New South Wales; Director of the Division of Critical Care and Trauma at the George Institute for International Health and senior intensive care physician at the St George Hospital, Sydney.

He also holds honorary professorial appointments at the University of Sydney and Monash University School of Public Health.

Professor Myburgh was a foundation member and past Chairman of the Australian and New Zealand Intensive Care Society (ANZICS) Clinical Trials Group. He has an extensive research record of accomplishment over 25 years.

Professor Myburgh is regarded as a national and international expert in:

  • catecholamines,
  • traumatic brain injury,
  • fluid resuscitation, and
  • endocrine dysfunction in critical illness.

He also has expertise from the development and co-ordination of over 40 studies in Intensive Care Medicine. He has been awarded over $75M in cumulative research funding from national and international research funding agencies.

His list of publications includes over 230 refereed research publications and 45 book chapters, with an h-index of 41. He has delivered over 400 presentations. This includes over 50 plenary presentations at major international and national scientific congresses.

Professor Myburgh has a long-established profile in education in Intensive Care Medicine, both at undergraduate and postgraduate levels. He was instrumental in establishing the College of Intensive Care Medicine of Australia and New Zealand. Furthermore, he served as its President from 2010-2012. In 2014, he was made an Officer of the Order of Australia for services to medicine.

In 2013, Professor Myburgh was elected to the WFSICCM Council. He was elected as Secretary-General in November 2017 and will hold this office until 2019.

IV fluids

 

With Professor John Myburgh, Intensivist at St George Hospital and Professor of Intensive Care Medicine at The University of New South Wales, Australia

 

Introduction

Intravenous (IV) fluids are an integral part of therapy in the hospital. In the context of hypovolaemia, IV fluids are life-saving. However, the decision to prescribe fluids is not one to be made lightly. The adverse effects, toxicities and complications of IV fluids need to be considered every time they are administered. Unless a patient is truly clinically hypovolaemic, the question should arise whether fluids need to be given at all.

  • Crystalloids, colloids, blood and blood products
  • Vast majority of patients will need crystalloids
    • E.g. Normal saline, Hartmanns, PlasmaLyte
  • In active bleeding, patients will need blood products
    • E.g. red blood cells, Fresh Frozen Plasma (FFP), cryoprecipitate
  • Colloids – emerging evidence: no place for synthetic colloids due to their toxicities
    • Albumin has a role in select patients
  • IV fluids are not “normal” physiology and can generate harm
    • Normal saline 0.9% – too much can increase serum Na and Cl and cause detrimental effects, e.g. hyperchloraemic metabolic acidosis
    • Hartmanns – contains lactate
    • PlasmaLyte – contains acetate
  • Always think: does the patient need fluid?
    • If the patient is not hypovolaemic, don’t give fluid
  • The selection of IV fluid depends on the clinical context
    • See the patient – fluid status exam, including vital signs, warmth, capillary refill
  • Ask – What is the likely fluid the patient has lost?
  • Replace the lost fluid with IV therapy that closely resembles it
    • E.g. Upper GI losses – losing chloride; can use Normal saline to replace the deficit
    • E.g. Lower GI losses – losing alkalinity; can replace with Hartmanns or PlasmaLyte
  • Use the patient’s serum pH and Na to help guide you – match the deficit
  • Fluid replacement is an iterative process – fluid requirements change over time

Case 1

You are working in the Emergency Department and you have been called into the Resuscitation Bay by the registrar to help with a 65-year-old gentleman, who is septic from a presumed urinary source. HR 140 and BP 90/60. He is confused and warm to the touch.

  • This patient is in early septic shock, as evidenced by the hypotension and tachycardia
  • Urosepsis is a condition that responds to antibiotics, without much fluid loss
  • The patient needs one bag of fluid (1000 mL) to correct the deficit (e.g. Hartmanns)
  • Antibiotics is truly what this patient needs
  • The team may consider an early vasopressor for this patient
  • Fluid accumulates!
    • 1L = 1kg!
    • In the brain, kidney, lungs, skin, gut – causes lots of morbidity
    • E.g. delirium and gut dysfunction – due to osmotic shifts from fluid administration
  • Give LESS – volume is more important than the crystalloid you choose
    • If the patient is hypovolaemic and needs fluid, give 500 mL to look for confirmatory evidence through clinical improvement
    • Oliguria can be considered to be ‘acute renal success’

Case 2

On your night shift, the nursing staff on the wards call you at 3 AM as they are concerned about a 65-year-old female, who is day 1 post-hemicolectomy. Her urine output has dropped to 20 ml/hr and they are asking you to please fill out a fluid order.

  • Oliguria not always bad – don’t use urine output as the main parameter
  • Approach:
    • Clinical status – talking, analgesed, warm to touch? – no fluid necessary
    • Urine output – what does it look like?
    • How small or large is the patient? – consider fluids for 45 kg frail lady vs. 95 kg
    • Examine the patient
      • How is the surgical site including the wound and abdomen?
        • Is there evidence of bleeding?
        • Abdominal compartment syndrome? – Fluid would be harmful
  • What is the serum sodium, osmolarity, bicarbonate (or pH)?
  • What fluids has she been given thus far?
  • Does this patient need fluids?
  • IV fluids are toxic drugs – their use needs to be rationalized
  • Crystalloids are first-line therapy
  • Always ask – does this patient really need IV fluids?

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Tags: #colloids,#critical care,#crystalloids,#Emergency Medicine,#fluid therapy,#Geriatrics,#hypotension,#hypovolaemia,#intravenous fluid,#IV fluids,#septic shock

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