Shanholtz: Accidental Drowning in the ICU

Clinical Pearls

• Why do critically ill patients become volume overloaded?
  • Inflammation
    • Sepsis
    • Pancreatitis
    • Trauma
    • Burns
  • CHF
  • Renal Failure

• Origins of Fluid Resuscitation
  • 1830: fluid resuscitation began with the European cholera epidemic
  • 1832: first successful saline fluid resuscitation
  • 1834: first use of albumin
  • 1903: sphygmomanometer invented; shock defined by Mummary and Crile as inadequate BP, with IV saline as one of few treatments
  • 1934: Blalock differentiated shock based on circulatory pathophysiology
    • Septic shock vasodilatory and hyperdynamic
    • Shock “a decrease in the ratio of the blood volume in circulation to the capacity of the vascular tree” (loss of effective blood volume)
• So why give fluids?
  • Frank-Starling curve
    • Successive increases the preload by filling the unstressed portions of the heart → increases in SV

• • • Where in that “a” is volume responsive.
    • However, as you continue to increase the preload, the gain to SV diminishes at “b” leading to an unresponsive state.
  • Seymour, NEJM, 2017
    • Analysis of NY state sepsis data
      • Found a 4% increase in mortality  for ever hour beyond the first 3 hours of the sepsis bundle
• Case Against Fluid Resuscitation (Except Early Resuscitation of Shock)
  • First off, most of all animal models of sepsis are hypodynamic; whereas human sepsis is mostly hyperdynamic
  • Starling curve is not perfect!
    • ↑ cardiac filling P → ↑ natriuretic peptide→ breaks down of endothelial glycocalyx→ ↑ endothelial permeability
      • Interstitial fluid→ pulmonary + tissue edema
      • Tissue edema→ impaired oxygen and metabolite diffusion, tissue architecture distortion, impedance of capillary blood flow and lymphatic drainage, disturbed cell-cell interactions
      • Kidney is affected: ↑ venous pressure→ ↑ renal subcapsular pressure→ ↓ RBF, ↓ GFR

• Major studies have failed to demonstrate support of massive IVF resus in sepsis:
  • SOAP Study
    • Multicenter cross-sectional cohort, 198 ICUs, 1,177 patients with sepsis
    • Each 1L of positive fluid balance —> ↑10% odds of mortality
  • VASST Study
    • Retrospective review of a prospective randomized controlled trial (RCT)
    • 778 patients with septic shock enrolled in vasopressin study
    • Each ↑ quartile of fluid administration associated with ↑ mortality
  • ICON study
    • Prospective, cross-sectional cohort, 84 countries, 730 ICUs, 1,808 patients with sepsis (61% septic shock)
      • Survivors had more negative fluid balance
    • After the initial resuscitation, higher hazard ratio for death for each quartile of more fluid
  • Andrews, JAMA, 2017
    • 212 patients in Zambia with sepsis
    • RCT sepsis protocol (including aggressive fluids) vs usual care
    • ↑ mortality in protocol group (48% vs 33%)
  • Classic Trial
    • Prospective RCT, 9 Scandinavian ICUs, 151 patients with septic shock
    • Beyond initial resuscitation phase
    • Standard care vs fluid boluses only if severe hypoperfusion
    • Non-significant trend to lower mortality in fluid restriction, less AKI (significant)
  • ProCESS, ARISE, ProMISe
    • All 3 trials found that EGDT was equivocal to usual resuscitation
  • FEAST trial
    • 3600 children in Uganda, Kenya, or Tanzania (not in shock), RCT btw 20-40 cc/kg bolus vs. no bolus
    • Fluid boluses significantly increased 48-hour mortality
• Question then becomes, should we fluid resus severe sepsis + septic shock?
  • Of course we should!
    • Early is best!!
  • Leisman, Crit Care Med, 2017
    • Observational cohort, 9 hospitals, 11,000 patients
    • Early fluid resuscitation (< 120 mins) had lower mortality, less risk for mechanical ventilation, shorter hospital stay, less ICU days….
  • Child, Clinicoecon Outcomes Res, 2017
    • Volume OL = higher infection rate, increased morbidity, increased costs!
  • Frutos-Vivar, Chest, 2006
    • Prospective cohort, 37 hospitals, 8 countries
    • 24 h fluid balance pre-extubation a risk factor of reintubation
  • FACTT, NEJM, 2006
    • Prospective, multicenter RCT of liberal vs conservative fluid management of ARDS
      • 5 more ventilator-free days and 2.2 ICU-free days in liberal group
    • Keeping CVP constant over several days actually represented a more positive fluid balance
      • A declining CVP over several days actually represented an even fluid balance
      • … this mostly applied to the NON-shock group
    • No difference in need for dialysis to day 60, meaning more liberal fluids do NOT prevent renal failure
    • Relative 10% increase in death at 60 days in the liberal fluid vs conservative fluid group (28.4% vs 25.5%)
      • (though not statistically significant and not powered to detect a 10% relative difference in mortality)

• 54,130 expected deaths per year from ARDS, which would represent 5,413 excess deaths with liberal fluid
  • There are only 3,443 drowning victims in the US annually
• More patients drown in the ICU than in the rest of the US!!