December 5, 2019

Background: Saline (0.9% sodium chloride) has historically been one of the most common intravenous fluids administered in critically ill adults.  However, the supraphysiologic chloride concentration can cause hyperchloremia, metabolic acidosis, renal vasoconstriction and alter immune function.  There is nothing normal about normal saline. Balanced crystalloids (i.e. lactated Ringer’s solution, Plasma-Lyte A, etc) contain electrolyte compositions that are closer to physiologic levels.  Recently, the Isotonic Solutions and Major Adverse Renal Events Trial (SMART) [2] compared balanced crystalloids to saline among critically ill adults and found that balanced crystalloids decreased the composite outcome of death, new renal replacement therapy, or persistent renal dysfunction (This composite outcome was primarily driven by mortality benefit).  Interestingly, in the subgroup analyses of septic patients, balanced crystalloids seemed to have its biggest benefit in MAKE30 compared to saline.

October 10, 2019

Background: Serial lactate measurements is a common core measure that we follow in septic shock resuscitation. A number of readers have written in enquiring about whether resuscitation with lactated ringers instead of 0.9% saline would lead to increases in serum lactate.   It’s a great question, and one that I am not sure I had a solid answer for before reviewing this topic.  LR contains 28 mmol/L of sodium lactate and, on the surface, it seems reasonable to think that infusion of LR would lead to lactate increases. This could potentially confound the interpretation of serial serum lactate measurements.

September 25, 2019

Take Home Points
  • When looking at pH and bicarb, the differences between VBG and ABG are miniscule. For DKA patients, stick with the VBG as is less painful and has fewer complications. 
  • LR is probably a better fluid for the large volume resuscitation required in DKA. Start with a 20 cc/kg bolus and then reassess the patient’s perfusion status.
  • Stay on top of your electrolyte repletion. If the patient has a working gut, you can aggressively replete potassium orally and don’t forget that when you are repleting potassium you also must replete magnesium.
  • Bolus dose insulin gets the patient to super-physiologic levels and has been associated with higher potassium requirements and more episodes of hypoglycemia. It’s probably fine to skip the bolus and stick with a drip alone
  • Don’t forget to think of all possible etiologies of DKA, while we most often find this in patients who have not been taking their home meds for whatever reason, don’t forget a good history to look for sources such as infection and ischemia. 

August 26, 2019

Normal saline started being used based on work done in the 1830s with cholera.  We are still doing the same thing the same way and it’s not until recently we have begun to ask the hard questions about why we are doing things the same way 150 years later.  In this debate, titled "What the Fluid," from Rebellion in EM 2019, Scott Wieters, MD and Rob J. Bryant, MD debate the pros and cons of balanced and unbalanced crystalloids.

August 21, 2019

Take Home Points

  • Myxedema coma is severe, decompensated hypothyroidism with a very high mortality.
  • Classic features include: decreased mental status, hypothermia, hypotension, bradycardia, hyponatremia, hypoglycemia, and hypoventilation
  • Work up includes looking for and treating precipitating causes, most commonly infection as well as serum levels of TSH, T4 and cortisol
  • Treat for the possibility of adrenal insufficiency with stress dose steroids such as hydrocortisone 100 mg IV
  • The exact means of thyroid replacement is controversial. Definitely given 100-500 mcg levothyroxine and discuss the simultaneous administration of T3 with your endocrine and ICU teams.