Predicting Fluid Responsiveness by Passive Leg Raise (PLR)

passive leg raiseBackground: The best way to resuscitate critically ill patients with fluids has been a hotly debated topic in the FOAMed and Critical Care worlds. Fluids are important to optimize stroke volume and distal tissue perfusion, however, the administration of excessive fluids for shock can increase a patient’s morbidity and mortality by causing volume overload, which may lead to tissue edema and subsequently inadequate blood flow to tissues [1]. Accurately predicting when, whom, and how much fluid to administer remains a very challenging clinical question as only half of critically ill patients increase their cardiac output in response to the administration of fluids (i.e. the patient is preload or fluid responsive) [1].

Clinical signs and pressure/volumetric static variables are unreliable predictors of fluid responsiveness [1]. Ventilator-induced dynamic variables such as stroke volume variation and pulse pressure variation, however, have been shown to be more accurate in predicating fluid responsiveness. These tests can only be applied when several criteria are present (e.g., sinus heart rate, mechanical ventilation with a tidal volume of 8-10cc/kg of ideal body weight).

Passive leg raise (PLR) is another method to assess preload responsiveness. PLR produces a temporary and reversible increase in ventricular preload through an increase in venous return from the lower extremities, which mimics fluid administration without actually having to give exogenous fluids. This sounds great in theory, but PLR requires a hemodynamic assessment to be made during the maneuver to determine if the patient is preload responsive or not. There are multiple techniques for assessing changes in stroke volume but the diagnostic performance of each method still remains unknown. The two most commonly described methods are changes in pulse pressure variation and variables of flow. Continue reading

The PATCH Trial: Hold the Platelets in Spontaneous Intracerebral Hemorrhage?

PATCH TrialBackground: Hemorrhagic stroke accounts for 11 – 22% of strokes, half of all stroke deaths, and a significant amount of disability in many of the remaining survivors. Spontaneous, non-traumatic, intracerebral hemorrhage (ICH) accounts for 2/3 of hemorrhagic strokes; estimated at > 2 million ICHs each year. To date several studies have suggested that antiplatelet therapy use before ICH might worsen outcomes by increasing the risk of early ICH volume growth, due to platelet dysfunction, and pathophysiologically this makes sense. Platelet transfusion has been used therapeutically in many clinical settings for acute ICH, but there is a paucity of randomized trials investigating its effectiveness for reducing death or dependence.  Continue reading

Forget the PediaLyte and Just use Dilute Apple Juice in Mild Gastroenteritis

Dilute Apple JuiceBACKGROUND: Every year in the United States there are an estimated 178.8 million episodes of acute gastroenteritis resulting in 473,832 hospitalizations.  Most of the evidence surrounding oral rehydration centers around Oral Rehydration Therapy (ORT) studies in low-income countries where children suffer from more extensive gastrointestinal losses.  Theoretically, electrolyte maintenance solutions are recommended in order to prevent increasing diarrheal losses through the osmotic diuresis that can occur with glucose-rich drinks like juice.  However, these electrolyte maintenance solutions can cost up to $10 for a 1-liter bottle and are unpalatable to some children.  Refusal to drink often results in the need for IV hydration and can potentially result in disease progression and hospitalization.  This study attempted to look at whether a dilute apple juice solution or preferred fluids was equal to, if not superior to oral hydration with an electrolyte maintenance solution. Continue reading

The ENCHANTED Trial: Is Low-Dose the Right Dose for Intravenous tPA in Acute Ischemic Stroke?

The ENCHANTED TrialBackground: Despite continued debate on the efficacy of alteplase (tPA), it currently remains one of the major interventions directed at patients presenting with acute ischemic stroke. The current standard dose of the drug is 0.9 mg/kg given over 1 hour. It is unclear whether lower doses would be equally effective in increasing good neurologic outcomes after stroke while simultaneously decreasing the rate of intracerebral hemorrhage (ICH); the most serious side effect. Evidence showing that lower doses of tPA are non-inferior to standard-dose tPA could lead to a shift in treatment.  Continue reading

Changing Arm Position for Ultrasound Guided Subclavian Central Lines?

Changing Arm Position for Ultrasound Guided Subclavian Central Lines?The subclavian route is known to be the site for central line placement with the lowest risk of infection, but can also lead to many mechanical complications [2]. The biggest risk of subclavian line placement is an iatrogenic pneumothorax. The use of ultrasound for subclavian line placement can greatly reduce this risk by watching the needle enter the vein. But does arm position matter for ultrasound guided subclavian central lines? Continue reading