In the critically ill population, fluid administration in an unstable patient is perhaps the most common intervention that is performed. Uncorrected hypovolemia with inappropriate vasopressors lead to organ hypoperfusion where as overzealous fluid administration especially in ARDS (Adult respiratory distress syndrome) can increase mortality. It has been estimated that only 50% of hemodynamically unstable critically ill patients are volume responsive, hence dynamic assessment of preload responsiveness has been proposed to better identify those individuals who would benefit from fluid bolus.
Age between 30 - 90 years
Diagnosis of Vasodilatory Shock with no other obvious cause of hypotension
Diagnosis of ARDS with PF ratio < 150 , PEEP > 8
Patients who are under paralysis or deeply sedated, on a mechanical ventilator
Patients with arrhythmias including atrial fibrillation
Patients with chest tube, intra-abdominal hypertension or with its risk factors
Patients with structural heart disease including pulmonary hypertension (RVSP > 45) and heart failure
Patients on extracorporeal support such as ECMO, CRRT or MCS.
Screening criteria: 1. New onset of hypotension: MAP \< 65 mm HG for \> 5 min 2. Escalation in Nor-epinephrine needs\> 0.03 ug/kg/min 3. High MAP goal Low Urine output \< 0.5ml/kg/hr for \> 2 hours Elevated Lactate \> 4 moles/L Decreased Lactate clearance (\< 40%) 4. Bedside Echo Inc. VTI No obvious Hypovolemia No Low EF or No Pericardial effusion
Cohort
Prospective
Passive leg raise, SVI via bioreactance, Echo based VTI
Diagnostic testNo interventions other than fluid challenge
Vasopressor dose in Nor-epinephrine equivalents (NE) measured as mcg/kg/min
We shall assess the need for vasopressor dose e.g nor-epinephrine dose. If the dose remains constant after fluid bolus until 3 hours, we shall consider them fluid resposive. If the dose requirement goes up despite fluid bolus, we shall label them fluid un-responsive
