ABSTRACT
BACKGROUND: Fluid bolus therapy (FBT) is common in ICUs but whether it achieves the effects expected by intensivists remains uncertain. We aimed to describe intensivists' expectations and compare them to the actual physiological effects. METHODS: We evaluated 77 patients in two ICUs (Sweden and Australia). We included patients prescribed a FBT ≥250 ml over ≤30 minutes. The intensivist completed a questionnaire on triggers for and expected responses to FBT. We compared expected with actual values at FBT completion and after one hour. RESULTS: Median bolus size (IQR) was 300 ml (250-500) given over a median (IQR) of 21 minutes (15-30 mins). Boluses were 57% Ringer´s Acetate and 43% albumin (40-50g/L). Hypotension was the most common trigger (47%), followed by oliguria (21%). During FBT, 55% of patients received noradrenaline and 38% propofol. Intensivists expected a median MAP increase of 2.6 mmHg (IQR: -3.1 to +6.8) at end of bolus and of 1.3 mmHg (-3.5 to + 4.1) after one hour. Intensivist´s' expectations were judged to be accurate if they were within 5% above or below measured values. At FBT completion, 33% of MAP expectations were overestimations and 42% were underestimations. One hour later, 19% were overestimations and 43% were underestimations. Only 8% of expectations of measured urine output (UO) were accurate and 44% were overestimations. Correction for sedation or vasopressors did not modify these findings. CONCLUSIONS: The physiological expectations of intensivists after FBT carried a high risk of both over and underestimation. Since the physiological effect FBT was often small and did not meet clinical expectations, a reassessment of its rationale, effect, duration, and role appears justified.
Subject(s)
Critical Illness , Hypotension , Critical Care , Critical Illness/therapy , Fluid Therapy , Humans , Hypotension/therapy , MotivationABSTRACT
BACKGROUND: The management of COVID-19 ARDS is debated. Although current evidence does not suggest an atypical acute respiratory distress syndrome (ARDS), the physiological response to prone positioning is not fully understood and it is unclear which patients benefit. We aimed to determine whether proning increases oxygenation and to evaluate responders. METHODS: This case series from a single, tertiary university hospital includes all mechanically ventilated patients with COVID-19 and proning between 17 March 2020 and 19 May 2020. The primary measure was change in PaO2 :FiO2 . RESULTS: Forty-four patients, 32 males/12 females, were treated with proning for a total of 138 sessions, with median (range) two (1-8) sessions. Median (IQR) time for the five sessions was 14 (12-17) hours. In the first session, median (IQR) PaO2 :FiO2 increased from 104 (86-122) to 161 (127-207) mm Hg (P < .001). 36/44 patients (82%) improved in PaO2 :FiO2 , with a significant increase in PaO2 :FiO2 in the first three sessions. Median (IQR) FiO2 decreased from 0.7 (0.6-0.8) to 0.5 (0.35-0.6) (<0.001). A significant decrease occurred in the first three sessions. PaO2 , tidal volumes, PEEP, mean arterial pressure (MAP), and norepinephrine infusion did not differ. Primarily, patients with PaO2 :FiO2 approximately < 120 mm Hg before treatment responded to proning. Age, sex, BMI, or SAPS 3 did not predict success in increasing PaO2 :FiO2 . CONCLUSION: Proning increased PaO2 :FiO2 , primarily in patients with PaO2 :FiO2 approximately < 120 mm Hg, with a consistency over three sessions. No characteristic was associated with non-responding, why proning may be considered in most patients. Further study is required to evaluate mortality.
