title: Mini-fluid challenge predicts fluid responsiveness during spontaneous breathing under spinal anaesthesia: An observational study.
abstract: BACKGROUND
  The ability to predict fluid responsiveness in spontaneously breathing patients under spinal anaesthesia is desirable.
  
  
  OBJECTIVE
  The objective of this study was to test whether variations in stroke volume (SV) in response to a fixed mini-fluid challenge (ΔSV100) measured by thoracic impedance cardiography (ICG) can predict fluid responsiveness in spontaneously breathing patients under spinal anaesthesia.
  
  
  METHODS
  A prospective observational study.
  
  
  METHODS
  Anaesthesiology department in a university hospital.
  
  
  METHODS
  Seventy-three patients monitored by ICG during surgery under spinal anaesthesia.
  
  
  METHODS
  Patients received a 100 ml fluid challenge followed by volume expansion with 500 ml of crystalloid.
  
  
  METHODS
  Haemodynamic variables and bioimpedance indices [blood pressure, SV, cardiac output (CO)] were measured before and after fluid challenge and before and after volume expansion. Responders were defined as those with >15% increase in SV after volume expansion.
  
  
  RESULTS
  SV increased by at least 15% in 27 (37%) of the 73 patients. ΔSV100 predicted fluid responsiveness with an area under the receiver operating characteristic (AUC) curve of 0.93 [95% confidence interval (95% CI) 0.8 to 0.97, P < 0.001]. The cut-off was 7% and a grey zone ranging between 3 and 8% was observed in up to 14% of patients. SV baseline was a poor predictor of fluid responsiveness [AUC of 0.69 (95% CI 0.57 to 0.79, P = 0.002)].
  
  
  CONCLUSIONS
  ΔSV100 greater than 7% accurately predicted fluid responsiveness during surgery with a grey zone ranging between 3 and 8%.
authors.affiliation: From the Anaesthesiology and Critical Care Department, Amiens University Hospital, Place Victor Pauchet, Amiens, France.
authors.forename: Pierre-Grégoire
authors.initials: PG
authors.lastname: Guinot
authors.forename: Eugenie
authors.initials: E
authors.lastname: Bernard
authors.forename: Fanny
authors.initials: F
authors.lastname: Defrancq
authors.forename: Sandra
authors.initials: S
authors.lastname: Petiot
authors.forename: Yazine
authors.initials: Y
authors.lastname: Majoub
authors.forename: Herve
authors.initials: H
authors.lastname: Dupont
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Lorne
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000775:Anesthesia, Spinal / Q000379:methods*; D000077324:Crystalloid Solutions; D005260:Female; D005440:Fluid Therapy / Q000379:methods*; D006801:Humans; D007552:Isotonic Solutions / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012119:Respiration / Q000187:drug effects
chemical_list: D000077324:Crystalloid Solutions; D007552:Isotonic Solutions