Pharmacodynamic analysis of a fluid challenge with 4 ml kg-1 over 10 or 20 min: a multicenter cross-over randomized clinical trial.

PURPOSE: A number of studies performed in the operating room evaluated the hemodynamic effects of the fluid challenge (FC), solely considering the effect before and after the infusion. Few studies have investigated the pharmacodynamic effect of the FC on hemodynamic flow and pressure variables. We designed this trial aiming at describing the pharmacodynamic profile of two different FC infusion times, of a fixed dose of 4 ml kg-1. METHODS: Forty-nine elective neurosurgical patients received two consecutive FCs of 4 ml kg-1 of crystalloids in 10 (FC10) or 20 (FC20) minutes, in a random order. Fluid responsiveness was defined as stroke volume index increase ≥ 10%. We assessed the net area under the curve (AUC), the maximal percentage difference from baseline (dmax), time when the dmax was observed (tmax), change from baseline at 1-min (d1) and 5-min (d5) after FC end. RESULTS: After FC10 and FC20, 25 (51%) and 14 (29%) of 49 patients were classified as fluid responders (p = 0.001). With the exception of the AUCs of SAP and MAP, the AUCs of all the considered hemodynamic variables were comparable. The dmax and the tmax were overall comparable. In both groups, the hemodynamic effects on flow variables were dissipated within 5 min after FC end. CONCLUSIONS: The infusion time of FC administration affects fluid responsiveness, being higher for FC10 as compared to FC20. The effect on flow variables of either FCs fades 5 min after the end of infusion.

Laryngeal Mask Airway Supreme vs. the Spritztube tracheal cannula in anaesthetised adult patients: A randomised controlled trial.

BACKGROUND: The Spritztube is a new supraglottic airway device combining the ability to allow extraglottic ventilation of the lungs with the opportunity to perform fibreoptic-assisted intubation. OBJECTIVES: To compare the Spritztube tracheal cannula with the Laryngeal Mask Airway Supreme (LMA-S) in anaesthetised adult patients. DESIGN: A single-centre, randomised controlled study. SETTING: Tertiary hospital. PATIENTS: Mechanically ventilated patients undergoing elective surgery in the supine position under general anaesthesia were included. Main exclusion criteria were a history of, or predicted, difficult airway management according to SIAARTI guidelines and absence of written informed consent. INTERVENTIONS: Patients received the LMA-S or Spritztube tracheal cannula to facilitate ventilation of the lungs. MAIN OUTCOME MEASURES: Successful placement (primary outcome), time required for insertion, number of attempts, subjective assessment of ease of insertion, safety and incidence of complications were recorded. RESULTS: One hundred and sixty seven patients were allocated to the LMA-S or Spritztube group, respectively, a total of 334 patients. In the LMA-S group, the device insertion failed in nine patients, compared with none in the Spritztube group (P = 0.002). Spritztube insertion was easy in 100% of cases compared with 94.6% of the cases in the LMA-S group (P = 0.03). The number of attempts was significantly higher with the LMA-S compared with the Spritztube (P = 0.0007), whereas the insertion times were comparable (P = 0.06). Except for the incidence of blood-staining, which was higher in the LMA-S group (P = 0.01), the number of complications was comparable in the two groups. CONCLUSION: The Spritztube was as effective as the LMA-S in maintaining the airway with all patients being successfully ventilated without difficulty. The success rate of achieving a patent airway was comparable between the groups, with a similar occurrence of complications. TRIAL REGISTRATION: NCT03443219.