Reducing the time to successful intravenous cannulation in anaesthetised children with poor vein visibility using a near-infrared device: A randomised multicentre trial.

BACKGROUND: During inhalational induction of anaesthesia for children, severe respiratory events can occur but can be rapidly treated once intravenous access is in place. Reducing the time to successful cannulation during inhalational induction for children with poor vein visibility would improve safety. OBJECTIVE: To study the effectiveness of a near-infrared (NIR) vascular imaging device (Veinviewer) to facilitate intravenous cannulation. DESIGN: A prospective, multicentre, randomised, open clinical trial. SETTING: The operating rooms of three paediatric hospitals in Paris, France, from 1 October 2012 to 31 March 2016. PATIENTS: Children up to the age of 7 years, with poor vein visibility requiring general anaesthesia. INTERVENTION: Inhalational anaesthesia was initiated and intravenous cannulation was performed with the standard approach or with the Veinviewer Vision. MAIN OUTCOME MEASURES: The primary outcome was the time to successful intravenous cannulation. A secondary outcome was the proportion of successful first attempts. RESULTS: The mean time to successful intravenous cannulation was 200 (95% CI, 143 to 295) seconds in the Veinviewer and 252 (95% CI, 194 to 328) seconds for the control group: hazard ratio 1.28 (1.02 to 1.60) (P = 0.03). The adjusted hazard ratio for known predictive factors was 1.25 (0.99 to 1.56) (P = 0.06). Success at the first attempt was 64.6% (102/158) in the 'Veinviewer' group vs. 55.6% (85/153) in the 'control' group (P = 0.10). CONCLUSION: The Veinviewer has limited value in reducing the time to successful intravenous cannulation during inhalational anaesthesia for young children with poor vein visibility. However, there is a strong trend to reducing the delay in some cases and, given its absence of side effects, it could be part of a rescue option for a difficult venous-access strategy. CLINICAL TRIAL REGISTRATION: NCT01685866 (http://www.clinicaltrials.gov).

The effect of preoperative heart rate and anxiety on the propofol dose required for loss of consciousness.

BACKGROUND: Conflicting results have been reported on the effect of anxiety on the propofol dose required for inducing loss of consciousness (LOC). The hemodynamic effects of anxiety, increased heart rate (HR), and cardiac output may account for these discrepancies. We therefore designed this study to address, first, the effect of perioperative HR on propofol dose required for LOC and, second, the effect of perioperative anxiety on HR. METHODS: Forty-five ASA physical status I-II female patients undergoing gynecological surgery were studied. Anxiety was assessed in the operating room with the State-Trait Anxiety Inventory (STAI)-state Spielberger scale (situational anxiety). After HR recording, anesthesia was induced with a 200-mL/h 1% propofol infusion with the Base Primea pump (Fresenius-Vial, Brezins, France) until LOC. The propofol dose was recorded at the time of LOC. Relationships between STAI-state and HR versus propofol dose at LOC were tested with the Spearman test with a P value of 0.01. RESULTS: A significant relationship was observed between HR and propofol dose at LOC (rho = 0.487, P = 0.0012) but not between STAI-state and propofol dose (rho = 0.330, P = 0.0306). However, a significant relationship was observed between STAI-state and HR (rho = 0.462 and P = 0.0054). CONCLUSION: Increased perioperative HR is associated with increased propofol dose required for LOC. Perioperative anxiety accounts for increased HR.