Maintenance Of Intravenous Anesthesia Research Articles

Blood pressure nomograms for children undergoing general anesthesia, stratified by age and anesthetic type, using data from aretrospective cohort at a tertiary pediatric center.

Reference values for non-invasive blood pressure (NIBP) are available for children undergoing general anesthesia, but have not been analyzed by type of anesthetic. This study establishes age-specific pediatric NIBP reference values, stratified by anesthetic type: inhalational anesthesia (IHA), total intravenous anesthesia (TIVA), and mostly intravenous anesthesia (MIVA, an inhalational induction followed by intravenous maintenance of anesthesia). NIBP measurements were extracted from a de-identified vital signs database for children < 19years undergoing anesthesia between Jan/2013-Dec/2016, excluding cardiac surgery. We automatically rejected artifacts and randomly sampled 20 NIBP values per case. Anesthetic phase (induction/maintenance) was identified using operating room booking times for procedure start, and anesthetic types were identified based on intraoperative minimum alveolar concentration values in the different phases of the anesthetic. From 36,347 cases in our operating room booking system, we matched 24,457 cases with available vital signs. Of these, 20,613 (84%) had valid NIBP data and could be assigned to one anesthetic type: TIVA 11,819 [57%], IHA 4,752 [23%], and MIVA 4,042 [20%]. Mean NIBP during anesthesia increased with age, from median values of 48mmHg (TIVA), 45mmHg (IHA), and 41mmHg (MIVA) in neonates, to 70mmHg (TIVA), 68mmHg (IHA), and 64mmHg (MIVA) in 18-year-olds, respectively. In children < 1year, mean NIBP values were 4mmHg higher with TIVA than IHA (p < 0.001). These pediatric NIBP reference values contribute to ongoing debate about alarm limits based on age and anesthetic type, and may motivate prospective studies into the effects of different anesthesia regimes on vital signs.

Comparison of Fentanyl-Propofol and Ketamine-Propofol Combination in Induction and Maintenance with Intravenous Anesthesia for Short Surgical Procedures at Moderate Elevations.

The aim of the study is to evaluate the efficacy of Ketamine-Propofol compared to Fentanyl-Propofol combination during induction and maintenance of total intravenous anesthesia for short surgical procedures at moderate elevation. A prospective pilot study was done comparing between Fentanyl (1.2 mcg/kg)- Propofol and Ketamine (0.5mg/kg)-Propofol with 30 in each group at moderate altitude of approximately 2514 meters for the requirement of positive pressure ventilation, changes in heart rate and mean arterial pressure intraoperatively, total Propofol consumption and time to attain Modified Steward Score of 6. Requirement for positive pressure ventilation was significantly high in Fentanyl-Propofol group 18 (60%) compared to Ketamine-Propofol 1 (0.03%) [P = 0.00]. Fall in oxygen saturation was significant at 2 minute of Ketamine or Fentanyl [95% CI, 3.10-5.76, P = 0.00], after induction with Propofol [95% CI, 2.30-4.03, P = 0.00], 5 minute [95% CI, 1.66-3.54, P = 0.00], 10 minutes [95% CI, 0.55-2.32, P = 0.02], 15 minutes [95% CI, 0.50-2.09, P = 0.00] and 20 minutes [95% CI, 0.43-2.23, P = 0.00] respectively after study drug between the groups. Total Propofol consumption was significantly higher [95% CI, 0.19-0.43, P = 0.00] in KP (1.55±0.27mg/kg) compared to FP (1.23±0.16 mg/kg). At moderate elevations of 2514 meters, during the induction and maintenance of intravenous anesthesia, Ketamine-Propofol causes significantly less fall in oxygen saturation in the first 20 minutes requiring lesser need of positive pressure ventilation with comparable least fall in heart rate and mean arterial pressure with higher total Propofol consumption when compared to Fentanyl-Propofol. It took a significantly longer time to recovery with Modified steward score of maximum 6 with Ketamine-Propofol.

The Effect of Rocuronium during Concomitant Propofol and Rocuronium Intravenous Injection

Background: The induction and maintenance of intravenous anesthesia by propofol-TCI has been popular. When infusing propofol with other drugs at the same intravenous access line, incompatibility may result. We attempted to evaluate the incompatibilities between propofol and rocuronium by subtherapeutic dosing of rocuronium. Methods: Eighty patients were randomized into two groups. Induction of anesthesia was done by propofol-TCI. The patients in group 1 received rocuronium 0.6 mg/kg at the same intravenous access line with propofol infusion and in group 2 received rocuronium at the different intravenous access line with propofol infusion. One Hz single twitch responses were measured by acceleromyography after rocuronium administration. Intubation was done when the twitch height depressed more than 95% of the baseline. The intubating conditions were assessed and graded as excellent, good, poor and bad. Onset time, recovery index and duration were compared between the two groups. Results: The onset was significantly delayed in group 1 (124.9 35.5 vs. 101.8 22.1), but there were no significant differences in the intubating condition, recovery index, duration and the incidence of withdrawal response to rocuronium injection. Conclusions: Onset time was delayed when administrating rocuronium at the same intravenous access line with propofol-TCI. So giving rocuronium at the different intravenous access line with propofol infusion would be helpful to achieve adequate intubating condition rapidly.

Using Simulations in the Design of an Anesthesia System

The authors are developing a closed-loop system for intravenous anesthesia in humans. Using published pharmacokinetic data for the intravenous anesthetic agent, propofol, they have generated a population of “virtual patients” and simulated their response to induction and maintenance of intravenous anesthesia using a feedback system based on an electroencephalogram derivative. Their simulations suggested that the proposed system would accommodate patients with widely varying pharmacokinetic characteristics. The system was subsequently tested in humans, and successfully induced and maintained anesthesia in 7 volunteers.