Pressure support ventilation augments spontaneous breathing with improved thoracoabdominal synchrony in neonates with congenital heart disease

Comparison of Spontaneous Ventilation, Pressure Control Ventilation and Pressure Support Ventilation in Pediatric Patients Undergoing Infraumbilical Surgery Using ProSeal Laryngeal Mask Airway

Background:

Pediatric infraumbilical surgeries are often performed under general anaesthesia using different modes of ventilation through Laryngeal Mask Airway .Although controlled ventilation has been successfully used, very less studies have been done to compare them with spontaneous ventilation for short duration surgeries.

Aims:

We tried to measure quantitave differences in haemodynamic and respiratory parameters and assess the recovery profile between controlled and spontaneous ventilation using Proseal LMA.

Settings and Design:

This was a prospective, randomized, double-blind study that comprised 90 American Society of Anaesthesiologist (ASA) classes I and II pediatric patients posted for infra umbilical surgery.

Materials and Methods:

90 paediatric patients undergoing infraumbilical surgeries were included. Three different ventilation strategies: spontaneous , pressure support and pressure-controlled ventilation were applied depending on attending anaesthesiologist's preference. Haemodynamic and respiratory parameters were recorded during the procedure. Post procedure parameters including need for supplementary oxygen, recovery time, complications were recorded.

Statistical Methods:

Analysis of variance (ANOVA) was employed for inter group analysis and for multiple comparisons, least significant difference (LSD) test was applied. Chi-square test or Fisher's exact test, whichever appropriate, was used for comparison of categorical variables.

Results:

The mean time interval between end of surgery and removal of LMA was significantly higher in PCV group in comparison to SV and PSV groups. In SV group lesser number of patients required oxygen supplementation and had shorter stay in recovery than PCV group.

Conclusion:

We conclude that spontaneous mode of ventilation can be used as safely as controlled /assist ventilation mode in short duration surgeries in high turn over settings.

Pressure support ventilation-pro decreases propofol consumption and improves postoperative oxygenation index compared with pressure-controlled ventilation in children undergoing ambulatory surgery: a randomized controlled trial

PURPOSE

The PSVPro mode is increasingly being used for surgeries under laryngeal mask airway owing to improved ventilator-patient synchrony and decreased work of breathing. We hypothesized that PSVPro ventilation mode would reduce consumption of anesthetic agents compared with pressure control ventilation (PCV).

METHODS

Seventy children between three and eight years of age undergoing elective lower abdominal and urological surgery were randomized into PCV group (n = 35) or PSVPro group (n = 35). General anesthesia was induced with sevoflurane and a Proseal LMA™ was inserted. Anesthesia was maintained with propofol infusion to maintain the entropy values between 40 and 60. In the PCV mode, the inspiratory pressure was adjusted to obtain an expiratory tidal volume of 8 mL·kg-1 and a respiratory rate of 12-20/min. In the PSVPRO group, the flow trigger was set at 0.4 L·min-1 and pressure support was adjusted to obtain expiratory tidal volume of 8 mL·kg-1. Consumption of anesthetic agent was recorded as the primary outcome. Emergence time and discharge time were recorded as secondary outcomes.

RESULTS

The PSVPro group showed significant reduction in propofol consumption compared with the PCV group (mean difference, 33.3 µg-1·kg-1·min-1; 95% confidence interval [CI], 24.2 to 42.2). There was decrease in the emergence time in the PSVPro group compared with the PCV group (mean difference, 3.5 min; 95% CI, 2.8 to 4.2) and in time to achieve modified Aldrete score > 9 (mean difference, 3.6 min; 95% CI, 1.9 to 5.2).

CONCLUSION

The PSVPro mode decreases propofol consumption and emergence time, and improves oxygenation index in children undergoing ambulatory surgery.

TRIAL REGISTRATION

Clinical Trial Registry of India (CTRI/2017/12/010942); registered 21 December, 2017.

Neonatal ventilatory techniques - which are best for infants born at term?

Few studies have examined ventilatory modes exclusively in infants born at term. Synchronous intermittent mandatory ventilation (SIMV) compared to intermittent mandatory ventilation (IMV) is associated with a shorter duration of ventilation. The limited data on pressure support, volume targeted ventilation and neurally adjusted ventilatory assist demonstrate only short term benefits in term born infants. Favourable results of high-frequency oscillatory ventilation (HFOV) in infants with severe respiratory failure were not confirmed in the two randomised trials. Nitric oxide (NO) in term born infants, except in those with congenital diaphragmatic hernia (CDH), reduces the combined outcome of death and requirement for extracorporeal membrane oxygenation (ECMO). In infants with severe refractory hypoxaemic respiratory failure, ECMO, except in infants with CDH, reduced mortality and the combined outcome of death and severe disability at long-term follow-up. Randomised studies with long term outcomes are required to determine the optimum modes of ventilation in term born infants.