Peak Inflation Pressure Research Articles

FEM Simulation of Subintimal Angioplasty for the Treatment of Chronic Total Occlusions

Subintimal angioplasty is a highly challenging technique for percutaneous treatment of chronic total occlusion (CTO) in blood vessels, and the development of predictive tools for preliminary evaluation of potential outcomes and risks could be very useful for clinicians. While finite element (FE) simulation is a well-established approach to investigating partial occlusions, its extension to CTO has not been investigated yet, because of several additional issues that have to be addressed. In this work, we discuss the implementation of a FE model to simulate the main steps of the procedure, i.e., subintimal insertion of an initially folded balloon in a false lumen, inflation from eccentric position, deflation, and extraction. The model includes key morphological features of the CTO and possibility of varying spatial distribution of material properties to account for different constituents and degree of calcification. Both homogeneous and heterogeneous CTO configurations were analyzed, comparing arterial stress state, plaque compression, and postprocedural recoil. For a peak inflation pressure of 12 bar, the degree of lumen restoration was in the range 65-80%, depending on plaque heterogeneity. After balloon extraction, homogeneous highly calcified plaques exhibited substantial recovery of original shape. For homogeneous and heterogeneous CTO, values of peak von Mises stress in the arterial wall were of the same order of magnitude (range 1-1.1 MPa) but at different locations. Results compared favorably with data reported in literature for postprocedural lumen restoration and arterial stress data, confirming potential usefulness of the approach.

Analysis of peak inflating pressure and inflating pressure limit during neonatal volume guaranteed ventilation

To report how peak inflating pressure (PIP), tidal volume (VT) and low-tidal volume alarms are affected by maximum allowed inflating pressure (Pmax) during volume guarantee (VG) ventilation. Ventilation data were analysed with 1 Hz sampling rate from 25 neonates receiving synchronised intermittent positive pressure ventilation with VG for >12 h. The difference between Pmax and PIP (Pdiff) ranged between 5 and 20 mbar (median = 11 mbar) despite a protocol to keep Pmax 5 mbar above the "working PIP". Pmax was reached in 5.2% of inflations. Computational modelling demonstrated that had Pdiff been kept at 5 mbar more consistently, >10% of inflations would have reached Pmax. The frequency of low-tidal volume alarms showed inverse correlation with Pdiff. It is difficult to implement a simple Pmax strategy due to variability of PIP. Setting Pmax close to the "working PIP" limits VT delivery and triggers frequent alarms.

DURATION OF SUSTAINED INFLATION DURING SUSTAINED INFLATION AND CHEST COMPRESSION IN A PORCINE MODEL OF ASPHYXIA

Abstract BACKGROUND Current resuscitation guidelines recommend 3:1 C:V ratio, however the most effective C:V ratio in newborns remains controversial. We recently demonstrate that combining chest compressions (CC) with a sustained inflation (SI) (=CC+SI) significantly improves return of spontaneous circulation (ROSC) in asphyxiated newborn piglets compared to 3:1 C:V resuscitation. However, the optimal length of SI during CC+SI is unknown. OBJECTIVES To examine if a 60sec SI compared to a 20sec SI or 3:1 C:V will reduce will reduces ROSC during resuscitation in asphyxiated newborn piglets. DESIGN/METHODS Cardiac arrest with achieved was induced in newborn piglets and then randomized to receive either “3:1 C:V ratio, SI+CC-20sec” or “SS+CC-60sec”. Piglets randomized to “SI+CC+20sec” or “SI+CC+60sec” received 90/min CC during a SI of 20sec or 60sec. Piglets randomized to 3:1 C:V received 90/min CC and 30 inflations/min. The default settings for airway pressures were peak inflation pressure of 30 cm H2O and a positive end expiratory pressure of 6 cm H2O. The primary outcome was duration of CC to achieve ROSC. RESULTS Eight piglets were randomized to each group; the mean (SD) age and weight was similar between groups. Median (IQR) ROSC was significantly shorter in the SI+CC-20sec and SI+CC-60sec group with 96 (68–168) sec and 78 (60–91) sec compared to the 3:1 C:V group with 235 (182–347)sec (p=0.002). 5/8 in the SI+CC-60sec group, 7/8 in the SI+CC-20sec and 8/8 in the 3:1 C:V group received epinephrine (p=0.82). CONCLUSION Lengths of SI during CC+SI does not affect ROSC, however CC+SI compared to 3:1 C:V does improve ROSC in newborn piglets.

T-piece resuscitators: how do they compare?

BackgroundThe T-piece resuscitator (TPR) has seen increased use as a primary resuscitation device with newborns. Traditional TPR design uses a high resistance expiratory valve to produce positive end expiratory pressure...

Elevated airway liquid volumes at birth: a potential cause of transient tachypnea of the newborn.

Excessive liquid in airways and/or distal lung tissue may underpin the respiratory morbidity associated with transient tachypnea of the newborn (TTN). However, its effects on lung aeration and respiratory function following birth are unknown. We investigated the effect of elevated airway liquid volumes on newborn respiratory function. Near-term rabbit kittens (30 days gestation; term ~32 days) were delivered, had their lung liquid-drained, and either had no liquid replaced (control; n = 7) or 30 ml/kg of liquid re-added to the airways [liquid added (LA); n = 7]. Kittens were mechanically ventilated in a plethysmograph. Measures of chest and lung parameters, uniformity of lung aeration, and airway size were analyzed using phase contrast X-ray imaging. The maximum peak inflation pressure required to recruit a tidal volume of 8 ml/kg was significantly greater in LA compared with control kittens (35.0 ± 0.7 vs. 26.8 ± 0.4 cmH2O, P < 0.001). LA kittens required greater time to achieve lung aeration (106 ± 14 vs. 60 ± 6 inflations, P = 0.03) and had expanded chest walls, as evidenced by an increased total chest area (32 ± 9%, P < 0.0001), lung height (17 ± 6%, P = 0.02), and curvature of the diaphragm (19 ± 8%, P = 0.04). LA kittens had lower functional residual capacity during stepwise changes in positive end-expiratory pressures (5, 3, 0, and 5 cmH20). Elevated lung liquid volumes had marked adverse effects on lung structure and function in the immediate neonatal period and reduced the ability of the lung to aerate efficiently. We speculate that elevated airway liquid volumes may underlie the initial morbidity in near-term babies with TTN after birth.NEW & NOTEWORTHY Transient tachypnea of the newborn reduces respiratory function in newborns and is thought to result due to elevated airway liquid volumes following birth. However, the effect of elevated airway liquid volumes on neonatal respiratory function is unknown. Using phase contrast X-ray imaging, we show that elevated airway liquid volumes have adverse effects on lung structure and function in the immediate newborn period, which may underlie the pathology of TTN in near-term babies after birth.

Inflation pressures and times during initial resuscitation in preterm infants.

The optimal combination of inflation pressures and times to produce adequate expiratory tidal volumes during initial resuscitation in prematurely born infants has not been determined. The aim of this study was therefore to assess combinations of inflation pressures and times and the resulting expiratory tidal volume levels using a respiratory function monitor. Sixty-four infants born before 34 weeks of gestation were studied. The infants were divided according to whether the inflation pressure (peak inflation pressure minus positive end expiratory pressure) was < or ≥20 cmH2 O during the first five inflations delivered by a face mask, and those groups were then subdivided according to whether the inflation time was < or ≥1.5 s. Inflation pressure ≥20 cmH2 O compared with lower pressure at both inflation times produced significantly higher expiratory tidal volume. Longer compared with shorter inflation times when the inflation pressure was ≥20 cmH2 O resulted in no significant difference in expiratory tidal volume. At <20 cmH2 O inflation pressure, longer inflation time overall resulted in higher end tidal volume, but the majority of infants had a tidal volume less than the anatomical dead space. At higher inflation pressure, a longer inflation time was not necessary to increase expiratory tidal volume.

Using exhaled CO2 to guide initial respiratory support at birth: a randomised controlled trial

ImportanceA sustained inflation (SI) provided at birth might reduce bronchopulmonary dysplasia (BPD).ObjectiveThis study aims to examine whether an SI-guided exhaled carbon dioxide (ECO2) compared with positive pressure ventilation (PPV) alone...

Neutrophil gelatinase‑associated lipocalin as a potential novel biomarker for ventilator‑associated lung injury.

Neutrophil gelatinase-associated lipocalin (NGAL) is a 25-kDa protein of the lipocalin superfamily and its presence was initially observed in activated neutrophils. It has previously been demonstrated that the expression of NGAL is markedly increased in stimulated epithelia, and is important in the innate immunological response to various pathophysiological conditions, including infection, cancer, inflammation and kidney injury. The present study constructed a ventilator-associated lung injury model in mice. NGAL mRNA and protein expression levels in lung tissue were detected using reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. In addition, NGAL protein levels in bronchoalveolar lavage fluid and serum were measured via western blotting. The results of the present study suggested that NGAL expression increased under all mechanical ventilation treatments. The increase was most prominent in the high peak inflation pressure and high-volume mechanical ventilation groups, where there was the greatest extent of lung injury. In addition, NGAL expression increased in a time-dependent manner under high-volume mechanical ventilation, consistent with the degree of lung injury. These findings suggested that NGAL may serve as a potential novel biomarker in ventilator-associated lung injury.

Comparison of ventilation parameters and blood gas analysis in mechanically-ventilated children who received chest physiotherapy and suctioning vs. suctioning alone

Background Chest physiotherapy and suctioning are routine methods for airway clearance in mechanically-ventilated children. However, chest physiotherapy has not been confirmed to affect ventilation parameters, such as tidal volume (TV), peak inflation pressure (PIP), peak inspiratory flow (PIF), and peak expiratory flow (PEF), as well as blood gas analysis (BGA) values in pediatric intensive care unit (PICU) patients.Objective To determine the efficacy of chest physiotherapy and suctioning vs. suctioning alone for improving the mechanical ventilation parameters and BGA.Methods This randomized, single-blind, clinical trial was conducted from November 2012 to June 2013 in the PICU at Haji Adam Malik Hospital, Medan. A total of 40 mechanically-ventilated pediatric patients were enrolled and divided into either the chest physiotherapy and suctioning group (24 subjects) or the suctioning alone group (16 subjects). Subjects underwent treatment, followed by monitoring of their ventilation parameters and blood gas analyses. Data were analyzed by independent t-test and Mann-Whitney test.Results Subjects comprised of 23 boys and 17 girls, with an age range of 1–204 months. After the respective treatments (chest physiotherapy and suctioning vs. suctioning alone), the ventilation parameters were as follows: median TV (60.0 vs. 56.5 mL, respectively; P=0.838), median PEF (10.4 vs. 10.8 I/s, respectively; P=0.838), median PIF (7.4 vs. 8.2 I/s, respectively; P=0.469), and mean PIP (17.3 vs. 15.6 cmH2O, respectively; P=0.23). The BGA values were: median pH (7.4 vs. 7.3, respectively; P=0.838), median pCO2 (38.4 vs. 36.2 mmHg, respectively; P=1.000), mean pO2 (136.6 vs. 139.2 mmHg, respectively; P=0.834), median HCO3 (20.4 vs. 22.7 mmol/L, respectively; P=0.594), median TCO2 (22.0 vs. 23.7 mmol/L, respectively; P=0.672), mean BE (-4.3 vs. -3.1 mmol/L, respectively; P=0.629), and median O2 saturation (98.5 vs. 98.3 %, respectively; P=0.967).Conclusion In mechanically-ventilated children in the PICU, ventilation parameters and BGA values are not significantly different between subjects who received both chest physiotherapy and suctioning and those who received suctioning alone.

Can Ambu self-inflating bag and Neopuff infant resuscitator provide adequate and safe manual inflations for infants up to 10 kg weight?

BackgroundManual resuscitation devices for infants and newborns must be able to provide adequate ventilation in a safe and consistent manner across a wide range of patient sizes (0.5–10 kg) and...

Resuscitation of infants with congenital diaphragmatic hernia

ObjectiveTo determine whether the respiratory response to resuscitation in infants with congenital diaphragmatic hernia (CDH) as measured by a respiratory function monitor differed between those who did and did not...

A Novel Prototype Neonatal Resuscitator That Controls Tidal Volume and Ventilation Rate: A Comparative Study of Mask Ventilation in a Newborn Manikin.

The objective of this randomized controlled manikin trial was to examine tidal volume (VT) delivery and ventilation rate during mask positive pressure ventilation (PPV) with five different devices, including a volume-controlled prototype Next Step™ device for neonatal resuscitation. We hypothesized that VT and rate would be closest to target with the Next Step™. Twenty-five Neonatal Resuscitation Program providers provided mask PPV to a newborn manikin (simulated weight 1 kg) in a randomized order with a self-inflating bag (SIB), a disposable T-piece, a non-disposable T-piece, a stand-alone resuscitation system T-piece, and the Next Step™. All T-pieces used a peak inflation pressure of 20 cmH2O and a positive end-expiratory pressure of 5 cmH2O. The participants were instructed to deliver a 5 mL/kg VT (rate 40–60/min) for 1 min with each device and each of three test lungs with increasing compliance of 0.5, 1.0, and 2.0 mL/cmH2O. VT and ventilation rate were compared between devices and compliance levels (linear mixed model). All devices, except the Next Step™ delivered a too high VT, up to sixfold the target at the 2.0-mL/cmH2O compliance. The Next Step™ VT was 26% lower than the target in the low compliance. The ventilation rate was within target with the Next Step™ and SIB, and slightly lower with the T-pieces. In conclusion, routinely used newborn resuscitators over delivered VT, whereas the Next Step™ under delivered in the low compliant test lung. The SIB had higher VT and rate than the T-pieces. More research is needed on volume-controlled delivery room ventilation.

Mortality following congenital diaphragmatic hernia repair: the role of anesthesia.

Mortality following surgical repair of congenital diaphragmatic hernia (CDH) remains high. The volume and type of perioperative intravenous fluid administered, baro-trauma, oxygen toxicity, and the duration of anesthesia are thought to affect outcome in surgical populations. The aim of this retrospective observational study was to determine whether the perioperative volume or type of fluids and/or the duration of anesthesia were associated with postoperative mortality and if mortality was predicted by the oxygenation index (OI) prior to or following CDH surgical repair. The records of infants with a left-sided CDH and without other congenital anomalies, who underwent surgical repair between April 2009 and March 2015, were examined. The oxygenation index was used to "quantify" the severity of lung function abnormality and reported as the best OI on day 1 after birth (OIBEST ), the OI immediately prior to surgery (OIPRE ) and at 1, 6, 12, and 24h postsurgery (OI1h , OI6h , OI12h , OI24h ), respectively. The change in the OI index (delta OI) was calculated by subtracting OIPRE from postoperative OIs. The records of 37 CDH infants (median gestational age 35.8, range 31.5-41.4weeks) were assessed; six died postoperatively. Neither the duration of anesthesia, the volume of crystalloids or colloids administered, nor the peak inflation pressures used during surgical repair were significantly correlated with postoperative mortality. Neither fetal tracheal occlusion nor use of a parietal patch significantly influenced mortality. The postoperative OI1h , OI6h , OI12h showed weak evidence for a difference between survivors and nonsurvivors. An OI24h of ≥5.5 predicted mortality with 100% sensitivity (95% CI, confidence intervals (CI) 40-100) and 93.1% specificity (95% CI, 77-99). Neither the volume of intraoperative fluids administered nor the duration of anesthesia was associated with postoperative death. The OI 24h postsurgery was the best predictor of an increased risk of mortality.

The first breath during resuscitation of prematurely born infants

BackgroundThe first five initial inflation pressures and times during resuscitation of prematurely born infants are frequently lower than those recommended and rarely result in tidal volumes exceeding the anatomical dead space. Greater volumes were produced when the infant was provoked to inspire by an inflation (active inflation). AimsTo assess factors associated with a shorter time to the first active inflation. Study designRespiratory function monitoring was undertaken during resuscitation, peak inflation pressures (PIP), inflation times and the infant's respiratory activity were simultaneously recorded. SubjectsInfants with a gestational age<34weeks requiring resuscitation at birth. Outcome measuresThe relationships of the PIP and inflation time of the first five inflations and first active inflation to the time to the first active inflation. ResultsRecordings from 47 infants, median gestational age of 29 (23–34) weeks, were analysed. The median PIP of the first five inflations was 27 (range 9–37) cmH2O and inflation time 1.22 (range 0.32–4.08) s. The median PIP of the first active inflation was 25 (range 19–37) cmH2O and inflation time 1.35 (0.35–3.67) s. The median time to the first active inflation was 7 (range 0–50) seconds and was inversely correlated with the PIP (p=0.001) and inflation time (p=0.018) of the first five inflations and the PIP (p=0.001) and inflation time (p=0.008) of the first active inflation. ConclusionThe magnitude of the inflation pressures and times of the first five inflations inversely correlate with the time to the first breath during resuscitation.

Comparison of positive pressure ventilation devices in a newborn manikin

Objective: To compare tidal volume (VT) delivery and ventilation rate between devices for positive pressure ventilation (PPV) during newborn resuscitation.Methods: Neonatal resuscitation program providers (n = 25) delivered PPV to a newborn manikin in a randomized order with: a self-inflating bag (SIB), a disposable T-piece, a non-disposable T-piece, a stand-alone infant resuscitation system T-piece and the volume-controlled prototype Next StepTM device (KM Medical). All T-pieces used a peak inflation pressure of 20cmH2O and a 5cmH2O positive end-expiratory pressure (PEEP). The SIB neither had a PEEP valve nor manometer. The Next StepTM had a 5cmH2O PEEP valve. The participants aimed to deliver a 5 mL/kg VT (rate 40–60 min−1) for 1 min with each device and each of three compliances (0.5, 1.0 and 2.0 mL/cmH2O). VT and ventilation rate were compared between devices and compliance levels (ANOVA)Results: All devices, except the Next StepTM delivered a 4–5 mL/kg VT at the low compliance, but three- to four-fold that of the target at the higher compliance levels. The Next StepTM delivered a VT close to target at all compliance levels. The ventilation rate was within 40–60 min−1 with all devices and compliance levels.Conclusions: Routinely used ventilation devices for newborn resuscitation can triple intended VT and requires further investigation.

Prediction of infant extubation outcomes using the tension-time index

ObjectiveThe tension-time index of the diaphragm (TTdi) is a composite assessment of the load on and the capacity of the diaphragm. TTmus is a non-invasive tension-time index of the respiratory...

The effectiveness of Ambu neonatal self-inflating bag to provide consistent positive end-expiratory pressure

BackgroundThe self-inflating bag (SIB) is the most common device used to resuscitate newborn infants worldwide. Delivering positive end-expiratory pressure (PEEP) may be important in infant resuscitation and limited research using...

1: Sustained Inflation and Chest Compression versus 3:1 Chest Compression: Ventilation Ratio During Neonatal CPR – A Randomized Controlled Trial

Current resuscitation guidelines recommend 3:1 Compression:Ventilation (C:V) ratio, however the most effective C:V ratio in newborns remains controversial. We recently demonstrate that if chest compressions (CC) are superimposed by sustained inflations (SI) return of spontaneous circulation (ROSC) and mortality are improved in asphyxiated newborn piglets when compared to standard coordinated 3:1 resuscitation. However, this has not been studied in newborns. To determine if CC superimposed with SI impacts ROSC in infants <33 weeks with bradycardia or asystole compared to coordinated 3:1 C:V resuscitation. In a pilot study, infants born <33 weeks gestational age with an heart rate <60/min or asystole were randomized to receive either “3:1 C:V” or “SS+CC”. Infants randomized to 3:1 received coordinated CC and ventilation according to the current resuscitation guidelines. Infants randomized to “SI+CC” received uninterrupted CC at a rate of 90/min superimposed by a SI of 30 sec. The default settings for airway pressures were peak inflation pressure of 24 cm H2O and a positive end expiratory pressure of 6 cm H2O. The primary outcome was duration of CC to achieve ROSC. Deferral of consent was approved by the institutional ethics committee. The trial was registered at ClinicalTrials.gov: NCT02083705. Five infants were randomized to each group; the mean (range) gestational age was 25 (24–27) weeks vs. 26 (23–28) weeks in the in the SI+CC and 3:1 group (P=0.433), respectively. Mean (SD) birth weight in the SI+CC group was 797 (208) g vs. 808 (182) g in the 3:1 group, (P=0.465) respectively. Mean (SD) ROSC was significantly decreased in the SI+CC group with 31 (8) sec vs. 138 (72) sec in the 3:1 group (P=0.011). One infant in each group died and only one infant in the 3:1 group received epinephrine. One infant in the SI+CC group and three in the 3:1 had intracranial hemorrhage grade 3 or greater. Three infants in the SI+CC group had necrotizing enterocolitis vs. one infant in the 3:1 group (P=0.197). Preterm infants <33 weeks had significant shorter ROSC when CC were superimposed by SI compared to using 3:1.

Comparison of Sevoflurane and Propofol for Laryngeal Mask Airway Insertion in Children

INTRODUCTION: The major responsibility of an anaesthesiologist is to provide adequate ventilation for the patient by providing unobstructed airway. An anaesthetic technique is safe only when diligent efforts are devoted to maintain an intact functional airway. To maintain airway in an anaesthetized or unconscious patient we have supraglottic devices like anatomical face mask, laryngeal mask airway, cuffed oropharyngeal airway and combitube. Laryngeal mask airway was invented by Dr. ARCHIE BRAIN, United Kingdom in 1981. The LMA is an ingenious supraglottic airway device that is designed to provide and maintain a seal around the laryngeal inlet for spontaneous ventilation and allow controlled ventilation at modest levels of positive pressure. In controlled ventilation peak inflation pressure should not exceed 25cm H2O. An outstanding feature of LMA is that it provides a rapid clear airway in vast majority of patients and it is both faster and easier to insert than a tracheal tube. LMA can be used for pediatric and adult patients undergoing daycare surgeries. Successful insertion of LMA requires sufficient depth of anaesthesia and depression of airway reflexes to avoid gagging, coughing and laryngeal spasm. Propofol is the induction agent most commonly used for insertion of LMA. Sevoflurane is a recently introduced volatile anaesthetic agent which allows rapid smooth inhalational induction with excellent recovery. This study was being conducted to compare Sevoflurane and Propofol for insertion of laryngeal mask airway in children. This study was carried out in Dept. of Anaesthesiology, Stanley medical college, Chennai. AIM OF THE STUDY: The aim of the study is to compare the conditions of Laryngeal Mask Airway insertion in children after induction of anaesthesia with either inhalation of sevoflurane or intravenous propofol. The time taken for induction, time taken for jaw relaxation, time to LMA insertion, hemodynamic parameters, complications during induction and LMA insertion are compared. MATERIALS AND METHODS: Sixty patients of ASA physical status 1&2 undergoing elective minor surgical procedures below umbilicus lasting less than 60 mins. were included in the study. Patients belonged to age group of 4 – 12 of both sexes. It was a prospective randomized controlled study. The study was approved by institutional ethical committee and parent provided written informed consent before induction. Inclusion Criteria: 1. ASA I and II physical status. 2. No predicted airway difficulty. 3. Elective minor surgical procedures below umbilicus lasting less than 60 min. Exclusion Criteria: 1. Patients at risk of aspiration – upper GI surgery, gastroesophageal disease, not fasted. 2. Patients who require high positive pressure ventilation – eg. Pulmonary fibrosis. 3. Known allergy to any anaesthetic. MATERIALS: 1. Classic Laryngeal mask airways of appropriate size, 2. Propofol 1%, 3. Sevoflurane, 4. Fentanyl and glycopyrrolate, 5. Appropriate size oral airways, 6. 2,5 and 10 ml syringes, 7. Lubricant jelly. Preparation of the Patient: Informed consent from the parent obtained. All patients were fasted as per NPO guidelines. Premedication: Syp. Triclofos 60 mg/kg po given 45 min before shifting the child to operating room. METHODS: 1. Basal heart rate, blood pressure and oxygen saturation were recorded. 2. Intravenous access established. 3. Inj. Glycopyrrolate 10μg/kg and Inj. Fentanyl citrate 2 μg/kg i.v. given on table. 4. Preoxygenation with 100% O2 done for 3 min. SUMMARY: We assessed the conditions for insertion of LMA in two groups of patient receiving either inhalational sevoflurane or intravenous propofol and the following observations were made. • There were no significant differences between the two groups in demographic data. • The time to induction is less with sevoflurane compared to propofol in this study, though statistically not significant. • The time to jaw relaxation and the time to LMA insertion is less with propofol, with statistical significance. • The insertion is more successful by 1st attempt in the propofol group. But this is not statistically significant. • There are few cases who had movements during induction in propofol group and few cases had transient apnea during induction in sevoflurane group. • There is no significant difference between both groups in the incidence of coughing, gagging and laryngospasm. • There is significant difference in pulse rate in both groups. The pulse rates in propofol group decreased from baseline but within acceptable limits. In Sevoflurane group pulse rate increased from baseline during induction and LMA insertion, within acceptable limits. • The decrease in mean arterial pressure is observed in both groups and is not statistically significant. CONCLUSION: In conclusion, Propofol and Sevoflurane are equally effective for LMA insertion in children. However, Propofol has a faster insertion time due to early onset of jaw relaxation compared to sevoflurane and high success rate in 1st attempt for LMA insertion whereas Sevoflurane has better hemodynamic stability and less side effects compared to propofol.

PO-0614 How Doctors Learn And Perform Sustained Inflations With A Self-inflating Bag; A Manikin Study With A Newborn Lung Simulator

Background European guidelines recommend 5 sustained inflations (SI) of 2–3 seconds duration for initial resuscitation of the depressed infant. Long inflations may assist a more efficient transition from liquid to air-filled lungs. Objectives This study examines the ability of doctors of varying experience to manage a SI in two compliance settings (high versus low) and with an open or blocked pressure-relief valve (PRV), using a self-inflating bag. Methods We investigated the number of ventilations needed to manage a successful SI (inflation time ≥5 s and volume ≥10 ml) in a manikin model with a newborn lung simulator, randomised to high or low compliance settings. Forty-three doctors participated at first study visit and thirty-four at retest after three months. We measured tidal volume (TV), inflation time, peak inflating pressure (PIP) and mean inflating pressure (MIP) during SI with an open or blocked PRV. Results At first study visit 31/43 (72%) and at retest 21/34 (62%) (p = 0.169) doctors learned the SI technique within 3 ventilation attempts, irrespective of lung compliance setting and years of work experience. SI’s performed with a blocked versus open PRV had higher TV (27.8 vs. 22.6 ml, p 2 O; p = 0.012) and MIP (28.1 vs. 22.8 cmH 2 O; p Conclusion Most participants managed to deliver a SI >5 s duration with a self-inflating bag in a newborn lung simulator and it was perceived easy. A blocked PRV resulted in longer SI time and higher TV and pressure when compared to an open PRV.