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Intermittent Positive Pressure Ventilation (intermittent + positive_pressure_ventilation)
Selected AbstractsClinical application of continuous spirometry with a pitot-based flow meter during equine anaesthesiaEQUINE VETERINARY EDUCATION, Issue 7 2010Y. P. S. Moens Summary This report documents the feasibility and clinical information provided by a new method for spirometric monitoring adapted for equine anaesthesia. Monitoring of ventilatory function was done with continuous spirometry during general anaesthesia of client-owned horses presented for various diagnostic and surgical procedures. An anaesthetic monitor with a spirometry unit for human anaesthesia was used. To allow the measurement of large tidal volumes, a remodelled larger version of the pitot tube- based flow sensor was used. This technology provided reliable spirometric data even during prolonged anaesthesia when water condensation accumulated in the anaesthetic circuit and the sensor. In addition to flow and volume measurement and respiratory gas analysis, the continuous display of flow-volume and pressure-volume loops offered visually recognisable information about compliance, airway resistance and integrity of the circuit. Continuous spirometry with this monitoring system was helpful in evaluating the efficacy of spontaneous ventilation, in adjusting intermittent positive pressure ventilation and detecting technical faults in the anaesthetic apparatus and connection with the patient. This adapted spirometry method represents a practical and reliable measuring system for use during equine anaesthesia. The variety of information provides an opportunity to optimise anaesthetic management in this species. [source] One-lung ventilation of a preterm newborn during esophageal atresia and tracheoesophageal fistula repairACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 3 2002E. Tercan In this paper, we assessed the anesthesia management of a male, a 34-week gestation age newborn, weighing 1500 g, who has esophageal atresia and tracheoesophageal fistula localized just above the carina. Endotracheal intubation and intermittent positive pressure ventilation caused air leakage through the fistula into the stomach, causing abdominal distention. One-lung ventilation by left main bronchus intubation eliminated this problem. [source] Assessment of autonomic cardiovascular changes associated with recovery from anaesthesia in children: a study using spectral analysis of blood pressure and heart rate variabilityPEDIATRIC ANESTHESIA, Issue 6 2000ISABELLE CONSTANT MD PhD Recovery from anaesthesia is associated with large changes in cardiovascular autonomic activity, which are poorly documented in children. This study was undertaken to investigate the cardiovascular autonomic activity in anaesthetized and recovering children, using a noninvasive approach based on spectral analysis of heart rate (HR) and blood pressure (BP) variability. Ten children (aged 5,13 years) undergoing major surgery were studied. Continuous HR and BP were recorded using a noninvasive device during deep anaesthesia and recovery. Spectral analysis was used to determine the main oscillatory components of HR and BP signals. For each power spectrum, the frequency components were identified as follows (i): the low frequency (LF) component (0.04,0.14 Hz) both parasympathetically and sympathetically mediated for HR and corresponding to vasomotor sympathetic modulation for BP; and (ii) the high frequency (HF) component (0.2,0.6 Hz) parasympathetically mediated for HR, and reflecting mechanical influence of ventilation on cardiac output for BP. In addition, the LF : HF ratio for HR, reflecting the cardiac sympathovagal balance, was calculated. Under deep anaesthesia, HR variability and BP variability were very low and mainly due to mechanical influence of intermittent positive pressure ventilation. Conversely, the recovery period was associated with a marked increase of HR and BP overall variability. Compared to anaesthesia, spectral analysis of HR and BP revealed that the LF component of BP and HR spectra increased 40-fold during recovery; the LF : HF ratio of HR was also increased during recovery (0.1 ± 0.1 versus 1.3 ± 1.2, P=0.008). The results of this study demonstrate that the recovery period is associated with an increase of cardiovascular sympathetic drive in children after major surgery. [source] Volume targeted ventilation (volume guarantee) in the weaning phase of premature newborn infantsPEDIATRIC PULMONOLOGY, Issue 10 2007F. Scopesi MD Abstract Objective Several options are currently available in neonatal mechanical ventilation: complete breathing synchronization (patient triggered ventilation, synchronized intermittent positive pressure ventilation,SIPPV); positive pressure flow-cycled ventilation (pressure support ventilation, PSV); and volume targeted positive pressure ventilation (volume guarantee, VG). The software algorithm for the guarantee volume attempts to deliver a tidal volume (Vt) as close as possible to what has been selected by the clinician as the target volume. Main objectives of the present study were to compare patient,ventilator interactions and Vt variability in premature infants recovering from respiratory distress syndrome (RDS) who were weaned by various ventilator modes (SIMV/PSV,+,VG/SIPPV,+,VG and SIMV,+,VG). Methods This was a short-term crossover trial in which each infant served as his/her own control. Ten premature infants born before the 32nd week of gestation in the recovery phase of RDS were enrolled in the study. All recruited infants started ventilation with SIPPV and in the weaning phase were switched to synchronized intermittent mandatory ventilation (SIMV). Baseline data were collected during an initial 20-min period of monitoring with the infant receiving SIMV alone, then they were switched to SIPPV,+,VG for a 20-min period and then switched back to SIMV for 15 min. Next, they were switched to PSV,+,VG for the study period and switched back to SIMV for a further 15 min. Finally, they were switched to SIMV,+,VG and, at the end of monitoring, they were again switched back to SIMV alone. Results Each mode combined with VG discharged comparable Vts, which were very close to the target volume. Among the VG-combined modes, mean variability of Vt from preset Vt was significantly different. Variability from the target value was significantly lower in SIPPV and PSV modes than in SIMV (P,<,0.0001 and P,<,0.04 respectively). SIPPV,+,VG showed greater stability of Vt, fewer large breaths, lower respiratory rate, and allowed for lower peak inspiratory pressure than what was delivered by the ventilator during other modes. No significant changes in blood gases were observed after each of the study periods. Conclusions With regards to the weaning phase, among combined modes, both of the ones in which every breath is supported (SIPPV/PSV) are likely to be the most effective in the delivery of stable Vt using a low working pressure, thus, at least in the short term, likely more gentle for the neonatal lung. In summary, we can suggest that the VG option, when combined with traditional, patient triggered ventilation, adheres very closely to the proposed theoretical algorithm, achieving highly effective ventilation. Pediatr Pulmonol. 2007; 42:864,870. © 2007 Wiley-Liss, Inc. [source] The Diamedica Draw-Over Vaporizer: a comparison of a new vaporizer with the Oxford Miniature VaporizerANAESTHESIA, Issue 1 2009W. A. English Summary The Diamedica Draw-Over Vaporizer (DDV) has been developed as an alternative to the Oxford Miniature Vaporizer (OMV). Both can function as draw-over or plenum vaporizers. The performances of these two vaporizers were compared under conditions simulating intermittent positive pressure ventilation (IPPV) and continuous flow (CF). Series 1 experiments were conducted with the vaporizers in water baths at 20, 25 and 30 °C. Vaporizers were tested at dial settings of 1,4% over a range of minute volumes (1.75,6 l.min,1) and flow rates (3,8 l.min,1). Series 2 experiments compared output of the vaporizers over time at ambient temperatures of 20, 25 and 30 °C. A minute volume of 6 l.min,1 (IPPV) and a gas flow of 8 l.min,1 (CF) were used with a vaporizer setting of 2%. Vapour concentrations were recorded at 5-min intervals. In series 1 IPPV experiments, the DDV vaporizer was more accurate, producing significantly fewer vapour concentrations 0.5% more than or less than setting (p = 0.013). The OMV tended to produce more favourable results under continuous flow (p = 0.42). In series 2 experiments, the accuracy of both vaporizers was similar but consistency of output over time was better for the DDV and consistency of output according to differences in ambient temperature was better for the DDV. The OMV produced more vapour concentrations that were markedly higher than dial setting, particularly at high ambient temperatures. The DDV is a suitable alternative to the OMV with some distinct advantages. These include a larger reservoir, tendency towards greater accuracy during IPPV and improved consistency of output. [source] Monitoring pollution by proton-transfer-reaction mass spectrometry during paediatric anaesthesia with positive pressure ventilation via the laryngeal mask airway or uncuffed tracheal tubeANAESTHESIA, Issue 7 2002J. Rieder Summary Twenty children aged 2,66 months were randomly allocated for airway management with either the laryngeal mask airway or uncuffed tracheal tube using intermittent positive pressure ventilation with a tidal volume of 8 ml.kg,1 and a respiratory rate adjusted to maintain end-expiratory carbon dioxide concentration at 5.3 kPa. Induction was with fentanyl/propofol and maintenance was with sevoflurane 2.5% in oxygen/air. The airway device was removed when the patients were awake and the patients were transferred to the postanaesthesia care unit 10 min later. Air was sampled from a point 1.5 m above the floor at a location remote from the ventilation outlet and analysed using a proton-transfer-reaction mass spectrometer capable of continuous trace gas analysis at the parts per billion volume (ppbv) level. The concentration of sevoflurane was recorded every minute during three consecutive phases: for 5 min before the introduction of sevoflurane (background); after introduction of sevoflurane until removal of the airway device (intra-operative); and every minute after removal until the concentration returned to background levels. Median (interquartile range [range]) intra-operative sevoflurane concentrations were 200,400 times higher than background values for the laryngeal mask airway 1 (1,2 [0,3]) ppbv vs. 404 (278,523 [83,983]) ppbv, respectively, and the tracheal tube 2 (1,3 [0,5]) ppbv vs. 396 (204,589 [107,1735]) ppbv (both p <,0.0001), and returned to background values within 5 min of removal. There were no differences in sevoflurane concentration between devices intra-operatively or after removal. The performance of the proton-transfer-reaction mass spectrometer was identical at the start and end of the 30-day study. We conclude that peri-operative sevoflurane concentration in a modern operating theatre is similar for the laryngeal mask airway and the uncuffed tracheal tube in paediatric patients receiving intermittent positive pressure ventilation. Intra-operative sevoflurane concentrations are five times lower than occupational safety limit requirements, and 1000 times lower 5 min after removal of the airway device with the patient awake. The proton-transfer-reaction mass spectrometer has potential for monitoring air quality in the operating theatre. [source] Early nasal intermittent positive pressure ventilation versus continuous positive airway pressure for respiratory distress syndromeACTA PAEDIATRICA, Issue 9 2009M Sai Sunil Kishore Abstract Aim:, To determine whether early nasal intermittent positive pressure ventilation (NIPPV), in comparison to early continuous positive airway pressure (CPAP), can reduce the need for intubation and mechanical ventilation in preterm neonates with suspected respiratory distress syndrome (RDS). Methods:, In this stratified open-label randomized controlled trial, neonates (28,34 weeks gestation) with respiratory distress within 6 h of birth and Downe's score , 4 were eligible. Subjects were randomly allocated to ,early-NIPPV' or ,early-CPAP' after stratifying for gestation (28,30 weeks, 31,34 weeks) and surfactant use. Primary outcome was failure of the allocated mode within 48 h. Results:, Seventy-six neonates were enrolled (37 in ,early-NIPPV' and 39 in ,early-CPAP' groups). Failure rate was less with ,early-NIPPV' versus ,early-CPAP'[13.5% vs. 35.9%, respectively, RR 0.38 (95% CI 0.15,0.89), p = 0.024]. Similarly, need for intubation and mechanical ventilation by 7 days (18.9% vs. 41%, p = 0.036) was less with NIPPV. Failure rate with NIPPV was less in the subgroups of subjects born at 28,30 weeks (p = 0.023) and who did not receive surfactant (p = 0.018). Conclusion:, Among preterm infants with suspected RDS, early use of NIPPV reduces the need for intubation and mechanical ventilation compared to CPAP. [source] Survey of neonatal respiratory support strategiesACTA PAEDIATRICA, Issue 8 2007Atul Sharma Abstract Aim: To survey current practice regarding neonatal respiratory support strategies to determine whether it reflected evidence from randomised trials. Methods: A questionnaire (in Supplementary Material online) survey of all U.K. neonatal units was undertaken to determine what modes of ventilation, types of endotracheal tube, lung function monitoring and oxygen saturation levels were used. Results: There was an 80% response rate. Most (73%) units used in prematurely born infants (in the first 24 h) the intermittent positive pressure ventilation, and other respiratory modes included: CPAP (2%), triggered ventilation with or without volume guarantee (22%) and high frequency oscillation (2%). Only 15% of units used assist control mode for weaning; the preferred weaning mode was synchronous intermittent mandatory ventilation (73%). Few units used shouldered endotracheal tubes (3%) or lung function measurements (25%) to aid choice of ventilator settings. Oxygen saturation levels from 80% to 98% were used, levels greater or equal to 95% were used by 11% of units for infants with acute respiratory disease but by 34% of units for BPD infants (p < 0.001). Conclusion: Many practitioners do not base their choice of neonatal respiratory support strategies on the results of large randomised trials; more effective methods are required to ensure evidence-based practice. [source] Nasal continuous positive airway pressure versus nasal intermittent positive pressure ventilation for preterm neonates: a systematic review and meta-analysisACTA PAEDIATRICA, Issue 1 2003AG De Paoli Aim: To determine whether nasal intermittent positive pressure ventilation (NIPPV) is more effective in preterm infants than nasal continuous positive airway pressure (NCPAP) in reducing the rate of extubation failure following mechanical ventilation, and reducing the frequency of apnoea of prematurity and subsequent need for endotracheal intubation. Methods: Randomized trials of NIPPV versus NCPAP were sought and their data extracted and analysed independently by the authors using the methodology of the Cochrane Collaboration. The analysis used relative risk (RR), risk difference (RD) and number needed to treat (NNT) with 95% confidence intervals. Results: The three studies identified, comparing NIPPV with NCPAP in the postextubation period, all used synchronized NIPPV (SNIPPV), which was more effective than NCPAP in preventing failure of extubation [RR 0.21 (0.10, 0.45), RD -0.32 (-0.45, -0.20), NNT 3 (2, 5)]. Two studies compared NIPPV versus NCPAP for the treatment of apnoea of prematurity. Although meta-analysis was not possible one trial showed a reduction in apnoea frequency with NIPPV and the other a trend favouring NIPPV. Conclusion: SNIPPV is an effective method of augmenting the beneficial effects of NCPAP in preterm infants in the postextubation period. Further research is required to delineate the role of NIPPV in the management of apnoea of prematurity. [source] | ||||||||||