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Esophageal Pressure (esophageal + pressure)
Selected AbstractsPressure-rate product and phase angle as measures of acute inspiratory upper airway obstruction in rhesus monkeysPEDIATRIC PULMONOLOGY, Issue 7 2010FAAP, Patrick A. Ross MD Abstract Rationale There are limited validated, objective, and minimally invasive techniques for the bedside evaluation of upper airway obstruction (UAO) in sick infants, despite its frequency in pediatric medicine. Prior techniques include pressure-rate product (PRP), a product of esophageal pressure and respiratory rate and phase angles (PAs), a measure of asynchrony between ribcage and abdominal respiratory movements in infants with UAO. The purpose of this study is to validate the PRP and compare it to a previously validated PA in rhesus monkeys. Methods Calibrated resistors were applied to the inspiratory limb of 10 anesthetized, intubated, and spontaneously breathing rhesus monkeys (weight 8.7,±,2.5,kg). Airway pressure, respiratory rate, PAs, heart rate, and oxygen saturation were recorded. Obstruction was applied in random order as 0, 5, 20, 200, 500, and 1,000,cmH2O/L/sec for 2-min periods, the last 15,sec (10,20 breaths) were analyzed for each timeframe. Results PA increased significantly at the 200,cmH2O/L/sec level but it reached a plateau above 500,cmH2O/L/sec. PRP rose progressively and was significantly different at all levels of obstruction. Esophageal pressure change was progressively and statistically significantly different from baseline and each other at 200, 500, and 1,000,cmH2O/L/sec (P,<,0.001). Conclusions In this model of UAO, PRP tracks increasing inspiratory load better than PA. PRP continued to be linear up through the highest inspiratory resistance where the change in PA reached a plateau before the highest load. The assessment of esophageal pressure changes may offer the simplest objective measure of UAO. Pediatr Pulmonol. 2010; 45:639,644. © 2010 Wiley-Liss, Inc. [source] Three components of obstructive sleep apnea/hypopnea syndromePSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 2 2003Takayuki Kumano-Go Abstract The aims of this study were to calculate the apnea,hypopnea index (AHI), which represented as the number of apnea,hypopnea occurrences per hour, the 4% oxygen desaturation index (ODI4) and the breathing-related arousal index (B-ArI) in polysomnographic studies of obstructive sleep apnea/hypopnea syndrome (OSAHS) patients and to investigate whether there was any relationship between each pair of scoring schemes. Thirty-four cases of OSAHS were studied. Total OSAHS patients were subdivided into those with a high AHI (> 25), and those with a low AHI (< 25). The correlation between each pair of scoring schemes for OSAHS with a high AHI showed high value. The correlation between AHI and ODI4 for OSAHS with a low AHI was 0.18 and that between AHI and B-ArI showed a weak correlation of 0.59, while that between ODI4 and B-ArI was only ,0.078. Our results mean that oxygen desaturation and arousal occur separately in mild or moderate OSAHS patients, even though they are diagnosed with the same level of OSAHS by means of AHI. Breathing-related arousal without oxygen desaturation often occurs in mild or moderate OSAHS patients. We previously reported that AHI does not accurately reflect the severity of the increase in negativity of esophageal pressure manifested as respiratory efforts. We consider that the comprehension and assessment of OSAHS can be improved by the systematic differentiations among the three components: oxygen desaturation, arousals and respiratory efforts. [source] Relationship between hypersomnia and respiratory disorder during sleep in Prader,Willi syndromePSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 3 2000Yu Hiroe MD Abstract To assess whether hypersomnia in Prader,Willi syndrome (PWS) patients is related to the respiratory disorder during sleep (RDDS), we made a systematic evaluation regarding the relationship between the two disorders in three patients. All patients showed hypersomnia manifested as the long duration of night sleep and shortened sleep latencies of multiple sleep latency test. Although magnetic resonance imaging and laboratory studies revealed obstruction of the upper airway and mild increase of esophageal pressure during sleep, the number of other apneic episodes or awakenings was not as frequent. From the above results, we speculate that the mechanism of excessive daytime sleepiness in PWS is not caused by RDDS and quite resembles that of essential hypersomnia. [source] Basal and residual lower esophageal pressures increase in old age in classic achalasia, but not vigorous achalasiaJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 8 2010Kee Wook Jung Abstract Background and Aim:, The relationship between age and esophageal motility parameters (i.e. basal and residual pressure of the lower esophageal sphincter [LES]) remains to be established in achalasia patients, possibly because most previous studies did not distinguish between classic and vigorous achalasia patients. We investigated the relationship between age and esophageal motility parameters in both classic and vigorous achalasia patients. Methods:, A retrospective review of esophageal manometry data in a single center was undertaken. Basal and residual pressure for LES was analyzed. A total of 103 achalasia patients were enrolled, comprising 84 classic and 19 vigorous types. They were subdivided into three different age groups as follows: 21,40 years old (group A), 41,60 years old (group B), and over 60 years old (group C). Results:, In classic achalasia patients (M : F = 27:57, mean age = 44 ± 15 years old) the older age group showed a significantly higher basal LES pressure (49.62 ± 19.63 mmHg) than the younger age group (P < 0.0001). Moreover, the older age group also showed significantly high residual LES pressure (20.46 ± 8.61 mmHg) than the younger age group (P = 0.0006). In contrast, in vigorous achalasia patients (M : F = 12:7, mean age: 47 ± 15 years old) there were no difference between age and motility indices (all P > 0.05). Conclusion:, In classic achalasia patients there appears to be a correlation between age and esophageal motility indices, especially basal and residual LES pressure. Such correlations do not appear to exist for vigorous achalasia patients. [source] Beneficial effects of high positive end-expiratory pressure in lung respiratory mechanics during laparoscopic surgeryACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2009L. F. MARACAJÁ-NETO Background: The effect of neuromuscular blockade (NMB) and positive end-expiratory pressure (PEEP) on the elastic properties of the respiratory system during pneumoperitoneum (PnP) remains a controversial subject. The main objective of the present study was to evaluate the effects of NMB and PEEP on respiratory mechanics. Methods: We performed a dynamic analysis of respiratory mechanics in patients subjected to PnP. Twenty-one patients underwent cholecystectomy videolaparoscopy and total intravenous anesthesia. The respiratory system resistance (RRS), pulmonary elastance (EP), chest wall elastance (ECW), and respiratory system elastance (ERS) were computed via the least squares fit technique using an equation describing the motion of the respiratory system, which uses primary signs such as airway pressure, tidal volume, air flow, and esophageal pressures. Measurements were taken after tracheal intubation, PnP, NMB, establishment of PEEP (10 cmH2O), and PEEP withdrawal [zero end-expiratory pressure (ZEEP)]. Results: PnP significantly increased ERS by 27%; both EP and ECW increased 21.3 and 64.1%, respectively (P<0.001). NMB did not alter the respiratory mechanic properties. Setting PEEP reduced ERS by 8.6% (P<0.05), with a reduction of 10.9% in EP (P<0.01) and a significant decline of 15.7% in RRS (P<0.05). These transitory changes in elastance disappeared after ZEEP. Conclusions: We concluded that the 10 cmH2O of PEEP attenuates the effects of PnP in respiratory mechanics, lowering RRS, EP, and ERS. These effects may be useful in the ventilatory approach for patients experiencing a non-physiological increase in IAP owing to PnP in laparoscopic procedures. [source] | ||||||||||