Comment mesurer correctement la pression œsophagienne ?

Article

Auteur: Jean-Michel Arnal, Responsable des soins intensifs, Hôpital Sainte Musse, Toulon, France

Date: 19.10.2018

Last change: 09.09.2020

Formatting

Une étude physiologique récente a démontré que la pression œsophagienne fournit une estimation de la pression pleurale à mi-thorax à tous les niveaux de PEP. Par conséquent, une mesure absolue de la pression œsophagienne est utile pour le réglage de la PEP et le monitorage de la pression transpulmonaire.

Comment mesurer correctement la pression œsophagienne ?

Positionnement initial et gonflage

Alors comment procéder pour mesurer correctement la pression œsophagienne ?

Le ballonnet œsophagien doit être positionné et gonflé correctement et il convient de vérifier ensuite son positionnement.

La position optimale du ballonnet œsophagien se situe au niveau du tiers inférieur de l'œsophage, à une distance de 35 à 45 cm des narines. Lorsqu'un patient est en position semi-couchée, le ballonnet vide est d'abord introduit dans l'estomac, qui se situe à environ 50 à 60 cm des narines. Le ballonnet est ensuite gonflé à un volume standard (1 ml pour un cathéter Cooper Surgical et 4 ml pour un cathéter Nutrivent). La pression gastrique affiche une déflexion positive au cours de l'inspiration chez les patients passifs et respirant spontanément. La position gastrique est confirmée par l'application manuelle d'une compression épigastrique, qui déclenche immédiatement une augmentation de la pression gastrique (voir figure 1).

Capture d'écran d'une forme d'ondes affichant l'augmentation de la Pes — Figure 1

Retrait du ballonnet gonflé

Le cathéter œsophagien est ensuite doucement retiré alors que le ballonnet est toujours gonflé, afin de positionner le ballonnet dans le tiers inférieur de l'œsophage. Lors du passage de la pression gastrique (voir figure 2) à la pression œsophagienne (voir figure 3), la ligne de référence de la forme d'ondes de pression change et des oscillations cardiaques apparaissent.

Forme d'ondes affichant la ligne de référence de la pression gastrique — Figure 2 : pression gastrique

Forme d'ondes affichant la ligne de référence de la pression œsophagienne — Figure 3 : pression œsophagienne

Déflexions de pression œsophagienne

Les déflexions de pression œsophagienne sont positives pendant l'inspiration chez des patients passifs (voir figure 4), mais négatives chez des patients respirant spontanément (voir figure 5). Si des oscillations cardiaques perturbent le signal de pression œsophagienne, vous pouvez encore retirer le cathéter de 2 à 5 cm.

Forme d'ondes affichant des déflexions de Pes chez un patient passif — Figure 4 : Patient passif

Forme d'ondes affichant des déflexions de Pes chez un patient respirant spontanément — Figure 5 : patient respirant spontanément

Gonflage du ballonnet

Le volume d'air pour un gonflage adéquat du ballonnet doit être titré individuellement. Cela n'est possible qu'avec des patients passifs. Conformément à la méthode proposée par Mojoli et al (2016), le gonflage du ballonnet s'effectue progressivement de 0,5 à 3 ml suivant un incrément de 0,5 ml pour un cathéter Cooper Surgical et de 1 à 8 ml suivant un incrément de 1 ml pour un cathéter Nutrivent (voir figure 6). Au cours du gonflage progressif du ballonnet, la ligne de référence de la pression œsophagienne augmente et l'amplitude de la déflexion de la pression œsophagienne varie. Le volume de gonflage adéquat est celui associé à la plus grande déflexion de la pression œsophagienne. Si deux volumes de gonflage différents affichent la même amplitude de déflexion de la pression œsophagienne, le volume de gonflage le plus faible est sélectionné.

Vertification

Une fois le ballonnet positionné correctement dans l'œsophage et gonflé, la vérification est réalisée au moyen d'un test d'occlusion. Le principe consiste à fermer les voies aériennes en fin d'expiration pour en modifier la pression et à vérifier que la pression œsophagienne varie selon le même volume.

Chez des patients passifs, vous pouvez réaliser une occlusion de fin d'expiration. Lorsque la valve expiratoire est fermée, appliquez une compression manuelle externe sur la cage thoracique des deux côtés de la poitrine pour observer une déflexion positive des pressions des voies aériennes et œsophagienne. L'amplitude de l'augmentation des pressions des voies aériennes et œsophagienne doit être identique. En d'autres termes, la pression transpulmonaire ne doit pas changer (voir figure 7).

Chez des patients actifs, le test d'occlusion dynamique utilise également une occlusion de fin d'expiration. Il n'y a pas besoin d'appliquer une pression manuelle sur le thorax, car le patient délivrera un effort inspiratoire spontané pendant l'occlusion. Le résultat est une déflexion négative des pressions des voies aériennes et œsophagienne. L'amplitude de la diminution des pressions des voies aériennes et œsophagienne doit être identique, c.-à-d. que la pression transpulmonaire ne doit pas changer (voir figure 8).

Si vous souhaitez surveiller la pression œsophagienne en continu, il est important de réévaluer la bonne position et le volume de gonflage.

Citations complètes ci-dessous : (Yoshida T, Amato MBP, Grieco DL, et al. Esophageal Manometry and Regional Transpulmonary Pressure in Lung Injury. Am J Respir Crit Care Med. 2018;197(8):1018-1026. doi:10.1164/rccm.201709-1806OC1, Mojoli F, Iotti GA, Torriglia F, et al. In vivo calibration of esophageal pressure in the mechanically ventilated patient makes measurements reliable. Crit Care. 2016;20:98. Published 2016 Apr 11. doi:10.1186/s13054-016-1278-52, Baydur A, Behrakis PK, Zin WA, Jaeger M, Milic-Emili J. A simple method for assessing the validity of the esophageal balloon technique. Am Rev Respir Dis. 1982;126(5):788-791. doi:10.1164/arrd.1982.126.5.7883, Akoumianaki E, Maggiore SM, Valenza F, et al. The application of esophageal pressure measurement in patients with respiratory failure. Am J Respir Crit Care Med. 2014;189(5):520-531. doi:10.1164/rccm.201312-2193CI4, Mauri T, Yoshida T, Bellani G, et al. Esophageal and transpulmonary pressure in the clinical setting: meaning, usefulness and perspectives. Intensive Care Med. 2016;42(9):1360-1373. doi:10.1007/s00134-016-4400-x5)

Forme d'ondes affichant une augmentation de la Paw et de la Pes ; aucun changement de la Ptranspulm — Figure 7 : test d'occlusion sur un patient passif

Forme d'ondes affichant une diminution de la Paw et de la Pes ; aucun changement de la Ptranspulm — Figure 8 : test d'occlusion sur un patient actif

Notes en bas de page

Références

1. Yoshida T, Amato MBP, Grieco DL, et al. Esophageal Manometry and Regional Transpulmonary Pressure in Lung Injury. Am J Respir Crit Care Med. 2018;197(8):1018-1026. doi:10.1164/rccm.201709-1806OC
2. Mojoli F, Iotti GA, Torriglia F, et al. In vivo calibration of esophageal pressure in the mechanically ventilated patient makes measurements reliable. Crit Care. 2016;20:98. Published 2016 Apr 11. doi:10.1186/s13054-016-1278-5
3. Baydur A, Behrakis PK, Zin WA, Jaeger M, Milic-Emili J. A simple method for assessing the validity of the esophageal balloon technique. Am Rev Respir Dis. 1982;126(5):788-791. doi:10.1164/arrd.1982.126.5.788
4. Akoumianaki E, Maggiore SM, Valenza F, et al. The application of esophageal pressure measurement in patients with respiratory failure. Am J Respir Crit Care Med. 2014;189(5):520-531. doi:10.1164/rccm.201312-2193CI
5. Mauri T, Yoshida T, Bellani G, et al. Esophageal and transpulmonary pressure in the clinical setting: meaning, usefulness and perspectives. Intensive Care Med. 2016;42(9):1360-1373. doi:10.1007/s00134-016-4400-x

Esophageal Manometry and Regional Transpulmonary Pressure in Lung Injury.

Yoshida T, Amato MBP, Grieco DL, et al. Esophageal Manometry and Regional Transpulmonary Pressure in Lung Injury. Am J Respir Crit Care Med. 2018;197(8):1018-1026. doi:10.1164/rccm.201709-1806OC

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RATIONALE

Esophageal manometry is the clinically available method to estimate pleural pressure, thus enabling calculation of transpulmonary pressure (Pl). However, many concerns make it uncertain in which lung region esophageal manometry reflects local Pl.

OBJECTIVES

To determine the accuracy of esophageal pressure (Pes) and in which regions esophageal manometry reflects pleural pressure (Ppl) and Pl; to assess whether lung stress in nondependent regions can be estimated at end-inspiration from Pl.

METHODS

In lung-injured pigs (n = 6) and human cadavers (n = 3), Pes was measured across a range of positive end-expiratory pressure, together with directly measured Ppl in nondependent and dependent pleural regions. All measurements were obtained with minimal nonstressed volumes in the pleural sensors and esophageal balloons. Expiratory and inspiratory Pl was calculated by subtracting local Ppl or Pes from airway pressure; inspiratory Pl was also estimated by subtracting Ppl (calculated from chest wall and respiratory system elastance) from the airway plateau pressure.

MEASUREMENTS AND MAIN RESULTS

In pigs and human cadavers, expiratory and inspiratory Pl using Pes closely reflected values in dependent to middle lung (adjacent to the esophagus). Inspiratory Pl estimated from elastance ratio reflected the directly measured nondependent values.

CONCLUSIONS

These data support the use of esophageal manometry in acute respiratory distress syndrome. Assuming correct calibration, expiratory Pl derived from Pes reflects Pl in dependent to middle lung, where atelectasis usually predominates; inspiratory Pl estimated from elastance ratio may indicate the highest level of lung stress in nondependent "baby" lung, where it is vulnerable to ventilator-induced lung injury.

In vivo calibration of esophageal pressure in the mechanically ventilated patient makes measurements reliable.

Mojoli F, Iotti GA, Torriglia F, et al. In vivo calibration of esophageal pressure in the mechanically ventilated patient makes measurements reliable. Crit Care. 2016;20:98. Published 2016 Apr 11. doi:10.1186/s13054-016-1278-5

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In screening programmes it is important to assess a preliminary effectiveness of the screening method as soon as possible in order to forecast survival figures. In March 1981 a controlled single-view mammographic screening trial for breast cancer was started in the south of Stockholm. The population invited for screening mammography consisted of 40,000 women aged 40-64 years, and 20,000 women served as a well-defined control group. The main aim of the trial was to determine whether repeated mammographic screening could reduce the mortality in the study population (SP) compared to the control population (CP). The cumulative number of advanced mammary carcinomas in the screening and the control populations from the first five years of screening have shown a tendency towards more favourable stages in the screened population aged 40-64 years. A breakdown by age suggests an effect in age group 50-59 years, but not yet in age groups 40-49 and 60-64 years. When comparing the rates of stage II+ cancer, an increased number is found in the study group. As the total rate of breast cancer is higher in SP than in CP, there ought to be a concealed group of stage II+ cancers in the CP which makes the comparison biased. A new approach has been designed, where an estimation of the 'hidden' number of stage II+ cancers in CP is added to the clinically detected cases, and in this respect a comparison has shown a decrease in the cumulative number of advanced cancers in the SP in relation to the CP (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

A simple method for assessing the validity of the esophageal balloon technique.

Baydur A, Behrakis PK, Zin WA, Jaeger M, Milic-Emili J. A simple method for assessing the validity of the esophageal balloon technique. Am Rev Respir Dis. 1982;126(5):788-791. doi:10.1164/arrd.1982.126.5.788

Link to article

The validity of the conventional esophageal balloon technique as a measure of pleural pressure was tested in 10 subjects in sitting, supine, and lateral positions by occluding the airways at end-expiration and measuring the ratio of changes in esophageal (delta Pes) and mouth pressure (delta Pm) during the ensuing spontaneous occluded inspiratory efforts. Similar measurements were also made during static Mueller maneuvers. In both tests, delta Pes/delta Pm values were close to unity in sitting and lateral positions, whereas in the supine position, substantial deviations from unity were found in some instances. However, by repositioning the balloon to different levels in the esophagus, even in these instances a locus could be found where the delta Pes/delta Pm ratio was close to unity. No appreciable phase difference between delta Pes and delta Pm was found. We conclude that by positioning the balloon according to the "occlusion test" procedure, valid measurements of pleural pressure can be obtained in all the tested body positions.

The application of esophageal pressure measurement in patients with respiratory failure.

Akoumianaki E, Maggiore SM, Valenza F, et al. The application of esophageal pressure measurement in patients with respiratory failure. Am J Respir Crit Care Med. 2014;189(5):520-531. doi:10.1164/rccm.201312-2193CI

Link to article

This report summarizes current physiological and technical knowledge on esophageal pressure (Pes) measurements in patients receiving mechanical ventilation. The respiratory changes in Pes are representative of changes in pleural pressure. The difference between airway pressure (Paw) and Pes is a valid estimate of transpulmonary pressure. Pes helps determine what fraction of Paw is applied to overcome lung and chest wall elastance. Pes is usually measured via a catheter with an air-filled thin-walled latex balloon inserted nasally or orally. To validate Pes measurement, a dynamic occlusion test measures the ratio of change in Pes to change in Paw during inspiratory efforts against a closed airway. A ratio close to unity indicates that the system provides a valid measurement. Provided transpulmonary pressure is the lung-distending pressure, and that chest wall elastance may vary among individuals, a physiologically based ventilator strategy should take the transpulmonary pressure into account. For monitoring purposes, clinicians rely mostly on Paw and flow waveforms. However, these measurements may mask profound patient-ventilator asynchrony and do not allow respiratory muscle effort assessment. Pes also permits the measurement of transmural vascular pressures during both passive and active breathing. Pes measurements have enhanced our understanding of the pathophysiology of acute lung injury, patient-ventilator interaction, and weaning failure. The use of Pes for positive end-expiratory pressure titration may help improve oxygenation and compliance. Pes measurements make it feasible to individualize the level of muscle effort during mechanical ventilation and weaning. The time is now right to apply the knowledge obtained with Pes to improve the management of critically ill and ventilator-dependent patients.

Esophageal and transpulmonary pressure in the clinical setting: meaning, usefulness and perspectives.

Mauri T, Yoshida T, Bellani G, et al. Esophageal and transpulmonary pressure in the clinical setting: meaning, usefulness and perspectives. Intensive Care Med. 2016;42(9):1360-1373. doi:10.1007/s00134-016-4400-x

Link to article

PURPOSE

Esophageal pressure (Pes) is a minimally invasive advanced respiratory monitoring method with the potential to guide management of ventilation support and enhance specific diagnoses in acute respiratory failure patients. To date, the use of Pes in the clinical setting is limited, and it is often seen as a research tool only.

METHODS

This is a review of the relevant technical, physiological and clinical details that support the clinical utility of Pes.

RESULTS

After appropriately positioning of the esophageal balloon, Pes monitoring allows titration of controlled and assisted mechanical ventilation to achieve personalized protective settings and the desired level of patient effort from the acute phase through to weaning. Moreover, Pes monitoring permits accurate measurement of transmural vascular pressure and intrinsic positive end-expiratory pressure and facilitates detection of patient-ventilator asynchrony, thereby supporting specific diagnoses and interventions. Finally, some Pes-derived measures may also be obtained by monitoring electrical activity of the diaphragm.

CONCLUSIONS

Pes monitoring provides unique bedside measures for a better understanding of the pathophysiology of acute respiratory failure patients. Including Pes monitoring in the intensivist's clinical armamentarium may enhance treatment to improve clinical outcomes.