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Heili-Frades S, Suarez-Sipmann F, Santos A, Carballosa MP, Naya-Prieto A, Castilla-Reparaz C, Rodriguez-Nieto MJ, González-Mangado N, Peces-Barba G. Continuous monitoring of intrinsic PEEP based on expired CO 2 kinetics: an experimental validation study. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2019; 23:192. [PMID: 31142337 PMCID: PMC6540388 DOI: 10.1186/s13054-019-2430-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 04/10/2019] [Indexed: 12/03/2022]
Abstract
Background Quantification of intrinsic PEEP (PEEPi) has important implications for patients subjected to invasive mechanical ventilation. A new non-invasive breath-by-breath method (etCO2D) for determination of PEEPi is evaluated. Methods In 12 mechanically ventilated pigs, dynamic hyperinflation was induced by interposing a resistance in the endotracheal tube. Airway pressure, flow, and exhaled CO2 were measured at the airway opening. Combining different I:E ratios, respiratory rates, and tidal volumes, 52 different levels of PEEPi (range 1.8–11.7 cmH2O; mean 8.45 ± 0.32 cmH2O) were studied. The etCO2D is based on the detection of the end-tidal dilution of the capnogram. This is measured at the airway opening by means of a CO2 sensor in which a 2-mm leak is added to the sensing chamber. This allows to detect a capnogram dilution with fresh air when the pressure coming from the ventilator exceeds the PEEPi. This method was compared with the occlusion method. Results The etCO2D method detected PEEPi step changes of 0.2 cmH2O. Reference and etCO2D PEEPi presented a good correlation (R2 0.80, P < 0.0001) and good agreement, bias − 0.26, and limits of agreement ± 1.96 SD (2.23, − 2.74) (P < 0.0001). Conclusions The etCO2D method is a promising accurate simple way of continuously measure and monitor PEEPi. Its clinical validity needs, however, to be confirmed in clinical studies and in conditions with heterogeneous lung diseases. Electronic supplementary material The online version of this article (10.1186/s13054-019-2430-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sarah Heili-Frades
- Intermediate Respiratory Care Unit, Pulmonology Department, IIS-Fundación Jiménez Díaz, UAM, CIBERES, Madrid, Spain.,CIBER de Enfermedades Respiratorias, Instituto Carlos III, Madrid, Spain
| | - Fernando Suarez-Sipmann
- Servicio de Medicina Intensiva, Hospital Universitario de la Princesa, Madrid, Spain. .,CIBER de Enfermedades Respiratorias, Instituto Carlos III, Madrid, Spain. .,Department of surgical Sciences, Section of Anesthesia and Critical Care, Hedenstierna Laboratory, Uppsala University Hospital, Uppsala, Sweden.
| | - Arnoldo Santos
- ITC Ingeniería y Técnicas Clínicas, CIBER de Enfermedades Respiratorias (CIBERES), Madrid, Spain
| | - Maria Pilar Carballosa
- Intermediate Respiratory Care Unit, Pulmonology Department, IIS-Fundación Jiménez Díaz, UAM, CIBERES, Madrid, Spain
| | - Alba Naya-Prieto
- Intermediate Respiratory Care Unit, Pulmonology Department, IIS-Fundación Jiménez Díaz, UAM, CIBERES, Madrid, Spain
| | | | - Maria Jesús Rodriguez-Nieto
- Intermediate Respiratory Care Unit, Pulmonology Department, IIS-Fundación Jiménez Díaz, UAM, CIBERES, Madrid, Spain.,CIBER de Enfermedades Respiratorias, Instituto Carlos III, Madrid, Spain
| | - Nicolás González-Mangado
- Intermediate Respiratory Care Unit, Pulmonology Department, IIS-Fundación Jiménez Díaz, UAM, CIBERES, Madrid, Spain.,CIBER de Enfermedades Respiratorias, Instituto Carlos III, Madrid, Spain
| | - German Peces-Barba
- Intermediate Respiratory Care Unit, Pulmonology Department, IIS-Fundación Jiménez Díaz, UAM, CIBERES, Madrid, Spain.,CIBER de Enfermedades Respiratorias, Instituto Carlos III, Madrid, Spain
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Tobin MJ, Laghi F, Jubran A. Ventilatory failure, ventilator support, and ventilator weaning. Compr Physiol 2013; 2:2871-921. [PMID: 23720268 DOI: 10.1002/cphy.c110030] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The development of acute ventilatory failure represents an inability of the respiratory control system to maintain a level of respiratory motor output to cope with the metabolic demands of the body. The level of respiratory motor output is also the main determinant of the degree of respiratory distress experienced by such patients. As ventilatory failure progresses and patient distress increases, mechanical ventilation is instituted to help the respiratory muscles cope with the heightened workload. While a patient is connected to a ventilator, a physician's ability to align the rhythm of the machine with the rhythm of the patient's respiratory centers becomes the primary determinant of the level of rest accorded to the respiratory muscles. Problems of alignment are manifested as failure to trigger, double triggering, an inflationary gas-flow that fails to match inspiratory demands, and an inflation phase that persists after a patient's respiratory centers have switched to expiration. With recovery from disorders that precipitated the initial bout of acute ventilatory failure, attempts are made to discontinue the ventilator (weaning). About 20% of weaning attempts fail, ultimately, because the respiratory controller is unable to sustain ventilation and this failure is signaled by development of rapid shallow breathing. Substantial advances in the medical management of acute ventilatory failure that requires ventilator assistance are most likely to result from research yielding novel insights into the operation of the respiratory control system.
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Affiliation(s)
- Martin J Tobin
- Division of Pulmonary and Critical Care Medicine, Edward Hines Jr. Veterans Affairs Hospital and Loyola University of Chicago Stritch School of Medicine, Hines, Illinois, USA.
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Tobin MJ, Laghi F, Brochard L. Role of the respiratory muscles in acute respiratory failure of COPD: lessons from weaning failure. J Appl Physiol (1985) 2009; 107:962-70. [PMID: 19407256 DOI: 10.1152/japplphysiol.00165.2009] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
It is problematic to withhold therapy in a patient with chronic obstructive pulmonary disease (COPD) who presents with acute respiratory failure so that detailed physiological measurements can be obtained. Accordingly, most information on respiratory muscle activity in patients experiencing acute respiratory failure has been acquired by studying patients who fail a trial of weaning after a period of mechanical ventilation. Such patients experience marked increases in inspiratory muscle load consequent to increases in resistance, elastance, and intrinsic positive end-expiratory pressure. Inspiratory muscle strength is reduced secondary to hyperinflation and possibly direct muscle damage and the release of inflammatory mediators. Most patients recruit both their sternomastoid and expiratory muscles, even though airflow limitation prevents the expiratory muscles from lowering lung volume. Even when acute hypercapnia is present, patients do not exhibit respiratory center depression; indeed, voluntary activation of the diaphragm, in absolute terms, is greater in hypercapnic patients than in normocapnic patients. Instead, the major mechanism of acute hypercapnia is the development of rapid shallow breathing. Despite the marked increase in mechanical load and decreased force-generating capacity of the inspiratory muscles, patients do not develop long-lasting muscle fatigue, at least over the period of a failed weaning trial. Although the disease originates within the lung parenchyma, much of the distress faced by patients with COPD, especially during acute respiratory failure, is caused by the burdens imposed on the respiratory muscles.
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Affiliation(s)
- Martin J Tobin
- Division of Pulmonary and Critical Care Medicine, Edward Hines Jr. VA Hospital, Hines, Illinois 60141, USA.
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Abdel Kafi S, Leduc D, Sergysels R, Ninane V. La compression abdominale manuelle dans la détection de la limitation du débit expiratoire. Rev Mal Respir 2005; 22:93-101. [PMID: 15968762 DOI: 10.1016/s0761-8425(05)85440-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
INTRODUCTION Expiratory flow limitation (EFL) is a characteristic feature of chronic obstructive pulmonary disease (COPD) and leads to dynamic hyperinflation (DH) which is a major source of dyspnoea, particularly during exercise. STATE OF THE ART A new technique for the detection of EFL, based on manual compression of the abdomen (MCA), was assessed both in normal subjects and patients with COPD. MCA was always associated with a moderate increase in pleural pressure and allowed the detection of EFL in a reproducible manner, in both the seated and supine postures. The technique was well tolerated. It was also a reliable method for the detection of EFL during exercise since EFL detection was effectively associated with the development of DH. Finally, MCA was also compared to NEP in patients with obstructive sleep apnoea syndrome (OSAS) and in these patients, MCA invariably increased expiratory flow whereas the NEP method produced flow limitation in some cases because of upper airway collapse. PERSPECTIVES EFL detection with MCA may be clinically useful since EFL is a determinant of dyspnoea, affects ventilatory response to exercise as well as maximum exercise capacity. CONCLUSIONS MCA is a reliable technique for the detection of EFL in different positions, during resting breathing or exercise, requiring neither special equipment nor patient cooperation.
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Affiliation(s)
- S Abdel Kafi
- Service de Pneumologie et de Soins Intensifs, CHU Saint-Pierre, Bruxelles, Belgique.
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Ninane V, Leduc D, Kafi SA, Nasser M, Houa M, Sergysels R. Detection of expiratory flow limitation by manual compression of the abdominal wall. Am J Respir Crit Care Med 2001; 163:1326-30. [PMID: 11371396 DOI: 10.1164/ajrccm.163.6.2004150] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
We have assessed a new method, manual compression of the abdominal wall (MCA) during expiration, in the detection of expiratory flow limitation. Twelve stable patients with chronic obstructive pulmonary disease (COPD) and five normal subjects were studied during spontaneous breathing in the supine and seated posture. MCA was performed during expiration with one hand at the umbilical level and we measured flow, volume, pleural (Ppl) and gastric (Pga) pressures and abdominal anteroposterior (AP) diameter at the umbilical level with magnetometers. No increase in expiratory flow during MCA relative to the preceding breath despite associated increases in pressures was considered as indicating expiratory flow limitation. In seven additional patients with increased upper airway collapsibility (obstructive sleep apnea syndrome [OSAS]), MCA was compared with negative expiratory pressure (NEP). In normal seated subjects, MCA was associated with a decrease in abdominal AP dimension (mean +/- SD: -27 +/- 6%), an increase in Pga (14.7 +/- 7.4 cm H(2)O) and Ppl (6.2 +/- 2.2 cm H(2)O), and an increase in expiratory flow. MCA caused similar changes in abdominal AP dimension and pressures in seated patients with COPD but six of them (50%), including four patients with FEV(1) less than 1 L, had no increase in expiratory flow. In the supine posture, MCA always increased expiratory flow in normal subjects but four additional patients with COPD showed evidence of flow limitation. MCA invariably increased expiratory flow in patients with OSAS whereas the NEP method suggested flow limitation in some cases. We conclude that MCA is a very simple method that allows detection of flow limitation in different positions.
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Affiliation(s)
- V Ninane
- Chest, Neurology, and Intensive Care Services, Saint-Pierre University Hospital, Rue Haute, 300, 1000 Brussels, Belgium.
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