Spontaneous breathing during mechanical ventilation*

Objective Clinicians cannot precisely determine the time for withdrawal of ventilation. We aimed to evaluate the performance of driving pressure (DP)×respiratory rate (RR) to predict the outcome of weaning. Methods Plateau pressure (Pplat) and total positive end-expiratory pressure (PEEPtot) were measured during mechanical ventilation with brief deep sedation and on volume-controlled mechanical ventilation with a tidal volume of 6 mL/kg and a PEEP of 0 cmH2O. Pplat and PEEPtot were measured by patients holding their breath for 2 s after inhalation and exhalation, respectively. DP was determined as Pplat minus PEEPtot. The rapid shallow breathing index was measured from the ventilator. The highest RR was recorded within 3 minutes during a spontaneous breathing trial. Patients who tolerated a spontaneous breathing trial for 1 hour were extubated. Results Among the 105 patients studied, 44 failed weaning. During ventilation withdrawal, DP×RR was 136.7±35.2 cmH2O breaths/minute in the success group and 230.2±52.2 cmH2O breaths/minute in the failure group. A DP×RR index >170.8 cmH2O breaths/minute had a sensitivity of 93.2% and specificity of 88.5% to predict failure of weaning. Conclusions Measurement of DP×RR during withdrawal of ventilation may help predict the weaning outcome. A high DP×RR increases the likelihood of weaning failure. Statement: This manuscript was previously posted as a preprint on Research Square with the following link: https://www.researchsquare.com/article/rs-15065/v3 and DOI: 10.21203/rs.2.24506/v3

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Estimation of change in pleural pressure in assisted and unassisted spontaneous breathing pediatric patients using fluctuation of central venous pressure: A preliminary study

PLoS ONE ◽

10.1371/journal.pone.0247360 ◽

2021 ◽

Vol 16 (3) ◽

pp. e0247360

Author(s):

Nao Okuda ◽

Miyako Kyogoku ◽

Yu Inata ◽

Kanako Isaka ◽

Kazue Moon ◽

...

Keyword(s):

Mechanical Ventilation ◽

Spontaneous Breathing ◽

Pediatric Patients ◽

Venous Pressure ◽

Balloon Catheter ◽

Pleural Pressure ◽

Respiratory Effort ◽

Central Venous ◽

Mechanically Ventilated ◽

Esophageal Balloon

Background It is important to evaluate the size of respiratory effort to prevent patient self-inflicted lung injury and ventilator-induced diaphragmatic dysfunction. Esophageal pressure (Pes) measurement is the gold standard for estimating respiratory effort, but it is complicated by technical issues. We previously reported that a change in pleural pressure (ΔPpl) could be estimated without measuring Pes using change in CVP (ΔCVP) that has been adjusted with a simple correction among mechanically ventilated, paralyzed pediatric patients. This study aimed to determine whether our method can be used to estimate ΔPpl in assisted and unassisted spontaneous breathing patients during mechanical ventilation. Methods The study included hemodynamically stable children (aged <18 years) who were mechanically ventilated, had spontaneous breathing, and had a central venous catheter and esophageal balloon catheter in place. We measured the change in Pes (ΔPes), ΔCVP, and ΔPpl that was calculated using a corrected ΔCVP (cΔCVP-derived ΔPpl) under three pressure support levels (10, 5, and 0 cmH2O). The cΔCVP-derived ΔPpl value was calculated as follows: cΔCVP-derived ΔPpl = k × ΔCVP, where k was the ratio of the change in airway pressure (ΔPaw) to the ΔCVP during airway occlusion test. Results Of the 14 patients enrolled in the study, 6 were excluded because correct positioning of the esophageal balloon could not be confirmed, leaving eight patients for analysis (mean age, 4.8 months). Three variables that reflected ΔPpl (ΔPes, ΔCVP, and cΔCVP-derived ΔPpl) were measured and yielded the following results: -6.7 ± 4.8, − -2.6 ± 1.4, and − -7.3 ± 4.5 cmH2O, respectively. The repeated measures correlation between cΔCVP-derived ΔPpl and ΔPes showed that cΔCVP-derived ΔPpl had good correlation with ΔPes (r = 0.84, p< 0.0001). Conclusions ΔPpl can be estimated reasonably accurately by ΔCVP using our method in assisted and unassisted spontaneous breathing children during mechanical ventilation.

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The Use of Ventilatory Modes allowing Spontaneous Breathing during Mechanical Ventilation

Yearbook of Intensive Care and Emergency Medicine 2002 ◽

10.1007/978-3-642-56011-8_22 ◽

2002 ◽

pp. 243-252

Author(s):

R. Kuhlen ◽

C. Putensen ◽

R. Rossaint

Keyword(s):

Mechanical Ventilation ◽

Spontaneous Breathing

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Mechanical Ventilation: Approaches and Special Considerations

10.2310/7ccsp.2396 ◽

2018 ◽

Author(s):

Adrian A. Maung ◽

Lewis J Kaplan

Keyword(s):

Mechanical Ventilation ◽

Respiratory Failure ◽

Acute Respiratory Failure ◽

Key Words ◽

Spontaneous Breathing ◽

Functional Unit ◽

Spontaneous Breathing Trial

In this chapter, we complete the discussion of mechanical ventilation by examining approaches to mechanical ventilation for different patient populations and how to assess whether a patient is ready for liberation from mechanical ventilation. Each of the three chapters is intended to build on the preceding one and therefore establishes a functional unit with regard to mechanical ventilation, whether it is provided in an invasive or a noninvasive fashion. This review contains 1 Figure, 1 Table and 31 references Key Words: acute respiratory failure, ARDS, mechanical ventilation liberation, spontaneous breathing trial, tracheostomy

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Patients on Weaning Trials Classified with Neural Networks and Features Selection

Encyclopedia of Healthcare Information Systems ◽

10.4018/978-1-59904-889-5.ch132 ◽

2008 ◽

pp. 1061-1067

Author(s):

B. Giraldo ◽

A. Garde ◽

C. Arizmendi ◽

R. Jane ◽

I. Diaz ◽

...

Keyword(s):

Neural Network ◽

Neural Networks ◽

Mechanical Ventilation ◽

Intensive Care ◽

Spontaneous Breathing ◽

Selection Procedure ◽

Respiratory Pattern ◽

Features Selection ◽

Weaning From Mechanical Ventilation ◽

Pattern Variability

One of the challenges in intensive care is the process of weaning from mechanical ventilation. We studied the differences in respiratory pattern variability between patients capable of maintaining spontaneous breathing during weaning trials, and patients that fail to maintain spontaneous breathing. In this work, neural networks were applied to study these differences. 64 patients from mechanical ventilation are studied: Group S with 32 patients with Successful trials, and Group F with 32 patients that Failed to maintain spontaneous breathing and were reconnected. A performance of 64.56% of well classified patients was obtained using a neural network trained with the whole set of 35 features. After the application of a feature selection procedure (backward selection) 84.25% was obtained using only eight of the 35 features.

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Comparison of methods of measuring pulmonary artery pressure

American Journal of Critical Care ◽

10.4037/ajcc1997.6.4.324 ◽

1997 ◽

Vol 6 (4) ◽

pp. 324-332 ◽

Cited By ~ 8

Author(s):

JL Lundstedt

Keyword(s):

Mechanical Ventilation ◽

Cardiac Surgery ◽

Pulmonary Artery ◽

Pulmonary Artery Pressure ◽

Spontaneous Breathing ◽

Systolic Pressure ◽

Graphic Method ◽

Difference Scores ◽

Artery Pressure ◽

The Difference

BACKGROUND: Pulmonary artery waveforms fluctuate because of changes in intrathoracic pressure caused by respirations. Monitoring system algorithms determine digital displays of pressure measurements on the basis of recognition, analysis, and comparison of consecutive waveforms. OBJECTIVE: To compare three methods of measuring pulmonary artery pressure during mechanical ventilation and spontaneous breathing in cardiac surgery patients with stable hemodynamics. METHODS: Pulmonary artery pressure was measured during mechanical ventilation after cardiac surgery in 53 patients; 37 of the patients were studied again after extubation. Three monitoring methods were compared: graphic strip recording, the "stop cursor" (monitor screen freezing) method, and digital-display recording. Difference scores were calculated between the methods and analyzed for frequency and direction. RESULTS: All comparisons showed differences of at least +/-3 mm Hg in measurements obtained with the three methods. During mechanical ventilation, the digital and graphic measurements of systolic pressure varied most often; 57% (30/53) of the comparisons had difference scores of at least +/-3 mm Hg. The cursor and graphic measurements of diastolic pressures varied least often; 6% (3/53) of the comparisons had difference scores of at least +/-3 mm Hg. As expected, the digital method most often gave higher results than the graphic method. During spontaneous breathing, measurements of systolic pressure varied more often (38% to 53%) than did measurements of diastolic pressure (12% to 37%). Unexpectedly, for systolic pressures, the difference between digital and graphic measurements was 3 mm Hg or more 30% (11/37) of the time, and the difference between cursor and graphic measurements was 3 mm Hg or more 53% (17/32) of the time. CONCLUSIONS: Because of physiological and technical influences, measurements of systolic and diastolic pressures in the pulmonary artery made with the digital and cursor methods were not as reliable as measurements made with the graphic method. The findings support continued use of the graphic method for accurate measurements of pulmonary artery pressure.

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Costal diaphragm curvature in the dog

Journal of Applied Physiology ◽

10.1152/jappl.1993.75.2.527 ◽

1993 ◽

Vol 75 (2) ◽

pp. 527-533 ◽

Cited By ~ 23

Author(s):

A. M. Boriek ◽

S. Liu ◽

J. R. Rodarte

Keyword(s):

Mechanical Ventilation ◽

Muscle Fiber ◽

Lung Volume ◽

Spontaneous Breathing ◽

Total Lung Capacity ◽

Muscle Fibers ◽

Transdiaphragmatic Pressure ◽

Lung Capacity ◽

Principal Axes ◽

Quadratic Surface

The curvature of the midcostal region of the diaphragm in seven dogs was determined at functional residual capacity (FRC) and end inspiration during spontaneous breathing and mechanical ventilation and at total lung capacity in the prone and supine positions. Metallic markers were attached to muscle fibers on the abdominal surface of the diaphragm, and the dog was allowed to recover from surgery. The three-dimensional positions of the markers were determined by biplane videofluoroscopy. A quadratic surface was fit to the bead positions. The principal axes of the quadratic surface lie nearly along and perpendicular to the muscle fibers. In both the supine and prone positions, the values of the principal curvatures were similar at FRC and end inspiration during spontaneous breathing, when muscle tension and transdiaphragmatic pressure both increase with increasing lung volume, and during mechanical ventilation and passive inflation to total lung capacity, when both decrease relative to their magnitude at FRC. No abrupt change of curvature, which might be expected at the edge of the zone of apposition, was apparent. The curvature along the muscle fiber was 0.35 +/- 0.07 cm-1; the curvature perpendicular to the muscle fiber was much smaller, 0.06 +/- 0.01 cm-1. The costal region of the diaphragm displaces and shortens as lung volume increases, but its shape, as described by its curvatures, does not change substantially.

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