Acceptable Range of Inspiratory Effort During Mechanical Ventilation

Elective Cardiac Surgery Clinical Trial

— EFFORT  

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02838524
• Other study ID #: REB# 15-369
• Status: Completed
• First received: July 15, 2016
• Last updated: April 11, 2018
• Start date: September 2016
• Est. completion date: March 1, 2018

Study information

• Verified date: April 2018
• Source: St. Michael's Hospital, Toronto
• Contact: n/a
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

Partially assisted mechanical ventilation is ideally titrated to maintain adequate inspiratory muscle activity (i.e. preventing disuse atrophy) while avoiding excessive (i.e. fatiguing) inspiratory loads. The advent of ventilator modes enabling flow and pressure assistance in proportion to patient inspiratory effort (i.e. Proportional Assist Ventilation (PAV), Neurally-Adjusted Ventilator Assist (NAVA)) permit careful titration of ventilatory support to achieve desired levels of patient inspiratory effort. However, data on the acceptable range of values for inspiratory effort and respiratory muscle load-capacity balance during mechanical ventilation are currently very limited. Such data are critical to inform a physiologically sound evidence-based approach to titrating partially-assisted ventilatory support. This study is designed to ascertain a physiologically acceptable range of inspiratory effort in mechanically ventilated patients. The study protocol includes measurements of the respiratory system during spontaneous breathing as well as evaluating the diaphragm in real-time with the use of ultrasonography. The experimental design outlined in the present study is predicated on the assumption that the range of values for inspiratory effort and load-capacity balance observed in patients who are successfully weaned from mechanical ventilation represent the safe and appropriate range of target values.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 43
• Est. completion date: March 1, 2018
• Est. primary completion date: March 1, 2018
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Adult patients (>17) receiving invasive mechanical ventilation following elective cardiac surgery who will undergo a trial of spontaneous breathing

Exclusion Criteria:

• Pregnant women

• Decompensated cardiac insufficiency or acute coronary syndrome

• Severe COPD

• Contraindications to esophageal catheter placement, namely known esophageal varices

Related Conditions & MeSH terms

• Elective Cardiac Surgery

Locations

Country	Name	City	State
Canada	St. Michael's Hospital	Toronto	Ontario

Sponsors (1)

Lead Sponsor	Collaborator
St. Michael's Hospital, Toronto

Country where clinical trial is conducted

Canada, 

References & Publications (9)

Akoumianaki E, Maggiore SM, Valenza F, Bellani G, Jubran A, Loring SH, Pelosi P, Talmor D, Grasso S, Chiumello D, Guérin C, Patroniti N, Ranieri VM, Gattinoni L, Nava S, Terragni PP, Pesenti A, Tobin M, Mancebo J, Brochard L; PLUG Working Group (Acute Respiratory Failure Section of the European Society of Intensive Care Medicine). The application of esophageal pressure measurement in patients with respiratory failure. Am J Respir Crit Care Med. 2014 Mar 1;189(5):520-31. doi: 10.1164/rccm.201312-2193CI. Review. — View Citation

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 Nov;126(5):788-91. — View Citation

Carteaux G, Mancebo J, Mercat A, Dellamonica J, Richard JC, Aguirre-Bermeo H, Kouatchet A, Beduneau G, Thille AW, Brochard L. Bedside adjustment of proportional assist ventilation to target a predefined range of respiratory effort. Crit Care Med. 2013 Sep;41(9):2125-32. doi: 10.1097/CCM.0b013e31828a42e5. — View Citation

Goligher EC, Laghi F, Detsky ME, Farias P, Murray A, Brace D, Brochard LJ, Bolz SS, Rubenfeld GD, Kavanagh BP, Ferguson ND. Measuring diaphragm thickness with ultrasound in mechanically ventilated patients: feasibility, reproducibility and validity. Intensive Care Med. 2015 Apr;41(4):642-9. doi: 10.1007/s00134-015-3687-3. Epub 2015 Feb 19. Erratum in: Intensive Care Med. 2015 Apr;41(4):734. Sebastien-Bolz, Steffen [corrected to Bolz, Steffen-Sebastien]. — View Citation

Jubran A, Tobin MJ. Pathophysiologic basis of acute respiratory distress in patients who fail a trial of weaning from mechanical ventilation. Am J Respir Crit Care Med. 1997 Mar;155(3):906-15. — View Citation

Lerolle N, Guérot E, Dimassi S, Zegdi R, Faisy C, Fagon JY, Diehl JL. Ultrasonographic diagnostic criterion for severe diaphragmatic dysfunction after cardiac surgery. Chest. 2009 Feb;135(2):401-407. doi: 10.1378/chest.08-1531. Epub 2008 Aug 27. — View Citation

Thille AW, Richard JC, Brochard L. The decision to extubate in the intensive care unit. Am J Respir Crit Care Med. 2013 Jun 15;187(12):1294-302. doi: 10.1164/rccm.201208-1523CI. Review. — View Citation

Tobin MJ, Laghi F, Jubran A. Narrative review: ventilator-induced respiratory muscle weakness. Ann Intern Med. 2010 Aug 17;153(4):240-5. doi: 10.7326/0003-4819-153-4-201008170-00006. Review. — View Citation

Vassilakopoulos T, Zakynthinos S, Roussos C. The tension-time index and the frequency/tidal volume ratio are the major pathophysiologic determinants of weaning failure and success. Am J Respir Crit Care Med. 1998 Aug;158(2):378-85. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Maximal inspiratory effort generated by a patient		During 10-15 minutes of the spontaneous breathing trial
Secondary	Diaphragmatic thickening fraction		15 minutes
Secondary	Diaphragmatic excursion		15 minutes
Secondary	Success or failure of the spontaneous breathing trial		15 minutes
Secondary	Muscular load-capacity balance measured by the tension-time index of the respiratory muscles		15 minutes
Secondary	Airway occlusion pressure (P0.1) performed manually and as measured by the ventilator		15 minutes