Recruiting NCT07199881
Assessment of Respiratory Drive and Inspiratory Effort Across Pressure Support Levels in Patients After Major Abdominal Surgery
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Stepwise PSV adjustment protocol.
- Who it may be relevant to
- Registry conditions: Inspiratory Effort, Mechanical Ventilation, Major Abdominal Surgeries. Basic parameters: from 18 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Thailand
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
Unsure about the terms? Read our patient guide →
Overview
This physiological observational study will assess respiratory drive and inspiratory effort across varying levels of pressure support ventilation (PSV) in adult surgical ICU (SICU) patients after major abdominal surgery. By using non-invasive bedside indices (airway occlusion pressure at 100 ms after the onset of inspiration \[P0.1\], maximum negative occlusion pressure \[Pocc\], and pressure muscle index \[PMI\]), we aim to quantify how patients adapt to changes in ventilatory support and determine patterns of under- and over-assistance. Findings may inform optimal titration of PSV to reduce complications and improve clinical outcomes.
Interventions
- Procedure Stepwise PSV adjustment protocol
Patients will undergo standardized stepwise PSV changes (baseline, ±3 cmH₂O, ±6 cmH₂O, return to baseline), with 2-minute stabilization and repeated measurements of ventilatory parameters.
Primary outcome measures
- Respiratory drive and inspiratory effort across pressure support levels [Time frame: Baseline and during protocol sessions, up to 3 days after enrollment]
Secondary outcome measures (5)
- Incidence of ventilatory response patterns during PSV [Time frame: Baseline and during protocol sessions, up to 3 days after enrollment]
- Duration of mechanical ventilation after protocol [Time frame: Within 48 hours after extubation]
- Reintubation or non-invasive ventilation use [Time frame: 48 hours after extubation]
- ICU length of stay [Time frame: Through ICU stay, an average of 7-21 days]
- Hospital discharge disposition [Time frame: Through hospital stay, an average of 14-60 days]
Eligibility criteria
Inclusion criteria
- Adult patients (≥18 years) admitted to the surgical ICU
- Recent major abdominal surgery (intra-peritoneal operation without primary thoracic involvement, including luminal resection and/or resection of a gastrointestinal solid organ) requiring postoperative ICU care
- Receiving invasive mechanical ventilation in pressure support ventilation (PSV) mode at the time of enrollment
- Duration of invasive mechanical ventilation >48 hours
- Clinically stable, with no plan for extubation within 6 hours of study enrollment, defined by all of the following: Respiratory rate <35 breaths/min, SpO₂ ≥90%, Heart rate <140 bpm, No visible accessory muscle use, Hemodynamically stable without escalation of vasopressor support during the past hour, Able to tolerate short-term adjustments in PSV level as per protocol
Exclusion criteria
- Known neuromuscular disease affecting respiratory muscle function
- Hemodynamic instability requiring escalation of vasopressor support
- Severe hypoxemic respiratory failure requiring Positive End-Expiratory Pressure (PEEP) >10 cmH₂O or FiO₂ >60%
- Deep sedation (Richmond Agitation-Sedation Scale \[RASS\] score < -3) or ongoing neuromuscular blockade
- History of chronic obstructive pulmonary disease (COPD) or other obstructive lung disease
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- N/A
- Model
- Single group
- Masking
- Open label
- Primary purpose
- Diagnostic
Study locations
Thailand · 1 center
- Faculty of Medicine, Siriraj Hospital, Mahidol University — Bangkok
Publications
- He Q, Lai Z, Peng S, Lin S, Mo G, Zhao X, Wang Z. Postoperative pulmonary complications after major abdominal surgery in elderly patients and its association with patient-controlled analgesia. BMC Geriatr. 2024 Sep 10;24(1):751. doi: 10.1186/s12877-024-05337-y. PMID 39256677
- Miskovic A, Lumb AB. Postoperative pulmonary complications. Br J Anaesth. 2017 Mar 1;118(3):317-334. doi: 10.1093/bja/aex002. PMID 28186222
- Courtney A, Clymo J, Dorudi Y, Moonesinghe SR, Dorudi S. Scoping review: The terminology used to describe major abdominal surgical procedures. World J Surg. 2024 Mar;48(3):574-584. doi: 10.1002/wjs.12084. Epub 2024 Feb 11. PMID 38342951
- Docci M, Foti G, Brochard L, Bellani G. Pressure support, patient effort and tidal volume: a conceptual model for a non linear interaction. Crit Care. 2024 Nov 6;28(1):358. doi: 10.1186/s13054-024-05144-2. PMID 39506755
- Al-Bassam W, Parikh T, Neto AS, Idrees Y, Kubicki MA, Hodgson CL, Subramaniam A, Reddy MP, Gullapalli N, Michel C, Matthewman MC, Naughton J, Pereira J, Shehabi Y, Bellomo R. Pressure support ventilation in intensive care patients receiving prolonged invasive ventilation. Crit Care Resusc. 2023 Oct 18;23(4):394-402. doi: 10.51893/2021.4.OA4. eCollection 2021 Dec 6. PMID 38046681
- van Oosten JP, Akoumianaki E, Jonkman AH. Monitoring respiratory muscles effort during mechanical ventilation. Curr Opin Crit Care. 2025 Feb 1;31(1):12-20. doi: 10.1097/MCC.0000000000001229. Epub 2024 Nov 14. PMID 39560150
Identifiers
NCT: NCT07199881 · PSV-SICU_SIRIRAJ