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NCT Number: NCT07766967

Alveolar Recruitment Maneuver-Induced Hypotension: A Dynamic Consequence and Intraoperative Indicator of Fluid Responsiveness

This study investigates whether two simple bedside tests - the Passive Leg Raising (PLR) test and the Pleth Variability Index (PVI) - can predict a drop in blood pressure that sometimes occurs during a lung-opening procedure called an Alveolar Recruitment Maneuver (ARM).

ARM is routinely performed during general anesthesia to prevent lung collapse and improve oxygen levels. However, in some patients - particularly those with low fluid levels - ARM can cause a temporary but significant drop in blood pressure (hypotension), which may require immediate treatment.

In this prospective observational study, adult patients scheduled for elective non-cardiac, non-thoracic surgery under general anesthesia will be enrolled. Before each ARM is performed, PLR test and PVI values will be measured. We will then evaluate how well these measurements predict whether the patient will develop ARM-induced hypotension.

If PLR and PVI can reliably identify patients at risk, clinicians may be able to take preventive steps before performing ARM, making the procedure safer for vulnerable patients.

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Key information

Conditions

Hypotension Drug-Induced Atelectasis Cardiovascular Diseases Fluid Responsiveness General Anesthesia Using Endotracheal Intubation Hypotension Lung Diseases Mechanical Ventilation Pulmonary Atelectasis Respiratory Tract Diseases Vascular Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Balıkesir Atatürk City Hospital

Balıkesir, Altıeylül, 10100, Turkey (Türkiye)

Location contact

Hasan Duman

CONTACT

[email protected]

05547317716

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Age 18 years or older ASA physical status I or II Scheduled for elective non-cardiac, non-thoracic surgery under general anesthesia Able to provide written informed consent -

Exclusion criteria

Cardiac or thoracic surgery Hemodynamic instability at baseline (MAP <65 mmHg or requirement for vasopressors) Severe valvular heart disease or known cardiac dysfunction (EF <40%) Chronic obstructive pulmonary disease (COPD) or severe respiratory disease Atrial fibrillation or other significant arrhythmias Peripheral vascular disease affecting PVI signal quality Body mass index (BMI) >40 kg/m² Emergency surgery Refusal to participate or inability to provide informed consent Pregnancy

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Treatment and study plan

Alveolar Recruitment Maneuver (ARM)

Device

ARM is performed using a stepwise increase in positive end-expiratory pressure (PEEP) in pressure-controlled ventilation mode until peak inspiratory pressure reaches 40 cmH₂O, then stepwise decrease back to baseline. Hemodynamic parameters are continuously monitored throughout the maneuver.

Passive Leg Raising (PLR) Test

Behavioral

With the patient in supine position under general anesthesia, both legs are raised to 45 degrees for 60 seconds. The change in mean arterial pressure (ΔMAP) is recorded as an indicator of preload responsiveness. The test is performed immediately before each ARM.

Primary outcomes

  1. Prediction of ARM-Induced Hypotension by PLR Test and PVI

    Time frame: From induction of general anesthesia until 5 minutes after completion of the alveolar recruitment maneuver, assessed intraoperatively.

    Area under the ROC curve (AUC) of pre-ARM passive leg raising test (PLR-ΔMAP) for predicting ARM-induced hypotension (defined as MAP decrease ≥20% from baseline or MAP <65 mmHg during ARM).

  2. AUC of PVI for Predicting ARM-Induced Hypotension

    Time frame: Measured continuously from induction of general anesthesia until completion of the alveolar recruitment maneuver, assessed intraoperatively.

    Area under the ROC curve (AUC) of pre-ARM pleth variability index (PVI) for predicting ARM-induced hypotension (defined as MAP decrease ≥20% from baseline or MAP <65 mmHg during ARM)

Secondary outcomes

  1. Correlation Between ARM-Induced ΔMAP% and Post-ARM Fluid Responsiveness

    Time frame: From onset of ARM until 10 minutes after completion of ARM, assessed intraoperatively.

    Pearson or Spearman correlation coefficient between the maximum MAP decrease during ARM (ΔMAP%) and fluid responsiveness after ARM. Fluid responsiveness is defined as MAP increase ≥10% following 250 mL crystalloid bolus.

  2. Comparative Diagnostic Accuracy of PLR Test versus PVI for Predicting ARM-Induced Hypotension

    Time frame: From induction of general anesthesia until 5 minutes after completion of the alveolar recruitment maneuver, assessed intraoperatively.

    The difference in AUC values between PLR-ΔMAP and PVI will be compared using the DeLong method.

Study contacts

Contact information is provided by the study sponsor or research team.

Hasan Duman, M.D.

CONTACT

[email protected]

+905547317716

Sponsors and collaborators

Lead sponsor

University of Health Sciences Balikesir Hospital Eduation and Research

Other Gov

Registry information

Official study title

Alveolar Recruitment Maneuver-Induced Hypotension: A Dynamic Outcome and Intraoperative Indicator of Fluid Responsiveness

Important dates

Study start
2026
Primary completion
2026
Study completion
2026
First posted
Aug 17, 2026
Registry last updated
Aug 17, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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