An observational study in Fluid Responsiveness, Laparoscopic Surgery and Hemodynamic Monitoring, sponsored by University Of Perugia. Not yet recruiting. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-02.
Sponsored by University Of Perugia · Observational
Background Fluid management is central to perioperative care, but only about half of surgical patients increase their stroke volume after a fluid challenge. Dynamic indices such as pulse pressure variation and stroke volume variation are often unreliable during laparoscopy, because of low tidal volume ventilation and carbon dioxide (CO2) pneumoperitoneum. Functional hemodynamic tests may overcome these limitations. In the Mini fluid chAllenge aNd End-expiratory occlusion test to assess flUid responsiveness in the opeRating room (MANEUVER) study (NCT03808753), conducted in open abdominal surgery, the mini-fluid challenge predicted fluid responsiveness well, whereas the end-expiratory occlusion test did not. Pneumoperitoneum raises intra-abdominal pressure instead of abolishing it, so these results cannot be extrapolated to laparoscopy.
Design FLUID-LAP is a prospective, multicenter, observational diagnostic-accuracy cohort study conducted in four Italian centers and reported according to the Standards for Reporting of Diagnostic Accuracy (STARD) 2015 statement. Each patient is their own control: both index tests and the reference standard are performed in sequence in the same patient during a period of stable intraoperative hemodynamics, so the resulting receiver operating characteristic (ROC) curves are correlated. The study replicates the design of MANEUVER, changing only the surgical setting. Ventilation (volume-controlled, 7 ml/kg predicted body weight), the reference fluid challenge and uncalibrated pulse-contour monitoring are the same, to allow direct comparison with the open-abdomen data.
Procedures Tests are performed under standardized baseline conditions (stable pneumoperitoneum and position, unchanged ventilation, no recent drug changes or surgical manipulation, arterial waveform checked with a square-wave test). The order of the two index tests is chosen by the attending anesthesiologist, is recorded for every patient, and is analyzed as a pre-specified covariate. A 3-minute return to steady state separates the tests. The complete 4 ml/kg fluid challenge is given after both tests. The maneuvers are already part of routine goal-directed practice, and no treatment decision is dictated by the protocol. Patient safety always prevails over the protocol.
Analysis The primary analysis compares the areas under the ROC curves (AUC) of the two tests using the DeLong test. The expected AUCs are 0.90 for the mini-fluid challenge and 0.75 for the end-expiratory occlusion test. With 80% power and a two-sided alpha of 0.05, 87 evaluable patients are required; 104 will be enrolled to allow for 15% attrition (26 per center). Pre-specified analyses address the mathematical coupling between the mini-fluid challenge and the reference challenge, the effect of test order, and subgroups by intra-abdominal pressure and patient position.
Background Fluid management is central to perioperative care, but only about half of surgical patients increase their stroke volume after a fluid challenge. Dynamic indices such as pulse pressure variation and stroke volume variation are often unreliable during laparoscopy, because of low tidal volume ventilation and carbon dioxide (CO2) pneumoperitoneum. Functional hemodynamic tests may overcome these limitations. In the Mini fluid chAllenge aNd End-expiratory occlusion test to assess flUid responsiveness in the opeRating room (MANEUVER) study (NCT03808753), conducted in open abdominal surgery, the mini-fluid challenge predicted fluid responsiveness well, whereas the end-expiratory occlusion test did not. Pneumoperitoneum raises intra-abdominal pressure instead of abolishing it, so these results cannot be extrapolated to laparoscopy.
Design FLUID-LAP is a prospective, multicenter, observational diagnostic-accuracy cohort study conducted in Italian centers and reported according to the Standards for Reporting of Diagnostic Accuracy (STARD) 2015 statement. Each patient is their own control: both index tests and the reference standard are performed in sequence in the same patient during a period of stable intraoperative hemodynamics, so the resulting receiver operating characteristic (ROC) curves are correlated. The study replicates the design of MANEUVER, changing only the surgical setting. Ventilation (volume-controlled, 7 ml/kg predicted body weight), the reference fluid challenge and uncalibrated pulse-contour monitoring are the same, to allow direct comparison with the open-abdomen data.
Procedures Tests are performed under standardized baseline conditions (stable pneumoperitoneum and position, unchanged ventilation, no recent drug changes or surgical manipulation, arterial waveform checked with a square-wave test). The order of the two index tests is chosen by the attending anesthesiologist, is recorded for every patient, and is analyzed as a pre-specified covariate. A 3-minute return to steady state separates the tests. The complete 4 ml/kg fluid challenge is given after both tests. The maneuvers are already part of routine goal-directed practice, and no treatment decision is dictated by the protocol. Patient safety always prevails over the protocol.
Analysis The primary analysis compares the areas under the ROC curves (AUC) of the two tests using the DeLong test. The expected AUCs are 0.90 for the mini-fluid challenge and 0.75 for the end-expiratory occlusion test. With 80% power and a two-sided alpha of 0.05, 87 evaluable patients are required; 104 will be enrolled to allow for 15% attrition. Pre-specified analyses address the mathematical coupling between the mini-fluid challenge and the reference challenge, the effect of test order, and subgroups by intra-abdominal pressure and patient position.
134 studies on the registry are indexed under Pneumoperitoneum; 28 are open to participants now.
This study's planned enrollment of 104 is above the median of 59 across 48 observational studies indexed under Pneumoperitoneum.
Browse Pneumoperitoneum studies →University Of Perugia is the lead sponsor of 55 studies on the registry; 12 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Adults undergoing elective major laparoscopic or robot-assisted abdominal, urological or gynecological-oncological surgery under CO2 pneumoperitoneum, mechanically ventilated, with invasive arterial pressure and uncalibrated pulse-contour cardiac output monitoring, recruited at four centres.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
LVEF (left ventricular ejection fraction)
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Adults (18 years or older) scheduled for elective major laparoscopic or robot-assisted surgery under CO2 pneumoperitoneum, mechanically ventilated, with invasive arterial pressure and uncalibrated pulse-contour cardiac output monitoring. Each participant undergoes both index tests in sequence during a period of stable intraoperative hemodynamics: the end-expiratory occlusion test (30-second end-expiratory hold) and the mini-fluid challenge (100 ml of lactated Ringer's over 1 minute). The order of the two tests is chosen by the attending anesthesiologist and recorded. The reference standard is a fluid challenge of 4 ml/kg predicted body weight of lactated Ringer's over about 10 minutes; fluid responsiveness is defined as an increase in stroke volume index of 10% or more. The tests are already used in routine goal-directed practice.
Difference in area under the ROC curve (AUC) between the mini-fluid challenge and the end-expiratory occlusion test for predicting fluid responsiveness
Percent change in stroke volume index (ΔSVI%) after the mini-fluid challenge (100 ml lactated Ringer's over 1 minute) and after the end-expiratory occlusion test (30-second expiratory hold) is used as a continuous predictor. Fluid responsiveness is defined as an increase in stroke volume index of 10% or more after a fluid challenge of 4 ml/kg predicted body weight of lactated Ringer's over about 10 minutes. The AUCs of the two tests are compared as correlated ROC curves using the DeLong test. Stroke volume index is measured by uncalibrated pulse-contour analysis.
Time frame: Perioperative/Periprocedural
Area under the ROC curve (AUC) of each test for predicting fluid responsiveness
AUC with 95% confidence interval (DeLong) of the percent change in stroke volume index after the end-expiratory occlusion test (30 seconds) and after the mini-fluid challenge, and of baseline pulse pressure variation (PPV) and stroke volume variation (SVV), for predicting fluid responsiveness (increase in stroke volume index of 10% or more after a 4 ml/kg fluid challenge).
Time frame: Perioperative/Periprocedural
Optimal cut-off, sensitivity, specificity, predictive values and likelihood ratios of each test
For the end-expiratory occlusion test and the mini-fluid challenge: best cut-off of the percent change in stroke volume index by the Youden index, with sensitivity, specificity, positive and negative predictive values and positive and negative likelihood ratios, each with 95% confidence interval (Wilson method).
Time frame: Perioperative/Periprocedural
Prevalence of fluid responsiveness in the study population
Proportion of participants with an increase in stroke volume index of 10% or more after the 4 ml/kg fluid challenge of lactated Ringer's over about 10 minutes.
Time frame: Perioperative/Periprocedural
Grey zone of each test and comparison of grey-zone widths
Grey zone of the end-expiratory occlusion test and of the mini-fluid challenge, defined by a lower cut-off including 90% of non-responders and an upper cut-off predicting fluid responsiveness in 90% of cases. The intermediate range is considered inconclusive. The widths of the two grey zones are compared.
Time frame: Perioperative/Periprocedural
No study locations are listed for this record.
Plan to share: No — Individual participant data are not planned to be shared, as participants consented only to the use of aggregated, anonymous data. Any future sharing would require ethics committee approval and, if needed, a new participant consent.
No publications or documents are linked to this record.
Start is estimated for Jan 2027; primary completion for Sep 2027, 8 months later.
Of 26 observational studies under Pneumoperitoneum, half reached primary completion within 11 months of starting (the median), counting those still running; a quarter within 5 and three quarters within 17. This study's planned 8 months is below that.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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University Of Perugia