A Study of the Relationship between Recruitment Maneuvers and Blood Volume Status in Critically Ill Patients


About this study

The purpose of this pilot study is to see if recruitment maneuvers performed during ICU care in patients who have a breathing tube are useful in assessing a blood volume status based on changes in their blood pressure during the recruitment maneuver. The recruitment maneuver consists of increasing the pressure of the breath given through the breathing tube, and is commonly done as a standard part of ICU care for patients who are connected to a machine that helps them breathe. Results will be compared to ultrasound measurements of the main vein of the body (inferior vena cava) which serve as a non-invasive standard of care technique.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria:

  1. Mechanically-ventilated patients admitted to the trauma-surgical ICU (Mary Brigh 7 B/G)  with a clinical diagnosis of hypovolemic or distributive shock, who are undergoing active resuscitation by the ICU team members,
  2. Blood pressure monitoring via arterial line
  3. Arterial line systolic blood pressure ≥90
  4. Age ≥ 18

Exclusion Criteria: 

  1. Patients who are not mechanically ventilated
  2. Patients who do not have an arterial line at time of enrollment
  3. Patients with abdominal dressings which prevent the use of ultrasonography in the epigastrium
  4. Pregnant patients
  5. Patients <18 years of age
  6. Prisoners/Incarcerated individuals
  7. Recent pneumonectomy
  8. Occult pneumothorax (i.e. pneumothorax only visible on chest CT without clinical symptoms)
  9. Patients with angulated, displaced rib fractures with associated pneumothorax and no thoracostomy tube in place at the time of enrollment.
  10. Patients with difficult to control elevated intracranial pressure
  11. Patients with history of emphysematous bleb and spontaneous pneumothorax.
  12. Patients with a tube thoracostomy and active air leak.
  13. Recently placed internal mammary grafts.

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status

Rochester, Minn.

Mayo Clinic principal investigator

Erica Loomis, M.D.

Closed for enrollment

More information


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Additional contact information

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