Clinical trial NCT01825278: Evaluation of a Respiratory Monitor in Surgical Patients With a BMI>35
Official title: The Evaluation of a Respiratory Monitor in Surgical Patients With a BMI >35 Undergoing Elective Surgery Under General Anesthesia
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Obesity
Obstructive Sleep Apnea
Keywords: respiratory rate
tidal volume
minute ventilation
obese patients
obstructive sleep apnea
Lead sponsor: Tufts Medical Center
Sponsor class: OTHER
First posted: 2013-04-05
Enrollment: 90
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Obese surgical patients

Brief summary: This study proposes to evaluate the clinical applicability of the ExSpiron Respiratory Volume Monitor (RVM, ExSpiron™, Respiratory Motion, Inc.; Waltham, MA) in obese surgical patients undergoing general anesthesia. Previous work has demonstrated the ability of the ExSpiron monitor to provide non-invasive, real-time, continuous measurements of respiratory parameters such as tidal volume (TV), minute ventilation (MV) and respiratory rate (RR) mostly in normal weight patients but those studies did not specifically look at obese subjects. Respiratory depression, in the postoperative setting due to residual anesthetics and/or opioid administration, continues to be a significant cause of adverse outcomes. Obese patients are at increased risk for respiratory complications. Currently, there is no objective measure of early respiratory indicators for developing respiratory compromise. Current respiratory assessment in non-intubated patients relies on oximetry data and subjective clinical assessment. Pulse oximetry has been extremely helpful in recognizing oxygen desaturations but it is a late indicator of respiratory decline. There is no current device capable of giving real time ventilatory information such as tidal volume and minute ventilation of a patient that is not mechanically ventilated. The ExSpiron system utilizes an impedance based technology and proprietary algorithms (Respiratory Motion Inc.) to obtain these measurements. The study hypotheses are that the non-invasive, impedance-based RVM monitor will accurately reflect TV, RR and MV in obese surgical patients before induction of general anesthesia, during controlled ventilation and following extubation; that ExSpiron will accurately reflect the post-extubation respiratory status of the patient; and that apnea and hypopnea episodes in the recovery room as detected by the ExSpiron monitor are correlated with the individual risk for obstructive sleep apnea as determined by the STOP-Bang risk stratification.


Eligibility criteria: Inclusion Criteria:

* ASA 1 - 3 patients with a body mass index (BMI) ≥ 35kg/m2 presenting for elective surgery under general anesthesia aged \> 18 years. Ability to provide written informed consent.

Exclusion Criteria:

* Emergent surgical patients, patients with a BMI \< 35kg/m2, patients not competent to give informed consent, pregnant patients (women of child bearing potential who want to participate will have a pregnancy test done prior to enrollment in the study), patients with implantable electronic devices (pacemakers, stimulators, etc.); predictable interference with surgical procedure or standard of care.

Primary outcomes:
measure: ExSpiron monitor accurately reflects TV, MV and RR in obese patients in the preoperative holding area before surgery
timeFrame: 1 - 1.5 hours before surgery
Secondary outcomes:
measure: ExSpiron will accurately reflect the post-extubation respiratory status of the patient
timeFrame: 1 - 3 hours in the recovery room
Other outcomes:
measure: apnea and hypopnea episodes in the recovery room detected by the ExSpiron monitor are correlated with the individual risk for obstructive sleep apnea
timeFrame: 1 - 3 hours postoperatively
Locations:
city: Boston
country: United States
facility: Tufts Medical Center
state: Massachusetts
Study officials:
affiliation: Tufts Medical Center
name: Roman Schumann, MD
role: PRINCIPAL_INVESTIGATOR
References: