Incidence of Hypercapnea in Morbidly Obese Post-Surgical Bariatric Patients Using the Sen Tec Transcutaneous PCO2 Monitor
Condition: Bariatric Patients
Study type: Observational

Summary: 
      Hypercapnea is a condition where there is too much carbon dioxide (CO2) in the blood. Carbon
      dioxide is a gaseous product of the body's metabolism and is normally expelled through the
      lungs (breathed out). Hypoventilation (or respiratory depression) occurs when the ventilation
      is inadequate to perform needed gas exchange; therefore resulting in decreased levels of
      oxygen and increased levels of carbon dioxide in the blood. It can cause an increased
      concentration of carbon dioxide and respiratory acidosis. Obesity is a multi-system disorder,
      particularly involving the respiratory (lungs/breathing) and cardiovascular (heart/vessel)
      systems. Obesity increases the risks for surgical and anesthetic complications before, during
      and following surgery.

      Bariatric (weight loss) surgery is becoming a common procedure among the morbidly obese (100
      lbs or more above normal weight), with recent studies highlighting the long-term health
      implications of surgical weight reduction, to include a decreased risk of hypertension (high
      blood pressure) and diabetes (increased sugar in blood). Obese patients are at increased risk
      of sleep apnea (stop breathing while asleep) and hypoventilation even without surgery, and
      these risks increase following administration of medications typically given during and after
      major surgical procedures. Hypoventilation can lead to hypercapnea, sedation (sleepiness),
      and acidosis (blood imbalance), resulting in further respiratory compromise (breathing
      problems) and cardiac morbidity (heart problems) as well as the risks inherent in
      re-intubating (needing to have a breathing tube place down into the lungs) the
      obese.Monitoring for hypoventilation can be difficult. Quantitative capnography (measuring
      carbon dioxide) is only appropriate for intubated patients (on a ventilator - breathing
      tube), and pulse oximetry (clip on finger that measures oxygen levels) does not adequately
      detect hypoventilation in patients receiving supplemental (additional) oxygen. Serial
      arterial blood gas (blood taken from an artery to measure oxygen level in blood) measurement
      is expensive, time-consuming, and painful. Continuous respiratory rate monitoring is
      possible, and has been considered the gold standard of apnea detection (seeing stopped
      breathing), yet is seldom used. As a result of these limitations, there is currently no
      simple, cost-effective, and reliable means of detecting hypoventilation in this patient
      population either in the recovery room or inpatient unit. Transcutaneous (across the skin)
      pCO2 (t-pCO2) monitoring has been validated as a reliable and reproducible means of measuring
      pCO2 in newborn babies, and recently has also been used in adults, primarily in the ICU
      (intensive care unit) setting. When compared to standard end-tidal CO2 measurement, t-pCO2
      correlates better with pCO2 in the intraoperative period in both thin and obese patients.
      SenTec, is the manufacturer of a device used to measure t-pCO2 for this project. This study
      is designed to detect the incidence of hypercapnea in morbidly obese post-surgical bariatric
      patients in the postoperative period using the SenTec t-pCO2 monitor.

      Objective:To determine the incidence of hypoventilation and hypercapnea as measured by
      transcutaneous pCO2 monitoring in post-surgical bariatric patients as compared to thin
      controls.
    


Intervention name(s): Sentec monitoring device; sentec monitor
Intervention type(s): Device; Device
Intervention description(s): Sentec monitor applied transcutaneously to forehead; transcutaneous monitoring
Other intervention name(s): Sentec monitoring device
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        10 morbidly obese post surgical laparoscopic bariatric patients and 10 thin subjects
        undergoing laparoscopic procedures