Non Invasive End Tidal Carbon Dioxide Monitoring During Moderate Sedation
Condition: Carbon Dioxide
Study type: Observational [Patient Registry]

Summary: 
      CO2 monitoring through non-invasive methods at different O2 flow rates may provide an early
      warning sign of hypoventilation during procedural sedation.
    

Detailed description: 
      Sedation is a drug-induced depression in the level of consciousness. The clinical objectives
      of administering sedation for GI endoscopy are to relieve patient anxiety and discomfort,
      improve the outcome of the examination, and diminish the patient's memory of the event. A
      number of different sedatives and analgesics can be used to achieve appropriate levels of
      sedation for GI endoscopic procedures. The targeted level of sedation may vary depending on
      patient and procedural variables, and doses of sedatives should be titrated accordingly to
      achieve a safe, comfortable, and technically successful endoscopic procedure. Knowledge of
      the pharmacologic profiles of sedation agents is necessary to maximize the likelihood that
      the desired level of sedation is achieved.(1) All patients receiving sedation to facilitate
      endoscopic procedures should have monitoring of cardiorespiratory parameters before, during,
      and after administration of sedation/analgesia. Electronic monitoring may detect early signs
      of patient distress and is an adjunct to continuous clinical assessment. Commonly used
      monitoring equipment for patients undergoing endoscopic procedures includes pulse oximetry,
      single-lead continuous electrocardiographic (ECG) monitoring, and automated blood pressure
      monitoring. With the increased use of propofol to facilitate endoscopy in recent years, less
      familiar monitoring devices have been introduced, including end-tidal carbon dioxide (EtCO2)
      and level of consciousness monitors. Given a recent change in the American Society of
      Anesthesiologists (ASA) guidelines, recommending CO2 monitoring for patients undergoing both
      moderate and deep sedation, familiarity with capnography may become necessary.(2) Patients
      are at risk of respiratory depression and acute hypercapnia during sedation and recovery from
      anaesthesia . Desaturation on pulse oximetry for monitoring of hypoventilation is a late
      sign. Moreover, hypoventilation is masked by administration of supplemental O2. ( 3) For a
      sedated patient in spontaneous ventilation, hypoventilation (by airway obstruction or central
      respiratory depression) will likely precede hypoxemia. Hence, if the patient is monitored
      using a capnograph machine, when hypoventilation occurs, PEtCO2 increases and the shape of
      the capnography curve is modified.This may trigger an adequate response from the person
      monitoring the anesthesia (chin thrust, sedative dose modification, oxygen supplementation)
      so as to prevent hypoxemia. (5) Measuring CO2 noninvasively includes capnography and
      capnometry. capnography provides numerical and graphical (waveforms) forms, while capnometry
      provides only numerical form. (6) Arterial blood gas (ABG) can tell us about the patient's
      acid-base balance, which is measured by the hydrogen ion (H) concentration in the blood (pH),
      oxygen saturation (SaO2), partial pressure of oxygen (PaO2), partial pressure of carbon
      dioxide (PaCO2), concentration of bicarbonate (HCO3), base excess and base deficit.(7) ABG
      results can indicate how effectively the patient's body is compensating for the acid-base
      disturbance and whether the patient's total blood volume is adequate for transporting all the
      nutrients that the body's tissues require. (8)

      Hyopthesis of this trial: is CO2 monitoring through non-invasive methods may provide an early
      warning sign of hypoventilation during procedural sedation.

      Primary outcome: Measuring end-tidal carbon dioxide (EtCO2) that is taken during different
      flows of oxygen(O2) supplementation.

      Secondary outcome: Will include O2 saturation, haemodynamics (systolic blood pressure,
      diastolic blood pressure and mean blood pressure), time to recovery, patient satisfaction,
      Ramsay sedation scale (which is used to measure level of sedation through dividing patients
      level of sedation into 6 categories ranging from severe agitation to deep coma). (9) Ramsay
      Sedation Scale

        1. Patient is anxious and agitated or restless, or both.

        2. Patient is co-operative, oriented, and tranquil.

        3. Patient responds to commands only.

        4. Patient exhibits brisk response to light glabellar tap or loud auditory stimulus.

        5. Patient exhibits a sluggish response to light glabellar tap or loud auditory stimulus.

        6. Patient exhibits no response.
    

Intervention name(s): DualGuard
Intervention type(s): Device
Intervention description(s): DualGuard device (FlexiCare) which incorporate an endoscopy bite block with oxygen delivery and CO2 monitoring from both the mouth and nose simultaneously.
Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        : Two days before surgery, patients will visit the outpatient clinic for history taken,
        clinical assessment and explanation about the study protocol. Laboratory investigations
        will be performed and patients will be informed that they can stop participation in the
        study at any time without any loss of service.

        Patients will receive conscious sedation via propofol 1.5 mg/kg and lidocaine 1 mg/kg and
        CO2 monitored through non-invasive method.

        At the end of the procedure, all patients will recover until full consciousness regains and
        they are able to follow verbal commands. After the desired spontaneous ventilation, the
        patients will be transferred to the recovery room.
      
Keywords: Non invasive EtCO2 MONITORING