Ketamine Infusion and Hypoventilation
Condition: Hypoventilation
MeSH terms: Hypoventilation
Study type: Interventional

Summary: 
      Procedures performed under sedation have the same severity in regards to morbidity and
      mortality as procedures performed under general anesthesia1. The demand for anesthesia care
      outside the operating room has increased tremendously and it poses, according to a closed
      claim analysis, major risks to patients . Both closed claim analysis identified respiratory
      depression due to oversedation as the main risk to patients undergoing procedures under
      sedation. The major problem is that hypoventilation is only detected at very late stages in
      patients receiving supplemental oxygen. Besides the respiratory effects of hypoventilation,
      hypercapnia can also lead to hypertension, tachycardia, cardiac arrhythmias and seizures.

      The incidence of anesthetized patients with obstructive sleep apnea has increased
      substantially over the last years along with the current national obesity epidemic. These
      patients are at increased risk of hypoventilation when exposed to anesthetic drugs. The
      context of the massive increase in procedural sedation and the extremely high prevalence of
      obstructive sleep apnea poses major respiratory risks to patients and it may, in a near
      future, increase malpractice claims to anesthesiologists. The development of safer anesthesia
      regimen for sedation are, therefore, needed. The establishment of safer anesthetics regimen
      for sedation is in direct relationship with the anesthesia patient safety foundation
      priorities. It addresses peri-anesthetic safety problems for healthy patient's. It can also
      be broadly applicable and easily implemented into daily clinical care.

      Ketamine has an established effect on analgesia but the effects of ketamine on ventilation
      have not been clearly defined. The lack of validated and sensitive instruments to evaluate
      the effects of ketamine on ventilation is an important reason for the conflicting results.The
      investigators have demonstrated that the transcutaneous carbon dioxide monitor is accurate in
      detecting hypoventilation in patients undergoing deep sedation. Animal data suggest that when
      added to propofol in a sedation regimen, ketamine decreased hypoventilation when compared to
      propofol alone. It is unknown if ketamine added to a commonly used sedative agent (propofol)
      can decrease the incidence and severity of hypoventilation in patients undergoing deep
      sedation. It is also unknown if the effect of ketamine on ventilation are different in
      patients with and without obstructive sleep apnea.

      The investigators hypothesized that patients receiving ketamine and propofol will develop
      less intraoperative hypoventilation than patients receiving propofol alone. The investigators
      also hypothesized that this effect will be even greater in patients with obstructive sleep
      apnea than patients without obstructive sleep apnea.

      Significance: Respiratory depression due to oversedation was identified twice as the major
      factor responsible for claims related to anesthesia. The high prevalence of obstructive sleep
      apnea combined with more complex procedures done in outpatient settings can increase physical
      risks to patients and liability cases to anesthesiologists. The main goal of this project is
      to establish the effect of ketamine in preventing respiratory depression to patients
      undergoing procedures under sedation. If the investigators confirm the their hypothesis ,
      their findings can be valuable not only to anesthesiologist but also to other specialties (
      Emergency medicine, gastroenterologists, cardiologists, radiologists) that frequently
      performed procedural sedation. The research questions is;does ketamine prevent
      hypoventilation during deep sedation? The hypotheses is; ketamine will prevent
      hypoventilation during sedation cases.
    


Intervention name(s): Placebo; Ketamine
Intervention type(s): Drug; Drug
Intervention description(s): Placebo Comparator: Placebo
.9 normal saline infusion; Ketamine infusion .5mg/kg bolus followed by 1.5 mcg/kg/minute until end of case
Intervention MeSH terms: Ketamine
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Prevention