Intraoperative Fentanyl Dose on Respiratory Complications

Study Overview
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Brief Summary
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Fentanyl is the most commonly used opioid during anesthesia at Massachusetts General Hospital. Compared to other opioids, e.g. sulfentanil and remifentanil, fentanyl's pharmacokinetic properties are more problematic as the context sensitive half-time increases with duration of fentanyl infusion. This may lead to respiratory complications particularly in patients who receive fentanyl for surgical procedures of long duration. Considering the common use of fentanyl during surgery and its duration of action that is hard to predict during long surgical procedures, we will evaluate the association between intraoperative fentanyl dose and postoperative respiratory complications within 3 days of surgery.

Detailed Description
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Our team has conducted a series of studies to define the optimal anesthesia plan that minimizes the risk of postoperative respiratory complications. Opioids are almost always used in the perioperative management of patients undergoing surgery during anesthesia. Intraoperatively they are administered to achieve adequate surgical conditions. Opioids are respiratory depressants. They decrease dose-dependently the drive to the respiratory pump muscles and upper airway dilator muscles, which leads to respiratory acidemia and hypercapnia. Fentanyl is the most commonly used opioid during anesthesia at MGH. Compared to other opioids, e.g. sulfentanil and remifentanil, fentanyls pharmacokinetic is more problematic as the context sensitive half-life increases with duration of fentanyl administration. This may lead to respiratory complications. Considering the common use of fentanyl during surgery and its duration of action that is hard to predict during long surgical procedures, we will evaluate the association between intraoperative fentanyl dose and postoperative respiratory complications within 3 days of surgery. To account for other factors that may affect the incidence of postoperative respiratory complications, we included the following confounder model in all of our analyses: Gender Age BMI (body mass index) ASA status classification CCI (Charlson Comorbidity Index) Inhalational anesthetics as MAC Long lasting opioids as IV-morphine milligram equivalent including morphine, hydromorphone, methadone and sufentanil. Use of neuraxial anesthesia Intraoperative vasopressor dose Intraoperative NMBA (neuromuscular blocking agent) dose Intraoperative hypotension as number of minutes of an MAP (mean arterial pressure) <55 mmHG Duration of surgery Emergency status Intraoperative fluids PRBC (packed red blood cells) units Work RVU [relative value unit] Surgical service Admission type (ambulatory vs inpatient) SPORC (Score for Prediction of Postoperative Respiratory Complications) SPOSA (Score for Prediction of Obstructive Sleep Apnea) Inspiratory O2 - Fraction Protective ventilation (defined as PEEP=5 and plateau pressure between 0 and 16) Perioperative naloxone use Prescription of any of the following opioids within 90 days prior to surgery: oxycodone, codeine, hydrocodone, buprenorphine, butorphanol, opium, hydromorphone, fentanyl, meperidine, morphine, levorphanol, methadone, nalbuphine, tapentadol, oxymorphone, roxicodone, tramadol Code status (DNR)

Official Title
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Effects of Intraoperative Fentanyl Dose on Postoperative Respiratory Complications

Conditions
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Fentanyl, Opioid Use, Surgery, Respiratory Complication

Intervention / Treatment
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* Drug: Fentanyl dose administration


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Surgical patients at Massachusetts General Hospital and two affiliated community hospitals 18 years of age and older Only patients who required general anesthesia with an endotracheal tube for the surgical procedure and were extubated in the operating room at the end of the procedure. Exclusion Criteria: Brain dead patients (ASA greater than 5)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Reference group<br>No fentanyl dose administered during surgery | Drug: Fentanyl dose administration<br> <br> |
| Comparative group<br>Fentanyl dose administered during surgery | Drug: Fentanyl dose administration<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postoperative respiratory complications | New postoperative respiratory complications occuring within 3 days after surgery | Between the day of surgery and the third day after surgery |