gabapentin on postoperative pain associated with ureteroscopy and stents insertion

Conditions: Anesthesia; Urethral Obstruction

Summary: the study's objective is to determine the efficacy of preoperative gabapentin in relieving postoperative pain, reducing opioid use and improving quality of recovery in subjects undergoing urologic surgery. investigators hypothesize that subjects receiving gabapentin will have lower pain scores, less opioid consumption and better quality of recovery as compared to subjects who are given a placebo.

approximately one hour prior to induction of anesthesia in preoperative holding area all enrolled subjects will receive po acetaminophen 650 mg, the gabapentin group will receive po gabapentin 1200 mg, while the control group will receive po placebo, with a small amount of water. upon arrival in the operating room, standard asa monitors will be applied. intraoperative, patients will receive a standardized anesthetic care. this care consists of induction with iv propofol 2mg/kg, iv fentanyl 2 mcg/kg (adjusted body weight), and iv rocuronium 0.6 mg/kg for tracheal intubation or iv succinylcholine 1mg/kg if rapid sequence induction is needed. for maintenance of general anesthesia, investigators will use sevoflurane, with the goal to maintain bp within 20% of preoperative baseline and bis 40-60. if hr \> 100/min and bis 40-60 may use iv esmolol 0.5 mg/kg. if bp and/or hr \>20% preoperative baseline, and bis 40- 60 despite above management, may titrate iv antihypertensive agents. for ponv prophylaxis, 30 min before end of surgery investigatorswill administer iv ondansetron 8mg. the time from end of surgery to extubation in or will be documented with a free text note in the emr. after extubation all patients will be transported to pacu on 2-liter oxygen by nasal cannula, which will be weaned off in the pacu. the postoperative analgesics during phase i of recovery in pacu will consist of iv hydromorphone 0.2-0.4 mg prn pain to maintain adequate pain control (nprs\<4). during phase ii of recovery patients will receive po hydromorphone 2mg tablets every 4-6 hours as needed for pain (nprs ≥ 4) and acetaminophen: 650mg po every 6 hours the following data will be collected every hour during phase i and phase ii recovery: * pain (nprs) * sedation (ramsey sedation scale) * dizziness (1- mild, 2- moderate, 3- severe) * headache yes/no if yes: nprs score ha * respiratory depression (hypoventilation/ apnea: rr \< 10 bpm., desaturation: (spo2 \< 90%) * sedated but still in pain (yes/no) * ponv yes/no * ponv receiving antiemetic treatment * time to first opioid administration (iv hydromorphone) * total amount of iv hydromorphone in pacu phase i * total amount of oral analgesic (hydromorphone) in pacu phase ii * time to meet discharge criteria from pacu phase i * time to meet discharge criteria from phase ii study research personnel will contact participants by phone or in the hospital at 24 hours and 48 hours postoperative and at approximately one week in the urology clinic. the study research personnel will ask questions regarding pain (nprs) and analgesic consumption. the ipss and qor-40 questionnaires will be administered and data will be recorded.

Eligibility criteria:
inclusion criteria: * age 18 years to 75 years * patients with obstructive kidney stones undergoing elective ureteroscopy or cystoscopy with ureteral stent placement exclusion criteria: * age less than 18 or more than 75 years * acetaminophen allergy * gabapentin allergy * hydromorphone allergy * chronic use of gabapentin * history of chronic pain (pain for \> than 3 months) * chronic renal insufficiency (creatinine \> 1.3) * seizure disorder * psychiatric disorders (medically treated) * chronic use of anticonvulsants, antidepressants, antipsychotics (use \> 3 months) * antacids ingested within 2 hours prior to surgery * history of gastric or duodenal ulcer * pregnant or lactating * inability to communicate in english