Conditions: Postoperative Pain
Keywords: Visual analog pain score Length of stay Hospital Cost Subpleural pain catheter Bupivacaine
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 83
Healthy volunteers: no

Brief summary:
Rationale: For the past 3 years the investigators have routinely used an axial subpleural tunneling technique that del

Study Design: All patients over the age of 18 having an isolated thoracoscopic procedure performed at Inova Fairfax Hospital for therapeutic or diagnostics purposes will be screened. Patients will be excluded if they have: previous ipsilateral thoracic surgery, need for operative pleurectomy or pleurodesis, chronic use of pain medication, sedatives or hypnotics, drug allergies, liver dysfunction, renal dysfunction, history of peptic ulcerative disease, sleep apnea in need of Bipap, severe chronic obstructive pulmonary disease (COPD), inability to consent, or are pregnant. All patients included will be screened, consented, and operated on by the one year anniversary of institutional review board (IRB) approval.

Study Methodology: Eighty-six consented patients will be randomized into the study arm (use of a pain catheter with 0.125% bupivacaine) or the standard of care group (no pain catheter). The primary outcome is the use of narcotic pain medication post-operatively, compared between study groups. Secondary outcomes will include postoperative pain scores, hospital and length of stay.

The On-Q pump delivers local anesthetic to the intercostal space, without leakage elsewhere, creating a functional multi level rib block. Despite positive subjective results, objective data is lacking. The investigators have also noted that some patients develop an annoying short term paresthesia that has been minimized by using lower anesthetic concentrations than described in other publications.

Objectives: To evaluate visual analog pain scores post-operatively up to 30 days post-operative, and to determine any association between pain management and length of stay.

Study Type: A prospective randomized 2-arm study will be performed. Statistical Methodology: Total amount of narcotic pain medication administered through postoperative day 7, will be compared between the study groups using student's t-tests and Wilcoxon rank-sum tests. Secondary outcomes, overall sum of pain scores through postoperative day 7, then at day 30 post-operatively, hospital length of stay, and overall hospital cost, will also be compared among study groups using student's t-tests and Wilcoxon rank-sum tests.

Detailed description:
Video-Assisted Thoracic Surgery (VATS) has been shown to hasten patient recovery by attenuating the physiologic stress of surgery and decreasing post-operative pain. Despite this approach, incisions in the chest are proportionally more painful than in other parts of the body, and most patients require some form of narcotic pain medication.

Multiple strategies for post-operative pain control have been attempted in thoracic surgery with no obvious superiority of one versus another. Pain catheters have been increasingly used over the past decade in different surgical procedures in order to minimize incisional pain for the first 3 to 7 days after an operation. The published literature is equivocal as to the efficacy of such approach following thoracic surgery with most recent series reporting no benefit in the use of these catheters. Of utmost importance is the placement techniques described thus far, which in our opinion, have been suboptimal.

In order for a pain catheter to work, the infused local anesthetic has to constantly bathe the nerve in question thus preventing painful stimuli from being transmitted. It is hard to dispute the ability of local anesthetic to block pain conduction. Consequently, the success of the intervention is directly dependent on the placement technique to achieve such goal, hence the rationale for our study.

Arms:
arm 1: Patients in this arm will receive the standard acute pain management regimen during hospital admission and will be sent home after discharge with a subpleural pain catheter and instructions for removal when pump is empty (around 5 days time). The catheter will contain an infusion of 0.125% bupivacaine. The single lumen pain catheter is infused by a self deflating pump filled to 335ml, which delivers the infusate at a rate of 4ml/h. Pumps are expected to be empty in 4 to 5 days. arm 2: Patients in this arm will not receive a pain catheter in addition to the standard of care for pain management. Standard of care will consist of a standard balanced anesthetic consisting of midazolam 0.01-0.03mg/kg, induced with propofol (1-2mg/kg) or etomidate, fentanyl (1-2 mcg/kg) and rocuronium (0.1mg/kg) and maintained on a potent inhalation agent (sevoflurane 1.5%-2.5%) during procedures. Prior to emergence from anesthesia, patients will receive ketorolac 30mg IV once, neuromuscular reversal agents, and an antiemetic (ondansetron 4mg). Patients will also be given additional narcotics (fentanyl) upon emergence, as needed, to facilitate patient comfort and extubation.

The ASA guidelines for acute pain management in the perioperative period will also be provided. Patients shall receive 1,000 mg of acetaminophen orally every 6 hours, scheduled for 5 days. Other drugs will be given on as needed basis (PRN) to maintain an analog pain scale of ≤ 3.

Interventions: intervention 1: Subpleural pain catheter with infusion of 0.125% bupivacaine intervention 2: Standard acute pain management
Intervention descriptions: intervention 1: Patients in this arm will be provided with a subpleural pain catheter and instructions for removal when pump is empty (around 5 days time). The catheter will contain an infusion of 0.125% bupivacaine. The single lumen pain catheter is infused by a self deflating pump filled to 335ml, which delivers the infusate at a rate of 4ml/h. Pumps are expected to be empty in 4 to 5 days. intervention 2: A standard balanced anesthetic consisting of midazolam 0.01-0.03mg/kg, induced with propofol (1-2mg/kg) or etomidate, fentanyl (1-2 mcg/kg) and rocuronium (0.1mg/kg) and a potent inhalation agent (sevoflurane 1.5%-2.5%) during procedures.

Prior to emergence from anesthesia, patients will receive ketorolac 30mg IV, neuromuscular reversal agents, and ondansetron 4mg. Fentanyl will be given, as needed, to facilitate patient comfort and extubation.

The ASA guidelines for acute pain management in the perioperative period will be followed. Patients shall receive 1,000 mg of acetaminophen orally every 6 hours, scheduled for 5 days. Other drugs will be given on as needed basis (PRN) to maintain an analog pain scale of ≤ 3.

Protocol document: