Postoperative Pain

Introduction Major open abdominal surgeries often result in moderate to severe pain during the first 24-48 hours postoperatively. Epidural analgesia is effective in managing pain for open abdominal and thoracic surgeries during this immediate postoperative period and is considered the gold standard in accelerated rehabilitation protocols. The effectiveness of this pain relief method depends on the precise placement of the catheter in the epidural space. Since the procedure is performed blindly and relies on the anesthesiologist's skill, coupled with variations in anatomical structures, the failure rate of catheter placement ranges from 12% to 30%. Identifying catheter misplacement early in the postoperative period is challenging, as residual anesthetic effects may mask its ineffectiveness if the catheter is positioned outside the epidural space. This challenge can result in uncontrolled postoperative pain later on. Given the inherent difficulties in catheter placement and the limitations of relying on indirect anatomical assessment and sensory cues, even experienced clinicians may find epidural catheter insertion challenging. Sensory testing and patient-reported pain scores, while useful, do not consistently offer objective confirmation of correct catheter placement. Therefore, more practical and objective methods are needed. Ultrasound Techniques Color Doppler ultrasound, which visualizes fluid dynamics and flow direction, and M-mode ultrasound, which provides grayscale images of movement, could offer valuable insights. When fluid is injected into a confined space like the epidural space, it is expected to create turbulence, which would appear as a burst of color on the Doppler image. This turbulence arises because the fluid encounters resistance as it moves through the narrow epidural space. Although studies have demonstrated the reliability of color Doppler ultrasound for visualizing fluid flow through a needle in the caudal space in both adults and children, this does not directly translate to assessing catheter placement in the lumbar epidural space. For example, case series by Riveros-Pérez et al. and Elsharkawy et al. reported that only 37% and 68% of epidural catheter tips were visible in the posterior complex using color Doppler, respectively. Studies have shown mixed results regarding their effectiveness, and their application to detecting catheter placement in the lumbar epidural space has yet to be fully established. M-mode ultrasound, on the other hand, emits a single beam of ultrasound that traverses various structures, generating echoes that provide information on the mobility of different areas. This mode produces grayscale images where movement can be observed. Epidurography Epidurography, performed using radiographs, computed tomography, or fluoroscopy, remains the gold standard for verifying catheter placement when analgesia fails. This technique involves injecting an iodinated contrast agent through the catheter into the epidural space. The distribution of the contrast medium allows for visualization of the catheter's placement and verification of the correct vertebral level. Although epidurography provides definitive confirmation of catheter placement and helps mitigate patient dissatisfaction due to analgesic failure, it is less practical in the surgical setting due to the bulky equipment and the complexity of the procedure. Safety of Contrast Medium in Epidurography Epidurography, which utilizes fluoroscopy, has been employed for several decades by interventional pain specialists. The incidence of adverse effects related to the contrast medium is extremely low, approximately 0.007%, due to the minimal volume of contrast required for the procedure. Typically, epidurography involves the injection of 3 to 5 ml of iodinated contrast agent with a concentration of 240 mg/ml to verify accurate epidural placement. The rate of allergic reactions to iodinated contrast agents used in CT scans is estimated at around 0.6%, with severe reactions occurring in approximately 0.04% of cases. Most reactions are mild and can be managed or prevented with corticosteroids or small doses of adrenaline. Radiation Exposure in Epidurography Radiation exposure is a critical consideration in ensuring patient safety. The effective radiation dose from fluoroscopic epidurography is approximately 1 mSv for a procedure lasting about 60 seconds. This dose is comparable to 10 days of natural background radiation exposure. It is important to monitor both the duration of the procedure and the total radiation dose administered, which can be recorded by the imaging equipment. Despite its extensive use and low-risk profile in interventional pain management, epidurography is not ideal for intraoperative settings, underscoring the need for more practical, real-time methods to ensure effective epidural analgesia. Justification The literature has not yet established a systematic, objective method for evaluating the positioning of epidural catheters within the epidural space. Current research is exploring whether color Doppler and M-mode ultrasound could serve as reliable diagnostic tools for confirming correct catheter placement. Although alternative techniques like epidurography are available, they are less favored due to their requirement for bulky equipment and the exposure of patients to ionizing radiation. In contrast, ultrasound is a non-invasive and patient-safe option that is easy to learn and perform, offering high sensitivity and specificity. Problem Statement In major abdominal surgeries performed under general anesthesia, combining epidural techniques with general anesthesia complicates the early evaluation of the catheter's sensory and analgesic blockade. This difficulty arises because residual pharmacological and anesthetic effects can alter the effectiveness of the neuraxial blockade analysis postoperatively. Delayed assessment of epidural analgesia can lead to significant issues in patient recovery, particularly due to the context-sensitive half-life of anesthetics and opioids, which may result in unmanaged pain hours later. Hypothesis Research Question: What is the diagnostic accuracy of using ultrasound with Color Doppler Mode and M Mode for detecting the location of the epidural catheter in the epidural space compared to epidurography? Null Hypothesis (H0): The diagnostic accuracy of ultrasound using Color Doppler Mode and M Mode for detecting the location of the epidural catheter is less than 15% of the sensitivity of epidurography. Alternative Hypothesis (H1): The diagnostic accuracy of ultrasound using Color Doppler Mode and M Mode for detecting the location of the epidural catheter is at least 15% of the sensitivity of epidurography. Objectives Main Objective: Evaluate and compare the diagnostic accuracy of ultrasound using M-mode and color Doppler mode for locating the epidural catheter against epidurography. Specific Objectives: * Document and analyze demographic characteristics. * Compare sonoanatomical distances and catheter positioning as determined by ultrasound in 2D Mode, M-mode, and color Doppler mode with those identified by epidurography. * Determine and compare the diagnostic accuracy of ultrasound versus epidurography. * Assess clinical and sensory block correlation with sensory tests and ultrasound findings. * Measure analgesic efficacy using the verbal numerical scale (0-10) and the PAIN OUT international questionnaire (POD1). Methods This study, approved by the Research and Ethics Committee of the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, will be conducted at this tertiary hospital in Mexico City. This is a prospective, observational diagnostic test study aimed at evaluating and comparing the diagnostic accuracy of ultrasound (M-mode and color Doppler) versus epidurography for locating the epidural catheter. The study will involve the use of epidurography and ultrasound for each patient to assess diagnostic accuracy and is designed as a comparative study. Eligible patients will be provided with a detailed explanation of the study and will be required to sign written informed consent before participation. Universe: Patients undergoing abdominal surgery requiring an epidural block for postoperative analgesia. Observation Units: Each patient scheduled for abdominal surgery requiring an epidural block. Sampling Method: Recruitment based on the need for an epidural block for postoperative analgesia. Data Collection Ultrasound and Epidurography While the patient remains in the post-anesthesia care unit (PACU), an initial ultrasound assessment will be conducted by a trained anesthesiologist from the acute pain service. This scan will last between 15 and 30 minutes, and the observer will record the findings using a Google Form. Upon discharge from the PACU, an epidurography will be performed in the radiology department, where a radiologist and an interventional pain physician will be available to conduct and interpret the results of the epidurography. Following the epidurography, another ultrasound scan will be conducted by a second trained anesthesiologist from the acute pain service to evaluate interobserver variability. Sensitivity Assessment Within the first 6 hours post-procedure, the acute pain management team will evaluate the sensitivity of the dermatomes corresponding to the surgical wound on the abdominal wall at the bedside. Two methods will be employed for this sensitivity assessment: pinprick (using a blunt needle for point stimulation) and cold pressure (applying a cotton swab with alcohol). These assessments will be conducted symmetrically, beginning with the T5 dermatome and progressing in a caudal direction along the abdominal wall to define the region of reduced sensitivity. Assessment of Pain at Rest and Dynamic Pain To evaluate pain characteristics and patient satisfaction, the international PAIN OUT questionnaire will be administered 24 hours after the procedure. This questionnaire will help in assessing both pain at rest and dynamic pain levels experienced by the patient. Scanning Protocol: A scanning protocol, developed and refined since January 2023, will be followed for the study. This protocol outlines the methodology for performing the ultrasound scans in our Institute. Ultrasound with Color Doppler Mode and M-Mode: A Sonosite Nanomax ultrasound device equipped with a 2-5 MHz curved probe will be used. This device includes both Color Doppler mode and M-mode capabilities, enabling real-time visualization of the epidural catheter's position and assessment of flow distribution within the epidural space. Epidurography Equipment in the Radiology Area: Fluoroscopy equipment will be employed to perform epidurography. This involves injecting a contrast agent (Iopamidol, 3-5 milliliters) into the epidural space to obtain images that assess the catheter's positioning. Data Recording Equipment: Data will be systematically recorded using a Google Form. This system will collect and store all relevant information obtained during the study, including ultrasound data, epidurography results, and other pertinent details necessary for subsequent analysis.

This study aims to compare the effectiveness of lignocaine versus 0.2% glyceryl trinitrate (GTN) ointment as postoperative analgesics in patients who have undergone hemorrhoidectomy. Background Hemorrhoids are swollen veins in the anal region, commonly treated through Milligan-Morgan hemorrhoidectomy. Postoperative pain is a major concern, affecting mobility and delaying recovery. Various treatments have been explored to alleviate post-hemorrhoidectomy pain, including anal dilatation, NSAIDs, opioids, and topical treatments like nifedipine, botulinum toxin, lignocaine, and GTN ointment. Both GTN and lignocaine have been shown to reduce pain, but the most effective and safe option is still unclear. Study Objective To compare the outcomes of lignocaine versus 0.2% GTN ointment in reducing pain and promoting wound healing in post-hemorrhoidectomy patients. Hypothesis There is a difference in the pain relief and wound healing outcomes between lignocaine and GTN ointment in hemorrhoidectomy patients. Study Design Randomized clinical trial conducted at the Department of Surgery, Mayo Hospital, Lahore. Duration: 3-6 months after synopsis approval. Sample Size: 64 patients (32 in each group). Inclusion Criteria: Age 18-60, both genders, Grade III/IV hemorrhoids, ASA grades I \& II. Exclusion Criteria: Allergies to lignocaine or GTN, pregnancy, concomitant perianal pathology, cardiovascular issues, use of nitrates or calcium channel blockers. Methods Participants will undergo hemorrhoidectomy under spinal anesthesia/saddle block/general anesthesia. Group A will receive lignocaine cream, and Group B will receive 0.2% GTN ointment post-operatively (applied 3 times daily). Both groups will receive standard postoperative care (sitz baths, stool softeners, and paracetamol for pain). Outcome Measures: Pain Score using Visual Analogue Scale (VAS) at various time points (6, 12, 24, 48, 72 hours; 7, 14, 21, and 28 days post-surgery). Time to complete wound healing (measured in days). Level of patient satisfaction after 6 weeks using a 5-point Likert scale. Data Analysis Data will be analyzed using SPSS. Descriptive statistics for quantitative variables (e.g., age, pain scores) and qualitative variables (e.g., gender, patient satisfaction). Independent t-tests will be used to compare outcomes between groups. A p-value \< 0.05 will be considered statistically significant. Patient Follow-Up Patients will be followed for 6 weeks post-surgery to monitor pain levels, wound healing, and satisfaction. Conclusion This trial aims to determine which topical analgesic-lignocaine or GTN ointment-is more effective for postoperative pain management and wound healing in hemorrhoidectomy patients.

A three-arm randomized clinical study will be conducted: * Group 1 (study group): Ridge preservation with "Pontic-shield" technique. * Group 2 (positive control): Ridge preservation with deproteinized bovine bone and porcine collagen membrane after tooth extraction. * Group 3 (negative control): Tooth extraction only (fresh socket). A cone-beam computed tomography will be performed prior to tooth extraction and 4 months postoperative. Radiographic changes between before and after intervention will be evaluated to asses the effectiveness of "Pontic-shield" technique.

Title: Efficacy of 2% Lidocaine Gel in Reducing Postoperative Pain and Analgesic Consumption Following Haemorrhoidectomy: A Randomized, Double-Blind, Controlled Trial Objective: To assess the effect of 2% lidocaine gel on postoperative pain intensity and analgesic consumption following haemorrhoidectomy. Study Design: This study is a single-center, randomized, double-blind, controlled trial. Patients will be randomly assigned in a 1:1 ratio to receive either 2% lidocaine gel or a non-anaesthetic water-based lubricant gel (control) using a computer-generated randomization list. The randomization will be stratified by hemorrhoid grade (III or IV). The study medication will be prepared by the hospital pharmacy and provided in identical, pre-filled syringes to ensure blinding of participants and investigators. Intervention: The intervention group will receive 5 mL of 2% lidocaine gel, while the control group will receive 5 mL of a non-anaesthetic water-based lubricant gel. The study medication will be applied to the perianal region three times per day for 7 days following surgery. Patients will be instructed on the proper application technique and will be provided with a diary to record the time and date of each application. Outcome Assessment: Postoperative pain will be assessed using a 100 mm visual analog scale (VAS), with 0 representing no pain and 100 representing the worst imaginable pain. Pain scores will be recorded at 12 and 24 hours, and 2, 3, and 7 days after surgery. Patients will also record their analgesic consumption in a diary, including the type, dose, and frequency of analgesics used. Postoperative complications, such as bleeding, infection, or urinary retention, will be assessed by the treating surgeon at each follow-up visit. Sample Size: A sample size of 222 patients (111 per group) was calculated based on a power of 80%, a significance level of 0.05, and an expected difference in mean VAS scores of 15 mm between the groups, with a standard deviation of 30 mm.

To understand the impact of thumb-tack needle therapy on postoperative sleep and recovery in patients who have undergone general anesthesia, and to explore the clinical significance of thumb-tack needle therapy in improving postoperative sleep quality, preventing postoperative sleep disorders, and promoting postoperative recovery

Multi-center, prospective, single-blind, randomized and parallel controlled trials are used to evaluate the role and impact of "digital chronic pain treatment system equipment" based on MR mixed reality technology in the clinical basic treatment of patients clinically diagnosed with chronic pain.

This is a multi-center, randomized, double-blind, placebo/active-controlled study. 405 subjects undergoing orthopedic surgery under general anesthesia are planned to be enrolled and randomized into the HSK21542 group, morphine group, and placebo group.

Methods: The investigators will perform a pilot prospective randomized double-blinded placebo-controlled trial of 60 patients undergoing major elective reconstructive spinal surgery to investigate the effect of a postoperative lidocaine infusion on the incidence and severity of postoperative delirium. Major spine surgery is defined as posterior spine fusions \>3 levels of instrumentation and fusion, which allows standardization of the level of surgical insult and postoperative analgesic requirements. The intraoperative anesthetic regimen will be standardized to consist of total intravenous anesthesia using sevoflurane, propofol, lidocaine and magnesium (institutional protocol), and fentanyl with boluses allowed per provider discretion. Patient recruitment, inclusion and exclusion criteria: All surgeons will be contacted before the start of the study to obtain their consent to allow their patients to be studied. The research team has successfully completed multiple National Institutes of Health (NIH) funded cohort and clinical trials at our institution with no surgeon refusing to participate. Eligible patients will be screened from the operating room roster to determine their eligibility. Patients will be contacted by phone or in person for preoperative evaluation. Please see the other section for inclusion and exclusion criteria. Sample Size Calculation: The recruitment will be consecutive patients meeting inclusion criteria. Reductions in opioid consumption by \~25% using intravenous lidocaine infusions have been shown to decrease opioid related side effects, but there is essentially no data linking a specific degree of opioid reduction to effects on delirium (46, 47). The most comparable published study to the investigators' proposal is work done by Kaba (2009) studying a lidocaine infusion for abdominal surgery where the average opioid reduction was \~50% (24mg +/-16.3 of piritramide in the placebo vs. 10.33mg +/- 10.33 in the treatment group). Assuming similar reduction in opioids of 50% and similar variance, the proposed sample size, 60 (30 per group), provides a power of 0.8 (alpha = 0.05) to detect a 25% decrease in the use of postoperative opioids. Randomization: Patients will be randomized utilizing block randomization by a random number generator into either placebo or treatment groups by the research pharmacist. The randomization scheme will be blinded to the researchers and patients. Anesthetic Management: The anesthetic management will be standardized. All patients will receive a general anesthetic to consisting of 50% oxygen and total intravenous anesthetics consisting of infusions of propofol (60-150 mcg/kg/min), lidocaine (1 mg/kg bolus, then 1.5 mg/kg/hr infusion), magnesium (30 mg/kg bolus, then 6 mg/kg/hr infusion), fentanyl (1 mcg/kg bolus, then 1 mcg/kg/hr infusion, prn boluses), and 0.3 Minimum Alveolar Concentration (MAC) of sevoflurane. Anesthesiologists will be requested to maintain the patient's arterial blood pressure to within 20% of their preoperative baseline using vasoactive agents. Patients will receive mechanical ventilation to maintain normocarbia. Intraoperative warming devices will be used to keep body temperature between 36-37˚C. Oxygen saturation will be maintained \>95%. Muscle relaxants will be used during tracheal intubation and only as clinically indicated at other time periods. All patients will be continuously monitored before the induction of anesthesia and during surgery with SEDline Brain Function Monitor (Masimo, Inc., Irvine CA), a standard monitor at our institution. Anesthesiologists will be asked to minimize electroencephalogram (EEG) burst suppression by adjusting the doses of anesthetic drugs since prior studies have suggested a relationship between burst suppression and postoperative delirium (48, 49). Postoperatively, but before discharge from the post anesthetic care unit or upon arrival to the intensive care unit, patients will be randomized to receive either placebo or a lidocaine infusion. Please see the other sections for a list of primary and secondary outcomes. Briefly the primary outcome is the effect of an intravenous lidocaine infusion on the incidence and severity of postoperative delirium. Secondary outcomes include intravenous lidocaine safety and tolerability, the effect of a lidocaine infusion on opioid usage, pain scores, analgesic satisfaction, opioid related side effects, and functional benefits. Statistical Analysis The investigators will use descriptive statistics to summarize the characteristics of the study population by treatment groups. The investigators will use an intention to treat paradigm in assessing the effect of the intervention on the outcomes of interest. Aim 1: To evaluate the safety of a continuous infusion of lidocaine in the first two days after surgery. The investigators will compare the proportion of patients that experienced at least one of the adverse events between the two groups using either the Fisher Exact Test or Chi Square Test as appropriate. Aim 2: To compare postoperative pain, and opioid usage between patients who receive placebo infusions vs. lidocaine infusions. All opioid doses will be converted to oral morphine equivalents. Specifically, hydromorphone and fentanyl doses will be converted to morphine equivalents using the conversion formula: 1.5 mg of hydromorphone = 10 mg of morphine equivalents, 0.1mg of fentanyl = 10 mg of morphine equivalents (56,57). The investigators will compare the average pain scores and opioids doses between the two treatment groups using two-sample t-tests or Mann-Whitney nonparametric tests if the data are not normally distributed. Aim 3: To compare the incidence of postoperative delirium between patients who receive placebo infusions vs. lidocaine infusions. Chi-square tests will be conducted to determine the association between lidocaine infusions and incident delirium. Aim 4: To compare the functional recovery of patients between patients who receive placebo infusions vs. lidocaine infusions. The investigators will compare the results of the 36-Item Short Form Health Survey (SF-36), Oswestry Disability Index (ODI), time to discharge, and ability to participate in physical therapy, using the two sample t-test or Mann-Whitney nonparametric test for continuous outcomes, and Fisher exact Test or Chi Square test for binary outcomes. Relevant biologic variables - All analyzes will include sex and ethnicity as covariates. Missing Data - Sensitivity Analyses to Assess the Effects of Missing Data: The investigators will use model-based methods, such as Heckman and Predicted mean matching models to determine the effect of missing observations for each of these reasons on the estimates. The investigators will track the number of missing responses for delirium, and upwardly adjust the sample size accordingly. This strategy may result in having to recruit and follow an additional subject per week in the second year of data collection, which is feasible. The investigators will conduct sensitivity analyses to determine the effect of missing data on the outcomes of interest.

The aim of the study is to check whether vagus nerve stimulation (VNS) combined with manual therapy (TM), given its neuroanatomical relationship with the structures involved in pain in the TMJ, is more effective in reducing pain, increasing joint range and increasing the quality ofthe patient lives than TM alone. The research team is made up of three physiotherapists. It has been decided to distribute the tasks as follows: * Physiotherapist 1 will be in charge of the treatment of all patients. * Physiotherapist 2 will be responsible for screening the sample and evaluating the study. * Physiotherapist 3 will be in charge of analyzing the results and statistics. This component of the team, being blinded and not knowing the group of origin of the patient, will be able to interpret the results without any type of convenience bias, showing absolutely transparency in the elaboration of the conclusions. Once the screening will be completed, the patients will be divided into two groups: an experimental group (TM + ENV) and a control group (TM + ENV placebo).The randomization will be carried out through the statistical program Epidat 4,237 9 obtaining two homogeneous groups. Each patient will be assigned a code with the aim that the physiotherapist who is in charge of the statistical analysis is not able to establish links between the data and the subjects to which it refers.

Surgical pain is one of the common complications after surgery, which seriously affects the recovery and treatment quality of patients. More than 20% of patients will suffer from postoperative chronic pain. According to the data of the National Bureau of Statistics, there are more than 70 million surgeries in China every year. Nerve block is one of the most commonly used methods for postoperative pain management in clinical practice. In recent years, the developing nerve block needle has gradually begun to be used in clinical practice. Compared with the ordinary non-developing nerve block needle, it may have a better effect on pain management after surgery, but whether it has a reduction effect on chronic pain after surgery is still unknown. The purpose of this study is to explore the effect of developing nerve block needle on postoperative pain, and to compare the difference between it and the common non-developing nerve block needle, so as to provide new ideas and methods for postoperative pain management.