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MINISTRY OF EDUCATION AND TRAINING MINISTRY OF DEFENCE 108 INSTITUTE OF CLINI CAL M EDICAL AND PHARMACEUTICAL SCIENCES -------------------------------------------------------- TRAN THANH TRUNG STUDYING ON THE ANALGESIC EFFICACY AFTER LUNG SURGERY OF ULTRASOUND - GUIDED CONTINOUS THORACIC PARAVERTEBRAL BlOCK WITH BUPIVACAIN - FENTANYL Speciality: Ane sthesiology Code: 62.72.01.22 ABSTRACT OF MEDICAL PHD THESIS Hanoi – 2019 THE THESIS WAS DONE IN: 108 INSTITUTE OF CLINICAL MEDICAL AN D PHARMACEUTICAL SCIENCES Supervisor: 1. Ass. Prof. PhD. Trinh Van Dong 2. PhD. Dang Van Khoa Reviewer: 1. 2. 3. This thesis will be presented at Institute Council at: 108 Institute of Clinic al Medical and Pharmaceutical Scienc es Day Month Year The thesis can be found at: 1. National Library of Vietnam 2. Library of 108 Institute of Clinical Medical and Pharmaceutical Sciences 1 INTRODUCTION Lung surgery is one of the most painful thoracotomy, so treatment of postoperative pain is needed. Many methods of pain relief after lung surgery have bee n studied and applied, of which epidural anesthesia is considered the "Gold Standard". However, epidural anesthesia can cause hypotension, nerve dama ge, and is contraindicated in patients with coagulopathy. In recent years, thoracic paravertebral block as well as ultrasound – guided thoracic paravertebral block is being acc epted as an alternative m ethod for epidural anesthesia. It is becoming increa singly common and receiving attention from anesthesiologists. There has also been an increase in studies about thora cic paravertebral block all over the world . However, methods demonstrated in these studies are not homogeneous and the varying results are causing much debate. In Vietnam, there are only a few number of studies about thoracic para vertebra l block and no study about continuous thoracic paravertebral block as well as the application of ultrasound in the thoracic paravertebral block for pain after lung surgery. Therefore, we conduct research on this topic with the aim of: 1. Comparing the postoperative analgesis effect of ultrasound- guided continous thoracic paravertebral block with epidural anesthesia using bupivacaine and fentanyl after lung surgery. 2. Evaluating changes in circulation, respiratory and some undesirable effects from these two methods of postoperative pain relief. 2 Chapter 1 OVERVIEW 1.1. Overview of lung surgery 1.1.1. Anatomy summary 1.1.2. Chest opening lines in lung surgery 1.1.3. Methods of lung surgery 1.1.3.1. According to surgery: including cutting one side of the lungs, one lobe of the lung, two lobes of the lung, a part of the lobe of the lung or part of the lung, peeled lung surgery. 1.1.3.1. In terms of surgery: including thoracotomy, video assisted thoracic surgery (VATS) and endoscopic thoracic surgery. 1.2. Pain afte r lung sur gery 1.2.1. Definition of pain: Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage. 1.2.2. The degree and duration of pain after lung surge ry 1.2.3. Pathogenesis of pain after lung surgery 1.2.4. Effects of pain after lung surgery 1.2.5. Assess the levels of postoperative pain There are many ways to assess postoperative pain levels, such as examining gluc ose, cortisol le vels, using subjective scales, however, the VAS scale (Visual Analogue Scale) is more used. 1.3. Methods of pain relief after lung surgery 1.3.1. Systemic analgesia 1.3.2. Regional analgesia: continuous infusion of anesthetic into the incision, intercostal nerve block, intrapleural analge sia, epidural block and thoracic paravertebral block. 3 1.3.3. Patient Control Analgesia (PCA) 1.3.4.Drug-free technique 1.4. Thoracic paravertebral block 1.4.1. Brief history 1.4.2. Anatomy of the thoracic paravertebral space The thoracic paravertebral space is a wedge-shaped space tha t lies on either side of the vertebral column. It is wider on the left than on the right and ílimited by: - Front wall: The parietal pleura forms. - Posterior wall: The superior costotransverse ligament, which extends from the lower border of the transverse process above to the upper border of the transverse process below. This ligament connects with intercostal membrane in the outer. - Inner wall: the back side of the vertebral body, spinal disc and split holes between the vertebrae. 1.4.3. Drugs used in the research 1.4.3.1. Bupivacain: There are many drugs used in the paravertebral block but bupivacain is the most used. It is often combined with epinephrin to detect mistaken injection into the blood vessels, reduce circulatory absorption, decrease peak plasma concentrations and prolong analgesia. 1.4.3.2. Fentanyl: Used in the paravertebral block. The volume of fentanyl concentration when combined with anesthesia is 1 to 2 µg/ml. 1.4.3.3. The spread of anesth esia in the thoracic paravertebral space Thoracic paravertebral block takes effect at the corresponding segments marrow, or it may spread to the contiguous levels above and below, causing motor, sensory a nd sympathetic blockade on one side, including primary roots that dominate the abdominal segment of the abdomen. Eason and Wyatt found that at least four intercostal spaces could be covered by a single 15-ml injection of 0.375% bupivacain. 4 1.4.4. Methods to identify the thoracic paravertebral space 1.4.4.1. Loss of resistance method: Is the landmark classic method described by Eason and Wyatt. Anatomical landmark is the transverse process of the vertebra. Using "loss-of-resistance" technique to identify the needle that has entered the thoracic paravertebral space, usually about 1-1.5cm from the shore on transverse process. 1.4.4.2. Pressure measurement method: Pressure monitors are used to determine the epidural space , which can be used to determine the thoracic paravertebral space. 1.4.4.3. Neural stimulation method 1.4.4.4. Catheters under ultrasound guidance: Ultrasound can easily locate and measure the distance from the skin to the transverse process, the leaves of pleura and the thoracic paravertebral space. Ultrasound can also show the progress of the needle, determine the exact location of a needle or catheter whether or not it is within the the thoracic paravertebral space. Therefore, thoracic paravertebral block under ultrasound guidance allows for increased safety and efficiency. 1.4.4.5. Ultrasound coordination with nerve stimulation 1.4.4.6. Enter the cavity directly during thoracotomy 1.4.5. Undesirable effects of thoracic paravertebral block - Undesirable effects related to technical problem: including blood vessels or pleural puncture, pneumothorax; nerve damage; pulmonary hemorrhage; hematoma caused by poking into the epidural space; pain in the anesthesia area; local infection and infection in the paravertebral space. folding, clogging or slipping of the catheter - Undesirable effects related to anesthesia: anesthetic intoxication, anesthetize whole spinal, hypotension, Claude Bernard Horner syndrome. - Undesirable effects related to morphin: pruritus, vomiting and nausea, respiratory failure, urinary retention, excessive sedation. 5 Chapter 2 SUBJECTS AND METHODS 2.1. Studying subjects The study was conducted on 102 patients who received post opera tive pain relie f after lung surgery, or peeled lung, with the following criteria: 2.1.1. Selection criter ia for study patients - Patients with indication to have open lung surgery on one side according to the program. - Age: ≥16 year olds. - Patients who agreed to cooperate with the doctors to conduct post-operative pain relief methods. - ASA class I or II (According to the American Society of Anesthesiologists Classification). 2.1.2. Exclusive crite rial - Patients do not agree to participate in the study. - Patients with a history of allergy to anesthesia. - Patients with diabetes or adrenal insufficiency. - Drug addicts. - Patients with a history or currently suffering from mental illness. - Patients with an infection in anesthesia needle. - Endoscopic surgery or VATS. 2.1.3. Standard to discontinue the study - Patients with surgical complications. - Patients using brea thing machine a fter surgery > 4 hours. - Reopened. - Patients do not want to continue to participate in the study. 6 2.2. Times and places of study From September 2013 to December 2017 a t the anesthesia department, Central 74 Hospital. 2.3. Research methodology 2.3.1. Research design The study was conducte d using a randomized, controlle d, clinical intervention approach. 2.3.2. Sample size and grouping 2.3.2.1. Sample size Sample size calculated based on the formula for continuous va riable resea rch has two groups of subjects: = C In which, C is a constant defined from up the consta nt table C related to and ß. From looking and , we choose C = 10.5. ES is the coefficient of influence. In this study, we selected each group of 51 patients. 2.3.2.2. Divide the research groups Patients who had determined eligibility for the study will be randomly assigned to 2 groups: pa ravertebral block (PVB) and epidural block (EPB), each group consists of 51 patients. 2.3.3. Instruments, facilities and drugs used in the study The combination of 0.125% bupivacain - fentanyl 2 µg/ml: Take 12.5 ml of bupivacain 0.5% + 0.1 mg fentanyl (2ml) to get a bupivacain and fentanyl mixture. Mix the above mixture of bupivacain a nd fentanyl with 35.5 ml of 0.9% natricloride to get a 50 mixture of anesthetic bupivacaine 0.125% - fentanyl 2 µg/ml. 7 2.3.4. Method of proceeding 2.3.4.1. Examination, counseling, guiding patients before surgery 2.3.4.2. Prepare patients at the surgery room 2.3.4.3. Conducting anesthesia and surgery All patients in the study got an endotracheal anesthesia according to a general regimen. Maintain a nesthesia with c losed-loop anesthesia system. When the skin was closed, the patient was given 1 g of paracetamol. Endotracheal tube withdrawal when qualified. 2.3.4.4. Perform pain relief * For PVB group - Insert the catheter into the paravertebral space under ultrasound guidance + Performe when patients finish surgery + Patient posture: lying on the side + Needle position: T4-5 or T5-6 or T6-7. + Use ultrasound to identify anatomical landmarks such as transverse process, pleural, para vertebral space. Insert needle into paravertebral space, check the exac t position of the needle tip on the ultrasound and then proceed with the catheter insertion. Fixed catheter with optickin and adhesive tape. - Injection of analgesic + Conditions to relieve pain: ü Patient is alert and endotracheal tube has been withdrawn. ü Normal pulse, blood pressure, SpO2. ü Patie nt answere d the question of an asse ssment of pain level with a VAS pain measurement. + Postoperative analgesic injection: Patients who met the above conditions for pain relie f and have VAS ≥ 4 points. Inject b upivacaine 0.125% - fentanyl 2 µg/ml with 8 dose of bolus 0.1 ml/kg. Then continuously infuse 0.1 ml/kg/h/24h first; followed by 0.09 ml/kg/h/24h and lastly 0.08 ml/kg/h/48 - 72h after surgery. If VAS < 4 points, examine and evaluate until VAS score ≥ 4, then proceed to the above pain relie f. Cases of ineffective pain relief (VAS score > 4): install PCA morphine intravenously. PCA s ettings: Each press (bolus): 1mg/1ml morphin; lock time: 15 minutes; maintenance dose: no; total dose limit: 10 mg/4 hours. - Time of withdrawal of the catheter: After ge tting the research data of timestamp H 72 . - Design for pain relief after catheter withdrawal : If there is still pain after removing the catheter, install the PCA morphin intravenously with the above settings * For EPB group - Insert the catheter into the epidural space ü Perform when the surgery is finished ü Patient posture: lying on the side ü Needle position: T4-5 or T5-6 or T6-7. ü Using loss of resistanc e technique - Injection of analgesic + Conditions to relieve pain: similar to PVB group. + Postoperative analgesic injection: Patients who met the above conditions for pain relief and had VAS ≥ 4 points. Inject bupivac aine 0.125% - fentanyl 2 µg/ml with bolus dose: (height-100)/10 ml. Maintain dose as PVB group. Cases of poor or ineffective pain relief: install PCA morphin intravenously. PCA settings as PVB group. - Time of catheter withdrawal and design of pain relief after catheter withdrawal: similar to PVB group.