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: Ass Prof PhD Trinh Van Dong PhD Dang Van Khoa Reviewer: 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: National Library of Vietnam Library of 108 Institute of Clinical Medical and Pharmaceutical Sciences 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: Comparing the postoperative analgesis effect of ultrasound- guided continous thoracic paravertebral block with epidural anesthesia using bupivacaine and fentanyl after lung surgery Evaluating changes in circulation, respiratory and some undesirable effects from these two methods of postoperative pain relief Chapter 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 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 to 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 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 Chapter 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 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 > hours - Reopened - Patients not want to continue to participate in the study 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 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 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 µg/ml 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 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 ≥ points Inject b upivacaine 0.125% - fentanyl µg/ml with 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 < 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 ≥ points Inject bupivac aine 0.125% - fentanyl 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 12 3.2.2 Drug used and spread of anesthetic The total dose of bupivacaine used for 72 hours after surgery in the PVB group was 432.4 ± 75.01 mg and in the EPB group was 446.2 ± 74.53 mg The total dose of fentanyl used for 72 hours after surgery in the PVB group was 335.8 ± 58.21 µg, in the EPBl group was: 346.4 ± 57.86 µg There was no difference in the total dose of bupivacaine a nd fentanyl between the two groups The extent of the anesthetic spread after 15 minutes of injection in PVB group was 4.6 ± 0.8 vertebra, lower than EPB group: 4,9 ± 1,1 vertebra, the difference was statistically significant with p 0.05) 3.2.3 Postoperative pain level in two groups 3.2.3.1 The degree of pain when resting (VAS static ) in two groups Table 3.1 VAS scores when resting (VAS static ) in two groups Groups Times PVB (n = 51) X SD Min-Max EPB (n = 51) X SD Min-Max p H0 6.9 ± 1.4 - 10 6.5 ± 1.2 4-9 > 0.05 H1/4 3.5 ± 1.0* 2-6 3.5 ± 0.9* 2-6 > 0.05 H1/2 2.9 ± 0.8* 2-6 3.1 ± 0.7* 2-5 > 0.05 H1 2.7 ± 0.6* 2-4 2.7 ± 0.5* 2-4 > 0.05 H2 2.6 ± 0.6* 2-4 2.7 ± 0.8* 2-6 > 0.05 H4 H6 2.6 ± 0.6* 2.5 ± 0.9* 2-4 1-5 2.5 ± 0.6* 2.4 ± 0.6* 2-5 1-4 > 0.05 > 0.05 H12 2.1 ± 0.6* 1-5 2.2 ± 0.6* 1-4 > 0.05 H24 1.9 ± 0.5* 1-3 2.0 ± 0.72* 1-4 > 0.05 H48 1.6 ± 0.6* 0-3 1.7 ± 0.7* 0-3 > 0.05 H72 1.4 ± 0.8* 0-3 1.5 ± 0.8* 0-3 > 0.05 Notes: * p < 0.01 versus H0 13 Comment: The VAS static scores at the times of the study in the two groups was not statistically significant The VASstatic scores at the times of 15 minutes after injection was reduced statistically significant compared to H0 3.2.3.2 The degree of pain when dynamic (VASdyn ami c) in two groups Table 3.2 VAS score when dynamic (VAS dynamic ) in two groups Groups PVB (n = 51) X Time s SD EPB (n = 51) X Min-Max SD Min-Max p H0 8.0 ± 1.2 - 10 7.8 ± 1.1 - 10 > 0.05 H1/4 4.8 ± 0.9* 3-7 4.4 ± 0.9* 3-7 > 0.05 H1/2 3.9 ± 0.9* 3-6 3.7 ± 0.7* 3-5 > 0.05 H1 3.6 ± 0.8* 2-6 3.6 ± 0.7* 3-5 > 0.05 H2 3.4 ± 0.6* 2-5 3.4 ± 1.0* 2-8 > 0.05 H4 H6 3.1 ± 0.6* 3.1 ± 1.1* 2-4 2-7 3.2 ± 0.9* 3.0 ± 0.7* 2-7 2-5 > 0.05 > 0.05 H12 2.6 ± 0.8* 2-6 2.6 ± 0.8* 2-5 > 0.05 H24 2.4 ± 0.5* 2-4 2.5 ± 0.6* 2-5 > 0.05 H48 2.1 ± 0.6* 1-4 2.3 ± 0.6* 2-5 > 0.05 H72 2.0 ± 0.6* 1-3 2.0 ± 0.5* 1-3 > 0.05 Notes: * p < 01 versus H0 Comment: The VAS dynamic scores at the times of 15 minutes after injection onward was significantly reduced compared to H0 The VAS dynamic scores at the times of the study in the two groups was not statistically significa nt 3.2.4 Assess the levels of pain relief in two groups The level of pain relief when the patient remained still at the 14 postoperative time of the two groups was not statistica lly significant (p> 0.05) From the time of H24 onwards, the level of pain relief was good and approximately at 100% in both groups At H 48 and H 72, the proportion of patients with good a nalgesia in the PVB group was highe r than that of the EPB group, but the difference was not significant (p> 0.05) 3.2.5 Proportion of patients and additional morphin use d B ng 3.3 Percentage of patients required additional analgesia by PCA Groups PVB EPB PCA n % n % Yes 10 19,6 13,7 No 41 80,4 44 86,3 Total 51 100,0 51 100,0 p > 0,05 Comment: The percentage of patients required additional analge sia by PCA with morphin in PVB group and EPB group was not statistically significa nt Table 3.4 Total doses of additional morphin used Groups Morphin (mg) PVB EPB (n=10) (n=7) Total doses X ± SD 5.2 ± 3.6 3.7 ± 2.5 in 24 hours Min - Max - 20 - 10 Total doses X ± SD 8.6 ± 5.2 5.8 ± 4.0 in 48 hours Min - Max - 23 - 15 Total doses X ± SD 10.1 ± 6.6 8.7 ± 5.2 in 72 hours Min - Max - 23 - 16 p > 05 >0 05 > 05 15 Comment: The total doses of morphin used for additional pain relief in the two groups was not statistically significa nt 3.2.6 Characteristics of gluc ose and cortisol levels Table 3.5 Glucose levels (mmol/l) Groups PVB EPB Time s (n = 51) (n = 51) Before surgery 5.7 ± 1.0 6.1 ± 2.7 > 0.05 Before injecting drugs 8.5 ± 2.2* 8.5 ± 3.0* > 0.05 The first day after surgery 7.7 ± 2.4* 7.4 ± 3.1* > 0.05 The second day after surgery 6.7 ± 1.4* 6.3 ± 1.3 > 0.05 The third da y after surgery 6.3 ± 2.4 5.9 ± 1.3 > 0.05 p Notes: * p < 0.01 compared to before surgery Comment: The glucose leve ls at different times were not statistically significant The glucose concentration of the epidural group before injection and in the first day after surgery increased more than before surgery (p 0.05 Before injecting drugs 26.6±12.2* 28.4±11.5* > 0.05 The first day after surgery 19.6 ± 6.6* 22.6 ± 6.1* > 0.05 The second day after surgery 17.1 ± 5.4* 17.5 ± 5.3* > 0.05 The third day after surgery 15.6 ± 4.8* 14.9 ± 5.1* > 0.05 Time s Notes: * p < 0.01 versus before surgery p 16 Comment: The cortisol concentration of the two groups before the injection and after surgery increased significantly compared to before surgery At the second day after surgery, cortisol levels were lower in PVB group than in EPB group % 3.2.7 Satisfaction levels of patients of pain relief methods 100 78.5 82.3 PVB p > 0,05 EPB 80 60 17.6 15.7 40 3.9 20 Very satisfied Satisfied Satisfaction levels Unsatisfied Figure 3.1 Satisfaction le vels of pain relief methods Comment: The proportion of patients who rated from a bove satisfaction with PVB group and EPB group were 96.1% and 98% respectively There is no difference in satisfaction level between the two groups 3.3 Changes in circulation, respiratory and unwanted effects 3.3.1 Changes in circulation at the time of postoperative Heart rate after inj ection of the EPB group was higher than that of the EPB group The difference, however, was not statistically significant (p > 0.05) The average blood pressure of PVB group is higher than that of EPB group at H1 time (p < 0.01) and H (p < 0.05) At the remaining times, the difference was not statistica lly signific ant (p > 0.05) 17 3.3.2 Changes in respiratory at the time of postoperative 3.3.2.1 Changes in breathing rate and SpO2 After injection, breathing rate of EPB group wa s significantly lower than ve rsus H (p < 0.01) There was no difference in spO2 after surgery (p > 0.05) 3.3.2.2 Changes in respiratory function Ventila tion function of both groups was lower than before surgery (p 0.05) 3.3.3 Undesirable effects 10 9.8 p > 0,05 5.9 PVB EPB 5.9 3.9 Und esirable effects Poked into the blood vessels Pain at the needle position Figure 3.2 Undesirable effe cts related to technical Comment: The rate of poked into the blood vessels and pain at the needle position of the PVB group is lower than that of the EPB group, but the difference is not statistically significant No cases of pneumothorax, fold or occlusion of the catheter or infection at puncture point % 18 17.6 20 15 PVB p < 0,05 11.8 9.8 10 EPB 3.9 Hypotension Und esirable effects Respiratory inhibition Inhibition of movement Figure 3.3 Undesirable effects related to anesthetic Comment: The prevalenc e of complications of hypotension, respiratory depre ssion and inhibition of movement of the lower extremities in the EPB group was higher than versus the PVB group, the difference was statistica lly significant with p < 0.05 There were no cases of total spinal anesthesia, epidural anesthesia due to parave rtebral anesthesia or drug poisoning Proportion% 25 20 p > ,05 p > 0,05 15.7 15 7.8 10 p > 0,05 19.6 p > 0,05 15.7 11.8 9.8 5.9 7.8 Vomiting, nausea Tremor PVB Urinary retention EPB Undesirable Pruritus effects Figure 3.4 Undesirable effects related to morphin Comment: The rate of unwanted effects related to morphine family drugs such as vomiting, nausea, urinary retention, pruritus, tremor of two groups did not differ significantly 19 Chapter DISCUSSION 4.1 General char acte ristics 4.1.1 Characteristics of the research objects Our study found no significant difference in mean age, height, weight and BMI between the two groups (p> 0.05) Me n a ccount for a higher proportion than women, with no gender difference between the two groups (p > 0.05) This result is consistent with the study of Singh (2017) with the tio of male/female in groups at respectively 19/6 and 16/9 This is because the rate of patients with lung disease in men is usually higher than in women 4.1.2 Characteristics of surgery The surge ry in our study includes cutting: 41.2% and decortica tion: 58.8% There were no differences in the type of surgery between the two study groups (p> 0.05) The use of opioid drugs and the characteristics of anesthesia time, duration of surgery, pulmonary ventilation time and duration of endotracheal intubation a ffect the postoperative pain level 4.1.3 Characteristics of thoracic paravertebral block Our studies have used ultrasound-guided to locate the transverse process, paravertebral space, pleural as well as determining the distance from the skin to these anatomica l la ndmarks, therefore the success rate was relatively high 4.2 The postoperative analgesis effect of ultrasound- guided continous thoracic paravertebral block with epidural anesthesia 4.2.1 Waiting time for analgesic effect The duration of the a nalgesic effect varies depending on the 20 anesthetic technique, the conce ntration and volume of anesthesia used Acc ording to Nguyen Hong Thuy, the average waiting time for pain relief is 14.7 minutes (10-20 minutes) Hara found that she started to reduce the pain after 10 minutes For Abdallah, the average la tency is 10 minutes (10.3 - 14.3 minutes) 4.2.2 Drug used and spread of anesthetic There was no difference in the total dose of bupivacaine and fentanyl between the two gro ups The time from after the second injection onwards, the extent of the anesthetic spre ad in the two groups did not differ (p > 0.05) 4.2.3 Postoperative pain level in two groups The VAS score during both resting time and activities at the time of study of the EPB group was lower than the PVB group However, the difference was not statistically significant (p > 0.05) This result is similar to the s tudies of Pinta ric, Gulbahar In contrast, Richardson found that the VAS for rest point and c ough were significantly lower in the paravertebral anesthesia group compared with the e pidural group(p = 0.02 and 0.0001, respectively) 4.2.4 Assess the levels of pain relief in two groups The level of pain relief when the patient remained still at the postoperative time of the two groups was not statistically significant (p> 0.05) Doan Kim Huyen did not record a statistically significa nt difference in mild pain, moderate pain and severe pain between the two groups a t the study time both at rest and on exertion (p> 0.05) 4.2.5 Proportion of patients and morphin used after surgery The proportion of patients requiring analgesic supplementation with intravenous PCA morphin in the PVB group was 19.6% highe r than that of the EPBl group (13.7%), however the difference was not statistica lly significant with p > 0.05 Me anwhile, the total dose of morphine used, total times required for PCA and the number 21 of non-response times in the two groups were also not statistic ally significant (p> 0.05) Gulbahar found no difference in the need for morphine sulphate supplemental pain between the two groups 4.2.6 Characteristics of blood gluc ose and cortisol levels Blood glucose and cortisol c oncentrations at different times were not statistically significant (p > 0.05) Gulbahar's study s howed that the mean serum glucose concentration was higher post-surgery than before surgery with p = 0.001 in the PVB group and p < 0.01 in the EPB group El-Hamid sa id that there was an increase in blood cortisol levels at the postoperative time compared to before surgery and there was no differe nce in blood cortisol levels between the two groups at the corresponding times 4.2.8 Satisfaction levels of patients of pain relief methods The proportion of patients who rated from above satisfaction with PVB group was 96.1%; and that of EPB group was 98% There was no difference in satisfa ction level between the two groups (p > 0.05) Our results are consistent with Ria in, the post-opera tive satisfaction score on the average 10-points scale is points 4.3 Changes in circulation, respiratory and more undesirable effects 4.3.1 Changes in about circulation and respiratory at the time of postoperative The results of our study show that paravertebra l anesthesia is more hemodynamically stable than epidural anesthesia, which is also consistent with studies by Swati Bisht (2015), O Cucu (2005) a nd Richardson (1999) Pintaric (2011) also has similar conclusions that paravertebral anesthesia has consistently resulted in similar analgesic but hemodynamic stability compared to epidural anesthesia in patients with thoracotomy 22 After surge ry, lung ventilation function decreased significantly compared to before surgery (p < 0.01) However, rehabilitation of postoperative ventilation is better than in the PVB group This result is also consi stent with the research results of Bisht and Richardson , which state that respiratory function is better preserved in the PVB group than the EPB group Throughout the study, the pH, PCO 2, PO2 and HCO 3- index of the two groups did not differ (p > 0.05) Our results are consistent with Aly (2010), the author also commented that pH, PaO 2, PaCO of PVB group and EPB groups were similar at the postope rative time 4.3.2 Some undesirable effects Undesirable effects related to anesthesia technique of PVB group include poking into the blood vessels: 3.9%, pain at the needle position: 5.9% The effects were lower than the EPB group (5.9% and 9.8%), but the difference was not statistica lly signific ant with p > 0.05 According to Na ja, the rate of blood vessels was 6.8%, blood stasis was 2.4%, pain at the nee dle position was 1.3%, pleural perforation was 0.8% and pneumothorax was 0.5% Our te of hypotension is similar to that of El-Hamid (no respiratory depression, hypotension: 3.3% in PVB group compared to 20% in EPB group), lower than Öztürk (28% in EPB group) and highe r than the PVB group (p = 0.02) The rate of unde sirable effects related to morphine family drugs of the two groups did not differ significantly (p> 0.05) Marret found that side e ffects (nausea, vomiting, urinary retention) were less common in PVB group (30% compared with 75%, p 0.05) The percentage of patients requiring PCA and total doses of supplemental morphin in the ultrasound- guided continous thoracic paravertebral block group and the epidural group were not significantly different (p> 0.05): 19.6% and 10.1 ± 6.6 mg versus 13.7% a nd 8.7 ± 5.2 mg, respectively Thoracic paraverte bral block was less like ly to affect circulation and breathing than epidural anesthesia: the perce nta ge of patients with hypotension and respiratory depression was 3.9 and 0% ve rsus 17, 6% and 9.8% (p < 0.05) The recovery of FVC, FEV1 and PEF of the thoracic paravertebral block group was better than epidural anesthesia group (p 0.05): poke d into the blood vessels (3.9% versus 5.9%); pain at the needle position (5.9% versus 9.8%); urinary retention (7.8% ve rsus 19.6%), pruritus (11.8% versus 15.7%), corresponding to two groups 24 PROPOSALS The technique of thoracic paravertebral anesthesia should be brought into training and continuous training mate rials for Vietname se a nesthesiologist It should be used more widely to reduce postoperative pain, especially in cases when epidural anesthesia fail or is contraindicated Continue to conduct more research on the efficacy and safety of thoracic paravertebral block in general, thoracic paravertebral block under ultrasound guidance in particular in ma ny different types of surgery LIST OF PUBLISHED ARTICLE RELATING TO THESIS Tr an Thanh Trung, Trinh Van Dong, Dang Van Khoa et al (2018), “Comparing the postoperative analgesis effect after lung surgery of e pidural anesthesia with Ultrasound- guided continous thoracic paraverte bral block”, Jounal of 108 – Clinic al Medicine and Pharmacy, (13), pp 81-87 Tran Thanh Trung, Trinh Van Dong, Dang Van Khoa (2018), “Changes in circulation and respiration of ultrasoundguided continuous paravertebral block versus continuous thoracic epidural for pain relief after lung surgery”, Journal of Practical Medicine, (1075), pp 271-276 Tran Thanh Trung, Trinh Van Dong, Dang Van Khoa (2018), “The side effects of ultrasound - guided continous thoracic paravertebral block for pain relief after lung surgery”, Journal of Practical Medicine, (1075), pp 276 -280 ... combination of 0.125% bupivacain - fentanyl 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... ultrasound- guided continous thoracic paravertebral block with epidural anesthesia using bupivacaine and fentanyl after lung surgery Evaluating changes in circulation, respiratory and some undesirable... 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