1 IN TRO DUC TIO N Limit ing r isks an d complicat ions when conduct ing an esthe sia an d intensive care for elderly pat ient s is a t opical issue because in r eality t he number of elderly pat ients requirin g surgery is inc rea sing. Th e classic anesthesia is a generalized int ubat ion with anest hesia t hat sat isfies most surgeries. It is accomp anied by many vent ilat ion complicat ions, especially diff icult intubat ion an d art ificial vent ilat ion, which can easily cause lung comp licat ions. Int ubat ion anesthe sia must use muscle rela xants, so t he r isk of residual muscle rela xants aft er surgery , to use cent ral painkillers of t he whole family morphine family leads t o slow provin ce, weak cough ref lex, high risk of lung collapse and collapse P ulmonary is a serio us co mplicat ion aft er surgery , requirin g mechanical vent ilat ion to incre ase mort alit y. All this leads t o slow recovery of pat ients. Classic postoperat ive analgesia is an o pioid-intensive method. But today it is proved that t his method has many undesirable effect s because it causes respirat ory depression, addict ive. T hat ''s why mult imo dal anest hesia was born. Centr al an esthe sia (sp inal + epidural) is popular, a simple and anest hesia met hod t hat provides high efficiency and quick onset t ime. However, it s disadvantage is that it is limit ed in t ime when used as a single dose so it does not meet long-term surgery. Spina l anest hesia t echnique combined wit h epidural analgesia has overcome t his disadvant age of spinal anesthe sia alone because it is possible t o add lo nglast ing epidural drugs t o reduce pain and meet long-term surgery. Spina l anest hesia combined wit h epidural analgesia for domest ic and foreign gast rointestinal surgery is small, so we continue to research on this issue. Multi-modal analgesia combined wit h adequat e sedat ion under t he guidance o f digit ized electro encephalography via P SI is a t echnique t hat can limit int ubat ion and t he use of muscle relaxat ion. However, current ly, th ere is no r esearch in the world an d in Vietn am, conduct ing a combination of epidural spinal anest hesia in combination wit h continuous analgesia in combinat ion with sedat ion with t arget concentr at ion contro lled T CI propofo l under inst ruct ions. of electr oencephalo graphy digit ized via P SI index for lower abdomin al surgery in elderly pat ients. So we co nduct ed this st udy wit h t hree goals:
MINISTRY OF EDUCATION AND TRAINING MINISTRY OF DEFENCE 10 IN STI TU TE OF C LI NI C AL ME DI C AL A N D PHA RM A C EU TI C AL SC IE N CE S - NGUYEN MANH HO NG STUDY O N SPINAL - EPIDURAL SPINAL ANESTH ESIA EFFECT C O MBINED W ITH SEDA TIO N BY TCI PRO PO FO L UNDER TH E GUIDANCE O F DIGITIZED ELECTRO ENC EPHALO GRAPHY IN LOW ER ABDO MINAL SURGERY IN TH E ELDERLY Spe ciality: Resuscitation Anesthesia Code : 62.72.01.22 ABSTRAC T O F MEDICAL PHD THESIS Hanoi – 2020 INTRO DUCTIO N Limiting risks and complications when conducting anesthesia and intensive care for elderly patients is a topical issue because in reality the number of elderly patients requiring surgery is increasing The classic anesthesia is a generalized int ubation with anesthesia that satisfies most surgeries It is accompanied by many ventilation complications, especially difficult intubation and artificial ventilation, which can easily cause lung complications Intubation anesthesia must use muscle relaxants, so t he risk of residual muscle relaxants after surgery, to use central painkillers of the whole family morphine family leads to slow province, weak cough reflex, high risk of lung collapse and collapse Pulmonary is a serious complication after surgery, requiring mechanical ventilation to increase mortality All this leads to slow recovery of patients Classic postoperative analgesia is an opioid-intensive method But today it is proved that this method has many undesirable effects because it causes respiratory depression, addictive T hat's why multimodal anesthesia was born Central anesthesia (spinal + epidural) is popular, a simple and anesthesia method that provides high efficiency and quick onset t ime However, its disadvantage is that it is limited in time when used as a single dose so it does not meet long-term surgery Spinal anesthesia technique combined with epidural analgesia has overcome this disadvantage of spinal anesthesia alone because it is possible to add longlasting epidural drugs t o reduce pain and meet long-term surgery Spinal anesthesia combined with epidural analgesia for domestic and foreign gastrointestinal surgery is small, so we continue to research on this issue Multi-modal analgesia combined with adequate sedation under the guidance of digitized electroencephalography via P SI is a t echnique that can limit intubation and the use of muscle relaxation However, currently, there is no research in the world and in Vietnam, conducting a combination of epidural spinal anesthesia in combination with continuous analgesia in combination with sedation with target concentration controlled T CI propofol under instructions of electroencephalography digitized via PSI index for lower abdominal surgery in elderly patients So we conducted this study with three goals: Evaluating the anesthesia effect of spinal anesthetic with bupivacaine 0.5% in combination with epidural anesthesia with bupivacaine 0.2% -sufentanil 0.5mcg/ml in lower abdominal open surgery in the elderly Evaluating the sedative effect of TCI-propofol on PSI digitized electroencephalography Giving comments on the effects of spinal - epidural spinal anesthesia combined with sedation with propofol - TCI on respiration, circulation, and some undesirable effects in lower abdominal surgery in the elderly NEW CONTRIBU TIO NS O F TH E TH ESIS T he research is necessary and topical, especially when applying t he method of spinal anesthesia - epidural with T CI propofol sedation under the guidance of digitized elect roencephalography in human lower abdominal surgery elderly The topic has scientific and practical implications Proper, scientific and logical research design, reliable data and data processing, large enough patient population The technique of applying spinal-epidural anesthesia in combination with T CI sedation by propofol under the guidance of digitized electroencephalography P SI is a new technique It ensures t hat during the operation, the patient is sedated, does not know the operation is in progress, is of good insensitivity, early awareness, good quality of recovery and few unwanted effects suitable for lower abdominal surgery, especially in the elderly people This technique could completely replace t he classic endotracheal anesthesia method It helps determine the target brain concentration of propofol, with Cp = 1.98mcg/ml and Ce = 1.25mcg/ml just enough sedation with PSI = 75.27 just enough for this surgery This is the new point, the contribution of the topic to the scientific practice TH E TH ESIS STRUC TURE T he thesis consists of 124 pages Introduction: pages Chapter I Lit erature overview: 40 pages Chapter II - Research subject s and methods: 22 pages Chapter III - Results: 32 pages Chapter IV Discussion: 23 pages Conclusion: pages The t hesis has figures, 13 charts, 32 tables, 228 references (28 documents in Vietnamese and 200 documents in foreign languages) Chapte r LITERA TUR E O VERVIEW 1.1 Anatomical and physiological changes i n el de rly people relate d to anesthesia and intensive care 1.1.1 What is the elderly? The Vietnam Elderly Ordinance states that the elderly are 60 years of age or older 1.1.2 Changes in the nervous system: T he nervous system is the target organ for anesthesia In general, the brain size of the elderly decreases, the average brain weight decreases by 18% in t he 80s compared t o the 30-year-olds Decreased gray matter ratio as well as cranial index Micro, the number of nerve cells and the number of synapses, the concentration of neurotransmitters are reduced P ain thresholds increase, resulting in less need for opioid and sedative analgesics than younger people However, they are also more suscept ible to cognitive and respiratory depression 1.1.3 Changes in respiratory function: All measurable respirat ion indicators are decreasing The three mechanisms that alleviate pulmonary ventilation are: a sharp decrease in the ventilation function of the respiratory organs due to a decrease in respiratory muscle tone, stiffness of the chest (calcification of ribs joints, narrowing of t he cleft joints and variables) the form of vertebrae) reduces copliance of the chest and changes the characteristic elasticity of the lungs Ventilatory fraction imbalances and alveolar dispersion volume 1.1.4 Changes in cardiovascular function Cardiovascular function in the elderly is constantly changing: reducing vasoconstriction, reducing the number of cardiac muscle cells, reducing the response to stimulation by Beta-adrenergic, ventricular hypertrophy and reducing the number of cardiac muscle conduction cells A decrease in ventricular tone is associated with hypertrophic cardiomyopathy, making the flow of the heart very dependent on the ret urn circulation 1.1.5 Changes in renal function Renal blood vessels, glomerular filtration and altered t ubular function in the elderly For example, glomerular filtration rate drops by 50% at 80 years of age compared to at the age of 20 Elderly people are more likely to suffer from all kinds of acute kidney failure because - like other organs - kidney function is poorly adaptive with stress 1.1.6 Changes in the spine, ligaments and cerebrospinal fluid 1.1.6.1 Spine: The spine deteriorates over time Spinal degeneration is a chronic degenerative lesion of the vertebrae and disc discs and ligaments of the spine Scoliosis of the vertebrae, the edge of the medulla grows out of bone T he spinal edge muscles also contract, t he ligaments near the spine are pulled too much, making the spine deformed, making it difficult to identify the vertebrae and when conducting the spinal needle and needle epidural 1.1.6.2 Ligament systems: The intercostal ligament becomes thick and supple, making it difficult to poke T uohy needles In the elderly, the fibrous ligaments become fibrous, thickening making it difficult to puncture the spinal cord and epidural 1.1.6.3 Cerebrospinal fluid: T he amount of cerebrospinal fluid also decreases, thus slowing down t he diffusion of anesthetic 1.1.9 Pharmacological effects of drugs in the elderly: In general: Older people need a smaller amount of anesthetic than younger people This comment speaks to the relationship between age and pharmacodynamics and the pharmacokinetics of elderly anesthetics 1.2 Advantages of spinal-e pidural spinal anesthesia in surgery The technical advantage of anesthesia-epidural spinal anesthesia is Combining the advantages of both spinal anesthesia (short waiting time, strong anesthetic effect) with the advantage of epidural anesthesia (for pain relief) long) It can overcome t he case of spinal anesthesia that is not insensitive enough for surgery It meets long-term pain reduction requirements by placing catheters in epidural spaces to relieve postoperative pain, obstetric pain 1.3 Methods of assessing and controlling se dation and anesthesia 1.3.1.1 Several scales to assess sedative and clinical anesthetic OAA/S score Se dative scores for patients in intensive care room: Ramsay tranquilizer score, Cohen tranquilizer scale, Riker tranquilizer scale, RASS tranquilizer scale, Evans's PRST scale assesses clinical anesthesia sieve 1.3.1.2 Assess anesthesia, sedation by BIS BIS index is calculated based on the combination of time, frequency and spectrum of EEG and is digitized from 100 t o When anesthetic, BIS index decreases from 100 to and loss of tri cupping tends to occur when the BIS value is between 80 and 70 BIS between 40 and 60 is deep enough BIS 0,05 36 75 41 - 70 Min - Max 3.1.2 Gender Table 3.2 Patient distribution by gender Group Group Total Gender p n (rate %) n (rate %) n (rate %) Male 36 (72%) 39 (79,59%) 75 (75,76%) Female 14 (28%) 10 (20,41%) 24 (24,24%) >0,05 Total 50 (100%) 49 (100%) 99 (100%) 3.1.3 Types of surgery: Statistics show that the surgery is subcutaneous mesenteric surgery, lateral peritoneal 3.1.4 Time of surgery Table 3.5 Surgical time (minutes) Value (minute ) Group I (50) Group II (49) p 151,10 ± 53,32 147,73 ± 56,22 X SD >0,05 Min - Max 45 - 260 55 – 273 3.3.2 Evaluating the anesthesia effect of spinal anesthetic with bupivacaine 0.5% in combination with epidural anesthesia with a mixture of bupivacaine 0.2% - susfentanil 0.5mcg/ml in lower abdominal surgery in the elderly (Objective 1) 3.2.1 Sensory suppression results 12 3.2.1.1 The time of occurrence of pain relief at all levels T12, T10, , T6 , T4 Table 3.8 Time appears loss of pain sensation at all levels T12 , T10, T6 , T4 (minutes) Level Value Average (minutes) T12 2,40 ± 0,68 X SD (n = 99) Min - Max -5 T10 3,68 ± 1,08 X SD (n = 99) Min - Max -7 T6 5,51 ± 1,16 X SD (n = 99) Min - Max - 10 7,73 ± 1,74 T4 X SD (n = 37) Min - Max - 13 3.2.1.2 Prolonged time inhibits sensation at levels T 4, T6 and T10- T4: Because of the lengthy operation and abdominal surgery, we could not evaluate this time 3.2.2 Results of inhibiting movement 3.2.2.1 Time of occurrence of motor paralysis at levels (minutes) Table 3.11 Complete paralysis time at levels of groups (minutes) Level Value (minutes) Research group 2,91 ± 0,69 M1 X SD (n = 99) Min - Max 2-5 M2 4,04 ± 0,81 X SD (n = 99) Min - Max 2-7 M3 5,47 ± 1,01 X SD (n = 99) Min - Max 2-10 3.2.2.2 Number of paralyzed patients at all levels (%) Table 3.12 Number of paralyzed patients at all levels Research group Level Level I Level II Level III Number of patients 100 50 50 50 Rate 100% 100% 100% 100% 3.3 Evaluating the sedative effe ct of TCI propofol on PS I digitized ele ctroence phalography (O bje ctive 2) 3.3.1 PSI index at the level of the OAA/S through titration times Table 3.20 PSI index at the level of the OAA/S through titration times Group I Group II Level O AA/S p X SD X SD 13 54,44 ± 6,64 53,28 ± 5,01 < 0,05 n= 34 n= 64 63,22 ± 3,37 61,91 ± 4,20 < 0,01 n= 98 n= 227 75,28 ± 3,08 74,34 ± 3,27 < 0,01 n= 144 n=2 84,07 ± 3,08 81,74 ± 3,13 < 0,01 n= 237 n= 130 92,97 ± 3,75 90,76 ± 4,84 < 0,01 n= 358 n= 68 3.3.5 Correlation of PSI index with OAA/S sedative score - Correlation of PSI index with OAA/S sedative score in group I according to PSI equation = 9.63 OAA/S + 45.22 with r = 0.953, n = 816 - Correlation of PSI index with OAA/S sedative score in group II according to PSI equation = 9.66 OAA/S + 43.45 with r = 0.936, n = 658 3.3.6 Determining the correlation between PSI and Ce, Cp concentrations in the two groups 3.3.6.1 Correlation between PSI and Cp index For group I, PSI is negatively correlated with Cp with the equation PSI = 0.343Cp + 74.60, but the correlation is not statistically significant (p> 0.05) For group II, Cp has a statistically significant positive correlation with p