General Surgery Department 2

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General Surgery Department 2

nd

Clinic Hospital in Kaunas

Grzegorz Stempiński

“Postoperative Epidural Anaesthesia: Effect, Side Effects and Analysis of

the Need for Additional Anaesthesia”.

Medicine Faculty VI year program

Work manager:

Edvardas Daugėla,

asist.

General Surgery Clinic.

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1. Table of content.

Summary  Page - 3

-

Acknowledgments -Conflicts of interest

-Clearance issued by the Ethics Committee

 Page - 4

Abbreviations  Page – 5

Introduction  Page – 6

Aim and Objectives  Page – 7

Literature review  Pages– (8-14)

Research methodology and methods  Page – 15

Results  Pages - (16-21)

Discussion of the results  Pages – (22-30)

Conclusions  Page – 31

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2. Summary (Lithuanian and English).

Grzegorz Stempiński

"Epidurinė analgezija po didžiųjų chirurginių intervencijų: efektyvumo ir pašalinių reiškinių retrospektyvi analizė.”

Raktažodžiai: epidurinė anestezija, skausmo vertinimas, pašaliniai reiškiniai, žarnų rezekcija, inksto šalinimas, prostatektomija.

Pristatoma epidurinės analgezijos po didžiosios chirurgijos retrospektyvi studija: efektyvumo, eigos ir pašalinių reiškinių analizė. Į studija įtrauktas 231 pacientas iš Kauno Klinikines ligonines, gydytais 2012-2015 metais. Pacientai suskirstyti į 3grupes. Į pirmą grupę įtraukti 87 pacientai po radikalios prostatektomijos. Į sekančias - 87 pacientai po abdominalinės chirurgijos ir 36 pacientai po inksto šalinimo operacijų. Tarp grupių atlikta analgezijos efektyvumo, trukmės, skausmo trukmės, pašalinių reiškinių analizė, abejų grupių panašumai ir skirtumai. Ši analizė gali pasitarnauti

pooperacinės epidurinės analgezijos eigos optimizavimui.

“Epidural analgesia after major surgery: effect and side effects retrospective analysis.”

Keywords : epidural analgesia, pain scores, side effects, colon resection, nephrectomy, prostatectomy. We conducted this retrospective study to characterize course of the epidural analgesia after major surgery: effectiveness, course parameters and side effects. Study population consisted of 231 patients from Kaunas Clinical Hospital . We collect patients from 2012, 2013, 2014, 2015 years. Patient were divided in 3 groups. In 1 st group analyzed 108 patients after radical prostatectomy. Patients after abdominal surgery (87 cases) in 2nd group and after nephrectomy 3rd group ( 36 cases) .We observe some parameters about epidural anaesthesia, duration in association with pain score, frequent side effects and overall effectiveness and differences in all group. Data analysis can help with postoperative epidural analgesia course

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3. Acknowledgments.

The author thanks to doctor Edvardas Daugėla from “General Surgery Clinic in Kaunas” for his assistance in making this research.

4. Conflicts of interest.

In this work I have no conflict of interest.

5. Clearance issued by the Ethics Committee.

This research is retrospective. We analyzed only regular hospital document (anesthesiologist reports) from last 4 years. We decided that there was not need to ask ethic committee.

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6. Abbreviations.

EA – Epidural Analgesia

PCIA – Patient controlled intravenous analgesia VAS – Visual analog scale of pain

PCEA- Patient controlled epidural analgesia IV - Intravenous

CVP - Central venous pressure PA - Pulmonary artery

ASA - American Society of Anesthesiologists APMS - Acute Pain Management Service CSF – Cerebrospinal fluid

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7. Introduction.

This research was made according retrospective observational study conducted over 4 years. We checked our patients after major surgery - prostatectomy, abdominal surgery (mainly resection of colon) and nephrectomy, who had epidural analgesia for postoperative pain relief. According to the

documentation it was easier to find the way how the patients after surgery procedure according to the VAS of pain from 0-10.

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8. Aims and objectives of the thesis.

The aim of our study - was to determine difference in patients status during epidural analgesia, pain score and side effects of epidural analgesia after major surgery.

The research task - was to analyze the data from special observation sheets, which was collected in last 4 years.

All patients after surgery procedures with epidural analgesia was visited by a anesthesiologist doctor 4 times per day. In observations sheets was insert patients VAS of pain before and 45 – 60 min, after epidural injection.

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9. Literature review.

Epidural nerve block is a significant advance in neuraxial anesthesia and analgesia. Dr. James Leonard Corning described the procedure in 1885 and Cuban anesthesiologist Manual Martinez Curbelo, in 1947, first used an epidural catheter. Epidural anesthesia, the same like spinal anesthesia, is used as firstly anesthetic for surgeries who involve the abdomen and lower extremities 1,2,3.

Epidural Anatomy.

The spinal canal contains the spinal cord, its coverings ( pia mater, arachnoid mater, dura mater, and cerebrospinal fluid). The pia mater is closely attached to the spinal cord. The dura mater is the separate, toughest, and outer covering of the spinal cord. The arachnoid membrane is a membrane interposed between the dura mater and the pia mater. It is separated from the pia mater by the subarachnoid space, which contains the cerebrospinal fluid. 4,5

The epidural space is a place, external to the dura mater and located between the dura mater and the ligamentum flavum. The epidural space is a potential space and it is filled with spongy connective tissue, fat, and blood vessels. 1,2,13,14

9.1 Figure Epidural Space and Catheter

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9 Nerves categories:

Nociceptors are peripheral nerves responsible for carrying noxious stimuli, including pain, to the central nervous system (specifically, the dorsal horn of the spinal cord). Pain impulses are transmitted by A-delta and C nerve fibers, primary sensory afferent nerves 6,7 . A-delta fibers are myelinated, large-diameter, fast-conducting fibers that transmit well-localized sharp and prickling pain. C fibers are unmyelinated small-diameter slow-conducting fibers that transmit poorly localized dull, burning, and aching pain11. When these primary afferent nociceptors are blocked, they lose their ability to conduct noxious stimuli 12,24. Epidural analgesia is one of the method which is safe and effective way to manage pain in many of patients. The area of the body affected by epidural analgesia depends on the location of the tip of the epidural catheter in relation to the sensory nerve roots and the areas they innervate (dermatome) 8,11. That's why epidural analgesia should be administered close to the spinal nerves that innervate the dermatomes that correspond with the area requiring pain relief 11,12.

Epidural analgesia is the administration of opioids and/or local anesthetics into the epidural space through the epidural catheter 10. Pain relief is achieved by administering local anesthetics and/or opioids 2. These medications can be administered by bolus injection, continuous infusion of epidural solution. Pain management is best achieved when local anesthetics and opioids are combined because they work synergistically: anesthetics reduces pain transmission and opioids block pain by impact receptors in spinal cord (dorsal horn). Mixed epidural solution provide better pain relief with fewer adverse reactions than either drug can achieve alone. All medications or solutions introduced into the epidural space must be preservative-free because preservatives are toxic to the central nervous system.

It can be used to manage pain in patients on a short-term (hours to days) or long-term (weeks to months) basis. Short-term epidural analgesia is used to manage postoperative pain, procedural pain, trauma pain, or labor pain. 14,15

Long-term epidural analgesia is used to manage persistent (chronic) pain, including cancer-related pain12.

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10 How local anesthetics work?

Local anesthetics affect spinal nerve roots by binding to sodium channels and preventing the influx of sodium ions into the nerve cells. This prevents generation of action potentials and conduction of nerve impulses, so the pain "message" can't be transmitted along the spinal nerves 1,3 .

Local anesthetics can block pain transmission all types of nerves ( with and without myelin), but some diluted anesthetics have difficulties to pass fat ( myelin) and fully block only of C fibers 6,9 . Local anesthetics prevent pain by blocking small myelinated A-delta and C nerve fibers. If larger sympathetic, sensory, and motor nerve fibers are also fully or partially blocked, the patient may experience adverse reactions. 4

 Blocking sympathetic nerve fibers may cause bradycardia and hypotension (due to vasodilation).

 Blocking sensory nerve fibers alters sensitivity to touch and temperature.

 Blocking motor nerve fibers can cause muscle weakness or paralysis15,16.

Lidocaine, bupivacaine, and ropivacaine are local anesthetics that can be administered epidurally. Lidocaine which have a quick onset but short duration of action (up to 2.5 hours), are often used to test epidural catheter placement or for bolus dosing. Bupivacaine and ropivacaine have a longer duration of action (up to 4 hours) and are the drugs of choice for a continuous epidural infusion. Epinephrine may be added to the local anesthetic to extend the duration of action. 10,11

Epidural Agents to these agents we can accept two most commonly local anesthetics for epidural anes-thesia: lipophilic local anestetic like procaine and lidocaine and hydrophilic, like bupivacaine. Lidocaine has a rapid onset of action (5–15 minutes) and lasts 1 to 2 hours, and bupivacaine has a slower onset of action (10–20 minutes) and a longer duration of action, lasting 2 to 4 hours. In general increasing the concentration of the drug while maintaining the same volume decreases the latency (time to onset of anesthesia). 13,15

Table 9.3. Description of the drugs used during epidural anaesthesia. Concentration, time of

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11 Sorting out opioid options.

Opioids administered into the epidural space work by binding to opioid receptors in the dorsal horn of the spinal cord to block transmission of the pain message to the brain. Opioids have no effect on sympathetic, sensory, or motor nerve fibers. 11,12,16

The opioids most commonly used for epidural analgesia are:

Fentanyl, and morphine. The onset of action depends on the lipid (fat) solubility of the opioid. The more lipid soluble are opioids, the faster passes through the epidural space and CSF to bind to opioid receptors.

* Fentanyl is lipophilic (lipid soluble) and has a quick onset (5 to 15 minutes) but a short duration of action (2 to 3 hours).

* Morphine is hydrophilic and has a longer time to onset (30 to 60 minutes) and duration action (up to 24 hours) 11,12,15

Mixing local anesthetic with opioids for epidural injection provide better effect in lower doses and concentrations, especially if patients need better pain relief without anesthesia events 21,22,25 .

Indications and contraindications:

EA is preferred in some clinical situations. For surgical patients, EA provides better

postoperative pain relief than systemic opioids. EA improves gastrointestinal function, reduces the risk of postoperative myocardial infarction, and may decrease the risk of postoperative mortality 4. EA may also decrease the severity of a persistent pain syndrome (such as phantom limb pain or postthoracotomy pain). 11,14,17,18 . Local anesthetic toxicity can occur with the vascular uptake or injection of local anesthetics into systemic circulation 12.

Although it's an effective analgesic technique, EA is not for all of patients 9,11,19. The need for anticoagulation may influence the decision to use epidural analgesia, depending on the type of anticoagulant and how long it's needed, because of the risk of spinal hematoma and subsequent neurologic dysfunction 20.

Local anesthetics can cause sensory and motor deficits in dermatomes that aren't meant to be blocked. They can also cause bradycardia and hypotension related to blocking the sympathetic nervous system. Epidural catheter-related problems, which are rare but serious, include insertion site infection, epidural abscess, epidural hematoma, and postdural puncture headache syndrome.

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12 Absolute contraindications for epidural analgesia:

 Patient refusal

 Infection at the proposed insertion site

 Coagulopathy

 Allergy to local anesthetics or opioids 21

Discontinuing epidural analgesia.

Epidural analgesia is discontinued when VAS of pain decreased, and the patient's pain can be controlled by others, less expensive methods, like parenteral or enteral non steroid analgesics. Epidural analgesia is discontinued when the patient is experiencing adverse reactions that outweigh the benefits, pain isn't adequately controlled, or the patient's clinical status has changed and the risk of

complications associated with maintaining epidural analgesia increases (mostly in patients requiring anticoagulation).

Adverse reactions or complications of EA can be related to the medication used or to the epidural catheter itself. Adverse reactions to opioids administered epidurally include pruritus, nausea, vomiting, urinary retention, decreased level of consciousness, dysphoria and respiratory depression30 . Late-onset respiratory depression is a risk with hydrophilic opioids (morphine and hydromorphone) 11,14,19,21

. Urinary retention can occur with both opioids and local anesthetics, especially if they're administered in the lumbar region, but this problem is not actual for urologic patients. There's a decreased risk of urinary retention when the epidural catheter is placed in the thoracic region 22. For this reason, a urinary catheter may be kept in place until the epidural therapy is discontinued19,27,28,29.

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13 Equipment which we using for epidural anaesthesia:

 Tuohy epidural needle, 18 gauge , 3.5"

Table 9.4. Tuohy epidural needle showing 1-cm marks.  Epidural catheter, 20 G

 Lidocaine 1%, 5 mL ampule, for skin infiltration

 Lidocaine 1.5% with epinephrine 1:200,000, 5 mL ampule, for epidural test dose and bolus

 Appropriate needles and syringes

 Povidone-iodine or alcohol solution

 dressing

 Transparent drape with central opening and adhesive

 Preservative-free normal saline, 10 mL (Saline is sometimes used for the loss of resistance technique. Saline is also useful to expand the epidural space and to facilitate the passage of the epidural catheter.)

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14 Other required equipment includes the following:

 Airway and resuscitation equipment, including oxygen, masks, bag-valve-mask, laryngoscopes, endotracheal tubes.

 Intravenous access supplies, including fluids and tubing.

 Procedure table.

 Cushions and pillows for support and pressure point padding.

 Step stool to support the legs.

 Monitors, including heart rate and blood pressure, pulse oximeter, invasive monitoring ability (arterial line, [CVP], [PA] catheter), capnograph (Standard monitors are applied according to [ASA] guidelines).

 Essential drugs ( atropine, ephedrine).

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10. Research methodology and methods.

Data of the patient was collected from department of General Surgery from Second Clinic Hospital in Kaunas. The research was collected during last 4 years (2012, 2013, 2014, 2015). Patients undergoing prostatectomy, abdominal surgeries mainly resection and nephrectomy. Post-operative analgesic strategy, EA related procedures, VAS of pain, side effects which we found in patients.

The patient was followed-up at least twice daily by the doctor of acute pain service as per the routine practice of APMS. Pain score, sedation score, motor block, nausea, vomiting or any other

complication related to pain management was recorded. Pain was assessed by verbal numeric rating scale of 0-10, where 0 is no pain and 10 represents worst pain. Also patients was checked according the side effects. Data was analyzed in Microsoft Excel program, according the disease and years, duration, VAS of pain. From these values was made calculation, max, min, average and diagrams.

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11. Results.

We analyze data collected in Second Clinic Hospital in Kaunas.

11.1 Prostatectomy patients group is one of disease which we analyzed. Age.

We analyze108 patients after prostatectomy. Patients age: max 76 age, minimal 41, average 62 years. Medication.

We used as analgesia: we gave to patients epidural injection 2 times per day, every12 hours. In epidural injection we always use morphine sulfate, the most often used dose 2mg ( from 2,0 – 2,5 mg) with bupivacaine 0,125 % solution till average 10 ml of total volume ( max 13 ml, minimal 10, average 10,06 ml).

Duration of epidural analgesia.

The duration depends on the severity of pain and is not exactly determined in advance. Real average of duration for our analyzed patients is 3,17 days, maximal duration 6 days, minimal duration 2 days.

Measurement of pain.

We use VAS of pain analysis. We analyzing pain before and aprox. 60min after epidural injection. VAS of pain immediately before epidural injection for our analyzed patients:

 After 1st day was: min 1,max 8, average 3,67.

 After 2nd day was: min 0, max 7, average 3,10.

 Ater 3rd day was min 0, max 7, average 2,54.

VAS of pain 60 minutes after epidural injection for our analyzed patients:

 After1st day was: min 0, max 6, average 1,57.

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17 Side effects and complications:

For analyzed group of patients we did not see any severe complications connected with epidural space infections or bleeding. Another severe complications were absent in our analyzed patients.

Adverse effect:

During our observations of patients we found patients with epidural analgesia without adverse effects: 65, Adverse effect from the highest till smallest : -itching: 31, -nausea: 12, -Vomiting: 4, -hypotension: 4, -respiratory depression: 2

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18 11.2 Abdominal surgery patients group ( mainly resection of colon).

We analyze 87 patients after abdominal surgery (mainly resection of colon). Patients age: max 82 age, minimal 32, average 64 years. Abdominal surgery patients group the average of age was highest, than in other groups.

Medication.

We used as analgesia: we gave to patients epidural injection 2 times per day, every12 hours. In epidural injection we usually use morphine sulfate 2mg ( from 2,0 – 2,5 mg) with bupivacaine 0,125 % solution till average 10 ml of total volume ( max 20 ml, minimal 5ml, average 9,89 ml).

The duration depends on the severity of pain and is not exactly determined in advance. Real average of duration for our analyzed patients is 3,23 days, maximal duration 7 days, minimal duration 2 days. Measurement of pain.

We use VAS of pain analysis. We analyzing pain before and aprox. 60min after epidural injection. VAS of pain immediately before epidural injection for our analyzed patients:

 After 1st day was: min 0 ,max 8, average 3,71.

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For analyzed group of patients we did not see any complications connected with epidural space infections or bleeding. Another severe complications were absent in our analyzed patients.

Adverse effect:

During our observations of patients we found patients with epidural analgesia without adverse effects: 65, Adverse effect from the highest till smallest: no effect: 50, -nausea: 12, -Vomiting: 8, -respiratory

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20 11.3 Nephrectomy patients group.

Age.

We analyze 36 patients after nephrectomy. Patients age: max 80 age, minimal 43, average 57 years.

Medication.

We used as analgesia: we gave to patients epidural injection 2 times per day, every12 hours. In epidural injection we usually use morphine sulfate 2mg ( from 2,0 – 2,5 mg) with bupivacaine 0,125 % solution till average 10 ml of total volume ( max 12 ml, minimal 10 ml, average 10,06 ml).

The duration depends on the severity of pain and is not exactly determined in advance. Real average of duration for our analyzed patients is 3,03 days, maximal duration 4 days, minimal duration 2 days. Measurement of pain.

We use VAS of pain analysis. We analyzing pain before and aprox. 60min after epidural injection. VAS of pain immediately before epidural injection for our analyzed patients:

 After 1st day was: min 1 ,max 8, average 3,67.

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For analyzed group of patients we did not see any complications connected with epidural space infections or bleeding. Another severe complications were absent in our analyzed patients.

Adverse effect:

During our observations of patients we found patients with epidural analgesia without adverse effects: 65, Adverse effect from the highest till smallest: -no effect: 22, -itching: 12, -nausea: 6, -Vomiting: 3, - hypotension: 1, -respiratory depression: 0

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12. Discussion of the results.

12.1 Effectiveness of post-operative analgesia:

According VAS of pain (after injection) epidural analgesia was very effective almost 97% of patients had positive effect. Not insufficient analgesia was because different cause but dose of morphine was not more than 2,5 mg, because if we will give more than 2,5 mg , the risk of respiratory depression increased.

Now we will analyzed analgetic effect data from each of our 3 groups of patients: 12.1.1 Prostatectomy group:

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23 12.1.2 Abdominal surgery group ( resection of colon).

12.1.2. Diagram Overall Effectiveness of epidural analgesia in abdominal surgery( resection of colon)

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24 12.1.3 Nephrectomy group:

12.1.3 Diagram Overall Effectiveness of epidural analgesia in nephrectomy procedure. After our calculations we can decide that most effective epidural analgesia is in prostatectomy group of patients almost 97%, and on the 2nd position is nephrectomy group of patients and the lowest effect is for abdominal surgery group of patients.

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25 12.2 Adverse-effects of analyzed group according our group of patients.

12.2.1 Prostatectomy group of patients:

12.2.1. Diagram. Adverse effect in prostatectomy group.

Diagram is showing that 55 % have epidural analgesia without side effect with highest percentage compare to other groups from our research. Main adverse effect - morphine itching 26% - is frequent, but not dangerous for patient, main manifestation - second day after surgery , we can treat this adverse effect with naloxone injection, if patient feel severe itching. 10 % of patient had nausea, and 4 % had feeling of vomiting,

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26 12.2.2 Abdominal surgery (colon resection) group of patients.

12.2.2 Diagram. Adverse effect in abdominal surgery group (mainly resection of colon). Diagram in this group of patients we did not see so many adverse effects compare with other groups. Percentage of patients with itching is lower than in other groups. We can observe that light respiratory depression is higher than in other groups.

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27 12.2.3 Nephrectomy group of patients

12.2.3 Diagram. Adverse effect in nephrectomy group.

Diagram is showing the highest percentage of itching, nausea and vomiting as a side effects compare to another group from the research.

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28 12.3 Epidural analgesia duration analysis.

In this part we analyze VAS of pain before each of epidural injection, 11-12 hours after previously performed injection. Longer duration of epidural analgesia increase the risk of complications 17,22 , increase the price of hospitalization. Additional catheter in patient body leading to patient anxiety, stress and

dissatisfaction. Nausea and vomiting can disturb patient with normal nutrition and recovery 22,23. In our group we have patients with the VAS of pain and we analyze when last epidural injection stop working. We decide that if VAS of pain is less than 3 points two times consecutive, pain in not significant and we do not need epidural analgesia for patients. If VAS of pain is less than 3 points we can use another not

dangerous, less expensive method for pain relief like NSAIDs injection or per oral administration. VAS of pain less than 3 mean that we need stop administration of epidural analgesia and remove epidural catheter. 12.3.1 Prostatectomy group:

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29 12.3.2 Abdominal surgery ( colon resection).

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30 12.3.3 Nephrectomy group of patients:

12.3.3 Diagram VAS of pain before and after injection during analgesia.

During analysis of our group of patients we decided that the 3rd day of epidural analgesia before injection was 3 points according VAS of pain (12.3.1-12.3.3 diagrams). Low pain 12 hours after the previous completed epidural injection (immediately before next injection), mean that epidural analgesia is

unnecessary and we need to stop it and use another, lighter method for postoperative pain relief become more preferred. Our group diagrams show, when last epidural injection was not really needed.

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13. Conclusions.

13.1 Effect.

According to our research we can say that EA for postoperative pain relief is very effective for our group patients, especially for patient after radical prostatectomy.

13.2 Complications and side effect.

Side effects. During 4 years we did not observe serious complications for our group patients. Overall side effects risk is high on nephrectomy group. Most popular side effects is itching and the highest percentage of this effects we can also see in nephrectomy group. Serious side effect like respiratory depression is very rare in all groups and number of that patients are clinically not significant. Low number of serious side effects show that epidural analgesia is safe for patients. 13.3 Benefits.

Epidural analgesia has been demonstrated to have several benefits after surgery, including:

 Very effective postoperative pain relief improves overall patients feeling and satisfaction after surgery procedure.

 Unsuccessful EA risk is very low, but in abdominal surgery group more than 2 times, if we compare it to prostatectomy group.

 EA safe for patients – 4 years experience without serious complications.

 Used EA medications provide pain relief without motor nerve dysfunction and severe respiratory depression.

13.4 Duration.

Analysis show that last injection usually was unnecessary for all group patients. We recommend to make shorter duration of epidural analgesia minimum 12 hours. Also we recommend more carefully check

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