Abstract of medical phd thesis: research effectiveness of postoperative pain management of continuous wound infusion levobupivacaine 0 2% via multi hole catheter after abdominal surgery

MINISTRY OF EDUCATION AND TRAINING MINISTRY OF DEFENSE 108 INSTITUTE OF CLINICAL MEDICAL AND PHARMACEUTICAL SCIENCES LE SAU NGUYEN RESEARCH EFFECTIVENESS OF POSTOPERATIVE PAIN MANAGEM

MINISTRY OF EDUCATION AND TRAINING MINISTRY OF DEFENSE

108 INSTITUTE OF CLINICAL MEDICAL AND

PHARMACEUTICAL SCIENCES

LE SAU NGUYEN

RESEARCH EFFECTIVENESS OF POSTOPERATIVE PAIN MANAGEMENT OF CONTINUOUS WOUND INFUSION LEVOBUPIVACAINE 0.2% VIA MULTI-HOLE CATHETER

AFTER ABDOMINAL SURGERY

Specialty: Anesthesia and Critical Care

Code: 62.72.01.22

ABSTRACT OF MEDICAL PHD THESIS

Hanoi - 2020

THE THESIS WAS DONE IN: 108 INSTITUTE OF CLINICAL

MEDICAL AND PHARMACEUTICAL SCIENCES

1 Vietnam National Library

2 Library of 108 Institute of Clinical Medical and Pharmaceutical Sciences

INTRODUCTION

Postoperative pain is always a concern of both patients and physicians Postoperative pain has a great influence on the psychology and the recovery process of the patients In fact, postoperative pain has a great influence on the circulation, respiratory, digestive, endocrine systems and slow down the recovery of patients [104] Although many methods of postoperative analgesia have been applied, the postoperative pain management is still difficult because each method has different indications and contraindications [27] [76] [104]

A variety of postoperative analgesia methods have been used, of which morphine is previously considered the gold standard in pain treatment Since the 1980s, analgesia methods have been studied and applied with the desire to gradually reduce morphine use [98] Multi-modal analgesia is considered a new trend with the principle of combining different methods to improve the analgesic effect and reduce the dose, especially reducing the opioid dose [27] [104] [101]

After abdominal surgery, many analgesia methods have been applied Relieving pain caused by intravenous opioid-controlled patients is effective, but there are still many undesirable effects such

as nausea, vomiting [85] Continuous external epidural transmission is very effective However, there is a risk of dangerous events such as general spinal anesthesia, infection and central nerve damage [3] In addition, some common adverse effects of epidural anesthesia such as lowering blood pressure, inhibiting movement lead to more infusion, limiting early movement [3] [26]

Continuous infusion of anesthetic agent into the incision is a continuous method of maintaining the anesthetic agent at the surgical area The use of small multi-hole catheters increases the ability of pain relieving for the incision Continuous infusion of anesthetic agent at the incision does not affect sympathetic nerves such as spinal anesthesia, epidural anesthesia, but the effect on the incision and the whole body is also unclear [58] [60] [78] [117]

In the world, the method of analgesia by continuous infusion

of anesthetic agent into the incision through a small size multi line catheter is applied on many types of surgery such as spine surgery [33], joint surgery, inguinal bump drainage surgery, mastectomy and abdominal and thoracic surgery [33] [53] [73]

In Vietnam, there have not been any researches using hole catheters to relieve pain after abdominal surgery Therefore, we carried out this research with the following objectives:

multi-1 Comparing the abdominal postoperative analgesic effect between continuous infusion of 0.2% levobupivacaine into incision through the multi-hole catheter with the two methods: (1) intravenous morphine method controlled by the patient and (2) continuous infusion outside the epidural of levobupivacaine mixture 0.125% - fentanyl 2mcg / ml

2 Assessing the effects of three methods of postoperative analgesia on the condition of incision and restoration of digestive function

3 Determining some effects on circulation, respiration and undesirable effects of the three methods of postoperative analgesia.

Chapter 1 OVERVIEW 1.1 Abdominal postoperative Pain

1.1.1 Abdominal surgery

1.1.2 Openings to the abdomen

1.1.3 Mechanism of causing pain after abdominal surgery

Abdominal surgery is usually serious surgery, causing damage to many tissues and organizations Therefore, abdominal surgery can cause the moderate or severe pain to the patients Abdominal surgery pain has two mechanism: pain originating in the abdominal wall and pain originating from abdominal viscera [16], [36]

1.1.3.1 Mechanism of pain originating from abdominal viscera

Abdominal organs are often dominated by nerves that originate from yang plexus, including wandering nerves and some nerves from the sympathetic ganglion Several branches of the positive tangles diverge to the intestine to form the Auerback and Meissner [2] In the abdominal viscera, there are not many pain receptors of mechanical causes such as suturing, cutting… [115]

* Anemia

The mechanism of anemia that causes pain in the viscera is similar to that in other tissues, which bases on the synthesis of the final metabolic acid products or from damaged tissue, such as bradykinin, proteine-releasing enzymes, or other transmitters in nerve endings After surgery, areas of the anemia such as junctions, areas of vascular lesions are similarly affected and cause pain The extent of pain depends on the extent of anemia-induced damage [36] [121]

* Chemical stimulation

In some cases, such as perforation of an hollow viscera, acid from the stomach or digestive liquid from the small intestine will flow into the abdomen space This liquid can damage the peritoneum

so a series of stimuli will flare up and intense pain will occur In the abdominal surgery, abdominal cleaners or antiseptic solution may cause similar stimulation leading to pain sensation [36] [121]

* Spasm of hollow visceras

Spasms of hollow visceras such as the small intestine, bile duct, and ureter can cause irritation by increasing the pressure on the mechanical receptors at the end of nerve fibers At the same time, spasms also reduce tissue perfusion blood, in combination with the increased metabolism in the muscle to exacerbate the extension of pain Pain sensations from solid visceras appear to be strangled, gradually increasing in intensity to maximum and decreasing [36] [41]

* Excessive tension

If an hollow viscera is tensioned, it could be painful by stretching the tissues At the same time, it also causes compression that leads to anemia to the organ tissues, promoting pain due to tissue perfusion anemia

Anesthesia and surgery processes can cause functional bowel obstruction Stagnant circulation in the gastrointestinal tract, which can lead to excessive tension due to disrupted intestinal circulation, can also cause contractions, especially in the early stages of

restoration of gastrointestinal tract [36] [41]

1.1.3.2 Pain originating from the abdominal wall

This is the sensation of pain caused by physical injury caused by damage to the sensory nerves The damage of organ tissue stimulates the pain receptors to create the painful sensation [104]

At the abdominal wall, there are many receptors for pain, such as receptors for receiving the mechanical forces or receptors for sensing chemistry, heat, pressure, etc In surgery, it is necessary to enlarge the incision, and to move the abdominal wall for exploring as well as creating a surgical field for the surgical process Surgery caused lesions will produce pain-causing substances: kinin, histamine, serotonin, brandykinin H +, K + ions are released from the damaged cell The prostaglandin-related inflammatory substances such as PGE1, PGE2 would make receptors to be sensitive to pain [121]

Pain sensations from the incision on the abdominal wall are transmitted to the cerebral cortex by both fast and slow sensatory conductive fibers, so pain in the abdominal wall is perceived as acute, severe pain The level of pain originating from the abdominal wall is much clearer than that from viscera because the pain originating from abdominal visceras is mainly transmitted by slow pain conductive fibers [36]

1.2 Pain relief after abdominal surgery

1.4.2.2 Advantages

1.4.3 Anesthetic Agent

1.4.3.1 Effect of anesthetic agent on bacteria

1.4.3.2 Effects of anesthetic agent on wound healing

1.4.4 Catheter placement for pain control after abdominal surgery

In 1983, Thomas [38] and colleagues performed pain relieving study by catheter placement after cholecystectomy A catheter is placed between the peritoneum and muscle layer An analgesic bupivacaine 0.5%

is infused at a rate of 10ml / 4 hours for 48 hours For 3 groups of analgesia, there were catheters with bupi and n = 10, with catheters using saline with n

= 9 and no catheters with n = 10 Results showed that the opioid relating score of the anesthetic group decreased by 57% compared to the control group

In 2006, author SS Liu [78] performed a meta-analysis of 44 RCT studies with 2141 patients The statistical studies from 1983 to

2006 showed that pain relief by continuous infusion of anesthetic into the incision was performed on many types of surgeries such as thoracic surgery, abdominal surgery The author suggested that the group using continuous infusion had lower the pain threshold and fewer opioid dose

In 2012, author Marina Campolo of Center for Hydraulic and Hydraulic Mechanics, Udine University, Italy conducted an assessment on the distribution level of 4 types of multi-hole catheters used clinically as PAINfusor of Baxter, OnQ Pump by I Flow, Temena's PolyFuser Polymedic and Infiltralong by Pajunk The

results showed that the catheters of Baxter and Pajunk were able to distribute the flow better than those of I Flow and Temena [58]

Chapter 2 SUBJECTS AND METHODS 2.1 Subjects

2.1.1 Selection criteria

Patients are indicated for abdominal surgery

ASA I-III

Age: over 18 years

There are no contraindications to local anesthesia

Voluntarily participate in the study

2.1.2 Exclusion criteria

There are incisions less than 10cm and over 30cm

Are applying other methods of pain relief

The surgery time was longer than 6 hours

Having a history of using addictive drugs

Cases of complications during anesthesia and surgery Refuse to participate in the research

2.1.3 Conditions to remove from the research

The catheter is blocked during pain relief (within 72 hours) The case must be operated again

2.2 Methods

2.2.1 Research design

Prospective study, randomized clinical intervention with control

2.2.2 Sample selection and sample size

As a result of sample size calculation and research design,

we selected 3 patient groups with 40 patients each

After the selection, patients were randomized into 3 groups

Group 1: The group was relieved by continuous infusion of

0.2% levobupivacaine into the incision through a multi-hole catheter (CWI Group: Continuous Wound Infusion)

Group 2: The group was relieved by the method of

patients-control analgesia with intravenous morphine (PCA Group: Patient Controlled Analgesia)

Group 3: The group received pain relief with continuous

infusion of epidural levobupivacaine 0.125% in combination with fentanyl 2mcg / ml (CEA Group: Continuous Epidural Analgesia)

2.2.3 Proceed

2.2.3.1 Main research facilities

2.2.3.2 Patient preoperative preparation

2.2.3.3 Conduct anesthesia

2.2.3.4 Proceed with the placement of the catheter

When the surgeon performs an abdominal closure, the anesthetist cooperates with the surgeon to place the catheter into the incision

Unpack the catheter kit according to specification Use a 5ml syringe, take a diluted anesthetic with a concentration of 0.2%, expel the air from the catheter and try again to see if the catheter's openings are regular

After the peritoneal layer is sewed Use a specifically directional needle to poke through the skin, seperate 1.5-2 cm from the edge of the incision toward the tip of the needle at the site of the incision

Pass the catheter through the needle and position the catheter along the incision until the catheter end touches the other end of the incision Inject 1-2 ml of anesthetic solution, ensure that the catheter

is positioned above the peritoneal layer and the anesthetic agent is

released evenly through the catheter, and then fix the catheter to abdominal skin The catheter is fixed to the skin by stitches

Sewing the muscle layer, during the process, it must be ensured that the catheter is located between the peritoneal layer and the muscle layer Then, the surgeon sews the skin layer and organizes it under the skin

2.2.3.7 Postoperative analgesia protocol

Method of infusion the analgesia solution

Group 1: When eligible for pain relief, give bolus 5ml

levobupivacaine 0.2% Then relieve the pain for patients by continuous infusion of levobupivacaine 0.2% at rate 4-6 ml/hour, the total amount of anesthetic agent does not exceed 400 mg/24 hours Closely monitor the pulse, blood pressure, SpO2, breathing rate, clinical status Patients have pre-installed intravenous morphine PCA and use PCA morphine on demand

Group 2: When eligible for pain relief Carry out titration

with intravenous morphine The patient is then given an intravenous

morphine PCA, which performed pain relief with intravenous morphine Mix 1 mg morphine/ml solution: Put 5ml morphine 10mg/ml + 45ml natri clorid 0.9% into 50ml syringe to get morphine solution of 1 ml/ml Set the parameters after titration: The required dose is 1 ml, lockout was 10 minutes, limited was 20 ml/4 hours

Group 3: Pain relief by continuous infusion of anesthetic

agent of levobupivacaine 0.125% in combination with fentanyl 2µg/ml into NMC

The starting dose with volume is calculated based on the formula:

"Injection volume (ml) = (Height (cm) - 100) / 10"

The patients are then controled the pain by continuous infusion into the epidural space with levobupivacaine 0.125%, mixed with fentanyl

at a concentration of 2 µg/ml and adrenalin at a concentration of 5µg/ml at a rate of 4-6 ml/hour The total dose of anesthetic agents should not exceed 400mg/24 hours of levobupivacaine

2.3 Research diagram

Chapter 3 RESULTS 3.1 Characteristics of patients

The average age in the research was 56,23 ± 13,21 of which the lowest was 19 and the highest was 86 years

The average height in the research was 161,00 ± 7,19 cm, of which the lowest was 144 cm and the highest was 176 cm

The average weight in the research was 55,73 ± 8,32 kg, of which the lowest was 44 kg and the highest was 76 kg

The distributions of age, height, and weight of the 3 groups have different reduction which is not statistically significant (when comparing between 3 groups)

3.2 Postoperative analgesic effect

3.2.1 The resting VAS scores at research points

When comparing each pair of CWI and PCA, it was found that the resting VAS score was similar from H0 to H48, after 48 hours, the VAS score of CWI was lower than that of PCA When comparing the CWI and CEA groups, the resting VAS scores of the two groups are similar from the onset of pain relief to 24 hours From the 24th to the 60th hours, the resting VAS at rest of CEA group is lower than CWI group with p <0.05 From H60, resting VAS scores in two groups are different but not statistically significant

3.2.2 The activating VAS scores at research points