الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Patients undergoing orthopedic surgeries usually have musculoskeletal dysfunctions, such as unstable fractures, deformities, and traumas. The most frequent surgical procedures include open reduction with internal fixation and closed reduction with internal fixation in fractures. The goals of surgical procedures are: to improve patients’ body functions to recover their movement and stability, in addition to alleviating pain and incapacity.
Large amount of tissue injury messengers are released via manipulation of fractures, osteotomy or reaming the medullary canal of long bones, the propensity to peripheral and central hypersensitivity is great and the probability of hyperacute pain is high, and the need for analgesia is obvious.
Adequate postoperative pain treatment is not only a physiopathological issue, but also an ethical and economic one. In this way, better pain management prevents suffering, enables greater satisfaction of patients under care and reduces costs associated with possible complications that lead to longer periods of hospitalization.
The aim of modern anaesthesia is not only limited to diminish pain during surgery but to maintain this during postoperative period too.
Regional anaesthesia for lower limb has been provided by central neuraxial blockade. Local anaesthetics alone for subarachnoid block provide good operative conditions but have shorter duration of postoperative analgesia.
Anxiety is a relevant perioperative source of distress, affecting the quality of life, increasing perioperative pain perception and impairing outcome.
That is why; searching for a drug that would be effective in reducing pain and anxiety, safe from major adverse effects and can meanwhile possess an opioid-sparing potentiality.
Pregabalin, is one of these drugs that is coming into focus. It is a structural derivative of the inhibitory neurotransmitter GABA although it does not bind to its receptors or to that of benzodiazepines. It was originally developed as spasmolytic agents. Its anticonvulsant, anxiolytic and sleep-modulating utility permitted its use as adjuncts for management of generalized or partial epileptic seizures resistant to conventional therapies. Its therapeutic armamentarium was furthermore expanded over time to control chronic pain conditions as began to gain popularity also in some acute painful conditions. It is well tolerated with good safety profile, and minimal adverse events the most commonly being dizziness and somnolence.
Thus the present study was carried out to compare the effect of a single dose of pre-operative oral pregabalin 75 mg and 150 mg on duration of postoperative analgesia, analgesic consumption, anxiolytic effect, and sedative effect in patients undergoing surgery for fixation of traumatic tibial fractures under spinal anaesthesia.
The work was conducted in El Hadara University Hospital on forty five patients with ASA physical status I-II, of both sexes, BMI 18.5-30, and 18-50 years old. The patients were scheduled for fixation of traumatic tibial fractures under spinal anaesthesia. They were randomly and blindly divided into 3 groups (15 patients each) using the closed envelope technique.
• group P75: received 75 mg pregabalin capsule.
• group P150: received 150 mg pregabalin capsule.
• group P0: received matching placebo capsule.
After a written informed consent from each patient, all the patients were assessed pre-operatively by detailed history taking, complete clinical examination, and routine laboratory investigations. The concept of a visual analogue scale (VAS) for pain and anxiety were introduced to the patient. In the preoperative holding area an hour before surgery, all patients have been assessed for the level of anxiety using Visual analogue scale (VAS-A) and the degree of sedation using Ramsay Sedation Scale (RSS), then each patient received pregabalin 75 mg or 150mg or a matching placebo and were administered orally with sips of water. Then 1 hour later and before anaesthesia, anxiety and sedation were reassessed for the second time for all patients using VAS-A and RSS respectively. After entering the operating room (OR). All standard monitors were applied. Anaesthesia technique was standardized in all the groups. Spinal anesthesia has been instituted at L3-L4 interspace and a volume of 2.5-3.5 ml (according to the patient’s height and weight) of 0.5% heavy bupivacaine was injected over 30 seconds through a 25 Gauge spinal needle. Patient has been placed in the supine position immediately after spinal injection. During surgery, arterial blood pressure, heart rate, and oxygen saturation were continuously monitored. In the postoperative period, all patients received ketorolac 30mg/8 hours.
The following parameters were assessed in the present study:
1- Demographic data: as regard age, sex, body mass index and duration of surgery.
2- Postoperative pain: was assessed using the VAS. Assessment of pain began on arrival of patient to the ward, and then at 2, 4, 6,12,18,24 hours from the end of the operation. Also the time to first request and the total doses of nalbuphine required during the first 24 hours postoperatively were recorded.
3- Level of anxiety: Was assessed using visual analogue scale for anxiety (VAS-A). Assessment of anxiety was done one hour preoperatively before administration of the selected drug and one hour later before administration of the spinal anesthesia.
4- Level of sedation: was assessed with the Ramsay Sedation Scale. Assessment of sedation started on hour preoperatively before administration of the selected drug, then, immediately before administration of the spinal anesthesia after entering the OR. Then, on arrival of patient to the ward and then every 2 h till 6 hours after operation.
Results of the present work cleared that there was no statistically significant difference between the two groups as regards age, sex, body mass index or duration of surgery.
Focusing on immediate post-operative pain, current results did verify the efficacy of pregabalin 150 mg to induce significant reduction in VAS at zero time postoperatively as compared to placebo and to 75 mg dose. The reduction in VAS was pertained highly significant, lasting up to 6 hours postoperatively, then it became less significant at the interval time between12 and 24th hours post-operatively. But, regarding the 75 mg dose it showed no added benefits superior to placebo in controlling the postoperative pain. The total doses of nalbuphine consumed during the studied time postoperatively, was also significantly reduced by pregabalin 150 mg and 75 mg in comparison to control. Moreover, the time needed for initiation of first dose of nalbuphine was significantly delayed to a mean of 352±160 minutes by pregabalin 75mg and to a mean of 487±200 minutes by pregabalin 150 mg during the 24 hours post-operative period as compared to a mean of 240±101 minutes for placebo.
Regarding its anxiolytic effect, in the current study we found that pregabalin significantly decreased the preoperative anxiety.
When focusing on peri-operative sedation, current findings revealed a significant difference in Ramsay sedation score, when patients receiving single dose of 75 mg or 150mg pregabalin were compared to controls, with 150 mg pregabalin having higher sedation scores and longer effect than the 75 mg.
As a conclusion to this study:
from the primary end points assessed in this work, one can declare, that usage of a dose 150 mg of pregabalin was more effective in reducing post-operative pain intensity, and analgesic consumption and in increasing the time needed for initiation of any rescue analgesic in comparison to a dose 75 mg of pregabalin as preemptive analgesia, Both doses had a preoperative anxiolytic effect. While, the usage of a dose of 150 mg of pregabalin had a perioperative sedative effect more than a dose of 75 mg pregabalin, when neither doses caused any post-operative side effects.
Thus in light of previous conclusion, one could recommend;
1. The need for further studies evaluating the continued use of pregabalin in the postoperative period or the use of multiple doses preoperatively to achieve optimal postoperative analgesia.
2. The need for further studies to expand the use of the drug in control of post-operative pain and to decrease the use of opiates in other surgeries that are more painful or may need more analgesic consumption.
3. Further studies are needed to determine the long-term benefits, if any, of perioperative pregabalin. The real challenge in the clinical setting is not simply to minimize the dose of analgesic drug, but to minimize long-term complications and occurrence of chronic pain syndromes within weeks or months after surgery.