Comparison of different doses of injection Bupernorphine with intrathecal injection Ropivacaine in Cesarean section patients.

Spinal Anaesthesia is the method of choice for caesarean section especially in casc of clective procedures because it avoids the most common risks associated with G cneral Anacsthesia such as aspiration, difficult intubation and negative effccts of general anaesthetics on the fetus. However, certain side effects may also result from spinal anaesthesia, common being hypotension caused by the preganglionic sympathetic block. A decrease in systolic pressure can compromise uterine blood flow and fetal circulation, and thus cause fetal hypoxia and acidosis

Ropivacaine has been introduced for clinical use in 1996 (2009 in India). It isa amide pure S-type I-hydrochloric acid isomer and has low central nervous system toxicity and cardiotoxicity. In moderate drug concentrations, ropivacaine can produce the separation of mctor and sensory nerve block , Domestic studies have shown that a total dose of 10-22.5 mg of 0.5% ropivacaine is safe and reliable, and a lower dose should be selccted for older patients . This anesthesia scheme has the advantages ,of satisfactory analgesia, stabłe intraoperative hemodynamics, a low incidence of postoperative complications and early ambulation postoperatively"".

Opioids remain the mainstay among the various adjuvants to local anesthetics (LAs) in SAB primarily by virtue of its various properties such as reducing thc dose cf LA, minimizing side cffects, and prolonging the duration of anesthesia. American Society of Anesthesiologists (ASA) recommends neuraxial opioids over intermittent administration of parcntcral opioids for postoperative anaigesia after neuraxial anesthesia for caesarcan section." As sInaller doses are used intrathecally, neonatal drug transfer is negligible conıpared to epidural or parenterai opioids*". To overcome disadvantages like spinal hypotension and shivcring many kind of adjuvants have been used intrathecally like fentany sufentanil, dexmedetomidine0, buprenorphine,,,), Nalbuphine,0 clonidine etc. for spinal anaesthesia in LSCS patients. Different additives have been used to improve the efficacy of intrathecal Ropivacaine. However these adjuvants ure associated with urdesired side effects.

Buprenorphine is an agonist-artagonist opioid, about thirty times more potent tỉhan morplıine. It is a -centrally acting iipid soluble analog of the alkaloid thebainc with both spina! and supraspinal coinpoıents of anaigesia. In addition, it has a ceiling cfiect on respiratory depression but not on analgesia. The antihyperalgesic property of buprencrphine helps in preventing centra! sensitization. Its high lipid solubity, high affinity for epioid receptors, and long duration of action makes buprenorphine a good choice as an adjuvant to intrahecal LA for managing moderate to severe postoperat:ve pain. Buprenorphine is readily available as a preservative-free preparation which is compatible with the cerebrospinal fluid (CSr). Intrathecal doses (30 ug-150 ug) arc much smaller than parenieral doses and are known to prolong analgesia without sensory or motor blockade. Being more lipophilic than morphine, buprenorphine has low medullary bioavailability after neuraxial administration so that the occurrence of side cffects is lesser, making it an attractive altenative2)

Postoperative pain is a major causc of fear and anxiety in hospitalized patients and so if patients reinain pain-free during this period, they can cooperate with the circumstances well, leading to early recovery. Over the last two decades, there has been considerable revival of interest in the use of regional anesthesia techniques for surgery and pain management. Yet a gold standard method has not been determined which will have all desired effects during caeserean section without much of adverse effects on maternal and neonatal morbidity.

In this study, optimal dose of Bupcrnorphine which provides a balance betwecn analgesia and adverse effects was been studied in patients for cesarean section. The aim of this study was to compare the efficacy of two doscs uf buprenorphine (30 ug and 60 ug) as an adjuvant to hyperbaric Ropivacaine for postopcrative analgesia in cesarean section. The side cffect profile of neuraxial buprenorphine on the mother and the newbom in the early postopcrative period was also assessed.