Brief Summary
Modification(s)
|
INTRODUCTION Spinal anesthesia also called subarachnoid block, is a form of neuraxial anesthesia involving the injection of local anesthetic drug into the subarachnoid space through a fine spinal needle. It is a safe and effective form of anesthesia and is a preferred regional anesthesia technique for abdominal, pelvic and lower extremity surgeries. It has numerous benefits like lesser blood loss, reduced incidence of venous thromboembolism, decreased metabolic stress response to surgery, no pulmonary compromise etc[1]. Bupivacaine is long acting local anesthetic agent and drug of choice for spinal anesthesia, it blocks autonomic, sensory and motor nerve fibers when injected into subarachnoid space and produces desired anesthesia level. The currently available bupivacaine preparations in our institute are of two types isobaric bupivacaine (IB), with a density equal to that of cerebrospinal fluid (CSF), and hyperbaric bupivacaine (HB), with a density heavier than CSF. Bupivacaine hydrochloride heavy or HB preparation is the most commonly used for conventional spinal anesthesia (SA) and isobaric bupivacaine is used for segmental spinal anesthesia (SSA) [2]. Conventional spinal anesthesia may cause excessive sympathetic block due to excess spread in cephalad direction leading to hemodynamic changes causing hypotension, bradycardia. In SSA spread of isobaric solution in cerebrospinal fluid does not depend upon the patient’s position during and after the injection and hence may not cause undesired high level and consequent changes[3]. In our institute, earlier only SA was used but since the recent availability of isobaric bupivacaine, both the techniques are commonly used for various procedures. Therefore we planned this study to compare spinal block characteristics of SA and SSA in moderate duration abdominal surgeries. Available literature mentions that, the segmental spinal anesthesia can be given from the lumbar till the thoracic region using an isobaric drug and only the segments required for the surgery will be blocked and is safe and effective for abdominal surgeries. [4,5] Uppal V et al mentions that both the techniques provided effective anesthesia with no difference in the failure rate or adverse effects but differed in onset, duration of sensory and motor block and due to the small sample size and high heterogeneity of outcomes, suggest that more studies are required. [2] There is scarce evidence comparing two techniques of SA and SSA in Indian population. Hence, we decided to study and compare conventional spinal anesthesia and segmental spinal anesthesia in moderate duration abdominal surgeries with respect to subarachnoid block characteristics like onset, duration, hemodynamic stability, ambulation etc Research question:. Is spinal anesthesia and segmental spinal anaesthesia in moderate duration abdominal surgeries comparable with respect to subarachnoid block ? Hypothesis. Spinal anaesthesia and segmental spinal anaesthesia in moderate duration abdominal surgeries are comparable with respect to subarachnoid block characterstics
AIM Comparison of block characteristics of spinal anesthesia and segmental spinal anesthesia in open abdominal surgeries. OBJECTIVES: To compare spinal anesthesia and segmental spinal anesthesia in open abdominal surgeries with respect to following characteristics 1. To compare hemodynamic parameters like heart-rate, blood pressure, mean arterial pressure, oxygen saturation. 2. To compare the onset of surgical anesthesia. 3. To compare duration of action for sensory and motor block 4. To compare adequacy of abdominal relaxation 5. To compare the post operative VAS score. 6. To compare the time for first voiding 7. To compare time for ambulation of patients.
STUDY DESIGN: It is A Prospective, Randomized, Comparative, single blinded ( patient) Clinical study. ETHICS: Study will be initiated after obtaining permission from the institutional ethics committee. It will be done after obtaining written informed valid consent from the patient. This study is not going to effect standard care management of the patients and involves very minimal risk . Both the anesthesia techniques are currently used routinely for open abdominal surgeries of moderate duration. Identity of all the patients will be kept confidential.
STUDY POPULATION INCLUSION CRITERIA ï‚· Patients aged between 18 to 60 years ï‚· Patients undergoing open abdominal surgeries under spinal anesthesia (SA) or segmental spinal anesthesia (SSA). ï‚· Sex - male and female. ï‚· Patients who can understand the rate of their pain on visual analog scale(VAS) or pain scale ï‚· Patients who could provide written informed consent. ï‚· Open abdominal surgeries of moderate duration (60 - 120 minutes) EXCLUSION CRITERIA ï‚· Patients refusal to consent. ï‚· Pregnant women ï‚· Patients with history of allergy to local anesthetic agents. ï‚· Presence of pain or infection over the injection site ï‚· Patients having significant neurological disease with motor or sensory deficit ï‚· Any contraindication to spinal anesthesia.
SAMPLE SIZE S= r+1 (α1 2+α2 2 ) (Zα/2+Zβ) 2 r (µ1-µ2) 2 Where, r = Ratio of control to case α1 = Standard deviation of time to first sensory block in spinal anesthesia α2 = Standard deviation of time to first sensory block in spinal segmental anesthesia q = 100-P Zἀ/2= 0.84 Zβ = Standard normal deviate for power 80% - 0.84 For power 90% - 1.28 µ 1 – µ 2 = Expected mean time to first sensory block in spinal anesthesia– Expected mean time to first sensory block in spinal segmental anesthesia (effect size) Thus, we took r as 1, as we include equal number of cases and control. As per study by Paliwal et al. (1) α1 was 0.67 and α2 was 0.12,. So, putting the values n= 1+1/1 (402+7.482 )* (0.84+1.28)2 (40-20)2 = 34.5 ~ 35 Thus we include approximately 35 participants in each group Group A – 35 Group B - 35
Statistical analysis The hemodynamic, anesthetic and post anesthetic parameters will be compared among patients who will receive segmental anesthesia and general anesthesia in abdominal surgeries. Qualitative data will be represented in form of frequency and percentage. Among Qualitative data, Nominal data will include, gender of the patient, religion, co-morbid conditions (Diabetes Mellitus, Hypertension, Asthma, Malignancy, etc.), post operative pain etc. Association between qualitative variables will be assessed by Chi-Square test, with Continuity Correction for all 2 X 2 tables and by Fisher’s Exact test for all 2 X 2 tables where Chi-Square test will not be valid due to small counts. (E.g. Association between duration of onset of anasthesia and Group category (Segmental anasthesia/General anasthesia, Association between post operative vas score category and Group category (Segmental anasthesia/General anasthesia). Quantitative data will be represented using Mean ± SD and Median & IQR (Interquartile range). Quantitative data will include age of the patient, duration in minutes from onset of anasthesia. Results will be graphically represented where deemed necessary. Appropriate statistical software, including but not restricted to MS Excel, PSPP version 1.0.1 will be used for statistical analysis. Graphical representation will be done in MS Excel package included in Microsoft Office 365. An alpha value (p-value) of <=0.05 will be used as the cutoff for statistical significance. The collected data will be entered Microsoft Excel 365. 1. Paliwal N, Maurya N, Suthar OP, Janweja S. Segmental thoracic spinal anesthesia versus general anesthesia for breast cancer surgery: A prospective randomized-controlled open-label trial. J Anaesthesiol Clin Pharmacol. 2022;38(4):560–5. Thus we include 35 participants . Thus the minimum required sample size is 35 patients in each group , however to cover for the dropouts and attrition we will take 35 patients in each group .
METHODOLOGY : Place of study: General surgery Operation Theatres of T.N.M.C and B.Y.L Nair Hospital Mumbai- 400008. Will be used for conducting the study. Duration of study : Study will be conducted over a period of eighteen months DETAILS OF STUDY PROCEDURE: After Ethical committee approval, written informed valid consent will be taken from the all the patients who fits the inclusion criteria and are posted for open abdominal surgery under conventional spinal anesthesia (SA) and segmental spinal anesthesia (SSA). Each patient will be assessed at the preanesthetic visit in detail a day prior to surgery and necessary investigations according to the surgery and anesthesia required will be noted. Demographic parameters like age, sex, weight, diagnosis and proposed operation will be noted. The procedure to be done will be explained in detail to the patient and written informed valid consent will be obtained. On arrival to the operating room standard monitors i.e. Non-invasive Blood pressure (NIBP) monitor, Electrocardiogram(ECG) and Pulse oximeter will be attached and parameters will be noted. 18-G IV cannula will be inserted in the non-dominant hand. All patients will be preloaded and co-loaded with 10 ml/kg Ringer Lactate or Normal saline.
RANDOMIZATION Patients will be randomly divided into two groups SA and SSA using computer generated random number table. This study is a single blinded study as the patients are blinded and the investigator and observer are not blinded to the Study. According to the group allocation, SA group will be receiving 0.5% hyperbaric bupivacaine with 25 micrograms of fentanyl and group SSA will be receiving 0.5% isobaric bupivacaine with 25 micrograms of fentanyl in the subarachnoid block. The dose of the drug will be approximately 1.5 ml to 2.5ml depending on the patient and surgery requirement. Standard procedure for spinal anesthesia will be followed according standard protocol with all aseptic precautions in both the groups. SA and SSA will be performed with the patient in the sitting position with all aseptic precautions using 25-G Quincke’s spinal needle. Once continuous clear free flow of Cerebrospinal fluid (CSF) will be established, spinal drug will be administered over 10-second period as per the group allocation. At this stage group SA will receive 0.5% hyperbaric bupivacaine with 25 micrograms of fentanyl and group SSA will receive 0.5% isobaric bupivacaine with 25 micrograms of fentanyl in the subarachnoid block. The dose and time of injection will be noted. Throughout the procedure and intraoperatively till the end of procedure continuous monitoring of vital parameters will be done which will be continued in the post-operative period. Systolic blood pressure ( SBP), Diastolic blood pressure (DBP), Mean arterial pressure (MAP), Heart rate (HR), Oxygen saturation (SpO2), ECG ( Electrocardiogram), will be recorded preoperatively, immediately after spinal anesthesia, every 2 minutes for the first 10 minutes and then every 5 minutes till the end of the procedure followed by post operatively every 30 minutes till 4 hours after spinal anesthesia in both the groups. Any complication if occurred will be immediately treated accordingly. Onset of surgical anesthesia that is sensory and motor block in both patients will be noted and exact segment block will be noted. Duration of anesthesia which includes two segments regression of sensory will be checked in both the groups and noted. Adequacy of abdominal relaxation will be confirmed from operating surgeon as adequate or inadequate. Patients will be considered hypotensive when MAP decreased to less than 25% from baseline and were treated with ephedrine 6 mg intravenously, dose titrated according to response. If HR decreased to less than 50 beats per minutes, atropine 0.02 mg/kg was given intravenously. Complications such as nausea, vomiting, bradycardia, hypotension, shivering, headache or any other will be noted and treated immediately and appropriately. All patients will be monitored in postoperative recovery room as per standard protocol. Time for two segment regression and complete regression of motor and sensory action will be noted. The post operative pain, will be evaluated by VAS for pain scoring at 0,1, 2, 4, 8, 12, 18, 24 hours postoperatively. In case of VAS >3/4, Diclofenac will be used as rescue analgesic and time to first analgesia (TFA) will be recorded. The time for first voiding and time for ambulation of patients will be noted. Assessment parameters for the study will include 1. Demographic data ( age, sex, weight) 2. hemodynamic parameters like heart-rate, blood pressure, mean arterial pressure, oxygen saturation. 3. Time to onset of surgical anesthesia 4. duration of action for sensory and motor block 5. adequacy of abdominal relaxation 6. post operative VAS score 7. time for first voiding, and ambulation of patients 8. Any complications
STATISTICAL ANALYSIS The hemodynamic, subarachnoid block parameter will be compared among patients who receive spinal anesthesia and segment and spinal anesthesia in abdominal surgery. Qualitative data will be represented in the form of frequency and percentage. Among qualitative data nominal data will include gender, post-operative pain, surgical procedure, etc. Association between qualitative variables will be assessed by Kai Square test with continuity correction for all 2×2 tables and buy tissues extract test for all 2×2 tables where chi-square test will be not valid due to small counts. Example, association between duration of onset of Anesthesia and group category.(spinal anesthesia/segment and spinal anesthesia.) association between postoperative VAS score, category and group category(spinal anesthesia and segmental spinal anesthesia) Meditative data will be represented using Mean+ SD And median and IQR(interquartile range). Qualitative data will include age of the patient, duration in minutes from onset of Anesthesia. Results will be graphically represent it where deemed necessary. Appropriate statistical software, including but not restricted to MS, Excel, PSPP version 1.01 will be used for statistical analysis. Graphical representation will be done in MS Excel package included in Microsoft Office 65. An alpha value(p-value) off, less than 0.05 will be used as the cut-off for statistical significance . The collected data will be entered Microsoft Excel. 365
|