Comparison between the Effects of Acetaminophen, Dexmedetomidine, and Normal Saline Infusion on Pain Severity after Cataract Surgery.

Background: Cataract surgery is one of the most common eye surgeries, which is currently performed under topical anesthesia using sedative medications. Dexmedetomidine and acetaminophen are good candidates for analgesia in other circumstances, however, this study aimed to evaluate the effect of dexmedetomidine or acetaminophen infusion and normal saline (NS) alone compared with the control group on the severity of pain in cataract surgery. Materials and Methods: In this parallel randomized controlled clinical trial, the effect of dexmedetomidine or acetaminophen infusion and NS on level of pain, vital signs, recovery status, and surgeon satisfaction during cataract surgery were assessed. One hundred and thirty-five patients between the age of 50-80 years undergoing cataract surgery were recruited on a consecutive basis and randomized into three groups receiving acetaminophen (15 mg/kg), dexmedetomidine (0.5 µgr/kg), and NS. Baseline vital signs, blood pressure, arterial oxygen saturation, respiratory and heart rate at certain time-points including the start of surgery, 5, 10, and 15 min after surgery, after arrival to the recovery room, 20, 40, 60 min after recovery were measured. Pain intensity and drugs side effects were also recorded after surgery. Results: Level of respiratory depression was higher in patients receiving dexmedetomidine. Heart rate and oxygen saturation percentage had no significant differences in the three groups as well as pain intensity. Conclusions: Acetaminophen was as effective as dexmedetomidine with lower side effects and higher surgeons' satisfaction, without any interference with cardiovascular and respiratory parameters. Acetaminophen infusion should be considered as an acceptable analgesic drug for cataract surgery.

Acid-base and hemodynamic status of patients with intraoperative hemorrhage using two solution types: Crystalloid Ringer lactate and 1.3% sodium bicarbonate in half-normal saline solution.

BACKGROUND: Intraoperative hemorrhage is one of the problems during surgery and, if it happens in a high volume without an immediate action to control, it can be fatal. Nowadays, various injectable solutions are used. The aim of this study was to compare the acid-base and hemodynamic status of the patient using two solutions, Ringer lactate and 1.3% sodium bicarbonate, in half saline solution. MATERIALS AND METHODS: This clinical trial was performed at the Al-Zahra Hospital in 2013 on 66 patients who were randomly selected and put in two studied groups at the onset of hemorrhage. For the first group, crystalloid Ringer lactate solution and for the second group, 1.3% sodium bicarbonate in half-normal saline solution was used. Electrocardiogram, heart rate, O2 saturation non-invasive blood pressure and end-tidal CO2 were monitored. The arterial blood gas, blood electrolytes, glucose and blood urea nitrogen were measured before serum and blood injection. After the infusion of solutions and before blood transfusions, another sample was sent for measurement of blood parameters. Data were analyzed using SPSS software. RESULTS: The mean arterial pressure was significantly higher in the second group than in the first group at some times after the infusion of solutions. pHh levels, base excess, bicarbonate, sodium, strong ion differences and osmolarity were significantly greater and potassium and chloride were significantly lower in the second group than in the first group after the infusion of solutions. CONCLUSION: 1.3% sodium bicarbonate in half-normal saline solution can lead to a proper correction of hemodynamic instability. By maintaining hemodynamic status, osmolarity and electrolytes as well as better balance of acid-base, 1.3% sodium bicarbonate solution in half-normal saline solution can be more effective than Ringer lactate solution during intraoperative bleeding.

Assessment of the effects of ketamine-fentanyl combination versus propofol-remifentanil combination for sedation during endoscopic retrograde cholangiopancreatography.

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) as a diagnostic and treatment procedure is used in most biliary tract and pancreatic. Either sedation or general anesthesia could be considered for this procedure. Combining a sedative with an opioid agent can provide effective moderate sedation. This study compared the impact of ketamine-fentanyl (KF) versus propofol-remifentanil (PR) on sedation scale in patients undergoing ERCP. MATERIALS AND METHODS: As a double-blinded randomized clinical trial, 80 patients selected by convenient sampling, allocated randomly into two groups. KF group received ketamine 0.5 mg/kg body weight intravenously over 60 s and then fentanyl 1 mcg/kg body weight intravenously. PR group received propofol l mg/kg body weight intravenously over 60 s and then remifentanil 0.05 mcg/kg body weight/min intravenously. Intravenous (IV) infusion of propofol was maintained by 50 mcg/kg body weight/min throughout ERCP. Ramsay Sedation Score, vital signs, oxygen saturation (SpO2), recovery score (modified Aldrete score) and visual analog scales of pain intensity, and endoscopist's satisfaction were considered as measured outcomes. All analysis were analyzed by SPSS Statistics version 22 and using t-test, Chi-square and repeated measured ANOVA and Mann-Whitney tests for data analysis. RESULTS: Respiratory rate and SpO2 level during the time intervals were lower in PR group (P < 0.001). Sedation score at intervals was not significantly different (P = 0.07). The frequency of apnea in PR group was significantly higher than the KF group (P = 0.003). The percentage of need to supplemental oxygen in PR group was 35.1% that was also significantly higher than 8.8% in the KF group (P = 0.008), but the dosage frequency was significantly higher in KF group (P < 0.001). The KF and PR groups average length of stay in the recovery room were 50.71 standard deviation (SD = 9.99) and 42.57 (SD = 11.99) minutes, respectively, indicating a significant difference (P = 0.003). The mean severity of nausea in KF and PR groups was, respectively, 2.74 confidence interval (CI = 1.68-3.81) and 0.43 (CI = 0.11-0.75), that was significantly higher in KF group (P < 0.001). The average score of surgeon satisfaction in both KF and PR groups were 7.69 (CI = 7.16-8.21) and 8.65 (CI = 8.25-9.05), respectively, which was higher in KF group (P = 0.004), but the average level of patients satisfaction in KF group was 8.86 (CI = 8.53-9.19) and in PR group was 8.95 (CI - 8.54-9.35) that were not significantly different (P = 0.074). CONCLUSION: There is no statistically significant difference between KF and PR combinations in sedation score, but PR combination provides better pain control, with less nausea and shorter recovery time while causing more respiratory side effects, that is, apnea and need to oxygen.

Premedication with oral tramadol reduces severity of postoperative shivering after general anesthesia.

BACKGROUND: Postanesthetic shivering (PAS) is an accompanying part of general anesthesia with different unpleasant and stressful complications. Considering the importance of proper prevention of PAS in order to reduce its related adverse complications in patients undergoing surgery, in this study, we investigated the effect of orally administrated tramadol in the prevention of this common complication of general anesthesia. MATERIALS AND METHODS: In this prospective randomized double-blind clinical trial, 80 ASA I and II patients aged 15-70 years, scheduled for elective surgery under general anesthesia, were randomized to intervention (oral tramadol 50 mg) and placebo groups. PAS was evaluated during surgery and in the recovery room, and compared in the two study groups. RESULTS: PAS was seen in 5 patients (12.5%) in the intervention group and 10 patients (25%) in the placebo group (P = 0.12). The prevalence of grade III and IV shivering was 7.5% (3/40) and 25% (10/40) in tramadol and placebo groups, respectively (P = 0.03). CONCLUSION: The overall prevalence of PAS was not significantly different in the two study groups, but the higher grades of shivering which needed treatment were significantly lower in the tramadol group than in the placebo, and those patients who received tramadol experienced milder form of shivering. It is suggested that higher doses of tramadol would have better anti-shivering as well as analgesic effects. Studying different doses of tramadol would be helpful in this regard.

Preemptive analgesia with intra-articular pethidine reduces pain after arthroscopic knee surgery.

BACKGROUND: Postoperative pain relief is important in procedures of the lower extremity. Several previous studies have evaluated the efficacy of intra-articular (IA) pethidine as a compound, which has local anesthetic and opioid agonist properties, on postoperative pain relief in arthroscopic knee surgery (AKS). This study compared the postoperative analgesic effect of pre- and post-surgical IA pethidine administration in AKS. MATERIALS AND METHODS: Seventy-five patients of American Society of Anesthesiologists (ASA) I and II undergoing AKS with general anesthesia were enrolled in this double-blind study. Patients were randomized in three equal groups to receive either 50 mg IA pethidine before surgical incision incision and saline after skin closure (PS), saline before surgical incision and pethedine after skin closure (SP), and only saline at two different times (SS). In each patient with operated knee joint, pain at rest and joint movement was evaluated at 1, 2, 6, 12, and 24 h after surgery completion using Visual Analog Scale (VAS). Data were analyzed using analysis of variance (ANOVA)-repeated measure, t-paired, and Chi-square tests. RESULTS: Postoperative pain score at rest and joint movement in PS group was significantly lower than those in other groups. The time (Mean ± SD) between completion of operation and patient's request for morphine, total morphine consumption (Mean ± SD) in postoperative 24 h, and the numbers of patients requesting analgesic in PS, SP, SS, groups were: 5.2 ± 1.3, 3.3 ± 1.5, and 2 ± 1.3 h (P < 0.05); 4.4 ± 2.4, 8.7 ± 2, and 11.6 ± 4.4 mg (P < 0.05); 11, 18, and 21 persons (P < 0.05), respectively. CONCLUSION: The present study shows that preemptive intra-articular pethidine 50 mg injection is more effective than preventive injection for postoperative pain relief at rest and joint movement in arthroscopic knee surgery.

Lidocaine administration before tracheal extubation cannot reduce post-operative cognition disorders in elderly patients.

BACKGROUND: Cognitive dysfunction after surgery is common in elderly patients. Many factors such as anesthetic drugs can cause complication in this surgery. Lidocaine is one of the drugs commonly used during anesthesia. So, we designed this study to find out cognitive effect of lidocaine in elderly patients undergoing non-cardiac surgeries. MATERIALS AND METHODS: In this double-blinded clinical trial, we enrolled 70 patients older than 65 years age undergoing urologic or orthopedic surgeries, were divided in two groups. Patients randomly received intravenous lidocaine (1.5 mg/kg) or normal saline in the same volume immediately before extubation. Mini mental state examination (MMSE) test was used to evaluate cognitive state at discharge time, 6 and 24 h after surgery. RESULTS: Mean MMSE scores at the time of discharge from recovery room in lidocaine and saline groups were 22.4 ± 4.5 vs. 22.1 ± 4.4, P = 0.755, respectively. It was significantly lower than MMSE before surgery, 6 and 24 h after the operation. The mean MMSE scores and frequency distribution of intensity of cognitive impairments were not significantly different between two groups at different times. CONCLUSION: Bolus intravenous lidocaine before extubation, did not affect cognitive states in elders undergoing non-cardiac surgery. Effect of lidocaine on cardiac surgeries is clear, but in non-cardiac surgeries, lidocaine has no clinical effects. So, more studies with different doses of lidocaine and different assessment methods are recommended.

Comparing the preventive effect of midazolam and midazolam-dexamethasone on postoperative nausea and vomiting in elective middle ear surgery.

BACKGROUND: Nausea and vomiting are common postoperative complications with incidence of 20-80% depends on the surgery type, anesthetic drugs, age, sex, etc. This complication may lead to patient discomfort, intraocular, and intracerebral pressures increase, sutures rupture, esophageal injury, and rarely death. Many studies reported that midazolam and dexamethasone alone can decrease postoperative nausea and vomiting (PONV), but their combination has never been studied yet. The aim of this study was to compare the effect of midazolam and midazolam-dexamethasone on PONV after middle ear surgery. MATERIALS AND METHODS: 66 ASA I and II patients aged 15-65 year scheduled for elective middle ear surgery under general anesthesia randomly divided into two groups. Immediately after induction of the anesthesia group one (M) received midazolam 0.075 mg/kg and group two (M+D) received combination of midazolam (0.075 mg/kg) plus dexamethasone (0.05 mg/kg). Then the severity of nausea was measured by visual analog scales 0-10 (VAS) in recovery room at 6, 12, and 24 h after surgery. Metoclopramid (0.1 mg/kg) was administrated I.V. slowly if nausea score was above 3 or patient had vomiting. The postoperative need for antiemetics and the duration of stay in recovery room were recorded. Values of P<0.05 were considered statistically significant. RESULTS: There were no significant differences in age, gender, and weight between the two groups. There was no significant difference in the mean nausea scores between two groups except after 12 h postoperatively (1.39 ± 3.19 in M group vs. 0.42 ± 1.71 in M+D group). The mean vomiting frequency was significantly less in midazolam-dexamethasone group in the recovery room (0.9 ± 0.29 vs. 0 ± 0) and at 6-12 h (1.09 ± 2.41 vs. 0.3 ± 0.8), and 12-24 h (0.42 ± 1.32 vs. 0.03 ± 0.17) postoperatively. During the first 24 h postoperatively, the metoclopramid consumption was significantly less in combination therapy (6.48 ± 9.54) than in the midazolam group (12.9 ± 23.44) (Value<0.5). CONCLUSION: The combination of midazolam-dexametazone is more effective than midazolam alone in prevention of postoperative vomiting after middle ear surgery. Therefore, we recommend combination therapy for patients who are prone to PONV.

Effect of preoperative volume loading on the intraoperative variability of blood pressure and postoperative nausea and vomiting.

INTRODUCTION: Preoperative volume loading (PVL) in addition to counteract the decreases in blood pressure during intraoperative period, also may decrease postoperative nausea and vomiting (PONV). This study was designed to investigate the effect of preoperative volume loading on the intraoperative blood pressure variability and postoperative nausea and vomiting. METHODS: Thirty subjects scheduled for elective orthopedic procedures randomly divided into case and control groups. The patients in the case group received lactated Ringer 10 ml/kg before induction of general anesthesia. Mean arterial blood pressure (MAP) and heart rate were recorded in two groups every 3 minutes from induction of anesthesia until five minutes after extubation. Variability of mean arterial blood pressure and heart rate were defined as the standard deviation (SD) of the measured values for each patient. Means of these individual SD values were compared between two groups using Mann-Whitney U test. RESULTS: The mean variability of mean arterial blood pressure and heart rate ware significantly lower in case group (8.3 +/- 3 mmHg and 8.4 +/- 2.5 bpm vs. 13 +/- 6 mmHg and 11 +/- 2.6 bpm in control group; p < 0.5). The severity of nausea (measured as a ten-point visual analog scale) was significantly lower in case group (1.2 +/- 0.9 vs. 3.9 +/- 1.8 in control group; p < 0.05). No patients in case group developed postoperative vomiting (compared to 5 patients in control group). CONCLUSIONS: The results of this study shows that preoperative volume loading is associated with lower variability of blood pressure and heart rate during operative period and also reduces the severity and incidence of postoperative nausea and vomiting.