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Evaluation of the Effect of Propofol–Remifentanil and Propofol–Hydralazine on the Bleeding Volume During Dacryocystorhinostomy Surgery Under General Anesthesia
Hamidreza Shetabi1, Seyed Jalal Hashemi2, Somaye Ghaleshahi1
1 Department of Anesthesiology, Isfahan University of Medical Sciences, Isfahan, Iran
2 Department of Anesthesiology, Anesthesiology and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| Date of Submission | 19-Feb-2022 |
| Date of Acceptance | 18-Jun-2022 |
| Date of Web Publication | 31-Aug-2023 |
Correspondence Address:
Somaye Ghaleshahi
Department of Anesthesiology, Isfahan University of Medical Sciences, Isfahan
Iran
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/abr.abr_57_22
Background: The present study was performed to compare the effectiveness of propofol–remifentanil and propofol–hydralazine in inducing controlled hypotension in patients undergoing the dacryocystorhinostomy (DCR) surgery and reducing their bleeding volume during surgery.
Materials and Methods: The present double-blind, randomized clinical trial was performed on 70 patients who were candidates for DCR surgery and divided into two groups. In both the groups, general anesthesia protocol was performed. Moreover, in the first group, a syringe containing 2 mg of remifentanil in 20 ml of distilled water (0.1 mg/ml) was infused at the rate of 0.15 μg/kg/min (P + R group). In the second group, a syringe containing 20 mg of hydralazine in 20 ml of distilled water (1 mg/ml) was infused at the rate of 0.5–10 mg/h (P + H group).
Results: The hemodynamic parameters were not significantly different between the two groups in the studied times (P > 0.05). In contrast, the bleeding volume in the P + R group with the mean of 61.29 ± 50.06 ml was significantly lower than that of the P + H group with the mean of 152.31 ± 90.81 ml (P < 0.001). Moreover, the mean score of surgeon's satisfaction level in the P + R group was higher than that of the P + H group (5.91 ± 0.28 vs. 4.29 ± 0.65; P < 0.001).
Conclusion: According to the results of this study, there was no significant difference between the P + H and P + R groups in terms of fluctuations in the hemodynamic parameters and the occurrence of complications. However, a reduction in the bleeding volume and a higher satisfaction level of the surgeon were observed in the P + R group compared with the P + H group.
Keywords: Bleeding, dacryocystorhinostomy, hydralazine, hypotension, propofol, remifentanil
How to cite this article:
Shetabi H, Hashemi SJ, Ghaleshahi S. Evaluation of the Effect of Propofol–Remifentanil and Propofol–Hydralazine on the Bleeding Volume During Dacryocystorhinostomy Surgery Under General Anesthesia. Adv Biomed Res 2023;12:207 |
How to cite this URL:
Shetabi H, Hashemi SJ, Ghaleshahi S. Evaluation of the Effect of Propofol–Remifentanil and Propofol–Hydralazine on the Bleeding Volume During Dacryocystorhinostomy Surgery Under General Anesthesia. Adv Biomed Res [serial online] 2023 [cited 2023 Sep 28];12:207. Available from: https://www.advbiores.net/text.asp?2023/12/1/207/384882 |
| Introduction | |  |
The most important symptoms of nasolacrimal duct obstruction are excessive tearing and mucoid discharge.[1],[2] The mentioned condition accounts for about 10%–20% of patients referring to ophthalmology clinics.[3],[4] The proposed treatment in this regard is dacryocystorhinostomy (DCR) surgery, which is unilateral and open. It has the maximum success rate and creates a direct opening from the lacrimal sac to the nasal cavity.[5] In fact, the purpose of DCR surgery is to create a new epithelium-covered pathway between the nose and the lacrimal sac to stabilize lacrimal sac drainage into the nose.[6]
Considering the significance of the accuracy and delicacy of this surgery, the quality of the surgery is of special importance because a successful surgery in the facial area requires close vision conditions in the surgical field due to its proximity to the brain, cerebral nerves, and eyes. Therefore, hemostasis is of great significance in performing DCR surgery.[7],[8]
Intraoperative bleeding reduces the surgeon's visibility of the surgical field during surgery. Therefore, improving visibility in the surgical field and reducing bleeding are some of the main tasks of an anesthesiologist during surgery. Depending on the type and extent of the surgery as well as the tissue to be operated on, some bleeding is expected during each type of surgery; however, sometimes, more than the expected volume of bleeding occurs during or after the surgery and is indicated as bleeding from the surgical field during surgery and as bleeding from the drain or the edge of the wound, hematoma, hemothorax, or hemoperitoneum, and so on after the surgery.[9],[10]
In this regard, the reduction of controlled hypotension and the control of hemodynamic responses of the body to stress effectively reduce the bleeding volume during surgery and improve the surgical field in head and neck surgeries.[9],[10],[11],[12] For this reason, controlling and managing bleeding during surgery have been considered as major goals in the anesthetic procedure over the past decades.[13] The application of various anesthetic techniques and drugs such as volatile anesthetics, direct-acting vasodilators, ganglion-blocking drugs, α-adrenergic blockers, α- and β-blockers, calcium channel blockers, prostaglandins, and others reduces the bleeding volume and the need for blood transfusion.[14],[15],[16]
The ideal drugs for hypotension are drugs that are easy to prescribe, have a predictable dose-dependent effect, have a short onset time and rapid elimination without toxic metabolites, and have a minimal effect on vital organs. In addition, the ideal drug should not increase the intracranial pressure or affect brain autoregulation.[17] Therefore, the selection of the right medication is central in the management and control of bleeding.
In this regard, propofol is a fast-acting, non-barbiturate, intravenous anesthetic, provides a good-quality anesthesia and a rapid recovery, and results in a 20%–30% reduction in the systolic blood pressure (SBP) compared to before the induction of anesthesia. However, the sensation of pain and discomfort during injection are disadvantages of this drug.[18] Various methods such as changing the injection rate, diluting the drug, changing the temperature, changing the solvent, or using drugs have simultaneously been used to prevent the injection pain.[19],[20] Some studies have proposed the administration of drugs such as alfentanil and remifentanil as an effective way to prevent the injection pain.[21]
In this respect, the combination of remifentanil with propofol as a complete intravenous anesthesia is one of the methods that has been used recently to reduce blood pressure and, therefore, decrease bleeding.[22] In fact, remifentanil, as a selective opioid agonist, can centrally suppress the vasomotor system by releasing histamine and reduces blood pressure; however, it may be associated with complications such as decreased oxygen saturation (SpO2) and hypotension.[16] Another drug used to control blood pressure is hydralazine. The main effect of the mentioned drug is to dilate the arteries; however, it has little effect on the veins and also reduces peripheral resistance and increases systemic resistance.[23]
Several studies have been performed to evaluate the effectiveness of each of these drugs and their combinations in various types of surgeries. Some of the conducted studies have not found any difference between propofol, remifentanil, and hydralazine in lowering the blood pressure and pulse rate (PR). However, some studies have reported higher rate of hypotension in hydralazine compared to the other two drugs and higher decrease in bleeding volume by prescribing remifentanil compared to hydralazine.[24],[25],[26]
Therefore, considering the significance of the management of bleeding in improving the quality and success of surgery and the inadequacy of studies addressing the effects of propofol, hydralazine, and remifentanil on the control and reduction of bleeding, the present study aimed at comparing the effectiveness of propofol–hydralazine and propofol–remifentanil combinations in inducing controlled hypotension in patients undergoing DCR surgery, reducing intraoperative bleeding volume, and increasing surgeon's satisfaction level.
| Materials and Methods | | |
The present study was a double-blind, randomized clinical trial. The study population consisted of all candidate patients who referred to Feiz Hospital (Isfahan University of Medical Sciences) for DCR surgery during 2019–2020. Of the mentioned population, the sample size was considered to be 35 patients in each group (totally 70 patients), considering the confidence interval of 95%, the test power of 80%, and the results of previous studies indicating the standard deviation of bleeding in the two groups to be equal to 0.86 and 0.51, respectively, and the minimum difference in the bleeding mean to be equal to 0.5.[27] The simple random sampling technique was employed to select the patients with the indication for DCR surgery under general anesthesia.
The inclusion criteria were patients aged 18–68 years, belonging to the American Society of Anesthesiologist (ASA) status I or II, who agreed to participate in the study and were not prohibited from taking hydralazine, remifentanil, and propofol. Patients were not included in the study if they had diagnosed allergies to drugs, had diseases such as cardiovascular disease, diabetes mellitus, polycythemia, liver disease examined by liver function tests, ischemic cerebrovascular disease addressed by patient examinations and the evaluation of patient history, respiratory insufficiency addressed by patient examinations, the evaluation of patient history, and the analysis of VBG, systemic hypertension, overt anemia, coagulopathy disorders addressed by checking prothrombin time (PT), partial thromboplastin time (PTT), and international normalized ratio (INR), and hemoglobinopathy addressed by the analysis of complete blood count (CBC). Hemoglobin electrophoresis was performed in case of anemia and suspected hemoglobinopathies. In addition, the patients were excluded from the study in the event of any complications that altered the anesthetic plan, including drug side effects or inadequate patient response to induced hypotension conditions such as arrhythmia, cardiac conduction defect that required treatment and discontinuation of controlled hypotension, or the occurrence of cardiac arrest that prohibited or limited continuation of the intervention. The sample size did not decrease in this study [Figure 1].
After obtaining the code of ethics from the Ethics Committee of Isfahan University of Medical Sciences (IR.MUI.MED.REC.1398.528), the code of clinical trial (IRCT20171030037093N30), and written consent from eligible patients, patients' demographic information such as age, gender, ASA class, weight, height, and body mass index (BMI) were first recorded. Then, the patients were divided into two groups using random allocation software.
All patients were hospitalized 1 day before the surgery and were nil per os (NPO) for 8 h before the surgery. Upon entering the operating room, two venous catheters were inserted in different sites to inject the propofol–remifentanil or propofol–hydralazine combinations and intravenous fluids or other drugs. Before the induction of anesthesia, SBP, diastolic blood pressure (DBP), mean arterial pressure (MAP), PR, and oxygen saturation (SpO2) were measured and recorded.
At the beginning of the injection, 5 ml/kg crystalloid fluid was injected and 100% oxygen was administered through the facial mask in the first 3 min. Anesthesia was induced by the injection of 2 μg/kg fentanyl, 2 mg/kg propofol, and 0.5 mg/kg atracurium, and the intubation was performed. Then, the induction of anesthesia was performed in both groups.
In first group, the infusion of 40 ml propofol with the dose of 12 mg/kg/h (200 μg/kg/min) was started and then reduced to achieve the MAP of 65–75 mmHg, and the infusion rate was adjusted. Moreover, a syringe containing 2 mg of remifentanil in 20 ml of distilled water (0.1 mg/ml) was infused at the rate of 0.15 μg/kg/min (P + R group). In the second group, the infusion of 40 ml propofol with the dose of 12 mg/kg/h (200 μg/kg/min) was started and then reduced to achieve the MAP of 65–75 mmHg, and the infusion rate was adjusted. Moreover, another syringe containing 20 mg of hydralazine in 20 ml of distilled water (1 mg/ml) was infused at the rate of 0.5–10 mg/h (P + H group).[25]
It should be noted that in order to meet the blindness condition, the drugs were previously prepared by an anesthesiologist. Two syringes containing 40 ml of propofol were prepared and labeled A. In the third syringe, 2 mg of remifentanil was combined with 20 ml of distilled water and labeled B. In the fourth syringe, 20 mg of hydralazine was combined with 20 ml of distilled water and labeled C. Then, the first group was given two syringes labeled A and B and the second group received two syringes labeled A and C. In this case, the person prescribing the drug as well as the person recording the patients' clinical information and basic characteristics were not aware of the type of intervention, and the necessary blinding was performed.
Also, all patients underwent DCR surgery performed by a single professional surgery team.
In addition, duration of surgery and duration of anesthesia time (from induction to patient's extubation) were calculated. Patients' hemodynamic parameters including SBP and DBP, MAP, PR, and SpO2 were recorded before anesthesia, immediately after anesthesia, at 5, 10, 15, 20, 25, and 30 min during the surgery, immediately upon entering the recovery room, and after 30 min in the recovery room. Moreover, the volume of blood collected in the suction was evaluated and recorded in terms of ml to measure the bleeding volume at the end of surgery. In addition, surgeon's satisfaction level with the surgical field based on a score from 0 (dissatisfaction) to 5 (complete satisfaction), as well as the observed complications during the surgery (including hypertension, hypotension, bradycardia [heart rate {HR} ≤60 beats/min], tachycardia [HR ≥100 beats/min], SpO2 ≤90%, and arrhythmia) and complications during recovery (such as reoperation and bleeding, nausea, vomiting, and postoperative pain) were checked.
Finally, the collected data were entered into Statistical Package for the Social Sciences (SPSS) software (ver. 24). Data were presented as standard deviation, mean, or frequency (percentage). According to the results of Kolmogorov–Smirnov test indicating the normal distribution of data, the independent samples t-test was used to compare the mean of quantitative variables between the two groups. Moreover, the repeated measures analysis of variance (ANOVA) was used to compare the mean of quantitative variables over time in each of the groups. In addition, the Chi-square test was used to compare the frequency distribution of discrete data between the two groups. Significance level of less than 0.05 was considered in all analyses.
| Results | | |
The results of the present study revealed that the P + R group had seven male (20%) and 28 female (80%) patients with the mean age of 49.79 ± 13.56 years and the P + H group had five male (14.3%) and 30 female (85.7%) patients with the mean age of 50.18 ± 13.35 years (P > 0.05) [Table 1]. | Table 1: Basic and clinical characteristics of patients in the two groups
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In addition, SBP, DBP, MAP, PR, and SpO2 of patients before anesthesia (baseline) and immediately after anesthesia, during surgery, and during recovery were not significantly different between the two groups (P > 0.05). Changes in the blood pressure (MAP, SBP, and DBP) were significant in each of the two groups over time (P < 0.05). In contrast, changes in PR and SpO2 were not significantly different in each of the two groups over time (P > 0.05) [Table 2] and [Table 3]. | Table 2: Determination and comparison of patients' SBP, DBP, and MAP in the two groups
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 | Table 3: Determination and comparison of patients' PR and SpO2 in the two groups
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Moreover, the bleeding volume in the P + H group with the mean of 152.31 ± 90.81 ml was significantly higher than that of the P + R group with the mean of 61.29 ± 50.06 ml (P < 0.001) [Figure 2]. | Figure 2: Mean intraoperative bleeding volume of the two groups. P + R group: propofol + remifentanil group, P + H group: propofol + hydralazine group
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Finally, the surgeon's satisfaction level with the control of bleeding and improvement of the surgical quality in the P + R group with the mean of 4.91 ± 0.28 was higher than that of the P + H group with the mean of 4.31 ± 0.67 (P < 0.001). No complications during surgery were reported. However, the frequency distribution of complications during recovery, such as nausea, vomiting, and postoperative pain, was not significantly different between the two groups (P > 0.05). There was also no reoperation and bleeding in the recovery period [Table 4]. | Table 4: Determination and comparison of the surgeon's satisfaction level and the incidence of complications in the two groups
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| Discussion | | |
Controlled hypotension is commonly employed to reduce intraoperative blood loss and prevent transfusions and is required for DCR surgery under general anesthesia to improve the surgical conditions and reduce important complications such as heavy bleeding.[28],[29],[30]
In the present study, the combinations of hydralazine and remifentanil with propofol were used to induce controlled hypotension in patients undergoing DCR surgery. The results regarding hemodynamic parameters indicated that although the rate of blood pressure decrease in the P + H group was higher than that of the P + R group and the rate of PR decrease in the P + R group was higher than that of the P + H group, generally, hemodynamic parameters were not significantly different between the two groups during the studied times. The hemodynamic fluctuations were identical in the two groups and led to no cardiac complications that required discontinuation of the controlled hypotension.
In general, both groups in this study received propofol, which is commonly used in the induction and maintenance of anesthesia and is associated with a relative decrease in SBP.[11] However, another analgesic drug is usually used in addition to this drug to optimize the intraoperative monitoring. As compared to other analgesic drugs, remifentanil provides a better hemodynamic stability under surgical stress and maintains cerebral blood flow. Moreover, it averagely to weakly reduces blood pressure, but provides a better hemodynamic stability compared to fentanyl and alfentanil.[31],[32]
Yoo et al.[33] revealed that the effect of three drugs of sevoflurane, desflurane, and propofol–remifentanil combination resulted in no difference in lowering the blood pressure and PR.
In addition, the results of the present study indicated that the bleeding volume in the P + R group was significantly lower than that of the P + H group. The mentioned finding resulted in the surgeon's increased satisfaction with the surgical field in the P + R group compared with the P + H group. Moreover, due to better control of bleeding in the P + R group, the incidence of nausea and vomiting in this group was less than that of the P + H group. Generally, no cardiac complications were observed in both groups due to the low bleeding volume.
In line with the findings of this study, Khamestan et al.[26] compared remifentanil infusion with a single dose of hydralazine and propranolol in the induction of controlled hypotension in patients undergoing rhinoplasty and revealed that anesthesia induced by remifentanil infusion reduced the bleeding volume and increased the surgeon's satisfaction. The observed effect was significantly more than the effect of the single-dose administration of hydralazine and propranolol.
Complications of remifentanil include decreased DBP, decreased SpO2, and nausea and vomiting.[16] In our study, we did not experience hypotension as a complication due to the intentional induction of controlled hypotension, and only nausea with the incidence rate of 8.6% was observed in the P + R group.
Hydralazine has also been shown to reduce the peripheral resistance by relaxing the arterial smooth muscle, thereby lowering blood pressure. The mentioned reduction may be beneficial in preventing bleeding during surgery;[34] however, this drug significantly increases intracranial pressure.[16]
Controlled hypotension should be used with caution to minimize the risk of damage to vital organs. Significant risks that may arise from the use of controlled hypotension include the possibility of coronary, cerebral, or renal circulatory failure. The blood circulation to the brain and heart is not affected by adrenergic substances, but essentially responds to the metabolic demands of the myocardium and hydrogen ions or changes in pressure receptors in the brain. Blood pressure, PR, and cardiac output are reduced by the induction of controlled hypotension. Thereby, the cardiac work and, consequently, the myocardial metabolism reduce, so reduction of the coronary blood flow will be permissible.[35] Therefore, many other studies have reported remifentanil to have a more hemodynamic stability, less bleeding, a cleaner surgical field, and a better postoperative recovery, compared with other drugs.[30],[36]
Given that few previous studies have examined the effect of hydralazine on bleeding control, the present study was innovative in this regard and the mentioned point was its strength. As this drug in comparison with remifentanil has the same hemodynamic stability, it may be possible to use this drug instead of remifentanil, depending on the patient's condition. However, this can be one of the limitations of the present study, considering that only intra-suction blood was calculated in evaluation of the bleeding volume. Also, the small sample size and the lack of comparison made between various doses of the two drugs were some of the other study limitations. It is suggested that future studies evaluate the effects of these two drugs in combination with other drugs and in other types of surgeries with a more bleeding volume.
| Conclusion | | |
According to the results of this study, the effect of combining hydralazine and remifentanil with propofol on fluctuations in hemodynamic parameters and the occurrence of complications was not significantly different. However, a significant decrease in the bleeding volume and a significant increase in the surgeon's satisfaction level were reported in the group receiving remifentanil with propofol (P + R group) compared with the group receiving hydralazine with propofol (P + H group).
Ethics approval and consent to participate
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patients have given their consent for their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published, and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
| References | | |
| 1. | Ali MJ. Primary external dacryocystorhinostomy. In Principles and Practice of Lacrimal Surgery. Singapore: Springer; 2018. p. 189-95.  |
| 2. | Vinciguerra A, Nonis A, Resti AG, Bussi M, Trimarchi M. Impact of post-surgical therapies on endoscopic and external dacryocystorhinostomy: Systematic review and meta-analysis. Am J Rhinol Allergy 2020;34:846-56. |
| 3. | Kern C, Fu DJ, Kortuem K, Huemer J, Barker D, Davis A, et al. Implementation of a cloud-based referral platform in ophthalmology: Making telemedicine services a reality in eye care. Br J Ophthalmol 2020;104:312-7. |
| 4. | Heindl LM, Jünemann AG, Kruse FE, Holbach LM. Tumors of the lacrimal drainage system. Orbit 2017;29:298-306. |
| 5. | Saeed BM. Endoscopic DCR: A 10 years personal experience. Indian J Otolaryngol Head Neck Surg 2019;71:2039-43. |
| 6. | Van Rijn JC, Klemetso N, Reitsma JB, Bossuyt PM, Hulsmans FJ, Peul WC, et al. Observer variation in the evaluation of lumbar herniated discs and root compression: Spiral CT compared with MRI. Br J Radiol 2006;79:372-7. |
| 7. | Zheng SL, Chan FT, Nabeebaccus AA, Shah AM, McDonagh T, Okonko DO, et al. Drug treatment effects on outcomes in heart failure with preserved ejection fraction: A systematic review and meta-analysis. Heart 2018;104:407-15. |
| 8. | Chang W, Xu W, Hu R, An Y. Current perception threshold testing in pharyngeal paresthesia patients with depression or anxiety. Neuropsychiatr Dis Treat 2020;16:1023-9. |
| 9. | Aono H, Ohwada T, Hosono N, Tobimatsu H, Ariga K, Fuji T, et al. Incidence of postoperative symptomatic epidural hematoma in spinal decompression surgery. J Neurosurg Spine 2011;15:202-5. |
| 10. | Rahimzadeh P, Faiz SH, Alebouyeh MR. Effects of premedication with metoprolol on bleeding and induced hypotension in nasal surgery. Anesthesiol Pain Med 2012;1:157. |
| 11. | Ragab SM, Hassanin MZ. Optimizing the surgical field in pediatric functional endoscopic sinus surgery: A new evidence-based approach. Otolaryngol Head Neck Surg 2010;142:48-54. |
| 12. | Ramos AP, Varon J. Current and newer agents for hypertensive emergencies. Curr Hypertens Rep 2014;16:450. |
| 13. | Scaggiante J, Zhang X, Mocco J, Kellner CP. Minimally invasive surgery for intracerebral hemorrhage: An updated meta-analysis of randomized controlled trials. Stroke 2018;49:2612-20. |
| 14. | Bible JE, Mirza M, Knaub MA. Blood-loss management in spine surgery. J Am Acad Orthop Surg 2018;26:35-44. |
| 15. | Goobie SM, Faraoni D. Blood sparing techniques. In Essentials of Pediatric Neuroanesthesia. Cambridge, UK/New York, NY: Cambridge University Press; 2018. p. 32-4. |
| 16. | Miller RD, Eriksson LI, Fleisher LA, Wiener-Kronish JP, Cohen NH, Young WL. Miller's anesthesia e-book. Elsevier Health Sciences; 2014. |
| 17. | Degoute CS, Dubreuil C, Ray MJ, Guitton J, Manchon M, Banssillon V, et al. Effects of pos-ture, hypotension and locally applied vasoconstriction on the middle ear microcirculation in anaesthetized humans. Eur J Appl Physiol 2004;69:414–20. |
| 18. | Kang HJ, Kwon MY, Choi BM, Koo MS, Jang YJ, Lee MA. Clinical factors affecting the pain on injection of propofol. Korean J Anesthesiol 2010;58:239-43. |
| 19. | Han YK, Jeong CW, Lee HG. Pain reduction on injection of microemulsion propofol via combination of remifentanil and lidocaine. Korean J Anesthesiol 2010;58:435-9. |
| 20. | Shetabi H, Asadi N, Golparvar M, Shafa A. The comparison of the effect of ketamine-sufentanil combination and propofol-remifentanil combination on the quality of sedation during painful procedures in children with hematological malignancies. J Isfahan Med School 2018;36:548-56. [Persian]. |
| 21. | Iyilikci L, Balkan BK, Gökel E, Günerli A, Ellidokuz H. The effects of alfentanil or remifentanil pretreatment on propofol injection pain. J Clin Anesth 2004;16:499-502. |
| 22. | Khodadadian M, Kaviani N, Roozbehani NA, Ashin SF. Comparison of the quality of tracheal intubation in two techniques of anesthesia with Propofol/Remifentanil and Sevoflurane/Remifentanil without using muscle relaxant in candidate children of dentistry undergoing general anesthesia. J Adv Pharm Educ Res 2020;10:65. |
| 23. | Farag M, Mabote T, Shoaib A, Zhang J, Nabhan AF, Clark AL, et al. Hydralazine and nitrates alone or combined for the management of chronic heart failure: A systematic review. Int J Cardiol 2015;196:61-9. |
| 24. | Nguyen HP, Zaroff JG, Bayman EO, Gelb AW, Todd MM, Hindman BJ. Perioperative hypothermia (33°C) does not increase the occurrence of cardiovascular events in patients undergoing cerebral aneurysm surgery: Findings from the intraoperative hypothermia for aneurysm surgery trial. Anesthesiology 2010;113:327-42. |
| 25. | Scawn RL, Allen MJ, Rose GE, Verity DH. Randomised, masked study of local anaesthesia administered prior to external dacryocystorhinostomy under general anaesthesia. Eye 2019;33:374-9. |
| 26. | Khamestan M, Sadeghi S, Samadi K, Mohsen Forouzan. Evaluating the effect of Remifentanil infusion vs. single dose intravenous Hydralazine plus Propranolol to provide controlled hypotension in patients undergoing Rhinoplasty in Khalili hospital of Shiraz. J Anesth Pain 2016;6:21-9. |
| 27. | Salama HF. Remifentanil/propofol total intravenous anesthesia versus remifentanil/isoflurane inhalation anesthesia for controlled hypotension in lumbar spine fixation surgery. Ain-Shams J Anaesthesiol 2017;7:134. |
| 28. | Ryu JH, Sohn IS, Do SH. Controlled hypotension for middle ear surgery: A comparison between remifentanil and magnesium sulphate. Br J Anaesth 2009;103:490-5. |
| 29. | Nekhendzy V, Lemmens HJ, Vaughan WC, Hepworth EJ, Chiu AG, Church CA, et al. The effect of deliberate hypercapnia and hypocapnia on intraoperative blood loss and quality of surgical field during functional endoscopic sinus surgery. Anesth Analg 2007;105:1404-9. |
| 30. | Sajedi P, Rahimian A, Khalili G. Comparative evaluation between two methods of induced hypotension with infusion of Remifentanil and Labetalol during sinus endoscopy. J Res Pharm Pract 2018;5:264-71. |
| 31. | Kosucu M, Omur S, Beşir A, Uraloğlu M, Topbaş M, Livaoğlu M. Effect of preoperativeremifentanil with controlled hypotension on intraoperative bleeding and postoperative edema and echymosis in open rhinoplasty. J Craniofac Surg 2014;25:471-5. |
| 32. | Monteiro ER, Neto FJ, Campagnol D, Garofalo NA, Alvaides RK. Hemodynamic effects in dogs anesthetized with isoflurane and remifentanil-isoflurane. Am J Vet Res 2010;71:1133-41. |
| 33. | Yoo HS, Han JH, Park SW, Kim KS. Comparison of surgical condition in endoscopic sinus surgery using remifentanil combined with propofol, sevoflurane, or desflurane. Korean J Anesthesiol 2010;59:377-82. |
| 34. | Schilling RS, editor. Occupational Health Practice. Butterworth-Heinemann; 2013. |
| 35. | Brown IA, Diederich L, Good ME, DeLalio LJ, Murphy SA, Cortese-Krott MM, et al. Vascular smooth muscle remodeling in conductive and resistance arteries in hypertension. Arterioscler Thromb Vascular Biol 2018;38:1969-85. |
| 36. | Yun SH, Kim JH, Kim HJ. Comparison of the hemodynamic effects of nitroprusside and remifentanil for controlled hypotension during endoscopic sinus surgery. J Anesth 2015;29:35-9. |
[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3], [Table 4]
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