|Year : 2018 | Volume
| Issue : 3 | Page : 98-104
Hypotensive effect of labetalol and dexmedetomidine blood loss and surgical conditions in functional endoscopic sinus surgery: A double-blind randomized clinical trial
Aliakbar Eghbal1, Hesameddin Modir1, Esmail Moshiri1, Mohammad Khalili1, Farzad Zamani Barsari2, Abolfazl Mohammadbeigi3
1 Department of Anesthesiology and Critical Care, Arak University of Medical Sciences, Arak, Iran
2 Department of Rhinology and Ear Surgery, Arak University of Medical Sciences, Arak, Iran
3 Department of Neurology and Neuroscience Research Center, Qom University of Medical Sciences, Qom, Iran
|Date of Submission||19-Aug-2017|
|Date of Decision||02-Oct-2017|
|Date of Acceptance||20-Nov-2017|
|Date of Web Publication||21-Jun-2018|
Dr. Hesameddin Modir
Department of Anesthesiology and Critical Care, Arak University of Medical Sciences, Arak
Source of Support: None, Conflict of Interest: None
Background: Excessive bleeding occurs from mucosal edges during functional endoscopic sinus surgery (FESS). This could decrease the visibility of the surgeon and increase the risk incidence of complications. The current study aimed to evaluate the effect of labetalol and dexmedetomidine on intraoperative blood loss and surgical conditions in ESS.
Methods: A double-blind randomized clinical trial was conducted on 100 candidates for FESS that randomly were assigned by block randomization method in two groups including labetalol or dexmedetomidine. Heart rate (HR), mean arterial blood pressure, and the percent of arterial oxygen saturation were measured after induction and during the hypotension. These items were recorded till the end of the surgery. A blinded surgeon was assessed the bleeding of operation field. Data were analyzed using t-test, Chi-square, and analysis of variance for repeated measures.
Results: The mean time of surgery was not statistically significant between two groups (104.65 ± 7.38 vs. 105.12 ± 7.33). The mean of HR was higher in dexmedetomidine group in all times after induction (P < 0.001) and a significant decreasing trend observed in the mean of HR for labetalol while the HR in dexmedetomidine group was increasing. The extubation and recovery time in dexmedetomidine group was higher than labetalol group (P < 0.001). Moreover, the operation field without bleeding or with low bleeding was higher in labetalol group, and the labetalol could be controlled the bleeding better than the dexmedetomidine.
Conclusion: Bleeding score, extubation, and recovery time in labetalol group was lower than dexmedetomidine group. Moreover, patients in labetalol group have had higher recovery score and lower bleeding. Therefore, labetalol could reduce the bleeding during FESS and improved the visualization of the operation field and was superior to dexmedetomidine in concern to lower bleeding and extubation and recovery time.
Keywords: Anesthesia, bleeding, dexmedetomidine, functional endoscopic sinus surgery, labetalol
|How to cite this article:|
Eghbal A, Modir H, Moshiri E, Khalili M, Barsari FZ, Mohammadbeigi A. Hypotensive effect of labetalol and dexmedetomidine blood loss and surgical conditions in functional endoscopic sinus surgery: A double-blind randomized clinical trial. Formos J Surg 2018;51:98-104
|How to cite this URL:|
Eghbal A, Modir H, Moshiri E, Khalili M, Barsari FZ, Mohammadbeigi A. Hypotensive effect of labetalol and dexmedetomidine blood loss and surgical conditions in functional endoscopic sinus surgery: A double-blind randomized clinical trial. Formos J Surg [serial online] 2018 [cited 2018 Jul 22];51:98-104. Available from: http://www.e-fjs.org/text.asp?2018/51/3/98/234875
| Introduction|| |
Various pathological conditions are treated by functional endoscopic sinus surgery (FESS) which is a widely performed surgery., Excessive bleeding from mucosal edges during FESS interferes in optimal visualization of the intranasal anatomy. This could decrease the surgical visibility and increase the risk of complications incidence., However, after introducing the FESS, the illumination and visualization were enhanced dramatically and the surgical dissection improved.
Appropriate control of intraoperative bleeding during FESS could be adopted by different methods. Narcotic injection into the nasal mucosa, elevating the head of patients and using hypotensive anesthesia drugs are as a fast and accessible methods for controlled hypotension.,,, Among the various mentioned maneuvers, anesthetic agents can also influence the amount of blood loss and the condition of the surgical field through their hypotensive or vasodilative action. Controlling of hypotension during the surgery is a technique that used to limit the intraoperative blood loss and is effective to provide the best possible field for surgery.,,,
There are a few contradictory studies about the effect of anesthesia drugs for improvement of surgical condition of FESS. In a study by Sajedi et al. showed that labetalol prefers to remifentanil from the economic aspects in FESS. Nevertheless, in Hadavi's study, the average quality of operation in FESS and average blood loss from surgical sites were not statistically significant between labetalol and nitroglycerin groups. However, we did not find studies that assess the comparative effect of labetalol and dexmedetomidine in surgery condition of FESS such as blood loss during surgery and controversy effects of different anesthesia agents. The current study was designed as a double-blinded randomized clinical trial and aiming to evaluate the effect of labetalol and dexmedetomidine on intraoperative blood loss and surgical conditions in FESS.
| Methods|| |
A double-blind randomized clinical trial conducted on 100 patients who were candidate for FESS in one of general hospitals of Arak, Iran. The current trial is registered in Iranian Registration of Clinical Trials with IRCT2016080914056N8 code and the ethical committee of Arak University of Medical Sciences approved this project by IR.ARAKMU.REC.1394.288 in August 2016. Sampling conducted based on power of 0.90, alpha error of 0.05, and minimum difference between two study groups for bleeding score as 0.65 and standard deviation equal 0.70 and 0.80 for treatment and control groups. The minimum sample size for each group was calculated 40 patients based sampling formula. The study duration was 6 months from May to December 2016. All the eligible patients were enrolled based on the inclusion and exclusion criteria and they were signed the written informed consents after describing the study protocol. Patients who referred as sinus endoscopy surgery for the treatment of chronic rhinosinusitis, being 18–60 years old and ASA I and II patients who are treated hypertensive were inclusion criteria. The exclusion criteria were including ASA III and higher, coagulopathies, history of cardiovascular diseases, uncontrolled blood pressure, pregnancy, body mass index >35, chronic obstructive pulmonary disease (asthma), and addiction to opioids.
The enrolled volunteer patients were hospitalized 1 day before surgery and were holds fasting for 8 h before the surgical operation. First, demographic data and baseline measurements were collected and two different veins prepared on arrival to the operating room. One vein considered for injection of labetalol or dexmedetomidine and another for other intravenous fluids or other drugs. Before induction of anesthesia, electrocardiogram, the heart rate (HR) and the mean arterial blood pressure (MBP) and arterial oxygen saturation (SaO2) were measured and recorded by datoscope passport2 patient monitor. In the starting of induction, crystalloid fluids (5 ml/kg) were used for infusion, and 100% oxygen was administered for preoxygenation by mask during the first 3 min to the patient. In both groups, anesthesia was induced with intravenous fentanyl (1 mcg/kg) and propofol (2.5 mg/kg) and intravenous atracurium (0.5 mg/kg) was used for endotracheal intubation. The patients underwent mechanical ventilation to remain the concentration of exhaled carbon dioxide at 30–35 mmHg and SaO2 at 98%. After anesthetic induction, an arterial line from radial artery of the upper limbs created by catheter 20G for all patients to conducting the exact measurements for blood pressure of patients during the operation.
In the next step, block randomization method was used for random assignment of patients to study groups. The block size was four and the sequence of blocks was selected according to simple random. In the first group, dexmedetomidine (1 μg/kg) used for 10 min as the primary dose and consequently 0.4–0.8 μg/kg/h was infused as the maintenance dose. In the second group, labetalol (0.25 mg/kg/IV) administrated for 10 min as the primary dose and then 1–2 mg/min/IV was infused as the maintenance dose. Isoflurane (1%) was used for maintenance of general anesthesia of all patients during operation. The infusion rates of anesthetic drugs in both groups were set by the maintaining the mean of arterial blood pressure between 65 and 75 mmHg. The mean of arterial blood pressure, HR, and the percent of arterial SaO2 were measured continually after induction and during the hypotension. However, data were recorded every 10 min for every patient in our checklist until the end of the surgery. A blinded surgeon who was unknown about the assignment of study groups and the used anesthesia drugs assessed the bleeding of operation field in patients. The bleeding from the operation field scored from 0 to 5 as it was used in other studies., The bleeding scoring conducted as without bleeding 0, very mild bleeding that may be considered dry 1, mild bleeding that does not distort the clear-cut area 2, Moderate bleeding that clearly gives the surgical field affected 3, excessive bleeding that could be controlled, but destroys the clearly of surgical field 4, very much bleeding that cannot be controlled 5. In this scoring system for bleeding, the score 2 and lower shows the ideal situation of the operation area. The bleeding level was defined based on bleeding score as a categorical variable; 0 defined as none, 1 as low, 2 defined as higher score as moderate/sever bleeding labeled. 5 min before finishing the surgery, anesthesia gas was removed and the labetalol, dexmedetomidine and propofol infusion were terminated to make more comprehensive. Extubation was conducted based on the having suitable volume of breathing and backing the airway reflexes and recovery time (score 9 and higher) according to the Aldrete anesthesia scoring table. The HR and arterial SaO2 were measured immediately after induction until 2 h continually in all patients of two groups. However, these data were recorded every 10 min to comparing two groups. Moreover, the measurement of the mean of arterial blood pressure was conducted every 10 min during the operation. The side effects and consequences of surgery including decreasing the blood pressure to lower 60 mmHg, bradycardia (HR lower 50) during operation, vomiting/nausea, chills, bronchospasm, fatigue, headache, dizziness, and sore throat were recorded at the end of the operation and in the recovery room.
The collected data were analyzed using the PASW Statistics version 18 (IBM Co., Armonk, NY, USA). The normality of data was checked by histogram normal curve and Shapiro–Wilk test. Independent sample t-test, Chi-square, and analysis of variance for repeated measures were used for inferential statistical analysis. The statistical significance considered in 0.05 levels.
The study was conducted in accordance with the Declaration of Helsinki and was approved by the local ethics committee of the institute. Informed written consent was obtained from all patients prior to their enrollment in this study.
| Results|| |
The mean age of patients was 33.38 ± 9.43 years (31.7 ± 9 in labetalol vs. 35.06 ± 9.64 in dexmedetomidine) and 56% of patients were female. There was no statistically significant between two groups regarding age mean (P = 0.122) and sex distribution (P = 0.568). Moreover, there was no significant difference between two groups at the baseline measurement in concern to age, sex, surgery time, HR, arterial saturation of O2 (SaO2), and the mean of blood pressure (P< 0.05). In addition, the time of surgery was not statistically significant between two groups (104.65 ± 7.38 vs. 105.12 ± 7.33) minutes and these findings showed that two groups are comparable. The baseline measurement regarding types of nasal disease (choanal polyps with polyposis, and nasal tumor) showed that two groups were not statistically significant (P< 0.05) and all patients were under sinus endoscopy surgery for the treatment of chronic rhinosinusitis.
According to the results of [Table 1], there was a significant difference in mean of HR between two study groups in the induction and different time after induction of anesthesia (P< 0.001). The mean of HR was higher in dexmedetomidine group at all times after induction. The analysis of variance for repeated measures [Figure 1]a showed that a significant decreasing trend was in the mean of HR for labetalol (P = 0.038). Moreover, this trend for dexmedetomidine group was growing to upward (P< 0.001) and the mean of changes in HR from induction to 120th min was statistically significant between two groups (P< 0.001).
|Table 1: Comparison of heart rate (bpm) after induction times between labetalol and dexmedetomidine among patients who were candidate for nasal sinus endoscopic surgery|
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|Figure 1: Comparing the trend of changes in mean of heart rate, (a) mean of arterial blood pressure, (b) and mean of saturation of oxygen rate, (c) between dexmedetomidine and labetalol groups in induction and different continues times after starting surgery|
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[Table 2] shows that the MBP was statistically different between two study groups in 40th, 100th, and 120th min after induction of anesthesia. In a way that the MBP was higher at these times in dexmedetomidine group than the labetalol (P< 0.05). The analysis of variance for repeated measurements [Figure 1]b showed a decreasing significant trend in MBP after induction in both groups (P< 0.001). Nevertheless, the trend of MBP in labetalol was significantly decreasing (P = 0.030). However, the trend of MBP in dexmedetomidine group was not statistically significant based on analysis of variance for repeated measurements test (P = 0.256). In addition, the mean of changes in MBP from induction to 120th min was statistically significant between two groups (P< 0.001).
|Table 2: Comparison of the mean arterial blood pressure (mmHg) after induction times between labetalol and dexmedetomidine among patients who were candidate for nasal sinus endoscopic surgery|
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[Table 3] shows that the mean of SaO2 is different between two study groups immediately after induction, 10th, 90th, 100th, and 120th min after starting surgery (P< 0.05). The mean of SaO2 is higher in dexmedetomidine group than the labetalol at the mentioned times. There was not showed a significant trend in SaO2 in both labetalol (P = 0.754) and dexmedetomidine (P = 0.634) groups after induction [Figure 1]c based on the analysis of variance for repeated measurement test (P > 0.05). Moreover, there was no significant difference between two groups regarding mean of changes in SaO2 from induction to 120th min (P = 0.587).
|Table 3: Comparison of the oxygen saturation (percent) after induction times between labetalol and dexmedetomidine among patients who were candidate for nasal sinus endoscopic surgery|
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Based on independent t-test [Table 4], there was no significant difference between two study groups in concern to different times after starting surgery. Nevertheless, the extubation and recovery time in dexmedetomidine group was higher than labetalol group (P< 0.001). In a way that the extubation and recovery time in dexmedetomidine group is longer that labetalol group. The recovery score in labetalol group was higher and showed that the labetalol group has a better situation (P< 0.05). The bleeding score was lower in labetalol group based on t-test and Chi-square test showed that the rate of patients without bleeding (score 0) was higher in labetalol group. In a way that, area without bleeding or with low bleeding was higher in labetalol group and the labetalol could be controlled the bleeding better than the dexmedetomidine.
|Table 4: Comparison of the surgery, extubation and recovery time, bleeding severity and recovery score between labetalol and dexmedetomidine groups|
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Vomiting/nausea and chills were occurred in five patients (10.9%) of labetalol group and these side effects did not observe in dexmedetomidine group. Moreover, no complication was observed in induction and 2 h after starting surgery. Moreover, the patients of two groups were same regarding using medication for control of blood pressure.
| Discussion|| |
According to our results, the extubation and recovery time in dexmedetomidine group was higher than labetalol group. In a way that these times in dexmedetomidine group was higher than labetalol group. Moreover, the recovery score in labetalol group was higher and showed that the labetalol group has a better situation. In addition, the rate of patients without bleeding was higher in labetalol group and the bleeding score in labetalol groups was lower than other group. The labetalol could be controlled the bleeding better than the dexmedetomidine and our results suggested that labetalol is superior to dexmedetomidine in concern of lower bleeding and extubation and recovery time. Therefore, labetalol could reduce the bleeding during ESS and improve the visualization of the operation field.
In FESS, the highest risk of bleeding is related to the capillary bleeding and the capillary circulation could be decreased by declining the arterial blood pressure after narrowing of blood vessels. Bleeding could be effect on the surgical site and the patient' body temperature  and disturb the visibility of operation site and caused hard and longer surgery. Proper positioning of the patient, positive pressure ventilation, drugs, and epidural or spinal anesthesia are used methods in deliberate hypotension. The main goal in FESS is reducing the systemic vascular resistance or cardiac output. Some drugs and anesthetic agents are suggested for hypotension and decreasing of bleeding.,,,,,, It is supposed that decreased HR during deep general anesthesia due to lower cardiac output could cause better condition for ESS.
The effect of dexmedetomidine in comparing to other anesthetic agents such as esmolol, bisoprolol, magnesium sulfate and isoflurane-alfentanil on blood loss and surgical conditions in FESS is assessed in some studies.,,,,, These studies offer that the advantage of inherent analgesic, sedative and anesthetic sparing effect in comparing to other anesthetic agents.,,,, In addition, Sajedi et al. study showed that a bolus dose of labetalol infusion could be effective than remifentanil in controlled hypotension of patients who are under general anesthesia. However, other studies showed that the more effectiveness of dexmedetomidine than remifentanil., Other studies also, showed that the superiority of dexmedetomidine to other anesthetic drugs. Bajwa et al. study showed that dexmedetomidine and esmolol could be effective in providing better hemodynamic stability and increase the visibility of operative field in comparing to nitroglycerin during FESS. Moreover, providing postoperative sedation and decreasing the analgesic requirements of dexmedetomidine are additional benefit. In addition, Das et al. study found that dexmedetomidine could provide more effectively controlled hypotension and decrease the nasal bleeding. Moreover, it could increase the surgeons' satisfaction score. Moreover, Shams study showed that dexmedetomidine is a safe drug for controlled hypotension and could provide ideal visibility of surgical field during FESS.
Labetalol is antagonist for adrenergic receptors including β1, β2, and α1 and using for induction of hypotension. The drug targets of labetalol in β receptor is more specialized 5–10 times more than other receivers and used for management of tachycardia.,, The basic mechanisms of Labetalol function is related to competitive inhibition of β receptor in myocardia (β1) and in bronchial smooth muscle and blood vessels (β2) as well as alpha-1 receptors in vascular smooth muscles. These functions of Labetalol caused decrease in systemic arterial blood pressure and Systemic vascular resistance without a significant impact on the reduction of HR, cardiac output, and stroke volume at rest time, which is due to inhibitory activity of alpha and beta-adrenergic receptors.,
According to our results, the mean of HR was higher in dexmedetomidine group in all times after induction and a decreasing trend was observed in labetalol group, while the trend of HR in dexmedetomidine group was increasing. Since the increase in HR could increase the blood circulation and consequently the bleeding in FESS, it seems that labetalol is more effective in control of bleeding than the dexmedetomidine. In addition, the mean arterial was higher sometimes after induction of anesthesia in dexmedetomidine group than the labetalol. Moreover, a decreasing trend in blood pressure observed after induction in both groups. However, dexmedetomidine is α2 adrenergic agonist and has relaxation and lowering blood pressure effects.,, Some studies suggested dexmedetomidine for hypotension and for decreasing the bleeding in surgery.,,, In Hadavi study, there was no significant difference in bleeding due to FESS between labetalol and nitroglycerin. However, other studies showed that the dexmedetomidine is not different with remifentanil in satisfaction and bleeding of FESS, but has shorter extubation time. Moreover, Lee et al. study showed that recovery was faster with remifentanil than with dexmedetomidine. In addition, another study showed that dexmedetomidine decrease significantly the bleeding and HR in FESS comparing to Magnesium sulfate. Moshiri et al. study showed better recovery duration after anesthesia by dexmedetomidine.
| Conclusion|| |
The study results showed that the rate of patients without bleeding was higher in labetalol group and the bleeding score in labetalol groups was lower than another group due to more effect on HR and blood pressure control. Moreover, the extubation and recovery time in dexmedetomidine group was longer than labetalol group. Moreover, the recovery score in labetalol group was higher and showed that the labetalol group has a better situation. Therefore, the labetalol could be controlled the bleeding better than the dexmedetomidine, and our results suggested that labetalol is superior to dexmedetomidine in concern to lower bleeding and extubation and recovery time. Therefore, labetalol could reduce the bleeding of FESS and improve the visualization of the operative field. Nevertheless, the adverse effect including vomiting/nausea and chills was not observed in dexmedetomidine group while 11% of patients in labetalol group experience these complications. However, future studies seem to be necessary to demonstrate the hypotension effect of labetalol for Intraoperative blood loss in ESS.
The Authors would like to express their gratitude to the Deputy of Research of the University, the Clinical Research Development Center of Vali-Asr Hospital in Arak and all the colleagues who helped us during the study.
Financial support and sponsorship
This study was financially supported by Arak University of Medical Sciences.
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4]