Hemodynamic Effects of Fentanyl and Dexmedetomidine in Spine Surgery
Phase: PHASE4
Conditions: Spine Surgery, Hemodynamic Stability During Anesthesia
Sponsor: Universitas Sumatera Utara

Hemodynamic effects of fentanyl and dexmedetomidine in spine surgery 
 
 
NCT Number : 
Document Date : November 14, 2025 
 
 
 

Hemodynamic effects of fentanyl and dexmedetomidine in spine surgery 
 
ABSTRACT 
Introduction: Spinal surgery is of interest to anesthesiologists because it is often 
accompanied by perioperative problems, including blood pressure fluctuations and postoperative 
pain. Dexmedetomidine is one of the agents frequently used in spinal surgery. Dexmedetomidine 
is the dextro isomer of medetomidine, which is a selective alpha-2 agonist with high activity 
against alpha-1 adrenergic receptors. Hemodynamic stability during spinal surgery is essential to 
support rapid recovery, allowing early neurological assessment and more effective management 
of complications. 
Method: This study was an experimental double-blind randomized controlled trial 
conducted at the Adam Malik General Hospital in Medan, involving 50 adult patients undergoing 
elective spinal surgery. Patients were divided into two groups: dexmedetomidine and fentanyl, 
with consecutive sampling technique. Inclusion criteria included patients aged 17–60 years with 
ASA physical status 1–3, while exclusion criteria included a history of drug hypersensitivity, 
cardiac anatomical abnormalities, and blood vessel disorders. Trial registration: ClinicalTrials.gov 
NCTxxxxxxx. Registered 23 September 2025. Retrospectively registered. Collected data were 
tabulated tabulated using SPSS, with numerical data presented as mean ± SD and categorical data 
in frequency and percentage. Hypothesis testing was performed using the T-test or Wilcoxon test, 
and normality testing with Shapiro-Wilk, with a p value <0.05 considered significant.  
Result: showed that there was no significant difference in Mean Arterial Pressure (MAP) 
values between the two groups before T0 induction, with the dexmedetomidine group being 83.8 
± 12.58 and the fentanyl group being 85.7 ± 13.11. However, after induction at 15 minutes, MAP 
in the dexmedetomidine group dropped significantly lower than the fentanyl group (p < 0.05). In 
the Pulse of the two groups before induction (T0) there was no significant difference (P> 0.005), 
but at 15 minutes after induction there was a significant difference, where the pulse value in the 
dexmedetomidine group was lower than the fentanyl group. 
Conclusion: There was a significant difference in MAP and pulse values between 
dexmedetomidine and fentanyl administration during spinal surgery at Adam Malik Hospital 
starting from 15 minutes after induction. The dexmedetomidine group had lower MAP and pulse 
values compared to the fentanyl group. 

Keywords  : Spine surgery, fentanyl, dexmedetomidine, hemodynamics 
 
INTRODUCTION 
The prevalence of spinal surgery has increased, which is balanced by the complexity of the 
surgical procedure. The World Health Organization (WHO) in 2019 stated that the number of 
spinal surgery cases in the world was around 9,542 people. From the 2021 Riskesdas data in 
Indonesia, around 4,528 people underwent spinal surgery. Based on data from the Adam Malik  
Hospital in Medan in 2022, there were 182 spinal surgery patients. Spinal surgery is a concern for 
anesthesiologists because it is accompanied by perioperative problems including blood pressure 
fluctuations and severe postoperative pain. General anesthesia is a commonly used anesthesia 
modality and is more acceptable to patients.1,2 
General anesthesia can trigger a transient but significant sympathoadrenal response such 
as hypertension and tachycardia.2 Spinal surgery is a surgery with severe postoperative pain. The 
source of pain after spinal surgery is due to skin incision, inflammation of muscle tissue, roots, 
and neurons, excision of the vertebral bone and internal fixation devices that react with tissue. 
Spinal surgery is mostly performed under general anesthesia. Postoperative pain management is 
usually done conventionally with paracetamol, NSAIDs, and opioids used alone or in 
combination.1 
Other methods to reduce bleeding during spinal surgery include acute hypervolemic or 
isovolemic hemodilution, perioperative blood recovery, antifibrinolytic drugs, and controlled 
hemodynamics. Although acute hypervolemic hemodilution and acute normovolemic 
hemodilution play an important role in blood protection, hemodilution can affect the body's blood 
clotting function. Autologous blood transfusion can minimize the need for allogeneic blood 
transfusion, but spinal surgery is traumatic and causes a lot of bleeding, so allogeneic blood 
transfusion cannot be completely avoided. Antifibrinolytic drugs can reduce perioperative blood 
loss and the need for blood transfusion during spinal surgery, but this drug is still controversial 
because it can increase the risk of venous thromboembolism. Therefore, the application has a low 
risk. 1 
Stable hemodynamics can reduce intraoperative bleeding and ensure a clear field of vision, 
avoid damage to important nerves and blood vessels and shorten the duration of surgery, and 
reduce the need for blood transfusion, tissue ligation and cauterization, and the degree of edema, 

along with accelerating wound healing. This is a useful method in reducing intraoperative bleeding 
during spinal surgery.1 
There are several techniques to control hemodynamics, namely pharmacological and non-
pharmacological techniques. Pharmacological by numbing the pain and using active hypotensive 
drugs such as nitroglycerin, in addition according to the Ministry of Health, giving 500-1000 cc of 
crystalloid fluid can also help manage hypotension. From several research results, it was found 
that non-pharmacological therapy for hypotension can be done by giving leg elevation treatment. 
The results of research conducted by Raditya Fauzan by giving a sitting position for 5 minutes 
after anesthesia obtained data on a smaller decrease in mean arterial pressure compared to the 
position of being directly lying down. Anesthetic techniques can also reduce mean arterial blood 
pressure (MAP) which is done by giving fentanyl or dexmedetomidine. Fentanyl is a primary 
synthetic opioid, 100 times more potent than morphine. Fentanyl interacts with µ opioid receptors. 
This mu-binding is evenly distributed in the brain, spinal cord, and other tissues. Clinically, 
fentanyl has pharmacological effects especially on the central nervous system. The primary 
therapeutic actions of fentanyl are analgesia and sedation. Fentanyl is a synthetic opioid agonist 
derived from phenylpiperidine. It is structurally related to meperidine.3 Doses of 2 to 20 
micrograms/kg IV are given as an adjunct to blunt the circulatory response to direct laryngoscopy 
for tracheal intubation or during surgical stimulation. Its analgesic potency is 50–100 times greater 
than that of morphine. Fentanyl is a very popular anesthetic because of its short time to peak 
analgesic effect, cardiovascular safety, and rapid cessation of effects after small bolus doses. 
Fentanyl undergoes hepatic metabolism and renal excretion. Therefore, with higher doses or 
prolonged infusions, the effects of fentanyl are prolonged. 3,4,5 
Dexmedetomidine, is a dextro isomer and a pharmacologically active component of 
medetomidine, highly selective for alpha 2 adrenergic agonists with alpha-1 adrenergic receptors 
(selectivity ratio 1620:1) compared to 220:1 for clonidine which reduces the pressor response 
mediated by the sympathetic nervous system during general anesthesia. It also has anxiolytic, 
anesthetic and analgesic properties without respiratory depression and reduces postoperative 
shivering. Termination of pain signals is controlled by pre-synaptic activation of α2 adrenoceptors 
which inhibit norepinephrine release, decrease in heart rate (HR) and blood pressure (BP) is caused 
by activation of postsynaptic α2 receptors in the central nervous system which inhibits sympathetic 
activity. This reduces opioid requirements, helps early recovery after surgery. Dexmedetomidine 

undergoes hepatic metabolism involving hydroxylation and N-methylation, followed by 
conjugation. Metabolites are excreted in the bile and urine.6,7 
Research conducted by Rizkiya et al in 2020 found that the addition of dexmedetomidine 
provided significant stability of pulse and MAP during endotracheal intubation, prone positioning 
and incision in patients undergoing major spinal surgery.8,9,10 The addition of dexmedetomidine 
also caused a significant reduction in the need for opioid analgesia fentanyl up to 2x lower and a 
reduction in the average MAC isoflurane by 30% during surgery, thus providing a faster recovery 
process from anesthesia.11 
From another study conducted by Shujun et al in China in 2017 concluded that compared 
with fentanyl, dexmedetomidine (DEX) as an adjuvant local anesthetic in spinal anesthesia 
prolongs the duration of spinal anesthesia, improves postoperative analgesia, reduces the incidence 
of pruritus, and controlled hemodynamics. 10 The results of the study conducted in India showed 
that dexmedetomidine and fentanyl can be used safely to attenuate hemodynamic responses 
without significant side effects, while dexmedetomidine was shown to have better hemodynamic 
stability and was more effective in attenuating hemodynamic responses after intraoperative 
infusion when compared to Fentanyl. 1,2 
Based on the background above, this study was conducted to determine "Comparison of 
Hemodynamics Between Fentanyl and Dexmedetomidine in Spinal Surgery at Adam Malik 
Hospital, Medan". 
 
METHOD 
Study Design and Setting 
This study was a randomized, double-blind, controlled trial conducted at the Adam Malik 
General Hospital in Medan, Indonesia. The trial was carried out after obtaining ethical clearance 
and a research permit from the Health Research Ethics Committee of the Faculty of Medicine, 
Universitas Sumatera Utara, and the Ethics Committee of RSUP Haji Adam Malik. Patient 
recruitment and data collection were performed after these approvals, during the period following 
February 2024 (after ethical approval) until the target sample size was achieved. The study 
followed CONSORT guidelines for randomized trials and adhered to the principles of the 
Declaration of Helsinki. 

Participants (Inclusion and Exclusion Criteria) 
The study population included adult patients undergoing elective spinal surgery at Adam 
Malik Hospital. A total of 50 patients were enrolled, based on a priori sample size calculation (see 
below). Inclusion criteria were: 
• 
Age 17–60 years, undergoing elective spinal surgery expected to last more than 4 hours 
(for conditions such as traumatic injury, tuberculous spondylitis, or degenerative spine 
disease). 
• 
American Society of Anesthesiologists (ASA) physical status I–III. 
Exclusion criteria included: 
• 
Known hypersensitivity or allergy to dexmedetomidine or fentanyl. 
• 
Significant cardiac abnormalities (structural heart disease, significant arrhythmias, or 
history of cardiac arrest). 
• 
History of occlusive vascular disorders involving the heart or brain (e.g. coronary artery 
disease or cerebrovascular stroke). 
Patients meeting the inclusion criteria and none of the exclusion criteria were approached 
for participation. Written informed consent was obtained from all participants prior to enrollment. 
 
Sample Size 
The required sample size was determined using a two-group comparison of means formula. 
Based on an expected minimum meaningful difference in mean arterial pressure of 0.18 (with 
standard deviation of 0.36), with a Type I error α = 0.05 (one-tailed) and power (1–β) = 80%, the 
calculation indicated a minimum of 25 patients per group. To account for this, we set a total sample 
size of 50 (25 in each group). Fifty eligible patients were consequently recruited consecutively to 
reach this target. 
Randomization and Allocation Concealment 
After enrollment, patients were randomly assigned in a 1:1 ratio to one of two groups: the 
dexmedetomidine group or the fentanyl group. A computer-generated random sequence (simple 
randomization) was used to determine group assignments. Allocation concealment was ensured by 
using sequentially numbered, opaque, sealed envelopes containing the group assignments. An 
independent researcher prepared the envelopes and the study drug infusions according to the 

assignment. The envelopes were opened only once the patient had been consented and just before 
induction of anesthesia. 
Blinding 
This trial was conducted with a double-blind design. Neither the patients nor the attending 
anesthesiologists, surgeons, or outcome assessors were aware of the group allocations. The 
dexmedetomidine and fentanyl infusions were prepared in identical syringes (of the same volume 
and appearance) by a third party not involved in patient care or data collection. These syringes 
were labeled with a code (Group A or B) to mask the drug identity. The anesthesiologist 
administering the drugs and monitoring the patient intraoperatively was blinded to the syringe 
content, as were the patients and the staff recording the hemodynamic data. Blinding was 
maintained until all data analyses were completed. 
Anesthetic Procedure and Interventions 
All patients received a standardized anesthesia protocol. Upon arrival in the operating 
room, standard monitors (electrocardiogram, noninvasive blood pressure, pulse oximetry, etc.) 
were attached and baseline vital signs were recorded. Prior to induction, patients were 
premedicated with midazolam 0.07 mg/kg IV for anxiolysis. Baseline hemodynamic 
measurements (heart rate and blood pressure) were taken 5 minutes before induction of anesthesia 
(this pre-induction time point was designated T0). 
General anesthesia was induced in all patients with fentanyl 2 µg/kg IV (as an analgesic 
dose during induction) and propofol 2 mg/kg IV, followed by rocuronium 0.5 mg/kg IV to 
facilitate endotracheal intubation. After intubation, mechanical ventilation was initiated and 
adjusted to maintain normocapnia. No inhalational anesthetic or additional sedative was started at 
this point, to ensure that the only difference in anesthetic maintenance between groups was the 
study drug infusion. 
Immediately after induction and intubation, the study drug infusions were commenced 
according to group assignment: 
• 
Dexmedetomidine group: A loading dose of dexmedetomidine 1 µg/kg IV was given over 
10 minutes, followed by a continuous infusion at 0.5 µg/kg/hour intravenously using a 
syringe pump. 

• 
Fentanyl group: A continuous infusion of fentanyl at 0.5 µg/kg/hour IV was started 
(without any dexmedetomidine) using a syringe pump. 
These infusions were maintained throughout the surgery as the primary difference in 
anesthetic management between the two groups. Aside from the assigned study drug infusion, all 
other aspects of anesthesia management were kept identical to both groups to reduce bias. If 
additional anesthesia depth was required, minimal supplemental doses of anesthetic agents were 
given in both groups in a similar manner (none were routinely needed due to the effects of the 
study drugs). Intraoperative fluids, ventilation parameters, and other medications were managed 
according to standard practice and patient requirements, equally in both groups. Emergency drugs 
such as ephedrine (5 mg boluses) and atropine (0.25–0.5 mg) were prepared and administered as 
needed for hypotension (mean arterial pressure < 65 mmHg or > 30% drop from baseline) or 
bradycardia (heart rate < 50 beats/min), respectively. Vasopressors (e.g., norepinephrine) or 
inotropes (e.g., dobutamine) were available and used if severe hemodynamic instability occurred. 
All significant interventions and events were recorded. 
Outcome Measurements 
The primary outcomes of this study were the intraoperative hemodynamic parameters: 
mean arterial pressure (MAP) and heart rate (HR). These were measured at predefined time points 
to assess changes over time and differences between groups. Hemodynamic data were recorded at: 
baseline (T0, 5 minutes before induction, prior to drug administration) and at 5, 10, 15, 20, 25, 30, 
60, 120, 180, and 240 minutes after induction (T5, T10, T15, T20, T25, T30, T60, T120, T180, 
T240, respectively). These time points correspond to minutes elapsed after the completion of 
anesthesia induction/intubation and the start of the study drug infusion. Blood pressure was 
measured as non-invasive arterial pressure and MAP was calculated (diastolic pressure plus one-
third of pulse pressure). Heart rate was measured from the continuous ECG monitoring. All 
measurements were taken using the same multiparameter monitor (Infinity® monitor) to ensure 
consistency. If surgery lasted less than the maximum 240 minutes, data collection ended at the end 
of surgery (however, all cases in this study reached the 240 minute mark as per inclusion criteria 
of surgery duration). 
The hemodynamic readings at each time point were recorded on the case report form by 
investigators who were blinded to group allocation. The secondary outcomes evaluated included 

any requirement for rescue medication for hemodynamic instability, total intraoperative opioid 
consumption, and intraoperative blood loss, but the primary focus was on MAP and HR stability. 
 
Statistical Analysis 
All collected data were compiled and analyzed using IBM SPSS Statistics (IBM Corp., 
Armonk, NY; version 25). Prior to hypothesis testing, all numeric data were checked for 
completeness and assessed for normality of distribution using the Shapiro–Wilk test. Continuous 
variables are presented as mean ± standard deviation (SD) if normally distributed, or as median 
with interquartile range (IQR) if distribution was non-normal. Categorical variables are presented 
as counts and percentages. 
For baseline comparisons between the two groups, we used the independent samples t-test 
for continuous variables (or the non-parametric Mann–Whitney U test if the data were not 
normally distributed) and the chi-square test (or Fisher’s exact test when appropriate) for 
categorical variables. For the primary outcome (hemodynamic parameters at various time points), 
between-group differences at each time point were evaluated using independent t-tests (or Mann–
Whitney U tests for non-normal data). A repeated-measures analysis (e.g., ANOVA) was not 
performed due to the focus on comparing groups at each individual time point; instead, each time 
point was analyzed separately with appropriate adjustment for multiple comparisons if needed. 
A two-tailed p value of < 0.05 was considered statistically significant for all tests. The 
results are presented with 95% confidence intervals where relevant. No interim analyses were 
performed. There were no missing data for the primary outcomes, as all enrolled patients 
completed the surgery and all scheduled measurements. 
 
Ethical Approval 
This study received ethical approval from the Health Research Ethics Committee of the 
University of Sumatera Utara Medical Faculty and from the Ethics Committee of RSUP Haji 
Adam Malik Medan (approval reference No. No. 216/KEPK/USU/2024).). All methods were 
carried out in accordance with relevant guidelines and regulations. Each patient provided written 
informed consent after a thorough explanation of the study objectives, procedures, potential 
benefits, and risks. Participants were informed that their involvement was voluntary and that they 

could withdraw from the study at any time without consequence. The privacy and confidentiality 
of all patient data were strictly maintained throughout the study. 
 
RESULTS 
Table 1. Characteristics of the Samples 
Characteristics 
Dexmedetomidine 
Fentanyl 
Nilai P 
Age (years) 
43,3 ± 10,5 
42,01 ± 13,23  0,565* 
Gender (%) 
 
 
0,644** 
- Male 
16 
15 
 
- Female 
9 
10 
 
Etiology of Spinal 
Disease (%) 
 
 
0,312** 
- Degenerative 
10 
11 
 
- TB 
3 
3 
 
- Trauma 
8 
9 
 
- Tumor 
BMI  
4 
28,82 ± 8,59 
3 
27,90 ± 9,05  
 
0.590 
Duration of surgery 
(hours) 
5,4 ± 1,34 
5,13 ± 1,76 
0,341* 
Amount of bleeding 
Bleeding class 
I 
283 ± 50,4 
 
0 
351,44 ± 70,8 
 
0 
0,061* 
 
 
II 
III 
IV 
75% 
25% 
0 
52% 
48% 
0 
 
 
 
 
*Test T Independent  
**ChiSquare 
 
As shown in Table 1 Sample Characteristics, there was no statistically significant 
difference between the Dexmedetomidine and Fentanyl groups in terms of age, gender, disease 
etiology, or duration of surgery. However, the amount of bleeding The amount of bleeding during 
surgery showed a difference approaching significance. In the group using Dexmedetomidine, the 
average bleeding was 283 ± 50.4 cc, while in the Fentanyl group the average bleeding was higher, 
which was 351.44 ± 70.8 cc, with p = 0.061. Although not statistically significant, the p value 
approaching the significance limit (0.05) suggests that Dexmedetomidine may have the potential 
to reduce intraoperative bleeding compared to Fentanyl. 
 

Table 2. Comparison Pulse rate changes Between Dexmetomidine and Fentanyl 
Time 
(Minutes) 
Dexmedetomidine (Mean ± 
SD) 
Fentanyl (Mean ± 
SD) 
P-Value 
 
 
 
 
0 
85,0 ± 8,11 
88,2 ± 11,11 
0,311 
5 
83,1 ± 7,98 
88,5 ± 14,13 
0,08 
10 
83,3 ± 7,12 
87,2 ± 11,14 
0,052 
15 
81,7 ± 7,01 
87,1 ± 12,12 
0,003 
20 
80,7 ± 6,92 
87,2 ± 10,4 
0,002 
25 
80,0 ± 8,11 
85,4 ± 13,12 
0,003 
30 
79,5 ± 7,50 
84,8 ± 12,50 
0,004 
60 
78,0 ± 6,90 
83,0 ± 11,20 
0,002 
120 
77,0 ± 6,80 
81,5 ± 10,90 
0,003 
180 
75,0 ± 6,50 
80,0 ± 10,00 
0,001 
240 
73,5 ± 6,10 
79,0 ± 9,80 
0,001 
 
The table above shows a comparison of pulse changes between the groups given 
Dexmedetomidine and Fentanyl from 5 minutes to 240 minutes. The Dexmedetomidine group had 
an average pulse of 83.1 ± 7.98, while the Fentanyl group had 88.5 ± 14.13 with a p-value of 0.08, 
indicating an insignificant difference. At 10 minutes, the pulse of the Dexmedetomidine group 
decreased slightly to 83.3 ± 7.12, while Fentanyl became 87.2 ± 11.14, with a p-value of 0.052, 
which still showed a nearly significant difference. At 15 minutes, the difference in pulse between 
the two groups became more pronounced, with Dexmedetomidine recording 81.7 ± 7.01 and 
Fentanyl 87.1 ± 12.12, with a p-value of 0.003, indicating a significant difference. At 20 minutes, 
the Dexmedetomidine group showed an average heart rate of 80.7 ± 6.92, lower than Fentanyl 
which reached 87.2 ± 10.4, with a p-value of 0.002 indicating a significant difference. At 25 
minutes, the Dexmedetomidine heart rate was 80.0 ± 8.11, while Fentanyl recorded 85.4 ± 13.12 
with a p-value of 0.003, indicating a significant difference. At 30 minutes, Dexmedetomidine 
recorded an average heart rate of 79.5 ± 7.50, while Fentanyl had a heart rate of 84.8 ± 12.50, with 
a p-value of 0.004 indicating a significant difference. At 60 minutes, the pulse of the 
Dexmedetomidine group was 78.0 ± 6.90 and Fentanyl 83.0 ± 11.20 with a p-value of 0.002 
indicating a significant difference. At 120 minutes, the pulse of the Dexmedetomidine group was 

recorded at 77.0 ± 6.80, while Fentanyl 81.5 ± 10.90, with a p-value of 0.003 indicating a 
significant difference. At 180 minutes, the pulse of Dexmedetomidine was 75.0 ± 6.50, while 
Fentanyl 80.0 ± 10.00 with a p-value of 0.001 indicating a significant difference. At 240 minutes, 
Dexmedetomidine recorded a pulse of 73.5 ± 6.10, while Fentanyl was 79.0 ± 9.80 with a p-value 
of 0.001, indicating a significant difference. 
Table 3. Comparison of MAP Between Dexmedetomidine and Fentanyl 
Time 
(Minutes) 
Dexmedetomidine (Mean± 
SD)  
Fentanyl (Mean± SD) P-Value 
0 
83,8 ± 12,58 
85,7 ± 13,11 
0,073 
5 
82,72± 10,02 
85,1 ± 14,12 
0,059 
10 
81,7 ± 10,11 
86,1 ± 11,11 
0,053 
15 
70,7 ± 6,72 
82,1 ± 10,23 
0,002 
20 
70,2 ± 7,21 
81,0 ± 12,30 
0,001 
25 
69,8 ± 7,10 
80,5 ± 11,85 
0,001 
30 
68,2 ± 6,85 
78,2 ± 11,20 
0,002 
60 
66,5 ± 6,70 
76,9 ± 10,80 
0,002 
120 
65,3 ± 6,65 
75,2 ± 10,55 
0,001 
180 
64,1 ± 6,60 
74,0 ± 10,30 
0,001 
240 
63,5 ± 6,60 
73,2 ± 10,30 
0,001 
 
*T Independen 
 
Table 3 shows a comparison of mean arterial pressure (MAP) in 39 patients given 
Dexmedetomidine and Fentanyl during intubation, prone position, and incision. Data are presented 
at time intervals of 0, 5, 10, 15, 20, 30, 60, 120, 180, and 240 minutes, with analysis using the 
Independent T Test. The following is a detailed narrative based on the data: Intubation: At minute 
5, Dexmedetomidine showed a lower MAP (82.72 ± 10.02) compared to Fentanyl (85.7 ± 13.11), 
the value was not statistically significant (P = 0.073). At 10 minutes, MAP in Dexmedetomidine 
(81.7 ± 10.11) was lower than Fentanyl (86.1 ± 11.11), with a P value = 0.053, statistically not 
significant. However, at 15 minutes, the difference was more obvious with MAP 
Dexmedetomidine (70.7 ± 6.72) lower than Fentanyl (82.1 ± 10.23), with P = 002, indicating a 
significant difference. At 20 minutes, Dexmedetomidine still showed a lower MAP (70.2 ± 7.21) 
than Fentanyl (81.0 ± 12.30), with P = 0.01. At 25 minutes, MAP for Dexmedetomidine (69.8 ± 
7.10) was lower than Fentanyl (80.5 ± 11.85), with P = 0.001. At 30 minutes, Dexmedetomidine 
(68.2 ± 6.85) was lower than Fentanyl (78.2 ± 11.20), with P = 0.02. At 60 minutes, MAP for 

Dexmedetomidine (66.5 ± 6.70) was lower than Fentanyl (76.9 ± 10.80), with P = 0.002. At 120 
minutes, the MAP of Dexmedetomidine (65.3 ± 6.65) was lower than that of Fentanyl (75.2 ± 
10.55, with P = 0.001. At 180 minutes, the MAP of Dexmedetomidine (64.1 ± 6.60) was lower 
than that of Fentanyl (74.0 ± 10.30), with P = 0.001. At 240 minutes, the difference in MAP 
between Dexmedetomidine (63.5 ± 6.60) and Fentanyl (73.2 ± 10.30) was significant with P = 
0.001. 
 
DISCUSSION 
Dexmedetomidine has a faster effect in regulating heart rate and MAP, providing better 
hemodynamic stability in patients immediately after intubation. This shows the potential of 
Dexmedetomidine to prevent spikes in blood pressure and heart rate that can occur after anesthesia, 
which is a critical period in anesthesia procedures. In contrast, Fentanyl is slower in reducing 
cardiovascular parameters, although it still provides better pain control during the procedure, but 
does not provide hemodynamic stability as good as Dexmedetomidine in the early phase. 
Dexmedetomidine shows greater superiority in maintaining these parameters stable at longer time 
points. This can be explained by Dexmedetomidine's ability to provide a longer-lasting sedative 
effect and reduce cardiovascular fluctuations that can occur due to significant changes in body 
position. Meanwhile, the use of Fentanyl in this phase tends to show a less consistent decrease, 
with greater fluctuations in heart rate and MAP, indicating that Fentanyl may not be as effective 
as Dexmedetomidine in maintaining cardiovascular stability for a longer duration, such as in the 
prone and incision phases. 
A meta-analysis showed that the use of perioperative dexmedetomidine can reduce cortisol 
and catecholamine levels in the blood and this difference is quite significant when compared with 
placebo, but not significant when compared with other perioperative anesthetic drugs. 
Dexmedetomidine through activation of α2 adrenoceptors in the spinal cord provides an opioid 
sparing effect. In this study, the addition of dexmedetomidine 0.5 μg/kgBW/hour to the use of 
fentanyl 1.5 μg/kgBW/hour, has a synergistic effect. Proven by reducing the total dose of fentanyl 
administration in the study subjects. The administration of fentanyl maintenance in the 
dexmedetomidine group can be titrated down to off, with an average maintenance dose of 0.75 
μg/kgBW/hour and almost no need for additional rescue analgesia during surgery. This was found 
to be significantly different in the control group that only received fentanyl analgesia, where a 

maintenance dose of fentanyl was required up to 2 times greater and rescue analgesia was added 
more frequently during surgery.12,13 
Study by Zhai et al, 2020. This study examined the effects of dexmedetomidine on 
hemodynamic changes and inflammatory responses in patients undergoing off-pump coronary 
artery bypass grafting (OP CABG). Of the 300 patients studied, 123 received dexmedetomidine 
infusion, while the other 116 received physiological saline. The results showed that patients who 
received dexmedetomidine had lower heart rates and mean arterial pressures and lower levels of 
inflammation compared to the control group. Although not significant, IL-10 levels were also 
lower in the control group. Administration of dexmedetomidine was shown to stabilize 
hemodynamics and 45 reduce inflammation during OP CABG.13 
In the context of pharmacodynamics, Dexmedetomidine also improves the stability of the 
cardiovascular system during surgical procedures. By reducing sympathetic activity, it helps 
maintain stable blood pressure and heart rate. The bradycardia effect often observed with 
Dexmedetomidine, although caution should be taken, may be beneficial in conditions where 
control of sympathetic stimulation is desired. These pharmacological effects make 
Dexmedetomidine very useful for maintaining the physiological balance of patients during and 
after surgery, reducing the risk of complications, and supporting a faster and safer recovery.13 
 
CONCLUSION 
The average age in the dexmedetomidine group undergoing spinal surgery was 43.3 ± 
10.5 while in the fentanyl group it was 42.01 ± 13.23. The gender in the dexmedetomidine group 
undergoing spinal surgery was 64% male and 36% female. The duration of surgery in the 
dexmedetomidine group was 5.4 ± 1.34, while in the fentanyl group it was 5.13 ± 1.76.In both 
groups there were significant differences in MAP and HR after 15 minutes. The dexmedetomidine 
group was lower in MAP and HR after 15 minutes compared to the fentanyl group. 
 
 

 
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