European Journal of Cardiovascular Medicine

Awake fibreoptic nasotracheal intubation is a widely accepted technique for managing anticipated difficult airways, particularly in patients with anatomical abnormalities, airway trauma, morbid obesity, or cervical spine instability [1–3]. It allows for maintaining spontaneous ventilation and continuous airway evaluation. However, despite adequate topical anaesthesia, the procedure may still be uncomfortable for the patient [4]. One of the major challenges is achieving optimal sedation and anxiolysis while maintaining a patent airway and adequate ventilation, especially in critical airway cases.

Sedation plays a crucial role in ensuring patient comfort and procedural success during awake intubation. The ideal sedative should provide anxiolysis, amnesia, and analgesia without causing respiratory or cardiovascular compromise [5]. Over the past few decades, a variety of sedatives have been used, including benzodiazepines, opioids, alpha-2 agonists, and intravenous induction agents such as midazolam, fentanyl, remifentanil, clonidine, dexmedetomidine, ketamine, and propofol—either alone or in combination [5–9].

The combination of midazolam and fentanyl is commonly used. Midazolam offers sedation, anxiolysis, and amnesia, while fentanyl suppresses airway reflexes and minimizes discomfort. However, this combination may depress respiratory function and increase the risk of hypoxemia and aspiration [10,11].

Dexmedetomidine, a selective alpha-2 adrenergic agonist, is emerging as a preferred agent for awake fiberoptic intubation. It provides sedation, anxiolysis, hypnosis, analgesia, amnesia, and antisialagogue effects, with minimal respiratory depression. It also helps maintain hemodynamic stability and allows cooperative sedation [5,12–15].

Given these considerations, we conducted a randomized study to compare the effectiveness and safety of dexmedetomidine versus the midazolam-fentanyl combination for awake fiberoptic intubation, aiming to identify the superior agent for facilitating intubation in patients with anticipated difficult airways.

AIMS AND OBJECTIVES:

1. To compare the effects of dexmedetomidine and the combination of fentanyl with midazolam on hemodynamic stability during awake fiberoptic intubation.
2. To assess and compare the level of sedation achieved by dexmedetomidine and fentanyl-midazolam using the Ramsay Sedation Scale.
3. To evaluate and compare the ease of intubation between the two groups using a standardized intubation scoring system.

This prospective, double-blinded, randomized, parallel-group study was conducted over 18 months (Nov 2022–May 2024) at the Government General Hospital, Guntur.

Exclusion criteria included patient refusal, emergency surgeries, difficult airway, comorbidities like cardiac/renal/liver disorders, hypersensitivity to study drugs, psychiatric illness, and unstable vitals.

Sixty ASA grade I and II patients (age 18–50 years, BMI 16–30) scheduled for elective head and neck surgeries were randomized into two groups (n=30 each):

• Group D received dexmedetomidine 1 mcg/kg over 10 mins followed by 0.7 mcg/kg/hr infusion;
• Group FM received fentanyl 2 mcg/kg and midazolam 40 mcg/kg over 10 mins followed by normal saline infusion.

Double blinding was maintained by having drugs prepared by an independent anaesthesiologist. Sedation was initiated after pre-anaesthetic evaluation, airway preparation with 4% lignocaine nebulization, and glycopyrrolate premedication. Intubation was performed once the Ramsay sedation score reached grade 2. Parameters such as heart rate, SpO₂, blood pressure, sedation scores, comfort scores (modified Ambu scale), intubation ease (vocal cord movement score), intubation time, and airway trauma were recorded during and post-intubation.

Comfort was assessed across seven parameters with a maximum score of 35. Hemodynamic and sedation parameters were monitored at baseline, during, and post-intubation at intervals (6, 8, and 10 minutes). Categorical data were analysed using Chi-square, and continuous variables with independent t-tests. A p-value <0.05 was considered statistically significant.

Data were entered into a master sheet and analysed using SPSS software. The study was designed to evaluate hemodynamic stability, sedation, comfort, intubation ease, and safety between the two regimens.

The study population showed an even age distribution, with most participants falling within the 21–40 years age group. Group D had a higher representation in the 41–60 age range, while Group FM had slightly more participants in the ≤20 and >60 categories. Gender distribution was equal across both groups, with 30 males and 30 females overall, ensuring balance in gender-related variables.

Figure 1: Distribution of participants based on ASA grading

The majority of participants belonged to ASA Grade I, with a slightly higher number of ASA Grade II patients in Group D compared to Group FM.

Figure 2: Distribution Of Participants According to Mallampati Score

In terms of airway assessment, Group D had more participants with Mallampati Class I scores, indicating an easier airway, whereas Group FM had a higher frequency of Class III scores, suggesting a greater likelihood of difficult intubation.

Thyromental distance was greater than 6.5 cm in 96.7% of participants, with an equal distribution between both groups, indicating a generally low risk of difficult airway across the study population.

HEMODYNAMIC STABILITY DURING AWAKE FIBEROPTIC INTUBATION

Table 1: Group D Haemodynamic stability

Table 2: Group Fm Haemodynamic stability

Figure 3: Haemodynamic stability of both groups

Group D maintained a stable heart rate, blood pressure, and mean arterial pressure (MAP) throughout the procedure, indicating better haemodynamic control. In contrast, the Fentanyl-Midazolam (FM) group showed significant cardiovascular stimulation, particularly between 4- and 6-minutes post-intubation, with marked increases in heart rate, systolic and diastolic blood pressure, and MAP. However, by 10 minutes post-intubation, all haemodynamic parameters in both groups had returned to near-baseline levels, reflecting a transient nature of the changes in the FM group.

Figure 4: Line diagram of HR and Mean SBP between the groups

Figure 5: Line diagram of Mean DBP and Mean MAP between the groups

The line graphs illustrate the trends in heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) over time for Group D and Group FM. Both groups begin with comparable baseline values and show no significant differences two minutes before intubation. However, following intubation, Group FM exhibits a marked rise in all parameters, with HR and SBP peaking at 6 and 4 minutes, respectively. DBP and MAP also significantly increase in Group FM at 2-, 4-, and 6-minutes post-intubation. In contrast, Group D maintains relatively stable cardiovascular parameters throughout the observation period. By 8 to 10 minutes post-intubation, the values for all parameters in both groups converge, indicating a return to baseline levels. These findings suggest that Group FM experiences a transient but significant haemodynamic response to intubation, whereas Group D shows a more stable profile.

LEVEL OF SEDATION ASSESSMENT (RAMSAY SEDATION SCALE)

Table 3: Sedation Score Comparison

Sedation Level Interpretation: The Ramsay Sedation Score showed that Group FM had more patients at the cooperative and tranquil level (score 2), indicating better sedation control, while Group D had more patients at deeper sedation levels (scores 3 and 4). Group FM exhibited higher restlessness (score 1) and lower frequencies at deeper sedation levels (scores 4–6), whereas Group D had a more balanced distribution across moderate to deep sedation levels.

EASE OF INTUBATION ASSESSMENT

Table 4: Intubation Time and Total COMFORT Score Between Group D and Group FM

*Statistically significant

Group D demonstrated a significantly shorter intubation time (15.42 seconds) compared to Group FM (20.65 seconds), with a p-value of 0.000, indicating a statistically significant difference. Additionally, the total COMFORT score, which reflects patient discomfort and stress, was markedly lower in Group D (10.00) than in Group FM (15.87), also with a highly significant p-value of 0.000. These findings suggest that Group D not only facilitated quicker intubation but also provided better comfort and sedation compared to the Fentanyl-Midazolam combination.

Table 5: Intubation Complications

Airway trauma was observed in 4 patients (44.4%) in Group D and 5 patients (55.5%) in Group FM. Although slightly more cases occurred in the FM group, the difference was not statistically significant (χ² = 0.130, p = 0.718).

Table 6: COMFORT Scale Component Analysis

*Statistically significant

All components of the COMFORT scale—alertness, calmness, respiratory response, crying, physical movement, muscle tone, and facial tension—showed significantly lower scores in Group D compared to Group FM, with p-values < 0.05 for all comparisons. Lower scores indicate better sedation and less distress. Notably, the most significant differences were observed in crying, respiratory response, and calmness.

Table 7: Overall Intubation Ease Summary

*Statistically significant

Group D demonstrated superior overall ease of intubation compared to Group FM. Intubation was significantly faster in Group D (15.42s vs. 20.65s, p < 0.001), with better patient cooperation and higher comfort levels as indicated by lower sedation and COMFORT scores (p < 0.001 for both). The complication rates were comparable between the two groups, showing no significant difference (p = 0.718)

This study evaluated the safety and efficacy of dexmedetomidine (Group D) versus a midazolam-fentanyl combination (Group FM) for sedation during awake fiberoptic intubation (AFOI). Outcomes assessed included hemodynamic parameters, sedation and comfort scores, and airway trauma incidence.

Demographics:
The mean age of participants was 39.17 ± 11.92 years in Group D and 35.7 ± 13.11 years in Group FM, reflecting a relatively younger cohort compared to previous studies [43,51]. Mean weight and height were similar between groups (63.43 ± 12.91 kg; 164.65 ± 7.17 cm), consistent with earlier findings [16]. The average BMI indicated a healthy range (23.21 ± 3.79 kg/m²), higher than that reported by Sayeed et al. [6]. Most patients exhibited Mallampati Class I–II and thyromental distances >6.5 cm, aligning with previous literature [6].

Hemodynamic Stability: Dexmedetomidine provided superior hemodynamic stability with significantly lower heart rate, systolic, diastolic, and mean arterial pressures post-intubation compared to midazolam-fentanyl, which showed marked elevations indicative of stress response [17-22]. These effects are attributed to dexmedetomidine’s central sympatholytic and vagomimetic properties [17]. Findings are consistent with multiple prior studies demonstrating improved cardiovascular stability with dexmedetomidine [7,21].

Respiratory Outcomes: Oxygen saturation remained stable and near 100% in both groups throughout the procedure, with no significant desaturation events. However, literature suggests a higher incidence of desaturation with fentanyl-midazolam sedation due to respiratory depression, unlike dexmedetomidine which preserves respiratory drive [19,22–25].

Intubation Time and Sedation Quality: The dexmedetomidine group had significantly shorter intubation times (15.4 vs. 20.65 seconds) and deeper sedation (Ramsay Sedation Score 2.87 vs. 1.7), facilitating smoother intubation and better patient cooperation [43,50]. Cooperative sedation with dexmedetomidine allows patients to be easily aroused and communicative despite sedation [26–28].

Patient Comfort: Patients sedated with dexmedetomidine reported higher comfort levels and less agitation during the procedure, consistent with previous reports [2,7,29,16,20].

Dexmedetomidine proved superior to the fentanyl-midazolam combination for awake fiberoptic intubation. It provided better hemodynamic stability and deeper, more cooperative sedation. Patients in the dexmedetomidine group experienced greater comfort and ease during intubation. Intubation conditions were smoother with fewer complications in the dexmedetomidine group.

Both groups maintained adequate oxygen saturation without respiratory depression.

Dexmedetomidine is recommended as the preferred agent for awake fiberoptic intubation in difficult airway cases.

CONFLICT OF INTEREST: No

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