Comparative evaluation of two different loading doses of dexmedetomidine with midazolam-fentanyl for sedation in vitreoretinal surgery under peribulbar anaesthesia

Comparison of the Sedative Effects of Dexmedetomidine and Remifentanil in Vitrectomy Surgery: A Retrospective Study

Background Vitrectomy surgery is a painful and lengthy procedure. Therefore, administering sedation to reduce patient agitation provides both surgical comfort and hemodynamic stability. However, various complications can arise during the perioperative period depending on the sedation agent used. In our study, we aimed to evaluate the effects of dexmedetomidine and remifentanil sedation applications on patient hemodynamics and perioperative complications in vitrectomy surgery. Methods Our retrospective study included patients aged 18-70 who underwent vitrectomy surgery between 2021 and 2022 with complete file data and ASA scores of 1-3 after obtaining approval from our hospital's ethics committee. Patients were classified into two groups based on the sedation agent used: Group D for dexmedetomidine and Group R for remifentanil. Demographic data of patients, heart rate, mean arterial pressure, oxygen saturation, and bispectral index values during perioperative monitoring, operation duration, and complications such as perioperative nausea, vomiting, and low saturation were recorded. The data of both groups were statistically evaluated, with p<0.05 values considered statistically significant. Results Because of missing data in 18 out of 58 patient files, these cases were excluded from the study. A total of 40 patients were included in the study, with 20 in Group D and 20 in Group R. The mean age of the patients was 64. Among them, 18 (45%) were male, and 22 (55%) were female. The mean operation duration was 61.8 ± 24.1 minutes in Group D and 56.3 ± 17.2 minutes in Group R. The heart rate in Group D was statistically significantly lower than in Group R, starting from the 20th minute of the perioperative period. There were no significant differences between the groups in terms of mean arterial pressure, oxygen saturation, and bispectral index values. One case of bradycardia occurred in Group D, requiring intervention. Conclusion In vitrectomy surgery, both dexmedetomidine and remifentanil infusions can be used for sedation, but caution is advised regarding bradycardia in Group D. Anticipating potential complications with an experienced anesthesia team is crucial for both patient and surgical comfort.

Levobupivacaine Combined with Cisatracurium in Peribulbar Anaesthesia in Cats Undergoing Corneal and Lens Surgery

The aims of the study included evaluating the effects of levobupivacaine combined with cisatracurium on akinesia and mydriasis when administered by peribulbar injection, and evaluating if the chosen dose of cisatracurium is enough to avoid the use of systemic neuromuscular blockade in cats. The animals were divided into four groups as follows: group L received 1.25 mg kg^-1 levobupivacaine administered by peribulbar injection; group LC received the same dose of levobupivacaine combined with 0.01 mg kg^-1 of cisatracurium administered by peribulbar injection; group C received 0.01 mg kg^-1 of cisatracurium administered by peribulbar injection; group GC received 0.01 mg kg^-1 of cisatracurium intravenously. Physiological variables, intraocular pressure, akinesia, and mydriasis were measured before and up to 30 min after peribulbar injection. The onset of akinesia, duration of akinesia, and train of four (TOF) were evaluated. Physiological variables remained in the physiological range in all groups. Effective akinesia and mydriasis were observed in all groups. The (TOF) was 0.9 in all groups. Throughout the study was observed in group LC a shortened onset of akinesia and a prolonging its duration. The peribulbar injection of cisatracurium and levobupivacaine provided effective akinesia and mydriasis, and shortened the onset of akinesia while prolonging its duration.

Comparison of the Efficacy and Safety of Dexmedetomidine Administered in Two Different Modes Under Procedural Sedation and Analgesia in Plastic Surgery

Background

Dexmedetomidine (DEX), a highly selective α2-adrenergic receptor agonist, is now widely used in procedural sedation and analgesia. This study was designed to observe and compare the efficacy and safety of DEX administered in two different modes.

Methods

In total, 100 patients were randomly divided into two groups to receive intravenous DEX 1 µg/kg over 15 min followed by 0.4–0.7 µg/kg/h infusion or DEX 1 µg/kg over 30 min followed by 0.4–0.7 µg/kg/h infusion. Heart rate (HR), mean arterial pressure (MAP), respiratory rate (RR), bispectral index (BIS), Ramsay Sedation Scores (RSS scores), the lowest respiratory rates (LRR), incidences of respiratory adverse events and frequencies of body movements were recorded. Recovery time, recall of intraoperative events, pain scores in PACU and satisfaction of patients and surgeons were assessed.

Results

The BIS at time points from 5 min after anesthesia to the end of surgery in the intervention group were significantly higher (p < 0.05). The RSS scores at time points from 5 min after anesthesia to immediately after induction with DEX were significantly higher in the intervention group (p < 0.05). The HR at time points from the beginning of surgery to 30 min after local anesthesia, the MAP at time points from 30 min after local anesthesia to the end of surgery, and the RR at time points from 5 min after anesthesia to the end of surgery were significantly higher in the intervention group (p < 0.05). Patients in the intervention group had higher LRR, lower incidences of respiratory adverse events, and shorter recovery time (p < 0.05).

Conclusions

Dexmedetomidine infused with a loading dose over 30 min had less impact on patients’ hemodynamics and respiration and could shorten the recovery time after anesthesia in procedural sedation and analgesia.

Clinical Trial Registration

ClinicalTrials.gov, identifier: ChiCTR1900027958.

Effect of adding dexmedetomidine to 0.75% ropivacaine in peribulbar block for vitreoretinal surgery

Background and Aims

Peribulbar anesthesia is suitable for vitreoretinal (VR) surgery. Dexmedetomidine has been used in peribulbar block (PBB) to improve akinesia and analgesia. We aimed to study the efficacy of adding dexmedetomidine to 0.75% Ropivacaine in PBB for VR surgery. The primary outcome was the requirement of block supplementation and secondary outcome was post-operative analgesic requirement.

Material and Methods

100 adult patients undergoing VR surgery were included in this prospective randomized double-blinded controlled study. The composition of the drug used for PBB in the 3 groups was Group R (8 ml of 0.75% Ropivacaine +0.5 ml normal saline (NS)), Group D25 (8 ml of 0.75% Ropivacaine +25μg Dexmedetomidine) and Group D50 (8 ml of 0.75% Ropivacaine +50 μg Dexmedetomidine).

Results

The groups were comparable in terms of patient demographics. The requirement for block supplementation was 16.7% in Group R (5/30), 12.5% in Group D25 (4/32) and 8.8% in group D50 (3/34) (P = 0.64). The mean time to first request for post-operative analgesia was432 ± 362 min in Group R, 572 ± 339 min in Group D25 and 614 ± 394 min for Group D50 (P = 0.26). There was significant difference in the heart rate (P = 0.047), mean arterial pressure (P = 0.012) at 30 min and sedation (RASS) score at 15, 30, 60 (P < 0.001) and 120 (P = 0.019) min between the D50 and group R. Patients undergoing buckling procedures had significantly shorter time to request for analgesia (P = 0.003).

Conclusion

Addition of dexmedetomidine does not offer advantage over 0.75% Ropivacaine in PBB for vitrectomy. Its benefit in more painful procedures like scleral buckle needs further validation.

Effectiveness and safety of intravenous dexmedetomidine sedation for ophthalmic surgery under regional anesthesia

PURPOSE

To assess the effectiveness and safety of intravenous (IV) dexmedetomidine for sedation in ophthalmic surgery.

METHODS

Prospective, observational, uncontrolled, single-center study. Patients were sedated with a continuous dexmedetomidine IV infusion started 15 min before regional anesthesia administration and maintained up to the end of surgery. Effectiveness of dexmedetomidine was assessed by the Modified Observer's Assessment of Alertness and Sedation (MOAA/S) targeted at 5. Safety was assessed by the incidence of patients' movements/snoring and by the incidence of respiratory and haemodynamic complications. An eleven-point numerical rating scale (NRS) was used to assess the level of satisfaction of both the surgeon and the patient.

RESULTS

123 patients (73 males, mean age: 63 ± 13) were included; 81 (81/123; 65.8%) patients reached the requested MOAA/S score of 5. Any intraoperative movement - mostly voluntary - occurred in 34 (34/123; 27.6%) cases with no need for a switch to general anaesthesia; no ocular complications related to the intraoperative movements occurred. Intraoperative snoring occurred in 30 (30/123; 24.4%) patients and it did not affect the surgical manoeuvres. Respiratory drive depression requiring manual or mechanical ventilation never occurred. Bradycardia occurred in 14 (14/123; 11.3%), cases but only 4 (4/123; 3.2%) patients required atropine administration, which was always effective. Intraoperative analgesia was consistently obtained and both the surgeons and the patients reported a high NRS satisfaction score.

CONCLUSION

Dexmedetomidine provided adequate sedation in patients undergoing ocular surgery under local anaesthesia and showed a good effectiveness and safety profile. Upper airway obstruction, apnoea and snoring can occur.

Practical Considerations for Dexmedetomidine Sedation in Adult Cataract Surgery Under Local/Regional Anesthesia: A Narrative Review

Cataract surgery is predominantly performed under local/regional anesthesia, with or without sedation. The practice pattern of sedation is unknown and seems to vary significantly among institutions and countries, routinely administered in some parts of the world to the other extreme of none at all. The selection of sedative agents and techniques varies widely. Currently, there is no ideal sedative agent. Dexmedetomidine has gained recent attention for sedation in ophthalmic local/regional anesthesia due to its alleged advantages of effective sedation with minimal respiratory depression, decreased intraocular pressure, and reduced pain during the local anesthetic injection; however, they are subject to differing interpretations. Published literature also suggests that although dexmedetomidine sedation for cataract surgery under local/regional anesthesia is potentially useful, its role may be limited due to logistical difficulties in administering the recommended dose.

Evaluation of the effect and safety of dexmedetomidine as an additive to local anesthesia in peribulbar block for vitreoretinal surgery

Purpose:

We conducted a prospective, randomized study to evaluate the efficacy of dexmedetomidine as an additive to peribulbar block for vitreoretinal surgery in terms of onset time of block, hemodynamic stability profile, patient comfort, and surgeon satisfaction.

Methods:

One hundred patients of American Society of Anesthesiologists grade 1 and 2 scheduled for vitreoretinal surgery were randomly assigned into two groups: control group (n = 50) received lignocaine bupivacaine block, and Dex group (n = 50) received lignocaine bupivacaine plus 20 μg dexmedetomidine peribulbar block. Information regarding time for onset of block, hemodynamic data, visual analog scale for pain, sedation levels, total duration of surgery, and surgeon satisfaction levels were collected.

Results:

All the demographic characteristics including age, gender, American Society of Anesthesiologists grade, onset of anesthesia, and duration of surgery were comparable in both groups. At the baseline, there was no statistically significant difference in heart rate, mean arterial pressure, diastolic blood pressure, and respiratory rate between the two groups, with a difference noted in systolic blood pressure at the baseline. There was significant difference noted in the systolic blood pressure and mean arterial pressure at different time intervals with a decreasing trend as time progressed. The mean sedation score was significantly higher in the Dex group than that in the control group. The surgeon satisfaction was higher in the Dex group than that in the control group.

Conclusion:

Dexmedetomidine is a useful and safe drug in combination with lignocaine bupivacaine in peribulbar for vitreoretinal surgery as it maintains hemodynamic stability and provides sedation, which enables full cooperation and potentially better operating conditions.