Comparison of dexmedetomidine and sufentanil for conscious sedation in patients undergoing awake fibreoptic nasotracheal intubation: a prospective, randomised and controlled clinical trial

Evaluation of different doses of dexmedetomidine for awake fibreoptic nasotracheal intubation in patients undergoing oromaxillofacial and oral malignancy surgeries: A randomised, double-blind study

Background and Aims

In patients undergoing cancer surgeries with anticipated difficult airway, awake fibreoptic nasotracheal intubation (AFONI) is critical for securing the airway. However, different doses of dexmedetomidine (DEX) are yet to be evaluated in these patients. Thus, we compared three doses of DEX for AFONI in patients undergoing oromaxillofacial and oral malignancy surgeries.

Methods

In this randomised, double-blind study, 90 patients aged 18-60 years of either gender, with American Society of Anesthesiologists physical status I/II, and undergoing elective oromaxillofacial and oral malignancy surgeries were randomised to three groups: Group D1 (0.5 µg/kg DEX), Group D2 (1 µg/kg DEX), and Group D3 (1.5 µg/kg DEX). The primary outcome measure was the airway obstruction score. Secondary outcome measures were intubation scores (including vocal movement, coughing, and limb movements) and a 5-point fibreoptic intubation comfort score. Sedation was assessed using the Ramsay sedation score (RSS). One-way ANOVA and Chi-square test were used to assess the association between quantitative and qualitative variables, respectively. A P value of <0.05 was considered statistically significant.

Results

The airway obstruction score was comparable between the groups (P = 0.78). Similarly, vocal movement (P = 0.15), coughing (P = 0.31), limb movement (P = 0.51), and 5-point fibreoptic intubation comfort score (P = 0.49) did not differ between the groups. The mean RSS was significantly greater in Group D3 than in Groups D1 and D2 (P = 0.001).

Conclusions

In combination with topical spray and airway block, all three doses of DEX resulted in comparable airway obstruction scores and thus provided favourable conditions for AFONI.

Comparison of Cricothyroid Membrane Puncture Anesthesia and Topical Anesthesia for Awake Fiberoptic Intubation: A Double-Blinded Randomized Controlled Trial

Background: Awake fiberoptic intubation (AFOI) is commonly used for patients with a difficult airway. The purpose of this study was to evaluate the efficacy of cricothyroid membrane puncture anesthesia and topical anesthesia during AFOI.

Methods: A total of 70 patients (the American Society of Anesthesiologists score I-III) with anticipated difficult airways scheduled for nonemergency surgery with AFOI were randomly slated to receive cricothyroid membrane puncture anesthesia (n = 35) or topical anesthesia (n = 35). Each group received dexmedetomidine at a dose of 1.0 μg/kg and sufentanil at a dose of 0.2 μg/kg over 10 min for conscious sedation before intubation. The endoscopy intubation, post-intubation condition, and endoscopy tolerance as scored by the anesthetists were observed. The satisfaction of the operator regarding the procedure and the satisfaction of the patient 24 h after the surgery were also recorded. We recorded the success rate of the first intubation, intubation time, and hemodynamic changes during the procedure and also the adverse events.

Results: Better intubation scores, operator satisfaction, and satisfaction of the patient were observed in the cricothyroid membrane puncture anesthesia group than in the topical anesthesia group (p < 0.05). The intubation time in the cricothyroid membrane puncture anesthesia group was less than that in the topical anesthesia group (p < 0.05). There were no significant differences in the patient tolerance scores, the success rate of the first intubation, hemodynamic changes, and adverse events between both the groups.

Conclusion: Compared with topical anesthesia, cricothyroid membrane puncture anesthesia provided better intubation conditions and less intubation time with greater satisfaction of the patient and operator during endoscopic intubation.

Clinical Trial Registration: URL: http://www.chictr.org.cn/showproj.aspx?proj=42636, Identifier: ChiCTR 1900025820.

Efficacy of perioperative intravenous dexmedetomidine administration for the prevention of postoperative sore throat: a meta-analysis

Objective

Postoperative sore throat (POST) is an undesirable intubation-related complication after surgery. Several studies have investigated the efficacy of perioperative intravenous dexmedetomidine administration for the prevention of POST, but the results have been inconsistent. We aimed to summarize all existing evidence and draw a more precise conclusion to guide future clinical work.

Methods

PubMed, Cochrane Library, EMBASE and China National Knowledge Infrastructure databases were comprehensively searched for all randomized controlled trials published before 1 February 2021 that investigated the efficacy of dexmedetomidine for the prevention of POST.

Results

Nine studies involving 400 patients were included in our meta-analysis. Compared with the control groups (i.e., saline and anesthetic drugs), perioperative intravenous use of dexmedetomidine significantly reduced the incidence of POST [risk ratio (RR): 0.56; 95% confidence interval (CI): 0.40–0.77; I² = 0%) and coughing on the tube during extubation (RR: 0.58; 95% CI: 0.41–0.82; I² = 0%). Additionally, patients in the dexmedetomidine group were more likely to develop bradycardia (RR: 2.46; 95% CI: 1.28–4.71; I² = 0%) and hypotension (RR: 3.26; 95% CI: 1.14–9.33; I² = 0%) during the administration of dexmedetomidine than those in the control group.

Conclusion

Perioperative intravenous administration of dexmedetomidine has a positive effect on the prevention of POST.

A systematic review and meta-analysis of the safety and efficacy of remifentanil and dexmedetomidine for awake fiberoptic endoscope intubation

BACKGROUND

Awake fiberoptic endoscope intubation (AFOI) is the primary strategy for managing anticipated difficult airways. Adequate sedation, most commonly being achieved with remifentanil and dexmedetomidine, is integral to this procedure. This meta-analysis aimed to compare the safety and efficacy of these 2 sedatives.

METHODS

We conducted electronic searches in Embase, Web of Science, PubMed, Google Scholar, Medline, Springer, and Web of Science with no language restrictions. Studies comparing safety and efficacy between the sole use of remifentanil and dexmedetomidine among patients who underwent AFOI were included. Eight randomized controlled trials, comprising 412 patients, met the inclusion criteria. The primary outcomes were first attempt intubation success rate and incidence of hypoxia. The secondary outcomes were the Ramsay Sedation Scale score at intubation, memory recall of endoscopy, and unstable hemodynamic parameters during intubation.

RESULTS

Dexmedetomidine significantly reduced the incidence of hypoxemia during AFOI (risk ratio: 2.47; 95% confidence [CI]: 1.32-4.64]) compared with remifentanil; however, the first intubation success rates were equivalent (risk ratio: 1.12; 95% CI: 0.87-1.46]. No significant differences between the 2 sedatives were found for the Ramsay Sedation Scale score at intubation (mean difference: -0.14; 95% CI: -0.66-0.38) or unstable hemodynamic parameters during intubation (risk ratio: 0.83; 95% CI: 0.59-1.17). Dexmedetomidine reduced memory recall of endoscopy (risk ratio: 1.39; 95% CI: 1.13-1.72).

CONCLUSIONS

While both remifentanil and dexmedetomidine are effective for AFOI and well-tolerated, dexmedetomidine may be more effective in reducing the incidence of hypoxemia and memory recall of endoscopy.

PROSPERP REGISTRATION NUMBER

CRD42020169612.

A Randomized Controlled Study Comparing Dexmedetomidine-Midazolam with Fentanyl-Midazolam for Sedation during awake Fiberoptic Intubation in Anticipated Difficult Airway

Background:

Awake fibreoptic nasotracheal intubation is an effective technique for the management of patients with difficult airways. Adequate sedation with effective topicalization of the airway is important to overcome discomfort and achieve intubation successfully.

Aim and Objectives:

Our aim was to compare the effectiveness of dexmedetomidine-midazolam with fentanyl-midazolam infusion for providing conscious sedation during fibreoptic intubation in patients with anticipated difficult airway under topical anaesthesia.

Materials and Methods:

Thirty adult patients of ASA physical status classification I and II with anticipated difficult airway and planned for elective awake nasal fibreoptic intubation under conscious sedation were randomly allocated into two groups. Dexmedetomidine 1 μg.kg-1 diluted in 50 ml saline was infused in Group DM over 10 min and Fentanyl 2 μg.kg-1 diluted in 50 ml saline was infused in Group FM over 10 min. Topicalization of the airway was done in all patients. All patients were assessed for sedation score, ease of endotracheal tube placement, patient comfort and cooperation, tolerance to endotracheal tube, any adverse events and recall of procedure.

Results:

The score of the modified OAA/S was comparable between the groups (P > 0.05). Quality of AFOI was comparable in both groups (P > 0.05). The intubation time and first EtCO2 were significantly lower in dexmedetomidine group (P <0.05). Group DM also showed better hemodynamics and less episodes of desaturation than Group FM.

Conclusion:

Fentanyl-midazolam and dexmedetomidine-midazolam are both effective for awake fiberoptic intubation under topical anesthesia. Dexmedetomidine allows better endurance and more stable hemodynamics.

Transnasal Humidified Rapid Insufflation Ventilatory Exchange With Nasopharyngeal Airway Facilitates Apneic Oxygenation: A Randomized Clinical Noninferiority Trial

Background: Transnasal humidified rapid insufflation ventilatory exchange (THRIVE) was used to extend the safe apnea time. However, THRIVE is only effective in patients with airway opening. Nasopharyngeal airway (NPA) is a simple device that can help to keep airway opening. This study aimed to investigate the noninferiority of NPA to jaw thrust for airway opening during anesthesia-induced apnea. Methods: This was a prospective randomized single-blinded noninferiority clinical trial on the use of THRIVE in patients with anesthesia-induced apnea. The participants were randomly allocated to receive NPA or jaw thrust. The primary outcomes were PaO₂ and PaCO₂ at 20 min after apnea, with noninferiority margin criteria of -6.67 and 0.67 kPa, respectively. Results: A total of 123 patients completed the trial: 61 in the NPA group and 62 in the jaw thrust group. PaO₂ at 20 min after apnea was 42.9 ± 14.0 kPa in the NPA group and 42.7 ± 13.6 kPa in the jaw thrust group. The difference between these two means was 0.25 kPa (95% CI, -3.87 to 4.37 kPa). Since the lower boundary of the 95% CI was > -6.67 kPa, noninferiority was established because higher PO₂ is better. PaCO₂ at 20 min after apnea was 10.74 ± 1.09 kPa in the NPA group and 10.54 ± 1.18 kPa in the jaw thrust group. The difference between the two means was 0.19 kPa (95% CI, -0.14 to 0.53 kPa). Since the upper boundary of the 95% CI was <0.67 kPa, noninferiority was established because lower PCO₂ is better. No patient had a SpO₂ < 90% during apnea. Conclusion: When THRIVE was applied during anesthesia-induced apnea, NPA placement kept airway opening and was noninferior to jaw thrust in terms of its effects on PaO₂ and PaCO₂ at 20 min after apnea. Clinical Trial Registration: ClinicalTrials.gov (NCT03741998).

Dexmedetomidine in the Management of Awake Fiberoptic Intubation

Awake Fibreoptic Intubation (AFOI) is, nowadays, the gold standard in predicted difficult airway management. Numerous practice guidelines have been developed to assist clinicians facing with a difficult airway. If conducted without sedation, it is common that this procedure may lead to high patient discomfort and severe hemodynamic responses. Sedation is frequently used to make the process more tolerable to patients even if it is not always easy to strike a balance between patient comfort, safety, co-operation, and good intubating conditions. In the last years, many drugs and drug combinations have been described. This minireview aims to discuss the evidence supporting the use of Dexmedetomidine (DEX) in the AFOI management.

Conscious sedation with dexmedetomidine compared with asleep-awake-asleep craniotomies in glioma surgery: an analysis of 180 patients

OBJECTIVE

Awake craniotomies have become a feasible tool over time to treat brain tumors located in eloquent regions. Different techniques have been applied in neurooncology centers. Both “asleep-awake-asleep” (asleep) and “conscious sedation” were used subsequently at the authors’ neurosurgical department. Since 2013, the authors have only performed conscious sedation surgeries, predominantly using the α2-receptor agonist dexmedetomidine as the anesthetic drug. The aim of this study was to compare both mentioned techniques and evaluate the clinical use of dexmedetomidine in the setting of awake craniotomies for glioma surgery.

METHODS

The authors retrospectively analyzed patients who underwent operations either under the asleep condition using propofol-remifentanil or under conscious sedation conditions using dexmedetomidine infusions. In the asleep group patients were intubated with a laryngeal mask and extubated for the assessment period. Adverse events, as well as applied drugs with doses and frequency of usage, were recorded.

RESULTS

From 224 awake surgeries between 2009 and 2015, 180 were performed for the resection of gliomas and included in the study. In the conscious sedation group (n = 75) significantly fewer opiates (p < 0.001) and vasoactive (p < 0.001) and antihypertensive (p < 0.001) drugs were used in comparison with the asleep group (n = 105). Furthermore, the postoperative length of stay (p < 0.001) and the surgical duration (p < 0.001) were significantly lower in the conscious sedation group.

CONCLUSIONS

Use of dexmedetomidine creates excellent conditions for awake surgeries. It sedates moderately and acts as an anxiolytic. Thus, after ceasing infusion it enables quick and reliable clinical neurological assessment of patients. This might lead to reducing the amount of administered antihypertensive and vasoactive drugs as well as the length of hospitalization, while likely ensuring more rapid surgery.

Awake fiberoptic nasotracheal intubation for patients with difficult airway

Awake fiberoptic nasotracheal intubation is a useful technique, especially in patients with airway obstruction. It must not only provide sufficient anesthesia, but also maintain spontaneous breathing. We introduce a method to achieve this using a small dose of fentanyl and midazolam in combination with topical anesthesia. The cases of 2 patients (1 male, 1 female) who underwent oral maxillofacial surgery are reported. They received 50 µg of fentanyl 2-3 times (total 2.2-2.3 µg/kg) at intervals of approximately 2 min. Oxygen was administered via a mask at 6 L/min, and 0.5 mg of midazolam was administered 1-4 times (total 0.02-0.05 mg/kg) at intervals of approximately 2 min. A tracheal tube was inserted through the nasal cavity after topical anesthesia was applied to the epiglottis, vocal cords, and into the trachea through the fiberscope channel. All patients were successfully intubated. This is a useful and safe method for awake fiberoptic nasotracheal intubation.

Application of lower limb nerve block combined with slow induction of light general anesthesia and tracheal induction in elderly hip surgery

BACKGROUND

This study aims to evaluate the effectiveness and safety of lower limb nerve block combined with slow induction of light general anesthesia and tracheal intubation in hip surgery in the elderly.

METHODS

Thirty elderly patients who underwent hip surgery under the lower limb nerve block were randomly divided into 2 groups: slow induction of light general anesthesia and tracheal intubation group (group M), and laryngeal mask light general anesthesia group (group H). After undergoing total intravenous anesthesia without muscle relaxants, all patients received sciatic nerve, lumbar plexus, and paravertebral nerve blocks. The hemodynamic situations, dosage of anesthetics, time for awakening and extubation (or laryngeal mask removal), and incidence of respiratory adverse reactions in the induction period were recorded.

RESULTS

Compared with baseline levels, the difference in mean arterial pressure (MAP) value at each time point after intubation/laryngeal mask removal in both groups was not statistically significant (P > .05). Furthermore, the time for awakening and extubation/laryngeal mask removal, and anesthetic dosage were significantly decreased in group M, when compared with group H (P < .05). For the incidence of adverse reactions, the incidence of poor sealing and hypoxia was significantly lower in group M than in group H (P < .05), and the incidence of sore throat was significantly lower in group H than in group M (P < .05).

CONCLUSION

Lower limb nerve block combined with slow induction of light general anesthesia and tracheal intubation was associated with smaller anesthetic dosage, and shorter duration of anesthesia induction and extubation/laryngeal mask after surgery.

Placental Histopathology Differences and Neonatal Outcome in Dichorionic-Diamniotic as Compared to Monochorionic-Diamniotic Twin Pregnancies

OBJECTIVE

We aimed to compare the differences in placental histopathology lesions and pregnancy outcome in dichorionic-diamniotic (DCDA) versus uncomplicated monochorionic-diamniotic (MCDA) twin gestations.

STUDY DESIGN

Maternal characteristics, neonatal outcome, and placental histopathology reports of all twin deliveries between 24 and 41 weeks were reviewed. Excluded were pregnancies complicated by twin-to-twin transfusion syndrome, twin anemia-polycythemia sequence, selective intrauterine growth restriction, placenta previa, intrauterine fetal death, and malformation. Placental lesions were classified to maternal/fetal vascular malperfusion lesions. Umbilical cord abnormalities included hypo-/hypercoiling and abnormal insertion. Composite adverse neonatal outcome was defined as 1 or more early complications. Small for gestational age (SGA) was defined as birth weight ≤10th percentile.

RESULTS

The DCDA group (n = 362) was characterized by higher rates of assisted reproductive techniques ( P < .001) and nulliparity ( P = .03) as compared to the MCDA group (n = 65). Gestational age at delivery was similar between groups. Placental maternal vascular malperfusion lesions were more common in placentas from DCDA group (38.2% vs 23.1%; P = .016), while fetal vascular malperfusion lesions and abnormal cord insertion were more common in placentas from MCDA group ( P = .027; P< .001). The SGA and composite adverse neonatal outcome were more common in the MCDA group ( P = .031 and P = .038, respectively). By multivariate regression analysis, composite adverse neonatal outcome was found to be independently associated with the MCDA group, adjusted odds ratio (aOR) = 1.2, 95% confidence interval (CI) = 1.04 to 1.89, P = .041, and with placental fetal malperfusion lesions aOR = 1.3, 95% CI = 1.1 to 2.09, P = .038.

CONCLUSION

Placental pathology differs between MCDA and DCDA twin pregnancies. Adverse neonatal outcome in uncomplicated MCDA twins, as compared to DCDA twins, could be related to increased placental fetal malperfusion lesions and abnormal cord insertion.

Safety and Efficacy of Dexmedetomidine as a Sedative Agent for Performing Awake Intubation: A Meta-analysis

To compare the efficacy and safety of dexmedetomidine with other alternative sedative agents used for performing awake intubation. We conducted a meta-analysis of randomized controlled trials (RCTs) that compared the effects of dexmedetomidine with other alternative sedative agents used during awake intubation. The biomedical databases PubMed, Science Direct, and the Cochrane Library were searched for relevant RCTs with no restriction on the language of publication. The efficacy (level of sedation, success rate for intubation at the first attempt, intubation time, intubation conditions, and patient satisfaction) and safety (incidence of hypertension, hypotension, tachycardia, bradycardia, hypoxia, postsurgical memory, hoarseness, and sore throat) were assessed. Thirteen RCTs with a combined subject population of 591 patients came within the purview of this meta-analysis. Use of dexmedetomidine was associated with a higher Ramsay sedation scale score [mean difference (MD): 1.02, 95% confidence interval (CI), 0.77-1.28, P < 0.00001], vocal cord movement score (MD = 0.72, 95% CI, 0.20-1.24, P = 0.007), coughing scores (MD = 0.66, 95% CI, 0.10-1.22, P = 0.02), limb movement scores (MD = 0.69, 95% CI, 0.47-0.91, P < 0.00001); increased risk of bradycardia [relative risk (RR): 3.03, 95% CI, 1.38-6.68, P = 0.006] and hypotension (RR: 2.87, 95% CI, 1.44-5.75, P = 0.003); and lower risk of hypoxia (RR: 0.32, 95% CI, 0.15-0.70; P = 0.004) and postsurgical memory (RR: 0.50, 95% CI, 0.35-0.72, P = 0.0002). As indicated by our results, dexmedetomidine appears to be an effective and well-tolerated agent for performing awake intubation. Its use was associated with better intubation conditions, preservation of airway patency, and reduced recall of intubation, as compared with the traditional sedative agents. The risk of bradycardia and hypotension was significantly higher with dexmedetomidine as compared with that with other sedatives. However, these were easily managed with atropine and vasoactive agents.

Evaluation of different doses of dexmedetomidine alone versus the combination of dexmedetomidine and fentanyl in sedation during awake fiberoptic intubation in oral cancer surgery patients: A prospective, randomized, double-blind clinical trial

BACKGROUND

Awake fiberoptic intubation (AFOI) is one of the principal techniques in the management of difficult airway in oral cancer surgery. We hypothesized that the addition of a small dose of fentanyl could improve the sedative criteria of dexmedetomidine during AFOI technique, without the need to increase the dose of dexmedetomidine which may be associated with airway compromise.

PATIENTS AND METHODS

One hundred and fifty American Society of Anesthesiologists physical status 1 and 2 patients planned for AFOI for oral cancer surgery patients were allocated into three groups (fifty patients each). Group D1: Received an infusion of 1 μcg/kg dexmedetomidine diluted in 50 ml saline over 20 min. Group D2: Received an infusion of 2 μcg/kg dexmedetomidine diluted in 50 ml saline over 20 min. Group DF: Received an infusion of 1 μcg/kg dexmedetomidine added to 1 μcg/kg fentanyl diluted in 50 ml saline over 20 min. AFOI was done by topical anesthesia and with the same technique in all patients. All patients were assessed for: airway obstruction, intubation scores (vocal cord movement, coughing, and limb movement), fiberoptic intubation scores, and hemodynamic variables. Any episode of bradycardia or hypoxia was recorded and managed.

RESULTS

Group D2 showed more incidence of airway obstruction than the other two groups. Limb movement scores were more in Group D1 compared to the other two groups. All groups were comparable as regard fiberoptic intubation scores, coughing, and vocal cord opening scores.

CONCLUSION

Adding a low dose of fentanyl (1 μcg/kg) to a low dose of dexmedetomidine can prevent the risk of airway obstruction associated with increasing the dose of dexmedetomidine while achieving the same favorable intubation scores.

Efficacy of Dexmedetomidine as a Sole Sedative Agent in Small Diagnostic and Therapeutic Procedures: A Systematic Review

Dexmedetomidine is an upcoming agent with sedative, anxiolytic, and analgesic properties. This review summarizes empirical evidence for the efficacy of dexmedetomidine as a sole sedative agent, and its effectiveness for small diagnostic and therapeutic procedure, in comparison with other frequently used sedatives. All randomized controlled trials on the effect of dexmedetomidine were reviewed. Pain level, patient satisfaction, operator satisfaction, procedure duration, recovery time, and hemodynamic and respiratory characteristics were examined. A total of 1993 patients (1,621 adults; 372 children) from 35 studies were included. In the adult studies, dexmedetomidine yielded significantly lower pain levels compared to the other sedatives (in 31.25% of the included studies) and significantly more patient satisfaction (68.2%). In studies on children, more favorable results concerning respiratory safety and the level of adequate sedation were found compared to the control sedatives. Implications for future studies are discussed.

Dexmedetomidine-midazolam versus Sufentanil-midazolam for Awake Fiberoptic Nasotracheal Intubation: A Randomized Double-blind Study

BACKGROUND

Awake fiberoptic intubation (AFOI) is usually performed in the management of the predicted difficult airway. The aim of this study was to evaluate the feasibility of dexmedetomidine with midazolam (DM) and sufentanil with midazolam (SM) for sedation for awake fiberoptic nasotracheal intubation.

METHODS

Fifty patients with limited mouth opening scheduled for AFOI were randomly assigned to two groups (n = 25 per group) by a computer-generated randomization schedule. All subjects received midazolam 0.02 mg/kg as premedication and airway topical anesthesia with a modified "spray-as-you-go" technique. Group DM received dexmedetomidine at a loading dose of 0.5 μg/kg over 10 min followed by a continuous infusion of 0.25 μg·kg-1·h-1, whereas Group SM received sufentanil at a loading dose of 0.2 μg/kg over 10 min followed by a continuous infusion of 0.1 μg·kg-1·h-1. As necessary, since the end of the administration of the loading dose of the study drug, an additional dose of midazolam 0.5 mg at 2-min intervals was given to achieve a modified Observers' Assessment of Alertness/Sedation of 2-3. The quality of intubation conditions and adverse events were observed.

RESULTS

The scores of ease of the AFOI procedure, patient's reaction during AFOI, coughing severity, tolerance after intubation, recall of the procedure and discomfort during the procedure were comparable in both groups (z = 0.572, 0.664, 1.297, 0.467, 0.895, and 0.188, respectively, P > 0.05). Hypoxic episodes similarly occurred in the two groups, but the first partial pressure of end-tidal CO2after intubation was higher in Group SM than that in Group DM (45.2 ± 4.2 mmHg vs. 42.2 ± 4.3 mmHg, t = 2.495, P < 0.05).

CONCLUSIONS

Both dexmedetomidine and sufentanil are effective as an adjuvant for AFOI under airway topical anesthesia combined with midazolam sedation, but respiratory depression is still a potential risk in the sufentanil regimen.

Dexmedetomidine versus remifentanil for sedation during awake intubation using a Shikani optical stylet: a randomized, double-blinded, controlled trial

Background

The purpose of this study was to compare the efficacy and safety of dexmedetomidine versus remifentanil for sedation during awake intubation using a Shikani optical stylet (SOS).

Methods

Sixty-eight patients with cervical trauma or severe cervical spondylosis undergoing cervical spinal surgery were enrolled in this prospective study. They were randomly assigned to receive dexmedetomidine (Group D) or remifentanil (Group R). In Group D, the patients received an intravenous loading dose of dexmedetomidine 1 μg · kg⁻¹ over 10 min followed by a continuous infusion of 0.7 μg · kg⁻¹ · h⁻¹. In Group R, a target-controlled infusion of remifentanil was administered to achieve a plasma concentration of 2.5 ng · ml⁻¹, increased to 3 ng · ml⁻¹ 10 min later. An endotracheal tube was inserted using a SOS under dexmedetomidine or remifentanil sedation after topical anesthesia to the airway. Midazolam was given as rescue sedation. We recorded the first attempt intubation success rate, the dose of midazolam, duration of intubation, Ramsay Sedation Scale (RSS) score, tracheal tube tolerance score, duration of drug infusion, adverse events and patient satisfaction score.

Results

The RSS score was significantly higher in Group D than in Group R. First attempt success rate, rescue midazolam dose and the duration of intubation did not differ between the groups. Patients in Group R were significantly more tolerant of the tracheal tube. The incidence of hypoxia was significantly higher in Group R than Group D, but there was no significant difference in the incidence of other adverse events between the groups. The hemodynamic responses of the two groups were similar, but more patients in Group R were able to recall airway instrumentation.

Conclusions

Both dexmedetomidine and remifentanil are effective sedatives for awake intubation using an SOS. Although the first attempt success rates were similar, patients sedated with remifentanil tolerated the tracheal tube better after intubation with moderately increased risk of desaturation.

Trial registration

www.chictr.org.cn; ChiCTR-TRC-13003052 (February 4th, 2013).

Hypertensive disorders during monozygotic and dizygotic twin gestations: A population-based study

OBJECTIVE

To determine whether the incidence of hypertensive disorders is different in monozygotic compared to dizygotic twin pregnancies.

METHODS

A registry-based survey of twin pregnancies delivered during 2003 to 2012. We used the best clinical estimate of zygosity based on the concept that all monochorionic twins are monozygotic and all unlike-sex pairs are dizygotic, thus excluding same-sex dichorionic twin gestations for which zygosity cannot be ascertained on clinical grounds. Study cohorts were twin pregnancies with or without preeclampsia and gestational hypertension.

RESULTS

A total of 3419 twin gestations met the inclusion criteria, of which 442 (12.9%) were monochorionic and 1255 (36.7%) were unlike-sex twins, excluding 1722 same-sex dichorionic twin gestations (50.4%). There was no significant difference in the incidence of preeclampsia (OR: 0.9; 95% CI: 0.4-2.0 for monozygotic males and OR: 0.6; 95% CI: 0.3-1.4 for monozygotic females) and gestational hypertension (OR: 0.7; 95% CI: 0.2-2.5 for monozygotic males, and OR: 0.7; 95% CI: 0.2-2.3 for monozygotic females) between monochorionic and unlike-sex pairs. Maternal prepregnancy obesity and nulliparity were the only significant associated factors of preeclampsia (OR: 3.8; 95% CI: 2.0-7.0, and OR: 2.5; 95% CI: 1.4-4.4, respectively). Maternal prepregnancy obesity (OR: 5.5; 95% CI: 2.5-12.2), maternal age ≥36 years (OR: 2.5; 95% CI: 1.1-6.1), and family history of hypertension (OR: 2.6; 95% CI: 1.3-5.1) were significantly associated with gestational hypertension.

CONCLUSION

Based on a large population-based dataset and on the best clinical estimate of twin zygosity, it appears that zygosity is not associated with hypertensive disorders in twin gestations.