Comparison of Intraoperative Sedation With Dexmedetomidine Versus Propofol on Acute Postoperative Pain in Total Knee Arthroplasty Under Spinal Anesthesia: A Randomized Trial

The Effect of Postoperative Single-Injection Adductor Canal Block in Total Knee Arthroplasty Under Spinal Anesthesia With Intraoperative Dexmedetomidine Infusion

Background

Single-injection adductor canal block (SACB) is one of the multimodal pain managements in total knee arthroplasty. The effect of an intrathecal local anesthetic is prolonged with an intraoperative dexmedetomidine infusion. Currently, SACB's effect along with the prolonged spinal anesthesia effect by dexmedetomidine has not been studied elsewhere.

Methods

Seventy-eight patients were randomized to either the SACB group (n = 39) or the control group (n = 39). Spinal anesthesia and continuous infusion of dexmedetomidine were performed intraoperatively. The SACB was performed using 15 mL of either 0.5% ropivacaine or normal saline in postanesthesia care unit postoperatively. Primary endpoint examined the average numerical rating scale (NRS) pain scores at 2, 6, 12, and 24 hours after SACB while resting or moving. The secondary outcomes were the morphine equivalent, postoperative nausea and vomiting score, quadriceps strength, and overall satisfaction score.

Results

The SACB group showed a lower average NRS pain score until 24 hours than the control group (2.4 vs 3.3 resting, 3.4 vs 4.1 moving). Resting and moving NRS scores at 6 and 12 hours were significantly lower in the SACB group, whereas no difference was found at 2, 24, and 48 hours, regardless of movement. The satisfaction score was higher in the SACB group than in the control group (9 [7.3-10.0] vs 7 [5.3-8.8]), and morphine equivalent at 2 hours was lower in the SACB group (2 [1-3]) than in the control group (2.9 [1.6-4]).

Conclusions

SACB provided an additional analgesic effect in patients undergoing total knee arthroplasty under spinal anesthesia with continuous dexmedetomidine intravenous infusion.

Dexmedetomidine Prevents Chronic Incisional Pain After Brain Tumor Resection: A Secondary Analysis of the Randomized Control Trial

BACKGROUND

Dexmedetomidine was reported to reduce postoperative acute pain after neurosurgery. However, the efficacy of dexmedetomidine for preventing chronic incisional pain is uncertain.

METHODS

This article is a secondary analysis of a randomized, double-blind, placebo-controlled trial. Eligible patients were randomly allocated to either the dexmedetomidine group or the placebo group. Patients assigned to the dexmedetomidine group were given a 0.6 μg kg -1 dexmedetomidine bolus followed by a 0.4 μg kg -1 h -1 maintenance dose until dural closure; placebo patients were given comparable amounts of normal saline. The primary end point was the incidence of incisional pain at 3 months after craniotomy evaluated by numerical rating scale scores and defined as any score >0. The secondary end points were postoperative acute pain scores, sleep quality, and Short-Form McGill Pain Questionnaire (SF-MPQ-2) at 3 months after craniotomy.

RESULTS

From January 2021 to December 2021, a total of 252 patients were included in the final analysis: the dexmedetomidine group (n = 128) and the placebo group (n = 124). The incidence of chronic incisional pain was 23.4% (30 of 128) in the dexmedetomidine group versus 42.7% (53 of 124) in the placebo group (risk ratio, 0.55; 95% confidence interval, 0.38-0.80; P = .001). The overall severity of chronic incisional pain was mild in both groups. Patients in the dexmedetomidine group had lower acute pain severity on movement than those in the placebo group for the first 3 days after surgery (all adjusted P < .01). Sleep quality did not differ between groups. However, the SF-MPQ-2 total sensory ( P = .01) and neuropathic pain descriptor ( P = .023) scores in the dexmedetomidine group were lower than those in the placebo group.

CONCLUSIONS

Prophylactic intraoperative dexmedetomidine infusion reduces the incidence of chronic incisional pain as well as acute pain score after elective brain tumor resections.

Safety and effcacy of remimazolam tosilate for sedation during combined spinal-epidural anesthesia for orthopedic procedures: a randomized controlled trial

OBJECTIVE

The objective of this study was to assess the efficacy and safety of Remimazolam in the context of combined spinal-epidural anesthesia for sedation during orthopedic surgery.

METHODS

This randomized controlled trial enrolled patients scheduled for orthopedic surgery under combined spinal-epidural anesthesia (N = 80), who were randomly allocated to receive either dexmedetomidine (Group-D) or remimazolam (Group-R). The target sedation range aimed for a Ramsay score of 2-5 or a BIS value of 60-80 to evaluate the effectiveness and safety of remimazolam during sedation.

RESULTS

The time taken to achieve the desired level of sedation was significantly shorter in the remimazolam group compared to the dexmedetomidine group (3.69 ± 0.75 vs. 9.59 ± 1.03; P < 0.0001). Patients in the remimazolam group exhibited quicker recovery, fewer intraoperative adverse events, more consistent vital signs, and greater satisfaction at various time points throughout the surgery.

CONCLUSION

This preliminary study demonstrates that remimazolam tosilate serves as a safe and effective sedative for orthopedic surgery performed under combined spinal-epidural anesthesia, in comparison with dexmedetomidine.

Regional Anesthesia for Arthroscopic Knee Repair in a Patient With Hypertrophic Obstructive Cardiomyopathy (HOCM) Under Monitored Anesthesia Care With Dexmedetomidine Infusion

Patients with hypertrophic obstructive cardiomyopathy (HOCM) who are scheduled for elective, noncardiac surgery present a distinctive challenge for perioperative healthcare providers. The use of general anesthesia and neuraxial anesthesia carries the risk of unpredictable hemodynamic changes and potential complications. Regional anesthesia (RA) emerges as a prudent and effective option for HOCM patients. RA provides advantages such as minimizing hemodynamic fluctuations, avoiding intubation, reducing pharmacologic side effects, facilitating enhanced recovery after surgery, and contributing to greater patient satisfaction. We share the case of a 15-year-old individual diagnosed with HOCM and exercise intolerance, undergoing arthroscopic repair for right patellar instability. In this instance, the patient received preoperative peripheral nerve blocks for surgical anesthesia and underwent repair utilizing monitored anesthesia care (MAC) with a dexmedetomidine (DEX) infusion.

Effect of dexmedetomidine on postoperative nausea and vomiting in female patients undergoing radical thoracoscopic lung cancer resection

Introduction: Postoperative nausea and vomiting (PONV) is a prevalent postsurgical complication. The objective of our study was to compare the effect of different doses of dexmedetomidine on PONV in female patients undergoing radical thoracoscopic lung cancer resection. Methods: A total of 164 female patients undergoing elective thoracoscopic radical lung cancer surgery were enrolled and assigned to one of four groups. Patients received 0.2 μg/kg/h, 0.4 μg/kg/h, 0.8 μg/kg/h dexmedetomidine and normal saline in the Dex1, Dex2, Dex3 and Control groups, respectively. The primary outcome was the incidence of PONV during 48 h postoperatively. The second outcomes included the incidence of PONV and postoperative vomiting (POV) at four time points postoperatively (T1: PACU retention period; T2: PACU discharge to postoperative 12 h; T3: postoperative 12 h-postoperative 24 h; T4: postoperative 24 h-postoperative 48 h), the area under the curve of PONV grade (PONVAUC), PONV grade, POV grade and other postoperative recovery indicators. Results: The incidence of PONV differed among the four groups. The Dex2 group (29.27%) was lower than that in the Dex1 group (61.90%) and Control group (72.50%). The incidence of PONV at T2 in the Dex1 group (11.90%) and Dex2 group (9.76%) was lower than that in the Control group (42.50%). The incidence of PONV at T3 in the Dex2 group (29.27%) was lower than that in the Dex1 group (61.90%) and Control group (62.50%). The PONVAUC was lower in the Dex2 group than in the Control group. The incidence of POV at T3 in the Dex2 and Dex3 groups was lower than that in the Control group. The consumption of remifentanil, norepinephrine, PACU dwell time, VAS scores, postoperative PCA press frequency, and the time for the first postoperative oral intake were different among the four groups. The regression model shows that the Dex2 group is a protective factor for PONV. Conclusion: Dexmedetomidine can reduce the incidence of PONV and accelerate postoperative recovery in female patients undergoing radical thoracoscopic lung cancer resection. Compared with the other two dosages, 0.4 μg/kg/h dexmedetomidine is preferable. Clinical Trial Registration: chictr.org.cn, identifier ChiCTR2300071831.

Comparison of the effect of dexmedetomidine intrathecal injection and intravenous infusion on subarachnoid blockade during knee arthroscopy procedures: a randomized controlled trial

BACKGROUND

Comparison of whether intrathecal dexmedetomidine prolongs spinal anesthesia-associated sensorimotor blockade more than intravenous infusion during knee arthroscopy procedures performed under subarachnoid blockade.

METHODS

Ninety patients aged 18-75 years, ASA class I-II, who underwent knee arthroscopy between October 2022 and April 2023 were randomized into intrathecal、intravenous and control groups.Subjects received three modes of administration: an intrathecal group (2 ml of 1% ropivacaine + 1 ml of 5 μg dexmedetomidine, along with intravenous saline infusion), an intravenous group (intrathecal 2 ml of 1% ropivacaine + 1 ml of 0.9% saline, with dexmedetomidine pumped intravenously at a dose of 0.5 μg/kg/h), and a control group (intrathecal 2 ml of 1% ropivacaine + 1 ml of 0.9% saline, along with intravenous saline infusion). Total analgesic duration, duration of sensory and motor blockade, Ramsay sedation score, Visual Analogue Score (VAS) at different postoperative time points, and occurrence of adverse effects were recorded.

RESULTS

The total analgesia duration was significantly longer in the intrathecal group than in the intravenous and control groups (352.13 ± 51.70 min VS 273.47 ± 62.57 min VS 241.41 ± 59.22 min, P < 0.001).The onset of sensory block was shorter in the intrathecal group than in the intravenous and control groups (4 [3-4]min VS 5 [4-5]min VS 5 [4-5]min; P < 0.001);the onset of motor block was shorter in the intrathecal group than in the intravenous group and the control group (5 [4-5]min VS 5 [5-6]min VS 6[5.5-7]min; P < 0.001).Sedation scores were higher in the intravenous group than in the intrathecal and control groups (P < 0.001). At 5 h postoperatively, the VAS score in the intrathecal group was lower than that in the intravenous and control groups (P < 0.001). At 24 h postoperatively, the VAS score in the intrathecal group was lower than that in the control group (P < 0.001). In addition, the incidence of bradycardia was significantly higher in the intravenous group than in the intrathecal and control groups (30%, 6.5%, and 3.4%, respectively; P = 0.018, P = 0.007).

CONCLUSIONS

Intrathecal administration of dexmedetomidine did prolong the total analgesia duration, as well as accelerate the onset of sensory-motor blockade compared with intravenous infusion, and did not result in any hemodynamic instability or other adverse events at the doses studied.

TRIAL REGISTRATION

This single-center, prospective, RCT has completed the registration of the Chinese Clinical Trial Center at 26/09/2023 with the registration number ChiCTR2300076170.

Perioperative Hypotension in Patients Undergoing Orthopedic Upper Extremity Surgery with Dexmedetomidine Sedation: A Retrospective Study

(1) Background: limited data exist regarding the occurrence of hypotension associated with dexmedetomidine use and its risk factors in the context of intraoperative sedation for patients receiving peripheral nerve blocks. (2) Method: This single-center retrospective study assessed the incidence of hypotension in patients undergoing orthopedic upper extremity surgery with brachial plexus blockade. Patients were classified into three groups: group N (non-sedated), group M (midazolam), and group D (dexmedetomidine), based on their primary intraoperative sedative use. The primary outcome was the incidence of perioperative hypotension, defined as systolic blood pressure (SBP) < 90 mmHg or mean blood pressure (MBP) < 60 mmHg, at a minimum of two recorded time points during the intraoperative period and post-anesthesia care unit stay. Multivariable logistic models for the occurrence of hypotension were constructed for the entire cohort and group D. (3) Results: A total of 2152 cases (group N = 445, group M = 678, group D = 1029) were included in the analysis. The odds ratio for the occurrence of hypotension in group D was 5.68 (95% CI, 2.86 to 11.28) compared with group N. Concurrent use of a beta blocker, longer duration of surgery, and lower preoperative SBP and higher preoperative heart rate were identified as significant risk factors. (4) Conclusions: the increased risk of hypotension and the associated factors should be taken into account before using dexmedetomidine in these cases.

Effect of co-administration of intravenous lidocaine and dexmedetomidine on the recovery from laparoscopic hysterectomy: a randomized controlled trial

BACKGROUND

Some evidences have reported that intravenous lidocaine and dexmedetomidine alone can improve the quality of recovery after surgery. The main purpose of our study to explore whether co-administration of lidocaine and dexmedetomidine infusion could further improve the quality of recovery after laparoscopic hysterectomy compared to either lidocaine or dexmedetomidine administration.

METHODS

A total of 160 subjects were randomly allocated to four groups: the control group (group C) received an equal volume of normal saline, the lidocaine group (group L) received lidocaine (1.5 mg/kg for bolus over 10 min before induction of anesthesia, 1.5 mg/kg/h for continuous infusion), the dexmedetomidine group (group D) received dexmedetomidine (0.5 µg/kg for bolus over 10 min before induction of anesthesia, 0.4 µg/kg/h for continuous infusion), the lidocaine plus dexmedetomidine group (group LD) received lidocaine (1.5 mg/kg for bolus over 10 min before induction of anesthesia, 1.5 mg/kg/h for continuous infusion) and dexmedetomidine combined infusion (0.5 µg/kg for bolus over 10 minutes before induction of anesthesia, 0.4 µg/kg/h for continuous infusion). The primary endpoint was the quality of recovery-40 (QoR-40) scores on postoperative day 1 (POD1). The quality of sleep on POD1, remifentanil total dose, visual analog scale (VAS) pain scores, the number of patients with self-press the pump, time to open eye and extubation, length of postanesthesia care unit (PACU) stay, the incidence of intraoperative bradycardia, hypotension, arrhythmias, hypoxemia in the PACU, and nausea or vomiting within 24 h after surgery were regarded as the secondary outcomes.

RESULTS

The total QoR-40 scores were significantly increased in groups L, D, and LD on POD1 compared with group C (all P<0.05). The total QoR-40 scores were the highest in group LD on POD1 compared to other three groups (all P<0.001). Sleep quality was significantly improved in group LD compared to other three groups on POD1 (all P<0.05). The VAS pain scores were obviously reduced at 8 h in group L and at 4, 8 h in group D after surgery compared to group C and were the lowest in group LD (all P<0.05). The number of patients with self-press the pump was significantly reduced in groups D and LD compared to group C (8(20.0%) and 27(67.5%), P<0.001; 2(5.0%) and 27(67.5%), P<0.001, respectively). Length of PACU stay significantly prolonged in groups D (21.7±3.0) and LD (25.5±4.0) compared to group C (19.6±3.3) (P=0.028, P<0.001). The incidence of intraoperative bradycardia was significantly higher in groups D and LD than in groups C and L (all P<0.001). The rate of hypoxemia was higher in groups D (55.0%) and LD (70.0%) than in groups C (15.0%) and L (20.0%) (all P<0.05). The incidence of nausea was lower in group LD (10.0%) than in group C (37.5%) (P<0.05).

CONCLUSIONS

Co-administration of lidocaine plus dexmedetomidine infusion improved to some extent the quality of recovery on POD1 compared to lidocaine and dexmedetomidine alone, but it significantly increased the incidence of intraoperative bradycardia and hypoxemia in the PACU, and prolonged the length of PACU stay.

Association of intraoperative dexmedetomidine use with postoperative hypotension in unilateral hip and knee arthroplasties: a historical cohort study

PURPOSE

Dexmedetomidine is frequently used as a sedative agent for orthopedic surgery patients undergoing total hip or knee arthroplasty. Although the benefits of dexmedetomidine are well described in the literature, there is also potential for harm, especially regarding the hemodynamic effects of dexmedetomidine in the postoperative setting.

METHODS

This historical cohort study included all primary unilateral total hip or knee arthroplasties conducted from April 2017 to February 2020 in a single, university-affiliated, tertiary care centre (Jewish General Hospital, Montreal, QC, Canada). We used multivariable logistic regression to analyze the predictors for postoperative hypotension, defined as a systolic blood pressure < 90 mm Hg or any systolic blood pressure while on a vasopressor infusion in the postanesthesia care unit. Models were validated using calibration and discrimination with bootstrapping technique.

RESULTS

One thousand five hundred and eighty-eight patients were included in this study. Postoperative hypotension occurred in 413 (26%) patients. Statistically significant predictors for postoperative hypotension included female sex (adjusted odds ratio [aOR], 3.24; 95% confidence interval [CI], 2.29 to 4.58), a history of transient ischemic attack or cerebrovascular accident (aOR, 1.97; 95% CI, 1.04 to 3.72), and intraoperative dexmedetomidine use (aOR, 2.61; 95% CI, 1.99 to 3.42). Moreover, the risk of postoperative hypotension was approximately two times higher than baseline, with a total intraoperative dexmedetomidine dose above 50 μg (relative risk, 1.99; 95% CI, 1.63 to 2.44; P < 0.001). A higher preoperative systolic blood pressure (aOR, 0.98; 95% CI, 0.97 to 0.99) was a protective factor for postoperative hypotension.

CONCLUSION

In this historical cohort study, dexmedetomidine was a strong risk factor for postoperative hypotension in total hip or knee arthroplasty patients. Dexmedetomidine, and particularly at high cumulative doses above 50 μg, should be administered judiciously in high-risk surgical patients to minimize the risk of postoperative hypotension.

Risk factors for dexmedetomidine-associated bradycardia during spinal anesthesia: A retrospective study

Sedation with dexmedetomidine is needed for patients undergoing spinal anesthesia. However, dexmedetomidine sedation increases the incidence of bradycardia. We aimed to identify and to evaluate risk factors for bradycardia in patients undergoing spinal anesthesia with dexmedetomidine sedation. The records of 91 patients who underwent spinal anesthesia with sedation using dexmedetomidine were reviewed retrospectively. For this study, we identified 15 characteristics of included patients from this group who underwent lower leg surgery and had an estimated blood loss of <300 mL. We collected details on potential risk factors for bradycardia from their clinical records. These factors included age, American Society of Anesthesiologists classification, height, weight, sensory level of spinal anesthesia, history of hypertension, diabetes mellitus, loading, and maintenance dose of dexmedetomidine, tourniquet time, initial diastolic and systolic blood pressure, initial heart rate (HR), and anesthesia and surgery duration. The primary endpoint of this study was the occurrence of bradycardia. We identified potential risk factors using logistic regression analysis. The incidence of bradycardia was obtained in 23 (25%) of 91 patients. Initial HR and tourniquet time were significant individual predictive factors for the occurrence of bradycardia. Logistic regression analysis showed that adjusted baseline HR and duration of tourniquet use were risk factors for bradycardia. Patients should be monitored when undergoing spinal anesthesia with sedation using dexmedetomidine for bradycardia when they have a long tourniquet time. A low initial HR could also be a predictive factor for bradycardia.

Pain management after total knee arthroplasty: PROcedure SPEcific Postoperative Pain ManagemenT recommendations

BACKGROUND

The PROSPECT (PROcedure SPEcific Postoperative Pain ManagemenT) Working Group is a global collaboration of surgeons and anaesthesiologists formulating procedure-specific recommendations for pain management after common operations. Total knee arthroplasty (TKA) is associated with significant postoperative pain that is difficult to treat. Nevertheless, pain control is essential for rehabilitation and to enhance recovery.

OBJECTIVE

To evaluate the available literature and develop recommendations for optimal pain management after unilateral primary TKA.

DESIGN

A narrative review based on published systematic reviews, using modified PROSPECT methodology.

DATA SOURCES

A literature search was performed in EMBASE, MEDLINE, PubMed and Cochrane Databases, between January 2014 and December 2020, for systematic reviews and meta-analyses evaluating analgesic interventions for pain management in patients undergoing TKA.

ELIGIBILITY CRITERIA

Each randomised controlled trial (RCT) included in the selected systematic reviews was critically evaluated and included only if met the PROSPECT requirements. Included studies were evaluated for clinically relevant differences in pain scores, use of nonopioid analgesics, such as paracetamol and nonsteroidal anti-inflammatory drugs and current clinical relevance.

RESULTS

A total of 151 systematic reviews were analysed, 106 RCTs met PROSPECT criteria. Paracetamol and nonsteroidal anti-inflammatory or cyclo-oxygenase-2-specific inhibitors are recommended. This should be combined with a single shot adductor canal block and peri-articular local infiltration analgesia together with a single intra-operative dose of intravenous dexamethasone. Intrathecal morphine (100 μg) may be considered in hospitalised patients only in rare situations when both adductor canal block and local infiltration analgesia are not possible. Opioids should be reserved as rescue analgesics in the postoperative period. Analgesic interventions that could not be recommended were also identified.

CONCLUSION

The present review identified an optimal analgesic regimen for unilateral primary TKA. Future studies to evaluate enhanced recovery programs and specific challenging patient groups are needed.

Perioperative medicine role in painful knee prosthesis prevention

Total knee arthroplasty is one of the most frequently performed orthopaedic surgeries. However, up to 20% of patients develop persistent postoperative pain. Persistent postoperative pain may be an extension of acute postoperative pain, but can also occur after more than 3 months without symptoms. Risk factors associated with persistent postoperative pain after arthroplasty have now been characterised within the patient's perioperative context (preoperative, intraoperative and postoperative), and can be grouped under genetic, demographic, clinical, surgical, analgesic, inflammatory and psychological factors. Identification and prevention of persistent postoperative pain through a multimodal and biopsychosocial approach is essential in the context of perioperative medicine, and has been shown to prevent or ameliorate postoperative pain.

No Benefits of Adding Dexmedetomidine, Ketamine, Dexamethasone and Nerve Blocks to an Established Multimodal Analgesic Regimen after Total Knee Arthroplasty

BACKGROUND.

An optimal opioid-sparing multimodal analgesic regimen to treat severe pain can enhance recovery after total knee arthroplasty. We hypothesized that adding 5 recently described IV and regional interventions to multimodal analgesic regimen can further reduce opioid consumption.

METHODS.

In a double-blinded fashion, seventy-eight patients undergoing elective total knee arthroplasty were randomized to either (1) a control group (n=39) that received spinal anesthesia with intrathecal morphine, periarticular local anesthesia infiltration, IV dexamethasone and a single injection adductor canal block or (2) a study group (n=39) that received the same set of analgesic treatments plus 5 additional interventions - local anesthetic infiltration between the popliteal artery and capsule of the posterior knee, intraoperative IV dexmedetomidine and ketamine, and postoperatively, 1 additional IV dexamethasone bolus, and 2 additional adductor canal block injections. The primary outcome measure was 24-hour cumulative opioid consumption after surgery and secondary outcomes were other analgesic, patient recovery and functional outcomes and adverse events.

RESULTS.

Opioid consumption was not different between groups at 24 hours (oral morphine equivalents, mean ± SD), study: 23.7 ± 18.0 mg vs. control: 29.3 ± 18.7 mg; mean difference [95% CI], -5.6 mg [-2.7, 13.9]; P = 0.189) and all other time points after surgery. There were no major differences in pain scores, quality of recovery, or time to reach rehabilitation milestones. Hypotensive episodes occurred more frequently in the study group (25/39 (64.1%) vs. 13/39 (33.3%), p= 0.010).

CONCLUSIONS.

In the presence of periarticular local anesthesia infiltration, intrathecal morphine, single shot adductor canal block and dexamethasone, the addition of 5 analgesic interventions - local anesthetic infiltration between the popliteal artery and capsule of the posterior knee, IV dexmedetomidine, IV ketamine, an additional IV dexamethasone dose and repeated adductor canal block injections - failed to further reduce opioid consumption, pain scores or improve functional outcomes after total knee arthroplasty.

Recent Advances in the Clinical Value and Potential of Dexmedetomidine

Dexmedetomidine, a highly selective α2-adrenoceptor agonist, has sedative, anxiolytic, analgesic, sympatholytic, and opioid-sparing properties and induces a unique sedative response which shows an easy transition from sleep to wakefulness, thus allowing a patient to be cooperative and communicative when stimulated. Recent studies indicate several emerging clinical applications via different routes. We review recent data on dexmedetomidine studies, particularly exploring the varying routes of administration, experimental implications, clinical effects, and comparative advantages over other drugs. A search was conducted on the PubMed and Web of Science libraries for recent studies using different combinations of the words “dexmedetomidine”, “route of administration”, and pharmacological effect. The current routes, pharmacological effects, and application categories of dexmedetomidine are presented. It functions by stimulating pre- and post-synaptic α2-adrenoreceptors within the central nervous system, leading to hyperpolarization of noradrenergic neurons, induction of an inhibitory feedback loop, and reduction of norepinephrine secretion, causing a sympatholytic effect, in addition to its anti-inflammation, sleep induction, bowel recovery, and sore throat reduction effects. Compared with similar α2-adrenoceptor agonists, dexmedetomidine has both pharmacodynamics advantage of a significantly greater α2:α1-adrenoceptor affinity ratio and a pharmacokinetic advantage of having a significantly shorter elimination half-life. In its clinical application, dexmedetomidine has been reported to present a significant number of benefits including safe sedation for various surgical interventions, improvement of intraoperative and postoperative analgesia, sedation for compromised airways without respiratory depression, nephroprotection and stability of hypotensive hemodynamics, reduction of postoperative nausea and vomiting and postoperative shivering incidence, and decrease of intraoperative blood loss. Although the clinical application of dexmedetomidine is promising, it is still limited and further research is required to enhance understanding of its pharmacological properties, patient selection, dosage, and adverse effects.

Dexmedetomidine Combined with Femoral Nerve Block Provides Effective Analgesia Similar to Femoral Nerve Combined with Sciatic Nerve Block in Patients Undergoing Total Knee Arthroplasty: A Randomized Controlled Study

Background

Total knee arthroplasty (TKA) is a severe traumatic procedure, and femoral nerve block (FNB) combined with a sciatic nerve block (SNB) is widely used in TKA. However, injury of the sciatic nerve is clinically reported. Dexmedetomidine (DEX) could reduce stress and inflammation, as well as improve pain in TKA. This study aims to observe the analgesic impact of DEX combined with FNB in TKA.

Methods

Eighty-eight patients undergoing TKA were included and randomly divided into two groups: DF group (FNB combined with DEX 0.6μg/kg before surgery, followed by DEX 0.2–0.4μg/kg/h until articular closure) and SF group (FNB combined with SNB). Each nerve was blocked with 0.375% ropivacaine 20mL, and all patients received general anesthesia routinely. The primary endpoint was the pain visual analog scale (VAS) score during activities at postoperative 24 hours.

Results

There was no statistical difference in the pain VAS scores at any time point. The mean duration of analgesia for patients with rescue analgesic requests was comparable between the two groups: 25.4 ± 6.3 hours in the DF group vs 24.8 ± 6.4 hours in the SF group (two-sample t-test, p=0.738). The total dose of sufentanil was similar between groups (P=0.355). The maintenance dose of propofol and dose of rescue analgesics were comparable (all P>0.05). There were no statistical differences in the incidence of adverse events. However, the time to extubate in the DF group was significantly longer than those in the SF group (P<0.001).

Conclusion

DEX combined with FNB could provide effective analgesia similar to SNB combined with FNB in TKA.

Clinical Trial Registration

The trial was registered at the Chinese Clinical Trial Registry on November 17, 2019 (identifier: ChiCTR1900027552).

Impact of dexmedetomidine supplemented analgesia on delirium in patients recovering from orthopedic surgery: A randomized controlled trial

Background

Dexmedetomidine promotes normal sleep architecture; the drug also improves analgesia. We therefore tested the hypothesis that supplementing intravenous analgesia with dexmedetomidine reduces delirium in older patients recovering from orthopedic surgery.

Methods

In this double-blinded randomized controlled trial, we enrolled 712 older (aged 65–90 years) patients scheduled for major orthopedic surgery. Postoperative analgesia was provided by patient-controlled intravenous sufentanil, supplemented by randomly assigned dexmedetomidine (1.25 μg/mL) or placebo, for up to three days. The primary outcome was the incidence of delirium assessed twice daily with the Confusion Assessment Method. Among secondary outcomes, pain severity was assessed twice daily and sleep quality once daily, each with an 11-point scale where 0 = no pain/the best possible sleep and 10 = the worst pain/the worst possible sleep.

Results

The incidence of postoperative delirium was 7.3% (26 of 354) with placebo and 4.8% (17 of 356) with dexmedetomidine; relative risk 0.65, 95% CI 0.36 to 1.18; P = 0.151. Dexmedetomidine reduced pain both at rest (median difference -1 to 0 points, P ≤ 0.001) and with movement (-1 points, P < 0.001) throughout the first 5 postoperative days; it also improved subjective sleep quality during the first 3 postoperative days: day one median difference -1 point (95% CI -1 to 0), P = 0.007; day two 0 point (-1 to 0), P = 0.010; and day three 0 point (-1 to 0), P = 0.003. The incidence of adverse events was similar in each group.

Conclusions

Supplementing sufentanil intravenous analgesia with low-dose dexmedetomidine did not significantly reduce delirium, but improved analgesia and sleep quality without provoking adverse events.

Trial registration

www.chictr.org.cn: ChiCTR1800017182 (Date of registration: July 17, 2018); ClinicalTrials.gov:NCT03629262 (Date of registration: August 14, 2018).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-021-01441-3.

An Update on Multimodal Pain Management After Total Joint Arthroplasty

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Multimodal analgesia has become the standard of care for total joint arthroplasty as it provides superior analgesia with fewer side effects than opioid-only protocols.

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Systemic medications, including nonsteroidal anti-inflammatory drugs, acetaminophen, corticosteroids, and gabapentinoids, and local anesthetics via local infiltration analgesia and peripheral nerve blocks, are the foundation of multimodal analgesia in total joint arthroplasty.

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Ideally, multimodal analgesia should begin preoperatively and continue throughout the perioperative period and beyond discharge.

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There is insufficient evidence to support the routine use of intravenous acetaminophen or liposomal bupivacaine as part of multimodal analgesia protocols.

Perioperative medicine role in painful knee prosthesis prevention

Total knee arthroplasty is one of the most frequently performed orthopaedic surgeries. However, up to 20% of patients develop persistent postoperative pain. Persistent postoperative pain may be an extension of acute postoperative pain, but can also occur after more than 3 months without symptoms. Risk factors associated with persistent postoperative pain after arthroplasty have now been characterised within the patient's perioperative context (preoperative, intraoperative and postoperative), and can be grouped under genetic, demographic, clinical, surgical, analgesic, inflammatory and psychological factors. Identification and prevention of persistent postoperative pain through a multimodal and biopsychosocial approach is essential in the context of perioperative medicine, and has been shown to prevent or ameliorate postoperative pain.

Safety of treatment options available for postoperative pain

IntroductionPostoperative pain is one of the most common adverse events after surgery and has been shown to increase the risk of other complications. On the other hand, liberal opioid use in the perioperative period is also associated with risk of adverse events. The current consensus is therefore to provide multimodal, opioid minimizing analgesia after surgery.Areas CoveredIn this review, we will discuss the benefits and risks associated with non-opioid analgesics, including non-steroidal anti-inflammatory drugs, gabapentinoids, ketamine, α-2 agonists, and corticosteroids. In addition, we will discuss the general and block-specific risks associated with regional anesthestic techniques.Expert OpinionAdverse events associated with non-opioid analgesics are rare outside their specific contraindicated patient groups, especially when dosed appropriately. α-2 agonists can cause transient hypotension and bradycardia, and gabapentinoids may cause sedation in higher risk patient populations. Regional anesthesia techniques are generally safe when done by an experienced practitioner. We therefore encourage the development of standardized multimodal analgesic protocols, which may facilitate opioid minimization and lead to better patient outcomes.

The Effects of Propofol or Dexmedetomidine Sedation on Postoperative Recovery in Elderly Patients Receiving Lower Limb Surgery under Spinal Anesthesia: A Retrospective Propensity Score-Matched Analysis

Propofol and dexmedetomidine are the two most popular intravenous sedatives during anesthesia. However, data comparing the effects of these two sedatives during spinal anesthesia on postoperative recovery are still insufficient. We retrospectively analyzed the medical records of patients aged ≥65 years who underwent orthopedic surgery under spinal anesthesia between March 2012 and February 2017. The patients were allocated into two groups according to the intraoperative sedatives: the propofol group and dexmedetomidine group. We analyzed the incidence of postoperative delirium, analgesic requirement, and rescue anti-emetic treatment. A total of 1045 patients were included in the analysis. After propensity score matching with the propofol group, the dexmedetomidine group showed a lower incidence of postoperative delirium (odds ratio, 0.19; 95% CI, 0.07–0.56; p = 0.011). Postoperative analgesic and anti-emetic requirement were not significantly different between the two groups (p = 0.156 and 0.245, respectively). Multivariate logistic regression analysis revealed that intraoperative sedation, age, preoperative albumin level, and hip surgery were significantly associated with the incidence of postoperative delirium. This study showed that intraoperative dexmedetomidine sedation under spinal anesthesia during lower limb surgery is associated with a lower incidence of postoperative delirium compared with propofol sedation.

Impact of Dexmedetomidine Infusion on Postoperative Acute Kidney Injury in Elderly Patients Undergoing Major Joint Replacement: A Retrospective Cohort Study

Purpose

Postoperative acute kidney injury (AKI) is a frequent complication in elderly patients that increases morbidity and mortality. Approximately 1.7 million people die from AKI worldwide every year. Dexmedetomidine (Dex) is often used as an adjunct to multimodal analgesia. Our study investigated whether Dex could safely decrease the incidence of AKI in elderly patients undergoing major joint replacement.

Methods

A single-center retrospective study was conducted in patients aged >65 years undergoing major joint replacement. Propensity score–matching analysis was used, and a total of 1,006 patients were matched successfully. The primary outcome was the incidence of postoperative AKI. Secondary outcomes included perioperative adverse complications, opioid consumption, time to extubation, and length of hospital stay.

Results

Among the 1,006 patients included, postoperative AKI occurred in 9.3% (n=94). The Dex group (perioperative Dex infusion) had lower incidence of postoperative AKI than the control group (7.2% vs 11.5%, P=0.017). Compared with the control group, the Dex group had less opioid consumption (P<0.05), reduced time to extubation (P=0.004), and shorter length of hospital stay (P=0.001). The Dex group also showed higher incidence of bradycardia (20.1% vs 15.1%, P=0.038). There were no differences in intraoperative hypotension (19.5% vs 17.5%), postoperative nausea and vomiting (4.2% vs 5.4%), time in PACU (45.0±6.4 vs 45.5±6.2 minutes), or rate of ICU admission (9.7% vs 11.1%) between the Dex group and control group (All P>0.05).

Conclusion

This retrospective study showed Dex infusion in elderly patients undergoing major joint replacement was associated with lower incidence of postoperative AKI, less opioid consumption, and shorter extubation time and hospital stay. However, the Dex group had higher incidence of bradycardia. We found no statistical differences in other perioperative adverse complications between the groups.

Total knee arthroplasty under quadruple nerve block with ropivacaine 0.32%: effect of addition of intravenous dexmedetomidine to intravenous dexamethasone on analgesic duration

BACKGROUND AND OBJECTIVES

Peripheral nerve blocks reduce postoperative pain and enhance recovery after total knee arthroplasty (TKA). This study aims to assess the benefits of addition of intravenous dexmedetomidine (DexM) to intravenous dexamethasone on the analgesic duration of quadruple nerve blocks.

METHODS

This double-blind, randomized, controlled trial prospectively enrolled 90 patients scheduled for TKA under quadruple nerve blocks (sciatic, femoral, obturator, and lateral femoral cutaneous nerves blocks) with 70 mL, 0.32% ropivacaine. All patients received systemic dexamethasone 10 mg. Patients were randomized to receive DexM (2 µg/kg, intravenous) or placebo (1:1 ratio). The primary endpoint was the duration of analgesia defined as the time to first request for rescue analgesia (oxycodone).

RESULTS

Kaplan-Meier curves for the first analgesic request were similar between groups (log-rank test; p=0.27). Median (IQR) duration of analgesia was similar between placebo (1575 min (1211-1952)) and DexM (1470 min (1263-1700)) groups (p=0.56). Cumulative consumption of oxycodone at the 48th hour was 20 mg (10-30) and 30 mg (20-40) in placebo and DexM groups, respectively (p=0.14). The day after surgery, 93% and 89% of patients were able to walk in placebo and DexM groups, respectively (p=0.46). Intravenous DexM was associated with bradycardia, hypotension and longer recovery room stay (p<0.05 for all comparisons).

CONCLUSIONS

In a multimodal analgesic regimen, addition of systemic DexM (2 µg/kg) to systemic dexamethasone does not prolong the analgesic duration of quadruple nerve block with ropivacaine 0.32% after TKA.

TRIAL REGISTRATION NUMBER

NCT03834129.

Postoperative analgesia effects of sulfentanyl plus dexmedetomidine in patients received VATS

Background To evaluate sulfentanyl combined with dexmedetomidine hydrochloride on postoperative analgesia in patients who received video-assisted thoracic surgery (VATS) and its effects on serum norepinephrine (NE), dopamine (DA), 5-hydroxytryptamine (5-HT), and prostaglandin (PGE2).

Material and Methods Ninety-nine non-small cell lung cancer (NSCLC) patients who received VATS were included in the study. All the patients received intravenous inhalation compound anesthesia. Of the 99 cases, 49 subjects (control group) received sulfentanyl for patient controlled intravenous analgesia (PICA) and other 50 cases (experiment group) received sulfentanyl combined with dexmedetomidine hydrochloride for PICA after operation of VATS. The analgesic effects of the two groups were evaluated according to Visual Analogue Scales (VAS) and the Bruggrmann Comfort Scale (BCS). The serum pain mediator of NE, DA, 5-HT, and PGE2 were examined and compared between the two groups in the first 24 h post-surgery.

Results The VAS scores for the experiment group were significant lower than that of control group on the time points of 8, 16, and 24 h post-surgery (pall<0.05), and the BCS scores of the experiment group in the time points of 8, 16, and 24 h were significantly higher than that of controls (p<0.05). However, the VAS and BCS scores were not statistical differently in the time point of 1, 2, and 4 h post-surgery (pall>0.05). The mean sulfentanyl dosage was 63.01 ± 5.14 μg and 67.12 ± 6.91 μg for the experiment and control groups respectively with significant statistical difference (p<0.05). The mean analgesic pump pressing times were 4.30 ± 1.31 and 5.31 ± 1.46 for experiment and control groups respectively with significant statistical difference (p<0.05). The serum NE, DA, 5-HT, and PGE2 levels were significantly lower in the experimental group compared to that of control group in the time point of 12 h post-surgery (pall<0.05). The side effects of nausea, vomiting, delirium, rash, and hypotension atrial fibrillation were not statistically different between the two groups (pall>0.05).

Conclusion Patient controlled intravenous analgesia of sulfentanyl combined with dexmedetomidine hydrochloride was effective in reducing the VAS score and serum pain mediators in NSCLC patients who received VAST.

Impact of Intraoperative Infusion and Postoperative PCIA of Dexmedetomidine on Early Breastfeeding After Elective Cesarean Section: A Randomized Double-Blind Controlled Trial

Objective

Few studies have investigated the effects of dexmedetomidine (DEX) on breastfeeding after cesarean delivery. A randomized double-blind controlled trial was conducted to investigate whether the administration of DEX, immediately after delivery and for patient-controlled intravenous analgesia (PCIA), can be beneficial for breastfeeding.

Patients and Methods

One hundred sixty parturients scheduled for elective cesarean section under spinal anesthesia were randomly allocated to the DEX group (a loading dose of DEX was pumped at 0.5 μg/kg within 10 min, followed by a further infusion of DEX at 0.5 μg/kg/h until the end of the surgery and PCIA for 2 days with DEX plus sufentanil) or the standard care group (infusion saline intraoperatively, and PCIA for 2 days with sufentanil). The number of days required to switch to exclusive breastfeeding within six weeks of delivery, the time to first lactation and breast milk volume on day 1 and day 2 after delivery were recorded. Recovery quality, comfort, anxiety, depression, postoperative analgesia, and adverse reactions of parturients were also assessed.

Results

Compared with the standard care group, parturients in the DEX group could be converted to exclusive breastfeeding earlier (11 [14] vs 8 [10] days, log-rank P=0.025), the first lactation time was sooner (28.38 [13.82] vs 33.79 [14.85] hrs, P=0.024), and the amount of breast milk on the second day after delivery increased (P=0.012). There was no difference between the two groups in postpartum uterine contraction pain, but postpartum rest and movement VAS scores and recovery quality score in the DEX group were better than those in the standard care group (all P<0.05). Moreover, the hospital anxiety and depression scale and anxiety subscale score on the second day after delivery and the comfort score on the third day after delivery in the DEX group were significantly better than those in the standard care group (5 [5] vs 6 [8], 2 [2] vs 3 [3], 83.58 [6.75] vs 80.48 [6.58]; P=0.013, P=0.005, P=0.006, respectively). The incidence of adverse events, such as bradycardia, vomiting, hypersomnia, hypertension and hypotension, was not significantly different between the DEX and standard care groups (6.9% vs 2.7%, 5.6% vs 13.7%, 4.2% vs 0%, 5.6% vs 2.7%, 11.1% vs 8.2%; P=0.275, P=0.158, P=0.366, P=0.681, P=0.556, respectively), except more parturients experienced nausea in the standard care group than in the DEX group (28.8% vs 11.1%, P=0.012). Furthermore, there was no difference in Neonatal Behavioral Neurological Assessment scores on the first and second days after delivery between the DEX and standard care groups (38 [3] vs 37 [2], 38.5 [2] vs 38 [2]; P=0.173, P=0.312, respectively).

Conclusion

The application of DEX in the perioperative period of cesarean section was not only conducive to the early conversion of infant feeding to exclusive breastfeeding but could also improve the recovery quality and comfort of the parturient, optimize analgesia, shorten the time to first lactation, and increase lactation.

Clinical Trials Registration

NCT03805945.

Effect of Intraoperative Sedation with Dexmedetomidine Versus Propofol on Acute Postoperative Pain Following Major Foot Surgery under Popliteal Sciatic Nerve Block: A Randomized Controlled Trial

Intravenous (IV) dexmedetomidine is reported to prolong analgesia following peripheral nerve blocks. Popliteal sciatic nerve block provides effective postoperative analgesia, but some patients still experience severe pain during the early postoperative period. We aimed to evaluate the postoperative analgesic effects of IV dexmedetomidine versus propofol in patients undergoing foot surgeries under popliteal sciatic nerve block. Forty patients were enrolled and randomly assigned to receive either IV propofol (n = 20) or IV dexmedetomidine (n = 20) for intraoperative sedation. All the patients received continuous popliteal sciatic nerve block. The corresponding drug infusion rate was adjusted to achieve a modified observer’s assessment of alertness/sedation score of 3 or 4. The primary outcome was postoperative cumulative opioid consumption during the first 24 h after surgery. Thirty-nine patients were analyzed. The median (interquartile ranges) postoperative cumulative opioid consumption during the first 24 h after surgery was significantly lower in the dexmedetomidine group (15 (7.5–16.9) mg) than in the propofol group (17.5 (15–25) mg) (p = 0.019). The time to first rescue analgesic request was significantly greater in the dexmedetomidine group than in the propofol group (11.8 ± 2.2 h vs. 10.0 ± 2.7 h, p = 0.030) without the prolonged motor blockade (p = 0.321). Intraoperative sedation with dexmedetomidine reduced postoperative opioid consumption and prolonged analgesic duration after a popliteal sciatic nerve block.

Pain relieving effect of dexmedetomidine in patients undergoing total knee or hip arthroplasty: A meta-analysis

BACKGROUND

To evaluate the safety and efficacy of dexmedetomidine in patients undergoing total knee and hip arthroplasty for postoperative pain control.

METHODS

An updated systematic review and meta-analysis of randomized controlled trials (RCTs) identified in systematic searches of MEDLINE, EMBASE, Google Scholar, the Cochrane Database and the Chinese SinoMed Database.

RESULTS

Fourteen RCTs with a total of 1220 patients were included. Overall, dexmedetomidine therapy was associated with significantly decreased pain scores 24 hours after surgery (WMD, -0.36; 95% CI, -0.49 to -0.22; I = 90.0%, P < .001) compared with scores in the control group after total hip arthroplasty (THA) and total knee arthroplasty (TKA). Furthermore, the rate of postoperative delirium was also markedly decreased with dexmedetomidine therapy (RR, 0.38; 95% CI, 0.24 to 0.59; I = 0.0%, P < .001). Moreover, compared with the control group, dexmedetomidine treatment was associated with a decreased risk of postoperative nausea and vomiting in patients undergoing TKA (RR, 0.34; 95% CI, 0.15 to 0.79; I = 0.0%, P = .012), and there was a similar risk of hypotension (RR, 1.03; 95% CI, 0.72 to 1.49; I = 24.4%, P = .87) regardless of whether patients underwent TKA or THA. However, the rate of bradycardia was significantly increased with dexmedetomidine treatment in those undergoing TKA (RR, 6.11; 95% CI, 2.35 to 15.91; I = 0.0%, P < .001).

CONCLUSIONS

Dexmedetomidine therapy seems to be an effective treatment for pain control and postoperative delirium in patients undergoing TKA/THA. However, the incidence of bradycardia is markedly increased in patients undergoing TKA. Hence, much larger prospective clinical studies are warranted to confirm these findings.

Anesthesia for Same-Day Total Joint Replacement

Demand for low-cost, high-quality health care has forced the total joint replacement (TJR) industry to evaluate and mitigate high variable costs. Minimizing hospital stay can significantly reduce total cost of care. A shortened hospital stay does not compromise patient safety or satisfaction, and may reduce perioperative complications compared with multiple-day hospitalizations. Through the use of enhanced recovery clinical pathways, outpatient TJRs have progressively shortened hospitalizations. Successful ambulatory TJR can be accomplished through advances in surgical technique, presurgical patient education, opioid-sparing multimodal analgesia, anesthetic techniques that facilitate rapid recovery, and progressive rehabilitation.

Postoperative pain control after the use of dexmedetomidine and propofol to sedate patients undergoing ankle surgery under spinal anesthesia: a randomized controlled trial

Background: Dexmedetomidine is widely used for conscious sedation in patients undergoing lower-extremity surgery under regional anesthesia. We evaluated the postoperative analgesic effects of intravenous dexmedetomidine given during ankle surgery under spinal anesthesia.

Methods: Forty-three participants underwent repair of lateral angle ligaments under spinal anesthesia. For sedation during surgery, participants were allocated to a dexmedetomidine group (n=22) that received a loading dose of 1 mcg.kg⁻¹ over 10 min, followed by a maintenance dose of 0.2–0.7 μg.kg⁻¹.h⁻¹; and a propofol group (n=21) that received an effective site concentration of 0.5–2.0 μg.mL⁻¹ via target-controlled infusion. The primary outcome was the postoperative, cumulative, intravenous (IV) morphine equivalent dose delivered via IV patient-controlled anesthesia (PCA) and rescue analgesic consumption in the first 24 h after surgery. We recorded sensory and motor block durations.

Results: The postoperative IV morphine equivalent dose was 14.5 mg (0.75–31.75 mg) in the dexmedetomidine group compared to 48.0 mg (31.5–92.5 mg) in the propofol group (median difference, 33.2 mg; 95% confidence interval, 21.0–54.8 mg; P<0.001). The time to the first complaint of surgical site pain was significantly prolonged in the dexmedetomidine group (P<0.001), but the duration of motor block was comparable between the two groups (P=0.55).

Conclusion: IV dexmedetomidine given as a sedative during ankle surgery under spinal anesthesia reduced postoperative opioid consumption in the first 24 h. Thus, intraoperative dexmedetomidine is a versatile sedative adjunct.

Level of evidence: Level I, prospective randomized trial.

Intranasal Low-Dose Dexmedetomidine Reduces Postoperative Opioid Requirement in Patients Undergoing Hip Arthroplasty Under General Anesthesia

BACKGROUND

Patients undergoing total hip arthroplasty (THA) need substantial amount of opioids for postoperative pain management, which necessitates opioid-sparing modalities. Dexmedetomidine is a novel alpha-2-adrenoceptor-activating drug for procedural sedation. In addition to its sedative effect, dexmedetomidine has analgesic and antiemetic effects. We evaluated retrospectively the effect of intraoperatively administered intranasal low-dose dexmedetomidine on postoperative opioid requirement in patients undergoing THA.

METHODS

We included 120 patients with American Society of Anesthesiologists status 1-2, age between 35 and 80 years, and scheduled for unilateral primary THA under general anesthesia with total intravenous anesthesia. Half of the patients received 50 μg of intranasal dexmedetomidine after anesthesia induction, while the rest were treated conventionally. Postoperative opioid requirements were calculated as morphine equivalent doses for both groups. The impact of intranasal dexmedetomidine on postoperative hemodynamics and length of stay was evaluated.

RESULTS

The cumulative postoperative opioid requirement was significantly reduced in the dexmedetomidine group compared with the control group (26.3 mg, 95% confidence interval 15.6-36.4, P < .001). The cumulative dose was significantly different between the groups already at 12, 24, and 36 h postoperatively (P = .01; P = .001; P < .001, respectively). Dexmedetomidine group had lower mean arterial pressure in the postanesthesia care unit compared with the control group (P = .01). There was no difference in the postanesthesia care unit stay or postoperative length of stay between the two groups (P = .47; P = .10, respectively).

CONCLUSION

Compared with the control group, intraoperative use of intranasal low-dose dexmedetomidine decreases opioid consumption and sympathetic response during acute postoperative period in patients undergoing THA.

Comparison of bupivacaine plus intrathecal fentanyl and bupivacaine alone for spinal anesthesia with intravenous dexmedetomidine sedation: a randomized, double-blind, noninferiority trial

BACKGROUND AND OBJECTIVES

Fentanyl is widely used as an intrathecal adjuvant to local anesthetics to enhance the duration of spinal anesthesia. Recent evidence suggests that intravenous dexmedetomidine prolongs the duration of spinal anesthesia. This noninferiority study evaluated whether bupivacaine alone could provide a noninferior duration of block compared with bupivacaine and fentanyl when intravenous dexmedetomidine was administered intraoperatively.

METHODS

Fifty-six patients scheduled for total knee arthroplasty under spinal anesthesia were randomly allocated to receive either bupivacaine 13 mg with intrathecal fentanyl 20 µg (Group BF) or bupivacaine 13 mg (Group B). Both groups underwent intravenous dexmedetomidine sedation throughout the surgery (1 µg kg^-1 for 10 min, followed by 0.5 µg kg^-1 h^-1). The primary outcome was the time to two-segment regression of the sensory block. The noninferiority margin for the mean difference was predefined as -10 min. Secondary outcomes included postoperative pain scores, analgesics consumptions, and the incidences of pruritus, nausea, and vomiting.

RESULTS

There was no significant difference in the two-segment regression time of sensory block (Group B 109.1±25.0 min vs Group BF 104.3±25.9 min; p=0.484). The mean difference in the two-segment regression time between the 2 groups was 4.8 min (95 % CI -8.9 to 18.6), demonstrating the noninferiority of bupivacaine alone. Secondary outcomes showed no significant differences between the two groups.

CONCLUSIONS

The duration of spinal anesthesia with bupivacaine alone is noninferior to that of bupivacaine plus fentanyl in patients receiving intravenous dexmedetomidine intraoperatively. Our results suggest that intrathecal fentanyl may not be required when intravenous dexmedetomidine is administered.

TRIAL REGISTRATION NUMBER

NCT03105115.