Pharmacology of sedative-analgesic agents: dexmedetomidine, remifentanil, ketamine, volatile anesthetics, and the role of peripheral Mu antagonists

The impact of ketamine on outcomes in critically ill patients: a systematic review with meta-analysis and trial sequential analysis of randomized controlled trials

BACKGROUND

This meta-analysis aims to evaluate the effects of ketamine in critically ill intensive care unit (ICU) patients.

METHODS

We searched for randomized controlled trials (RCTs) in PubMed, Scopus, and the Cochrane Library; the search was performed initially in January but was repeated in December of 2023. We focused on ICU patients of any age. We included studies that compared ketamine with other traditional agents used in the ICU. We synthesized evidence using RevMan v5.4 and presented the results as forest plots. We also used trial sequential analysis (TSA) software v. 0.9.5.10 Beta and presented results as TSA plots. For synthesizing results, we used a random-effects model and reported differences in outcomes of two groups in terms of mean difference (MD), standardized MD, and risk ratio with 95% confidence interval. We assessed the risk of bias using the Cochrane RoB tool for RCTs. Our outcomes were mortality, pain, opioid and midazolam requirements, delirium rates, and ICU length of stay.

RESULTS

Twelve RCTs involving 805 ICU patients (ketamine group, n=398; control group, n=407) were included in the meta-analysis. The ketamine group was not superior to the control group in terms of mortality (in five studies with 318 patients), pain (two studies with 129 patients), mean and cumulative opioid consumption (six studies with 494 patients), midazolam consumption (six studies with 304 patients), and ICU length of stay (three studies with 270 patients). However, the model favored the ketamine group over the control group in delirium rate (four studies with 358 patients). This result is significant in terms of conventional boundaries (alpha=5%) but is not robust in sequential analysis. The applicability of the findings is limited by the small number of patients pooled for each outcome.

CONCLUSIONS

Our meta-analysis did not demonstrate differences between ketamine and control groups regarding any outcome except delirium rate, where the model favored the ketamine group over the control group. However, this result is not robust as sensitivity analysis and trial sequential analysis suggest that more RCTs should be conducted in the future.

Effect of Dexmedetomidine on Postpartum Depression in Women With Prenatal Depression: A Randomized Clinical Trial

Importance

Postpartum depression (PPD) is emerging as a major public health problem worldwide. Although the particular period and context in which PPD occurs provides an opportunity for preventive interventions, there is still a lack of pharmacologic prevention strategies for PPD.

Objective

To assess the efficacy and safety of dexmedetomidine for prevention of PPD among women with prenatal depression undergoing cesarean delivery.

Design, Setting, and Participants

This randomized clinical trial enrolled 338 women who screened positive for prenatal depression at 2 hospitals in Hunan, China from March 28, 2022, to April 16, 2023. Women with an Edinburgh Postnatal Depression Scale score of more than 9 who were 18 years of age or older and were scheduled for elective cesarean delivery were eligible.

Interventions

Eligible participants were randomly assigned in a 1:1 ratio to either the dexmedetomidine group or the control group via centrally computer-generated group randomization. Dexmedetomidine, 0.5 μg/kg and 0.9% saline were intravenously infused for 10 minutes after delivery in the dexmedetomidine and control groups, respectively. After infusion, sufentanil or dexmedetomidine plus sufentanil was administered via patient-controlled intravenous analgesia for 48 hours in the control group and dexmedetomidine group, respectively.

Main Outcomes and Measures

The primary outcome was positive PPD screening results at 7 and 42 days post partum, defined as a postpartum Edinburgh Postnatal Depression Scale score of more than 9. Analysis was on an intention-to-treat basis.

Results

All 338 participants were female, with a mean (SD) age of 31.5 (4.1) years. Positive PPD screening incidence at 7 and 42 days post partum in the dexmedetomidine group vs the control group was significantly decreased (day 7, 21 of 167 [12.6%] vs 53 of 165 [32.1%]; risk ratio, 0.39 [95% CI, 0.25-0.62]; P < .001; day 42, 19 of 167 [11.4%] vs 50 of 165 [30.3%]; risk ratio, 0.38 [95% CI, 0.23-0.61]; P < .001). The dexmedetomidine group showed no significant difference in adverse events vs the control group (46 of 169 [27.2%] vs 33 of 169 [19.5%]; P = .10), but the incidence of hypotension increased (31 of 169 [18.3%] vs 16 of 169 [9.5%]; risk ratio, 2.15 [95% CI, 1.13-4.10]; P = .02).

Conclusions and Relevance

Dexmedetomidine administration in the early postpartum period significantly reduced the incidence of a positive PPD screening and maintained a favorable safety profile.

Trial Registration

Chinese Clinical Trial Registry Identifier: ChiCTR2200057213.

Intra-articular remifentanil on postoperative pain in knee arthroscopic surgery; a double blind randomized clinical trial

BACKGROUND

We aimed to assess the efficacy of intra-articular remifentanil in relieving postoperative pain after knee arthroscopy.

METHODS

We conducted a double-blind randomized clinical trial study on 60 patients. Patients were divided into two equal groups. The control group received 25 ml of intra-articular normal saline, and the intervention group received 200 μg of remifentanil dissolved in 25 ml of saline. We evaluated at rest postoperative pain at 1, 3, 6, 12, 18, and 24 h after the surgery using the Visual Analog Scale (VAS). Patients with VAS scores of 4 or more received meperidine (pethidine). The first time meperidine was requested and the total amount of meperidine consumed was recorded.

RESULTS

Out of 60 patients, 49 were male (81.6%), and the mean age of participants was 32.71 (7.02) years. An hour after the surgery, the control group showed a mean VAS score of 8.66 (1.26), and decreased to 2.53 (1.67) at the end of 24 h. The intervention group started with a mean VAS score of 2.23 (1.81) and ended at 0.10 (0.305). All patients in the control group and 11 (36.7%) patients in the intervention group asked for analgesics during follow-up. The mean total meperidine dose in the control and intervention groups was 108.33 (23.97) mg and 13.33 (19.40) mg, respectively (P < 0.001; 95% confidence interval of the difference 83.72 to 106.27).

CONCLUSIONS

Intra-articular remifentanil may decrease postoperative pain and analgesic requirements in patients undergoing knee arthroscopy.

Effect of Dexmedetomidine on Postoperative Renal Function in Patients Undergoing Cardiac Valve Surgery Under Cardiopulmonary Bypass: A Randomized Clinical Trial

OBJECTIVE

The effect of dexmedetomidine on postoperative renal function was investigated in patients undergoing cardiac valve surgery under cardiopulmonary bypass (CPB).

DESIGN

A randomized controlled trial.

SETTING

University teaching, grade A tertiary hospital.

PARTICIPANTS

A total of 70 patients scheduled to undergo cardiac valve replacement or valvuloplasty under CPB were eligible and randomly divided into groups D (n = 35) and C (n = 35) between January 2020 and March 2021.

INTERVENTIONS

Patients in group D were administered 0.6 μg/kg/h of dexmedetomidine intravenously from 10 minutes before anesthesia induction to 6 hours after surgery; normal saline was used instead of dexmedetomidine in group C.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the incidence of acute kidney injury (AKI). Acute kidney injury was defined according to the Kidney Disease Improving Global Outcomes (2012). It was 22.86% and 48.57% in groups D and C, respectively (p = 0.025). The secondary outcomes were intraoperative hemodynamics and various indices in serum. Ten minutes before CPB (T₁), 10 minutes after CPB (T₂), and 30 minutes after CPB (T₃), mean arterial pressure in group D was lower than that in group C, with statistical significance (74.94 ± 8.52 v 81.89 ± 13.66 mmHg, p=0.013; 62.83 ± 11.27 v 71.86 ± 7.89 mmHg, p < 0.001; 72.26 ± 8.75 v 78.57 ± 8.83 mmHg, p = 0.004). At T₁, the heart rate in group D was significantly lower than in group C (80.89 ± 14.04 v 95.54 ± 12.53 bpm, p=0.022). The tumor necrosis factor α, interleukin-6, C-reactive protein, and cystatin C levels in group D were lower than those in group C after the surgery (T₄) and 24 hours after surgery (T₅), with statistical significance. The duration of mechanical ventilation, intensive-care-unit stay time, and hospital stay time in group D were significantly shorter than in group C. The incidences of tachycardia, hypertension, nausea, and vomiting in group D were similar to those in group C.

CONCLUSIONS

Dexmedetomidine may be considered as a way to reduce the incidence and severity of postoperative AKI in patients undergoing cardiac valve surgery under cardiopulmonary bypass.

Sedative Properties of Dexmedetomidine Are Mediated Independently from Native Thalamic Hyperpolarization-Activated Cyclic Nucleotide-Gated Channel Function at Clinically Relevant Concentrations

Dexmedetomidine is a selective α₂-adrenoceptor agonist and appears to disinhibit endogenous sleep-promoting pathways, as well as to attenuate noradrenergic excitation. Recent evidence suggests that dexmedetomidine might also directly inhibit hyperpolarization-activated cyclic-nucleotide gated (HCN) channels. We analyzed the effects of dexmedetomidine on native HCN channel function in thalamocortical relay neurons of the ventrobasal complex of the thalamus from mice, performing whole-cell patch-clamp recordings. Over a clinically relevant range of concentrations (1-10 µM), the effects of dexmedetomidine were modest. At a concentration of 10 µM, dexmedetomidine significantly reduced maximal I_h amplitude (relative reduction: 0.86 [0.78-0.91], n = 10, and p = 0.021), yet changes to the half-maximal activation potential V_1/2 occurred exclusively in the presence of the very high concentration of 100 µM (-4,7 [-7.5--4.0] mV, n = 10, and p = 0.009). Coincidentally, only the very high concentration of 100 µM induced a significant deceleration of the fast component of the HCN activation time course (τ_fast: +135.1 [+64.7-+151.3] ms, n = 10, and p = 0.002). With the exception of significantly increasing the membrane input resistance (starting at 10 µM), dexmedetomidine did not affect biophysical membrane properties and HCN channel-mediated parameters of neuronal excitability. Hence, the sedative qualities of dexmedetomidine and its effect on the thalamocortical network are not decisively shaped by direct inhibition of HCN channel function.

Safety and Efficacy of Ketamine-Fentanyl-Dexmedetomidine-Induced Anesthesia and Analgesia in Neonatal and Aged Rats

The efficiency of many anesthetic regimens is controversial, with side effects especially in the vulnerable children and old population. The study aimed to evaluate the safety and efficacy of low-dose combination of ketamine, fentanyl, and dexmedetomidine (KFD) for anesthesia and analgesia in the neonatal and elderly rats. KFD rapidly induced anesthesia and analgesia in either postnatal days 6 (P6) or 13 months (13M) old rats. Meanwhile, KFD administration had no adverse effects on the cardiovascular and respiratory systems. Compared with control group, there were no distinct morphologic changes in kidney, liver, and brain in KFD group. Moreover, administration of KFD had no influence on hepatic and renal function in rats of both ages. Furthermore, there was no obvious difference in cognitive function between control and KFD groups. These results indicated that the administration of KFD combination offered safe and efficient anesthesia. Collectively, our results suggest the potential implication of the KFD combination in anesthesia management.

Hepatic impairment as a risk factor of adverse drug reactions

There are a lot of clinical variants of hepatic impairment ranging from asymptomatic increase in transaminases to acute liver failure and fulminant hepatitis. Hepatic impairment is a polietiologic syndrome. According to the epidemiological study conducted in the United States (19982008), the main causes of hepatic impairment were paracetamol overdose (46%), idiopathic liver dysfunction (14%), other drugs (excluding paracetamol, 11%), viral hepatitis B (7%), other infectious and non-infectious diseases with liver damage (except for viral hepatitis) 7%, autoimmune hepatitis (5%), ischemic hepatitis (syn. hypoxic hepatitis, liver infarction) 4%, viral hepatitis A (3%) and Wilson's disease (2%). Hepatic impairment have a direct impact on the pharmacokinetics and pharmacodynamics of drugs decreasing clearance, elimination and excretion of drugs. Also Transjugular intrahepatic porto-systemic shunts, which are often used to treat portal hypertension in patients with liver cirrhosis, can significantly reduce the presystemic elimination of drugs, thereby increasing their absorption. Moreover, in patients with liver cirrhosis, concomitant renal dysfunction also requires an adjustment of the dose of drugs. Correction of pharmacotherapy in accordance to pharmacokinetic and pharmacodynamic changes of drugs ingested by patients with impaired liver function will improve the quality of medical care and reduce the risks of adverse drug reactions.

Distribution of the Noradrenaline Innervation and Adrenoceptors in the Macaque Monkey Thalamus

Noradrenaline (NA) in the thalamus has important roles in physiological, pharmacological, and pathological neuromodulation. In this work, a complete characterization of NA axons and Alpha adrenoceptors distributions is provided.

NA axons, revealed by immunohistochemistry against the synthesizing enzyme and the NA transporter, are present in all thalamic nuclei. The most densely innervated ones are the midline nuclei, intralaminar nuclei (paracentral and parafascicular), and the medial sector of the mediodorsal nucleus (MDm). The ventral motor nuclei and most somatosensory relay nuclei receive a moderate NA innervation. The pulvinar complex receives a heterogeneous innervation. The lateral geniculate nucleus (GL) has the lowest NA innervation.

Alpha adrenoceptors were analyzed by in vitro quantitative autoradiography. Alpha-1 receptor densities are higher than Alpha-2 densities. Overall, axonal densities and Alpha adrenoceptor densities coincide; although some mismatches were identified. The nuclei with the highest Alpha-1 values are MDm, the parvocellular part of the ventral posterior medial nucleus, medial pulvinar, and midline nuclei. The nucleus with the lowest Alpha-1 receptor density is GL. Alpha-2 receptor densities are highest in the lateral dorsal, centromedian, medial and inferior pulvinar, and midline nuclei.

These results suggest a role for NA in modulating thalamic involvement in consciousness, limbic, cognitive, and executive functions.

An Analysis of Prolonged, Continuous Ketamine Infusions

INTRODUCTION

Opioids carry high risk of dependence, and patients can rapidly build tolerance after repetitive dosing. Low-dose ketamine is an analgesic agent alternative that provides more hemodynamic stability. We sought to describe the effects of prolonged ketamine use in non-burn patients.

MATERIALS AND METHODS

We queried the electronic health system at the Brooke Army Medical Center for patient encounters with ketamine infusions lasting >72 hours. We abstracted data describing demographics, vital signs, ketamine infusion dose and duration, and discharge diagnoses potentially relevant to ketamine side effects.

RESULTS

We identified 194 subjects who met the study inclusion criteria. The median age was 39 years, most were male (67.0%), and most were primarily admitted for a non-trauma reason (59.2%). The mean ketamine drip strength was 43.9 mg/h (95% CI, 36.7-51.1; range 0.1-341.6) and the mean drip length was 130.8 hours (95% CI, 120.3-141.2; range 71-493). Most subjects underwent mechanical ventilation (56.1%) at some point during the infusion and most survived to hospital discharge (83.5%). On a per-day basis, the average heart rate was 93 beats per minute, systolic blood pressure was 128 mmHg, diastolic blood pressure was 71 mmHg, oxygen saturation was 96%, and respiratory rate was 22 respirations per minute.

CONCLUSIONS

We demonstrate that continuous ketamine infusions provide a useful adjunct for analgesia and/or sedation. Further development of this adjunct modality may serve as an alternative agent to opioids.

Suicidal attempt with caffeine overdose treated with dexmedetomidine: a case report

Background

Caffeine is a widely used dietary stimulant, and cases of caffeine overdoses, sometimes leading to death, are increasing. We encountered a case of caffeine intoxication resolved with administration of the sedative agent dexmedetomidine.

Case presentation

We administered dexmedetomidine for sedation and to suppress sympathetic nerve stimulation in the case of an 18-year-old Japanese male who ingested a massive dose of caffeine with the intention of committing suicide. The patient was in an excited state and had hypertension, sinus tachycardia, and hypokalemia with prominent QT prolongation. After dexmedetomidine administration, the patient’s mental state, hemodynamics, and electrolyte levels were improved immediately. He was discharged without any sequelae 3 days later.

Conclusion

Cases of acute caffeine intoxication with agitation, sympathetic overactivity and adverse cardiac events would benefit with dexmedetomidine treatment.

Examination of the sedative and analgesic effects of gabapentin and dexmedetomidine in patients undergoing laparoscopic cholecystectomy surgery: A randomized controlled trial

Introduction:

At present, laparoscopic surgery is a very common method, especially for the removal of the gallbladder, because pain and anxiety following surgery is a major problem in surgical operations. Various studies have demonstrated the effectiveness of gabapentin and dexmedetomidine in reducing pain intensity after surgery. The present study is aimed at examining the sedative and analgesic effects of gabapentin and dexmedetomidine in patients undergoing laparoscopic cholecystectomy.

Methods:

This was a double-blinded clinical trial involving 40 patients who were candidates for laparoscopic cholecystectomy. The patients were randomly allotted in two groups of dexmedetomidine (n = 20) and gabapentin (n = 20). Then, pain intensity based on the visual analog scale (VAS) and sedation level based on the Ramsay Sedation Scale (RSS) were measured at the curtained times. As the data were not normally distributed, the Mann–Whitney U test was used to analyze the data, and the significance level was set at 0.05.

Results:

Across the follow-up points, more reduction in pain intensity was observed in the dexmedetomidine group as compared with the gabapentin group. The available dissimilarities between these two groups in pain decrement at the recovery room and 3 h after being discharged from the recovery room were not significant (P ≥ 0.414). In addition, across all the time points, there was considerable growth in sedation in the dexmedetomidine group in comparison with the gabapentin group (P < 0.024). This finding indicated that dexmedetomidine was more effective than gabapentin in creating sedation.

Conclusion:

Compared with gabapentin, dexmedetomidine leads to more pain reduction after surgery and better sedation during and after surgery.

Pharmacotherapeutic management of acute alcohol withdrawal syndrome in critically Ill patients

INTRODUCTION

Alcohol withdrawal syndrome is a common and life-threatening condition in patients suffering from alcohol use disorder. Treatment of this syndrome is challenging, especially in patients that are critically ill, either because of withdrawal symptoms or underlying conditions. For the treatment, several pharmacological agents exist, such as benzodiazepines, barbiturates, or dexmedetomidine. Nonetheless, as alcohol withdrawal syndromes can occur in every clinical setting, it is necessary to provide a guideline for clinicians confronted with this syndrome in varying clinical contexts.

AREAS COVERED

The authors provide a systematic review of the literature found in PubMed and Embase following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines.

EXPERT OPINION

For the treatment of alcohol withdrawal syndrome, medications targeting the GABA system are preferred. Benzodiazepines are regarded as the gold standard. However, as many adjunct therapeutic options exist, it is essential to find symptom-triggered approaches and treatment protocols for the variety of clinical contexts. Apart from that, it is necessary to compare protocols toward clinical variables rather than investigating medications that are in use for the treatment of alcohol withdrawal syndrome.

Comparison of Transforaminal Triamcinolone and Dexmedetomidine in Radicular Low-Back Pain: A Randomized Double-Blind Clinical Trial

Background

Administration of steroids in the lumbar transforaminal block for lumbar radicular pain is considered one of the preferred treatment methods though it is associated with some complications.

Objectives

The effects and side effects of triamcinolone and dexmedetomidine in the lumbar transforaminal block were investigated in the present study.

Methods

In this study, 30 patients, aged 40 - 70 years, suffering from lumbar radicular pain arising from the lumbar disc protrusion were equally divided into two groups of triamcinolone (T) and dexmedetomidine (D). They all underwent lumbar transforaminal blocks. An injection solution of triamcinolone (20 mg) plus ropivacaine (0.2%) and another one containing dexmedetomidine (50 μg) plus ropivacaine (0.2%) were administered in the triamcinolone and dexmedetomidine groups, respectively. Visual Analog Scale (VAS), Oswestry Disability Index (ODI), Straight Leg Raise (SLR or lasègue’s test), and Fasting Blood Sugar (FBS) were measured at 0, 2 weeks, 1, 3, and 6 months post-procedure. The levels of calcium, magnesium, and vitamin D, as well as potential complications, were also evaluated.

Results

Significant differences were found in the VAS and ODI during the measurement times within each group. The VAS and ODI were remarkably different between the dexmedetomidine group and the triamcinolone group. In addition, there were considerable differences in the increased FBS and reduced calcium and vitamin D levels in the triamcinolone group from changes in the dexmedetomidine group.

Conclusions

The lumbar transforaminal block with triamcinolone or dexmedetomidine attenuates the lumbar radicular pain. Further, dexmedetomidine exerts a more potent pain relief effect than triamcinolone.

Dexmedetomidine Ameliorates Sleep Deprivation-Induced Depressive Behaviors in Mice

PURPOSE

Sleep deprivation induces depressive symptoms. Dexmedetomidine is a α2-adrenoreceptor agonist and this drug possesses sedative, anxiolytic, analgesic, and anesthetic-sparing effect. In this study, the action of dexmedetomidine on sleep deprivation-induced depressive behaviors was investigated using mice.

METHODS

For the inducing of sleep deprivation, the mice were placed inside a water cage containing 15 platforms and filled with water up to 1 cm below the platform surface for 7 days. One day after sleep deprivation, dexmedetomidine at the respective dosage (0.5, 1, and 2 μg/kg) was intraperitoneally treated into the mice, one time per a day during 6 days. Then, forced swimming test and tail suspension test were conducted. Immunohistochemistry for tyrosine hydroxylase (TH), 5-hydroxytryptamine (5-HT; serotonin), tryptophan hydroxylase (TPH) and western blot for D1 dopamine receptor were also performed.

RESULTS

Sleep deprivation increased the immobility latency in the forced swimming test and tail suspension test. The expressions of TPH, 5-HT, and D1 dopamine receptor were decreased, whereas, TH expression was increased by sleep deprivation. Dexmedetomidine decreased the immobility latency and increased the expressions of TPH, 5-HT, and D1 dopamine receptor, whereas, HT expression was decreased by dexmedetomidine treatment.

CONCLUSION

In our results, dexmedetomidine alleviated sleep deprivation-induced depressive behaviors by increasing 5-HT synthesis and by decreasing dopamine production with up-regulation of D1 dopamine receptor.

Efficacy and Safety of Morphine and Low Dose Ketamine for Pain Control of Patients with Long Bone Fractures: A Randomized, Double-Blind, Clinical Trial

Objective

To compare the effects of intravenous morphine and a low dose of ketamine on pain intensity of patients with traumatic fractures of the long bones.

Methods

This randomized, controlled, double-blinded, clinical trial was conducted in the adult emergency department (ED) of Emam Khomeini hospital, a tertiary general hospital affiliated with Mazandaran University of Medical Sciences, in Northern Iran, during a 6-month period. Patients were randomly assigned to receive intravenous morphine (0.1 mg/kg) or low dose ketamine (0.5 mg/kg) for control of the pain in the emergency room. The pain intensity was checked by a nurse using the visual analogue scale (VAS) at 30, 60, 90, 120, 180 and 240, minutes after the intervention.

Results

Overall we included a total number of 156 patients with mean age of 35.87±3.38 years. There were 111 (71.2%) men and 4 (28.8%) women among the patients. Patients were randomly assigned to receive intravenous morphine (n=78) or low dose ketamine (n=78). The pain intensity decreased significantly in both study groups after 240 minutes of intervention. However, there was no significant difference between the two study groups regarding the pain intensity at 30 (p=0.378), 60 (p=0.927), 90 (p=0.434), 120 (p=0.557), 180 (p=0.991) and 240 (p=0.829) minutes. The side effects were comparable while low dose ketamine was associated with higher need for rescue analgesic (p=0.036).

Conclusion

The results of the current study demonstrates that the intravenous low dose ketamine leads to successful pain control in patients with long bone fractures and the effects are comparable with intravenous morphine.

Exploring Opioid-Sparing Multimodal Analgesia Options in Trauma: A Nursing Perspective

Challenges with opioids (e.g., adverse events, misuse and abuse with long-term administration) have led to a renewed emphasis on opioid-sparing multimodal management of trauma pain. To assess the extent to which currently available evidence supports the efficacy and safety of various nonopioid analgesics and techniques to manage trauma pain, a literature search of recently published references was performed. Additional citations were included on the basis of authors' knowledge of the literature. Effective options for opioid-sparing analgesics include oral and intravenous (IV) acetaminophen; nonsteroidal anti-inflammatory drugs available via multiple routes; and anticonvulsants, which are especially effective for neuropathic pain associated with trauma. Intravenous routes (e.g., IV acetaminophen, IV ketorolac) may be associated with a faster onset of action than oral routes. Additional adjuvants for the treatment of trauma pain are muscle relaxants and alpha-2 adrenergic agonists. Ketamine and regional techniques play an important role in multimodal therapy but require medical and nursing support. Nonpharmacologic treatments (e.g., cryotherapy, distraction techniques, breathing and relaxation, acupuncture) supplement pharmacologic analgesics and can be safe and easy to implement. In conclusion, opioid-sparing multimodal analgesia addresses concerns associated with high doses of opioids, and many pharmacologic and nonpharmacologic options are available to implement this strategy. Nurses play key roles in comprehensive patient assessment; administration of patient-focused, opioid-sparing, multimodal analgesia in trauma; and monitoring for safety concerns.

Remifentanil: A help in topical strabismus surgery

OBJECTIVE

To analyze the analgesic effect of remifentanil, side effects and complications in topical strabismus surgery. To study the results of strabismus surgery with this type of anesthesia.

MATERIAL AND METHOD

Retrospective descriptive study. We included 39 patients undergoing strabismus surgery with topical anesthesia and analgesia-based sedation with remifentanil. The data of the anesthetic and surgical technique, surgical results and stability of the deviation angle were analyzed.

RESULTS

Thirty nine patients (54% women) were included, the average age was 37,4years old. The mean follow-up was 24,5months. The preoperative diagnoses were exotropia (21 patients), esotropia (12), paresis strabismus (4) and Duane's Syndrome (2). 15% patients had preoperative diplopia and 13 had received previous treatments. The dose range of remifentanil used was 0.05 to 0.2μg/kg/min. The side effects presented were 2 cases of vomit and one of bad collaboration during the intraoperative adjustment, one of the patient reported pain and one case of thoracic rigidity was reported. 79% of the patients obtained a good surgical result and 82% reported being satisfied with the results. The reintervention rate was 5%.

CONCLUSIONS

Analgesia-based sedation with remifentanil is an useful complement to topical strabismus surgery because it reduces pain during surgery and allows the patient to collaborate during intraoperative adjustment due to its pharmacokinetic characteristics.

The preventive effect of dexmedetomidine on paroxysmal sympathetic hyperactivity in severe traumatic brain injury patients who have undergone surgery: a retrospective study

Background

Paroxysmal sympathetic hyperactivity (PSH) results and aggravates in secondary brain injury, which seriously affects the prognosis of severe traumatic brain injury patients. Although several studies have focused on the treatment of PSH, few have concentrated on its prevention.

Methods

Ninety post-operation (post-op) severe traumatic brain injury (sTBI) patients admitted from October 2014 to April 2016 were chosen to participate in this study. Fifty of the post-op sTBI patients were sedated with dexmedetomidine and were referred as the “dexmedetomidine group” (admitted from May 2015 to April 2016). The other 40 patients (admitted from October 2014 to May 2015) received other sedations and were referred as the “control group.” The two groups were then compared based on their PSH scores and the scores and ratios of those patients who met the criteria of “probable,” “possible” and “unlikely” using the PSH assessment measure (PSH-AM) designed by Baguley et al. (2014). The durations of the neurosurgery intensive care unit (NICU) and hospital stays and the Glasgow outcome scale (GOS) values for the two groups were also compared to evaluate the therapeutic effects and the patients’ prognosis.

Results

The overall PSH score for the dexmedetomidine group was 5.26 ± 4.66, compared with 8.58 ± 8.09 for the control group. The difference between the two groups’ PSH scores was significant (P = 0.017). The score of the patients who met the criterion of “probable” was 18.33 ± 1.53 in the dexmedetomidine group and 22.63 ± 2.97 in the control group, and the difference was statistically significant (P = 0.045). The ratio of patients who were classified as “unlikely” between the two groups was statistically significant (P = 0.028); that is, 42 (84%) in the dexmedetomidine group and 25 (62.5%) in the control group. The differences in NICU, hospital stays and GOS values between the two groups were not significant.

Conclusion

Dexmedetomidine has a preventive effect on PSH in sTBI patients who have undergone surgery.

Preterm Caesarean Delivery in a Parturient with Candida parapsilosis Endocarditis

We present the first documented case of Candida parapsilosis infective endocarditis in a pregnant patient. While the incidence of infective endocarditis during pregnancy is rare, the incidence of C. parapsilosis endocarditis is even rarer. The numerous specific risks and decision making processes regarding this case are presented.

Dexmedetomidine in combination with midazolam after pediatric cardiac surgery

Objective

Although midazolam is one of the most commonly used sedatives for infants in the intensive care unit, it has well-known disadvantages including a dose-dependent potential to induce tolerance, withdrawal, and hemodynamic depression. The aim of this study was to evaluate the clinical effects of dexmedetomidine combined with midazolam in postoperative intensive care following pediatric cardiac surgery.

Methods

Forty consecutive infants who underwent cardiac surgery for isolated ventricular septal defects from January 2011 to July 2013 were enrolled in this retrospective study. They were divided into two groups according to postoperative sedation regimen: dexmedetomidine sedation with midazolam ( n = 20), or midazolam sedation without dexmedetomidine (control group, n = 20). Perioperative variables were compared between the two groups.

Results

There were no significant differences in patient characteristics between the two groups. During the first 24 h after intensive care unit admission, heart rate and serum lactate levels were significantly lower in the dexmedetomidine group compared to the control group ( p = 0.0292 and p = 0.0027, respectively). The maximal midazolam dose was also significantly lower in the dexmedetomidine group (0.12 ± 0.09 vs. 0.20 ± 0.08 mg kg−1 h−1, p = 0.0059). There were no adverse effects of dexmedetomidine such as bradycardia, hypotension, agitation, or seizures. Three (15%) patients in the control group and none in the dexmedetomidine group experienced sudden cardiopulmonary decompensation.

Conclusions

Dexmedetomidine can provide favorable sedative properties with a reduced requirement for concomitant midazolam and stable hemodynamics with tachycardia prevention, for postoperative intensive care following pediatric cardiac surgery.

Comparative analysis of efficacy of lignocaine 1.5 mg/kg and two different doses of dexmedetomidine (0.5 μg/kg and 1 μg/kg) in attenuating the hemodynamic pressure response to laryngoscopy and intubation

CONTEXT

Laryngoscopy and intubation cause an intense reflex increase in heart rate, blood pressure, due to an increased sympathoadrenal pressor response. Lignoocaine has shown blunting of pressor response to intubation. Dexmedetomidine has sympatholytic effects.

AIMS

To the best of our knowledge there is no study comparing the efficacy of lignocaine with two different doses of dexmedetomidine for attenuating the pressor response. With this idea, we planned to conduct the present study.

MATERIALS AND METHODS

After approval by the Hospital Ethics committee, 90 consenting adults aged 18-65 years of age of either sex of non-hypertensive ASA Grade I or II were randomly allocated into three groups. Group D1- IV Dexmedetomidine 0.5μg/kg over 10 minutes Group D2- IV Dexmedetomidine 1μg/kg over 10 minutes Group X- IV Lignocaine 1.5mg/kg in 10 ml normal saline.

STATISTICAL ANALYSIS USED

ANOVA and Student's t test used for analysis.

RESULTS

Dexmedetomidine 1µg/kg was more effective than 0.5µg/kg and lignocaine 1.5mg/kg in attenuating the pressor response.

CONCLUSIONS

We conclude that dexmedetomidine 1μg/kg adequately attenuates the hemodynamic response to laryngoscopy and endotracheal intubation when compared with dexmedetomidine 0.5μg/kg and lignocaine 1.5mg/kg.

Addition of dexmedetomidine to ropivacaine improves cervical plexus block

OBJECTIVE

To investigate the sensory block onset time, duration time, and side effects of adding dexmedetomidine to ropivacaine for cervical plexus block.

METHODS

Forty American Society of Anesthesiologists (ASA) Class I or II adult patients who were scheduled to undergo thyroid surgery were randomly allocated to the following groups to receive cervical plexus block: 30 mL of 0.375% ropivacaine combined with 1 μg kg(-1) of dexmedetomidine; 30 mL of 0.375% ropivacaine combined with saline (control). The sensory block onset time, duration of analgesia, mean arterial pressure (MAP), heart rate (HR), and the incidences of side effects, such as hypotension, bradycardia, and hypoxemia were recorded.

RESULTS

The addition of dexmedetomidine to ropivacaine (Group D) shortened the sensory block onset time compared with the ropivacaine group (Group C) (95% confidence interval [CI] 4.18-5.26; p < 0.05). The duration of analgesia of cervical plexus block in Group D was significantly longer than that in Group C (95% CI 295.96-311.12; p < 0.05). The Ramsay sedation score at 5, 10, 20, 40, 60, 90, and 120 minutes after local anesthetic administration in Group D was significantly higher than that in Group C (p < 0.05). MAP level and HR level in Group D were significantly lower than that in Group C (p < 0.05).

CONCLUSION

The addition of 1 μg kg(-1) dexmedetomidine to ropivacaine for cervical plexus block could shorten the sensory block onset time and extend the duration of analgesia, and increased the quality of analgesia, with the patients being sedated and arousable.

Sedation for critically ill or injured adults in the intensive care unit: a shifting paradigm

As most critically ill or injured patients will require some degree of sedation, the goal of this paper was to comprehensively review the literature associated with use of sedative agents in the intensive care unit (ICU). The first and selected latter portions of this article present a narrative overview of the shifting paradigm in ICU sedation practices, indications for uninterrupted or prolonged ICU sedation, and the pharmacology of sedative agents. In the second portion, we conducted a structured, although not entirely systematic, review of the available evidence associated with use of alternative sedative agents in critically ill or injured adults. Data sources for this review were derived by searching OVID MEDLINE and PubMed from their first available date until May 2012 for relevant randomized controlled trials (RCTs), systematic reviews and/or meta-analyses and economic evaluations. Advances in the technology of mechanical ventilation have permitted clinicians to limit the use of sedation among the critically ill through daily sedative interruptions or other means. These practices have been reported to result in improved mortality, a decreased length of ICU and hospital stay and a lower risk of drug-associated delirium. However, in some cases, prolonged or uninterrupted sedation may still be indicated, such as when patients develop intracranial hypertension following traumatic brain injury. The pharmacokinetics of sedative agents have clinical importance and may be altered by critical illness or injury, co-morbid conditions and/or drug-drug interactions. Although use of validated sedation scales to monitor depth of sedation is likely to reduce adverse events, they have no utility for patients receiving neuromuscular receptor blocking agents. Depth of sedation monitoring devices such as the Bispectral Index (BIS©) also have limitations. Among existing RCTs, no sedative agent has been reported to improve the risk of mortality among the critically ill or injured. Moreover, although propofol may be associated with a shorter time to tracheal extubation and recovery from sedation than midazolam, the risk of hypertriglyceridaemia and hypotension is higher with propofol. Despite dexmedetomidine being linked with a lower risk of drug-associated delirium than alternative sedative agents, this drug increases risk of bradycardia and hypotension. Among adults with severe traumatic brain injury, there are insufficient data to suggest that any single sedative agent decreases the risk of subsequent poor neurological outcomes or mortality. The lack of examination of confounders, including the type of healthcare system in which the investigation was conducted, is a major limitation of existing pharmacoeconomic analyses, which likely limits generalizability of their results.

Dexmedetomidine sedation in ICU

Dexmedetomidine (DEX), a highly selective α₂-adrenergic receptor agonist, is the newest agent introduced for sedation in intensive care unit (ICU). The sedation strategy for critically ill patients has stressed light sedation with daily awakening and assessment for neurologic, cognitive, and respiratory functions, since Society of Critical Care Medicine (SCCM) guidelines were presented in 2002. The traditional GABAergic agents, including benzodiazepines and propofol, have some limitations for safe sedatives in this setting, due to an unfavorable pharmacokinetic profile and to detrimental adverse effects (such as lorazepam associated propylene glycol intoxication and propofol infusion syndrome). DEX produces it's sedative, analgesic and cardiovascular effects through α₂ receptors on the locus ceruleus (LC). Activities of LC, the tuberomammillary nucleus (TMN) are depressed and activity of the ventrolateral preoptic nucleus (VLPO) is increased during DEX sedation, which is similar in features to normal non-REM (NREM) sleep. At the same time, perifornical orexinergic activity is maintained, which might be associated with attention. This mechanism of action produces a normal sleep-like, cooperative sedation. The characteristic feature of sedation, together with a concomitant opioid sparing effect, may decrease the length of time spent on a ventilator, length of stay in ICU, and prevalence and duration of delirium, as the evidence shown from several comparative studies. In addition, DEX has an excellent safety profile. In conclusion, DEX is considered as a promising agent optimized for sedation in ICU.