Hemodynamic Effects Of Dexmedetomidine Research Articles

Genetic polymorphisms are associated with individual susceptibility to dexmedetomidine.

Introduction: Dexmedetomidine (DXM) is widely used as an adjuvant to anesthesia or a sedative medicine, and differences in individual sensitivity to the drug exist. This study aimed to investigate the effect of genetic polymorphisms on these differences. Methods: A total of 112 patients undergoing hand surgery were recruited. DXM 0.5μg/kg was administered within 10min and then continuously injected (0.4μg/kg/h). Narcotrend index, effective dose and onset time of sedation, MAP, and HR were measured. Forty-five single nucleotide polymorphisms (SNPs) were selected for genotype. Results: We observed individual differences in the sedation and hemodynamics induced by DXM. ABCG2 rs2231142, CYP2D6 rs16947, WBP2NL rs5758550, KATP rs141294036, KCNMB1 rs11739136, KCNMA1 rs16934182, ABCC9 rs11046209, ADRA2A rs1800544, and ADRB2 rs1042713 were shown to cause statistically significant (p < 0.05) influence on the individual variation of DXM on sedation and hemodynamics. Moreover, the multiple linear regression analysis indicated sex, BMI, and ADRA2A rs1800544 are statistically related to the effective dose of DXM sedation. Discussion: The evidence suggests that the nine SNPs involved in transport proteins, metabolic enzymes, and target proteins of DXM could explain the individual variability in the sedative and hemodynamic effects of DXM. Therefore, with SNP genotyping, these results could guide personalized medication and promote clinical and surgical management.

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

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. 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. 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. 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.

The Therapeutic Antiemetic and Hemodynamic Effects of Dexmedetomidine, Ephedrine, and Dexamethasone in Combination with Midazolam on Laparoscopic Cholecystectomy Patients: A Randomised Clinical Trial.

Objective:The objective was to compare the hemodynamic and antiemetic effects of the combination of midazolam with ephedrine, dexamethasone, and dexmedetomidine in laparoscopic cholecystectomy surgical patients.Materials and Methods:This randomised, parallel-group, double-blind clinical trial was conducted by enrollment of 96 patients who were referred for laparoscopic cholecystectomy. Patients assigned into three equal-sized intervention arms having received anaesthesia induction with midazolam-ephedrine, midazolam-dexamethasone, and midazolam-dexmedetomidine using a block randomisation method. Frequency and severity of nausea and vomiting were observed from recovery to 24 h later, adverse events, and sedation on Ramsay sedation scale at recovery, 1, 2, and 4 h postoperatively. Data were recorded and analysed at a significance level lower than 0.05 in SPSS software.Results:The clinical parameters including mean blood pressure at all times and heart rate in 60–90 min were lower in the dexmedetomidine group when compared with other groups. The lowest severity of postsurgery nausea occurrence was observed in the midazolam-dexamethasone group and those receiving midazolam-dexmedetomidine from 4 to 24 h. In addition, vomiting scores were lower throughout recovery up to postoperative 4 h in the dexamethasone and dexmedetomidine groups (all P < 0.05). The highest sedation score was observed in the dexmedetomidine group during recovery up to 2 h (P = 0.001), reflecting a more clinically superior effect than dexamethasone (P = 0.01).Conclusions:A positive implication of dexmedetomidine was observed in attenuating postoperative nausea and vomiting and potentiating sedation. Nevertheless, it is providing a drop in the blood pressure and heart rate. Lending support to the potent adjuvant efficacy of dexamethasone following dexmedetomidine, consequently, a hypothesis can be put forward, stating that the dexmedetomidine and dexamethasone as adjuvants to midazolam are expected to bring the advantages of avoiding the adverse events and improving postoperative sedation.

Hemodynamic and respiratory effects of dexmedetomidine sedation in critically ill Covid-19 patients: A retrospective cohort study.

IntroductionDexmedetomidine has been suggested to be a promising sedative for patients with Covid‐19 infection (CV19). However, use of dexmedetomidine is limited by its heart rate (HR) and arterial blood pressure lowering effects. Moreover, CV19 is associated with cardiac manifestations including bradyarrythmias. The hemodynamic effects of dexmedetomidine have not been previously studied in CV19 patients. We evaluated the effects of dexmedetomidine on hemodynamic and respiratory parameters of CV19 patients.MethodsIn this single center study, all CV19 patients receiving dexmedetomidine for sedation during a one year period were included. Our primary outcomes included changes in HR, mean arterial pressure (MAP), respiratory rate (RR), partial oxygen pressure of arterial blood/fraction of inspired oxygen‐ratio (PF‐ratio), and Richmond Agitation and Sedation Score (RASS) during dexmedetomidine administration.ResultsWe identified 39 patients with a mean (SD) age of 58.3 (12.7) years. After initiation of dexmedetomidine, HR decreased by 16.9 (3.3) beats/min (95% CI 9.5–22.4; p < 0.001). During the 12‐hour follow‐up period, HR decrease was significant at 2 to 12 h. Incident bradycardia (<45/min) was reported in 12 (30.8%) patients and it was associated with lower plasma C‐reactive protein, Pro‐calcitonin, and troponin T levels. There was no change in MAP compared to baseline. Dexmedetomidine administration was associated with improvement of PF‐ratio (p < 0.001) and with decrease of RASS (p = 0.004).ConclusionsDexmedetomidine is an effective sedative for CV19 patients and may improve their oxygenation. However, dexmedetomidine administration is associated with marked decline in HR and with a high incidence of bradycardia in patients with CV19.

COMPARATIVE ASSESSMENT OF HEMODYNAMIC PARAMETERS DURING LAPAROSCOPY IN DEXMEDETOMIDINE VERSUS FENTANYL TREATED PATIENTS.

Background: Laparoscopic surgery is preferred for its advantages in shorter hospital stay, less amount of blood loss and aesthetic incisions. The problems are however evident when the complications of hemodynamic disturbances are enhanced due to pneumoperitoneum. Several newer formulations have ben tried to overcome this problem so that issues of hemodynamic stability can be addressed. Aim: The present study aims to comparatively evaluate the hemodynamic effects of dexmedetomidine and fentanyl in subjects undergoing elective laparoscopic surgeries. Methodology: The study involved a subject pool of 60 patients who were divided equally in two groups and administered the study drugs. Parameters of hemodynamic stability were recorded and analysed to ascertain comparative efficacy. Observations: The mean HR, SBP, DBP, MAP and sedation score were better in dexmedetomidine group as compared to fentanyl group. Conclusion: Dexmedetomidine is an effective adjuvant to anaesthetic medications in laparoscopic surgeries with a disadvantage of longer surgery duration as compared to fentanyl. Keywords: Dexmedetomidine, Comparative evaluation, fentanyl, Laparoscopic surgeries

Feasibility of Intranasal Dexmedetomidine in Treatment of Postoperative Restlessness, Agitation, and Pain in Geriatric Orthopedic Patients.

ObjectiveThe aim of this study was to report preliminary data on the use of intranasal dexmedetomidine to treat postoperative restlessness, agitation, and pain in 23 patients aged > 70 years and undergoing orthopedic surgery.BackgroundPostoperative agitation and delirium are common among older adult patients undergoing orthopedic surgery. Most preparations used to treat agitation and delirium carry a risk for adverse events such as respiratory failure. Moreover, mere opioid therapy may be insufficient in treatment of pain. Dexmedetomidine, an α2-adrenoreceptor agonist with sedative and analgesic properties, has been shown to reduce opioid requirement and reduce postoperative delirium in older adults.MethodsWe studied the use of post-operative intranasal dexmedetomidine in a retrospective study cohort of geriatric patients undergoing orthopedic surgery. Primary outcomes included alterations in heart rate (HR), mean arterial pressure (MAP), respiratory rate (RR), peripheral oxygen saturation (SpO2), Modified Richmond Agitation and Sedation Score (mRASS), and opioid consumption following dexmedetomidine administration.ResultsWe identified 23 patients with a mean (SD) age of 79.9 (7.5) years who received dexmedetomidine 100 µg intranasally postoperatively. After dexmedetomidine administration, HR decreased by 10.4 (3.7) beats/min (95% CI 2.9–17.8; p = 0.004) and MAP by 16.2 (4.4) mmHg (95% CI 7.3–25.1; p < 0.001). HR decrease was significant at 2 h and MAP decrease at 1, 2, and 3 h following dexmedetomidine administration. Dexmedetomidine administration was associated with significant reductions in opioid consumption (p < 0.001) and mRASS score (p < 0.001). SpO2 and RR remained unchanged.ConclusionsThese preliminary findings suggest that intranasal dexmedetomidine reduces opioid consumption without causing respiratory depression and may be used to treat postoperative restlessness, agitation, and pain in geriatric patients. However, hemodynamic effects of dexmedetomidine may require close observation for 3 hours following administration in older adult patients.Supplementary InformationThe online version contains supplementary material available at 10.1007/s40266-021-00846-6.

Comparison of dexmedetomidine-ketamine and propofol-midazolam in children undergoing MRI: A prospective randomised study

Background: Deep sedation required for magnetic resonance imaging (MRI) in paediatric age group is a challenge. This study is done to compare the sedative and hemodynamic effects of dexmedetomidine with ketamine (DK) in comparison to propofol with midazolam (PM) in children undergoing MRI. The primary objective is to compare the recovery time and recovery characteristics between the drug combination and secondary objectives were to compare the efficacy and adverse events between the two groups.Methods: This is a double blind randomised controlled study involving 100 patients posted for MRI in a tertiary care hospital between 01 Jan 2017 to 31 Dec 2018. Statistical analysis tests performed to compare the results between the two groups.Results: The average time to achieving the Aldrete score of 10/10 in DK group was 25.43 min as compared to 13.7 min in PM group which is statistically significant. Also, time to achieve Ramsay Sedation Scale (RSS) scale of 5 was significantly higher in the DK group (12.20min) in comparison to PM group (6.30 min). There was no significant difference between heart rate, respiratory rate, systolic blood pressures or oxygen saturation during the procedure.Conclusion: Combination of propofol with midazolam provided statistically significant rapid rates of anaesthetic induction as well as recovery when compared with dexmedetomidine ketamine group.

Hemodynamic Effects of Dexmedetomidine in Adults With Reduced Ejection Fraction Heart Failure.

Dexmedetomidine (DEX) can cause hypotension complicating its use in critically ill patients with labile hemodynamics secondary to an underlying disease state such as heart failure. The aim of this study was to determine the effect of DEX on mean arterial pressure (MAP) in nonsurgical patients with heart failure and reduced ejection fraction (HFrEF). This retrospective single-center cohort study evaluated patients who received DEX in the cardiac care and medical intensive care units at a large academic hospital. The primary end point was the change in MAP within 6 hours following DEX initiation. Sixty-five patients with HFrEF diagnosis were compared 1:1 to a control group without HFrEF. Both groups experienced a decrease in MAP over the study period. Patients with HFrEF had a greater absolute percentage reduction in MAP 1 hour following DEX initiation compared to the control group (-9.6% vs -5.2%; P < .01). When accounting for the combined effect of DEX initiation and HFrEF diagnosis on the primary end point, patients with HFrEF did not have a significant difference in MAP compared to the control group over the study period. Within 6 hours following DEX initiation, both groups experienced a decrease in MAP. The effect of DEX on MAP over the composite time period was not found to be significantly different in the HFrEF group compared to the non-HFrEF group. However, patients with HFrEF experienced a greater reduction in MAP in the first hour following DEX initiation compared to the non-HFrEF group. Prospective studies are needed to evaluate the effect of DEX on patients with acute decompensated HFrEF compared to patients with compensated HFrEF.

Prospective randomized trial evaluating the hemodynamic effects of dexmedetomidine on laryngoscopy and tracheal intubation in diabetic patients

Prospective randomized trial evaluating the hemodynamic effects of dexmedetomidine on laryngoscopy and tracheal intubation in diabetic patients

The protective and hemodynamic effects of dexmedetomidine on hypertensive cerebral hemorrhage patients in the perioperative period.

The aim of the present study was to analyze the protective and hemodynamic effects of dexmedetomidine in hypertensive cerebral hemorrhage (HCH) patients during perioperative period. In total, 50 HCH patients were selected and randomly divided into two groups, one group was administered with dexmedetomidine and the other groups with midazolam. The mean arterial pressure (MAP), heart rate (HR) and blood oxygen saturation (SpO2) were monitored in the two groups of patients before and during the operation. The MAP, HR, SpO2 and PETCO2 recorded 5 min after admission into the operation room was considered T1, the same parameters recorded 10 min after drug administration were considered T2, just after starting the operation were considered T3 and 30 min after start of operation were considered T4. The preoperative sedation and analgesia were evaluated by the Ramsay scoring method and the neuron-specific enolase (NSE) and S100 protein (S100β) were estimated using ELISA. The patients of the midazolam group experienced mild respiratory depression during the period of sedation. Levels of, MAP, HR and PETCO2 were significantly increased whereas SPO2 was decreased (P<0.05). The MAP, HR, SPO2 and PETCO2 were stable during the period of sedation (P>0.05). The plasma concentrations of epinephrine and norepinephrine at T1 were similar in the two groups (P>0.05), but decreased after drug administration. This decrease was more prominent in the dexmedetomidine group patients (P<0.05) than midazolam group patients. The epinephrine and norepinephrine concentrations just after starting operation (T3) were higher than the basal level (T1) in the midazolam group, but close to the basal level in the dexmedetomidine group (P<0.05). The serum concentration of NSE and S100β in the two groups showed no difference (P>0.05) at the end of operation (T5), but after 24 h of operation (T7) NSE and S100β in the dexmedetomidine group were significantly lower compared to the midazolam group (P<0.05). In conclusion, the administration of dexmedetomidine for patients with HCH during perioperative period is safe and serves as an effective sedative, without causing respiratory depression and does not influence stable haemodynamics with certain brain protective effect.

Effects of dexmedetomidine on hemodynamics and respiration in intubated, spontaneously breathing patients after endoscopic submucosal dissection for cervical esophageal or pharyngeal cancer.

We evaluated the hemodynamic and respiratory effects of dexmedetomidine in intubated, spontaneously breathing patients after endoscopic submucosal dissection (ESD) for cervical esophageal or pharyngeal cancer. This retrospective study included 129 patients aged 66.5±8.3years, who underwent ESD under general anesthesia, and who were kept intubated overnight to prevent airway obstruction, receiving sedation with dexmedetomidine. Constant dexmedetomidine infusion at 0.51±0.16μg/kg/h was started intraoperatively (n=109) or postoperatively (n=20), following (n=29) or not following (n=100) loading doses, and continued until extubation. Hemodynamic and respiratory variables, and Richmond Agitation-Sedation Scale (RASS) score, were recorded. Postoperatively, 129 patients remained intubated while breathing spontaneously for 16.4±3.3h, and 124 patients could be sedated solely with dexmedetomidine, whereas 5 required rescue sedatives. During infusion, blood pressure decreased progressively until 12h, whereas heart rate decreased only at 3h. Hemodynamic alterations during dexmedetomidine infusion greatly depended not only on its hemodynamic effects but also on baseline hemodynamics before anesthesia. No serious adverse effect was noted. Dexmedetomidine in intubated, spontaneously breathing patients after ESD was safe and effective. Patient baseline hemodynamics could significantly affect hemodynamics during drug infusion. Without loading doses, plasma drug concentrations were expected to increase progressively. A progressive decrease in blood pressure and unchanged heart rate after an initial decrease suggested that hemodynamic effects of dexmedetomidine in our patients might differ from those reported in young volunteers, although further studies are required to elucidate these points.

36th International Symposium on Intensive Care and Emergency Medicine : Brussels, Belgium. 15-18 March 2016.

36th International Symposium on Intensive Care and Emergency Medicine : Brussels, Belgium. 15-18 March 2016.

Hemodynamic effects of dexmedetomidine during intra-operative electrocorticography for epilepsy surgery.

The dominant challenge in epilepsy surgery is precise delineation of the epileptogenic zone in the brain. Noninvasive techniques such as video electroencephalography (EEG), single photon emission computerized tomography (SPECT), positron emission tomography (PET), magnetoencephalography (MEG), and high-resolution MRI all lack sufficient spatial resolution and sensitivity in many patients. Extraoperative seizure mapping with subdural and/or depth electrodes can be appropriate in many cases, but is not without significant drawbacks. Disadvantages include the requirement for more than one major intracranial operation, need for the patient to be reasonably compliant, insufficient seizure capture, and potential surgical complications including hemorrhage and infection. In addition, electrode coverage may not be adequate, and areas such as insular and frontobasal cortex can be technically challenging to access. Intraoperative electrocorticography (ECoG) avoids many of these disadvantages (notably aside from inadequate coverage), but at the expense of capturing only interictal EEG data. The quality of intraoperative EEG data, therefore, is of paramount importance during one-stage epilepsy surgeries in which ECoG is employed. Dexmedetomidine is an intravenous alpha 2-adrenergic receptor agonist whose use in neurological surgery has blossomed over the past several years due to its sedation properties and desirable neurophysiological profile.[1] This medication has been extensively studied in the context of various neurosurgical pathologies and treatment modalities including awake brain tumor surgery, functional MRI scanning, and endovascular aneurysm treatment.[2,3,4] Its use has also been studied with electroconvulsive therapy, where postprocedural agitation was found to be improved but induced seizure duration not apparently altered.[5,6] The primary concerns regarding dexmedetomidine use in epilepsy surgery revolve around two issues, alteration of the EEG profile and hemodynamic effects, particularly bradycardia and hypotension. Dexmedetomidine does not seem to be a significant EEG confounder.[7] Its intraoperative hemodynamic profile also seems to be safe, although this particular aspect has not previously been specifically addressed within the context of epilepsy surgery.[8] The present study addresses this concern directly with a series of patients undergoing ECoG-guided anterior temporal lobectomy and amygdalohippocampectomy, the most common resective surgery for epilepsy in the adult population.[9] The findings are that dexmedetomidine anesthesia does generate a measurable but clinically insignificant hemodynamic effect when used in this context, and that it does not otherwise adversely impact surgery. This study is a useful contribution to the body of data on which the practice of epilepsy surgery is based. Further studies such as this will allow epilepsy surgery to continue to become more safe and more efficacious.

Long-term dexmedetomidine use and safety profile among critically ill children and neonates.

To determine whether long-term dexmedetomidine dosing is associated with lower opioid and benzodiazepine use without risk of significant hemodynamic changes and/or withdrawal. Retrospective, observational study. PICU, cardiovascular ICU, and neonatal ICU in a single, tertiary care, academic children's hospital. We included all patients less than or equal to 21 years old, who received dexmedetomidine for greater than or equal to 72 hours from December 2008 to December 2010 resulting in a 98-subject cohort. None. The median duration of dexmedetomidine use was 141 hours. A decrease in systolic blood pressure and heart rate was seen after initiation of dexmedetomidine. After dexmedetomidine was discontinued, systolic blood pressure was statistically significantly higher than baseline. Similarly, heart rate showed a significant increase from baseline following discontinuation of dexmedetomidine. Starting dexmedetomidine was not associated with a significant difference in the dosing of opiates or benzodiazepines. Comfort scores were significantly lower at 2 and 72 hours of dexmedetomidine infusion. After stopping dexmedetomidine, the comfort score for patients at 1 hour was statistically higher than for patients at cessation of the infusion. Thirty percent of patients who were taken off dexmedetomidine, whether weaned or abruptly stopped, had withdrawal symptoms and scores recorded with agitation, tremor, and decreased sleep being most prominent. Hemodynamic effects of dexmedetomidine did not limit long-term use in this diverse population. After the addition of dexmedetomidine, opioid and benzodiazepine doses did not significantly escalate, and patients were more comfortable as evidenced by decreasing comfort scores. Withdrawal from dexmedetomidine may be an issue and manifests as agitation, tremors, and decreased sleep.

The effects of dexmedetomidine administration on the pulmonary artery pressure and the transpulmonary pressure gradient after the bidirectional superior cavopulmonary shunt.

The hemodynamic effects of dexmedetomidine (DEX) on pulmonary artery pressure (PAP) are not fully understood in patients with a single-ventricle physiology. The objective of this retrospective study was to characterize the effect of perioperative DEX infusion on PAP and the transpulmonary pressure gradient after a bidirectional superior cavopulmonary shunt (BCPS) operation. We retrieved physiologic data including the heart rate, incidence of cardiac pacing, systolic and diastolic arterial blood pressure (ABP), and superior vena cava (SVC) and inferior vena cava (IVC) pressures from the medical records of all patients <12 months of age who underwent a BCPS operation. Patients with an additional Norwood or Damus-Kaye-Stansel procedure, those with additional pulmonary blood flow, and those without both a SVC and an IVC catheter were excluded from the present study. Following the BCPS operation, the SVC pressure is equivalent to the PAP. Similarly, the IVC pressure is equivalent to the common atrial pressure (CAP). Accordingly, we can directly assess the transpulmonary pressure gradient, defined as the difference between the PAP and the CAP, using simultaneous SVC and IVC pressure measurements. Twenty-nine patients were included in the present study. We did not find any increase in the PAP, CAP, PAP/systolic ABP ratio, or the transpulmonary pressure gradient as of 6 h after admission to the intensive care unit when the patients were treated with DEX infusion at a median (interquartile ranges) dose of 0.6 mcg/kg/h (0.4, 0.64 mcg/kg/h). We concluded that the administration of DEX to children with a single-ventricle physiology is acceptable.

The analgesic and hemodynamic effects of dexmedetomidine and remifentanil during chest tube removal

Amac: Bu calismada remifentanil ve deksmedetomidinin gogus tupu cekilmesi sirasinda agri giderici etkileri incelendi ve bu etkiler sedasyon seviyeleri ile pulmoner ve hemodinamik yanitlar acisindan karsilastirildi. Ca­lis­ma­ pla­ni:­ Calisma prospektif, randomize ve cift kor olarak tasarlandi. Calismaya Subat 2011 Temmuz 2011 tarihleri arasinda koroner arter baypas greft (KABG) cerrahisi yapilan ardisik 41 hasta (31 erkek, 10 kadin; ort. yas 55.7±10.3 yil; dagilim 27-77 yil) dahil edildi. Tum gogus tupleri ameliyat sonrasi 48. saatte cekildi. Hastalar deksmedetomidin (0.5 mg/kg) (grup D) ve remifentanil (0.5 mg/kg) (grup R) olmak uzere rastgele iki gruba ayrildi. Agri ve sedasyon seviyeleri numerik dereceleme skalasi (NRS) ve Ramsay skorlari ile degerlendirildi. Kan basinclari [sistolik (SAB), diyastolik (DAB) ve ortalama (OAB)], periferik oksijen saturasyonlari (SpO2), solunum hizlari (SH) ve kalp hizlari (KH) ilac perfuzyonu oncesinde, sonrasinda ve tup cekildikten sonra ikiser dakika ara ile kaydedildi. Bul gu lar: Iki gruptaki hastalarin demografik ozellikleri benzerdi. Grup D’de agri skorlari tup cekildikten sonra alti ve 10. dakikalarda kaydedilen olcumlerinde daha dusuktu. Baslangic olcumleri ile karsilastirildiginda, Ramsay skorlari perfuzyon sonrasi tum olcumlerde anlamli olarak farkli bulundu (p<0.05). Sistolik arteriyel kan basinci, OAB ve KH olcumleri grup D’de daha dusuk olup tekrarlayan olcumlerde saptanan farklilik istatistiksel olarak daha anlamli idi. So­nuc:­Gogus tupu cekilmesi sirasinda ve sonrasinda deksmedetomidin, remifentanile kiyasla, daha iyi sedasyon ve analjezinin yani sira, benzer hemodinamik kontrol saglar. Bu etkiler, kardiyak cerrahi sonrasi yogun bakim hastalarinda kardiyak veya solunum depresyonu olmadan guvenle saglanabilir. Anah tar soz cuk ler: Gogus tupu cekilmesi; deksmedetomidin; yogun bakim unitesi. Background:­ This study aims to investigate the effects of remifentanil and dexmedetomidine in alleviating pain during chest tube removal and these effects were compared in terms of sedation levels, pulmonary and hemodynamic responses. Methods: The study was designed as a prospective, randomized, double-blinded study. Between February 2011 and July 2011, 41 consecutive patients (31 males, 10 females; mean age 55.7±10.3 years; range 27 to 77 years) who underwent coronary artery bypass graft (CABG) surgery were enrolled. All chest tubes were removed in postoperative 48th hour. The patients were randomized into two groups as dexmedetomidine (0.5 mg/kg) group (group D) and remifentanil (0.5 mg/kg) group (group R). The pain and sedation levels were assessed by numerical rating scale (NRS) and Ramsay scores. Blood pressures [systolic (SAP), diastolic (DAP) and mean (MAP) pressures], peripheral oxygen saturation (SpO2), respiratory rate (RR) and heart rate (HR) were recorded before and after the agent perfusion and every two minutes after the tube was removed. Results:­The demographic characteristics of the patients in both groups were similar. The pain scores were lower during the measurements which were recorded at six and 10 minutes after chest tube removal in group D. The Ramsay scores were found to be statistically different at all measurements following perfusion, compared to the baseline measurements (p<0.05). Systolic arterial blood pressure, MAP and HR were significantly lower in group D and the difference was more pronounced statistically with repeated measurements. Conclusion:­ Dexmedetomidine provides a comparable hemodynamic control along with better sedation and analgesia during and after chest tube removal than remifentanil. These effects can be provided safely without having cardiac or respiratory depression in post-cardiac surgery intensive care patients.

Insight into the effects of dexmedetomidine on intraoperative hemodynamics and postanesthetic recovery speed

Dexmedetomidine is a potent alpha-2-adrenergic agonist, more selective than clonidine, with widespread actions that include anxiolysis, sedation, anesthetic-sparing, analgesia and sympatholytic properties. Since its release in the US market in late 1999, it has gained remarkable attention in the adult, pediatric and geriatric populations, predominantly because of its minimal respiratory depression. A large body of recent work supports its favorable profile in many other clinical scenarios, including neuroprotection, cardioprotection and renoprotection, with promising results [1]. Even though dexmedetomidine displays various favorable pharmacological actions, it is believed that its routine use on patients undergoing surgery is not the current trend. The reason for this can be summed up in two ways. First, intraoperative hemodynamic unstability including hypotension and/or bradycardia due to sympatholysis may be problematic in some patients. Such hemodynamic effects of dexmedetomidine may be expected to be more pronounced in hypovolemic patients and in those with diabetes mellitus or chronic hypertension and in the elderly. Secondly, a delay in postanesthetic recovery is expected due to dexmedetomine’s relatively long duration of action compared to other short-acting anesthetics. This disad vantage means that dexmedetomidine is not suitable for day surgery patients. An interesting study has been carried out associated with the effects of dexmedetomidine on intraoperative hemodynamics and postoperative recovery in this issue of Korean Journal of Anesthesiology [2]. Kang et al. [2] found that the changes in mean arterial pressure (MAP) during the operation in the dexmedetomidine group were significantly less than those in the control group, which means that intraoperative administration of dexmedetomidine produced more stable hemodynamics than in the control. In addition, the authors claimed that dexmedetomidine was not associated with prolongation of extubation time or compromised recovery profile. Although their study was small-scaled, with only 10 patients involved in each group, their results are interesting in that they presented some evidence to dispel our concerns about dexmedetomidine-induced intraoperative hypotension and delay in postanesthetic recovery. These concerns have made us reluctant to the routine use of dexmedetomidine in the operating room. The hemodynamic effects of dexmedetomidine are somewhat controversial. Hypotension and/or bradycardia are not unusual, because dexmedetomidine decreases sympathetic ner vous system activity. On the other hand, transient hypertension has been observed primarily during the loading dose in association with the initial peripheral vasoconstrictive effects, although treatment of transient hypertension has generally not been necessary. Investigations in both humans and animals have revealed significant cerebral vasoconstrictive effects of dexmedetomidine [3,4]. Also, dexmedetomidine is known to be associated with higher MAP than midazolam in patients under epidural anesthesia [5]. Such controversies regarding hemodynamic effect are thought to be caused by biphasic action of dexmedetomidine, characterized by an initial short-term increase in MAP followed by a longer lasting hypotension. The biphasic action of dexmedetomidine is sometimes displayed in a dose-dependent manner, i.e., lower dosages reduce norepinephrine release, resulting in decrease

Dexmedetomidine: Applications for the Pediatric Patient With Congenital Heart Disease

This study aimed to provide a general description of the cardiovascular and hemodynamic effects of dexmedetomidine and an evidence-based review of the literature regarding its use in infants and children with congenital heart disease (CHD). A computerized bibliographic search of the literature on dexmedetomidine use in infants and children with CHD was performed. The cardiovascular effects of dexmedetomidine have been well studied in animal and adult human models. Adverse cardiovascular effects include occasional episodes of bradycardia, with rare reports of sinus pause or cardiac arrest. Both hypotension and hypertension also have been reported. The latter is related to peripheral α(2B) agonism leading to vasoconstriction. No adverse effects on the pulmonary vasculature have been noted even in patients with preexisting pulmonary hypertension. Although there are no direct effects on myocardial function, decreased cardiac output may result from changes in heart rate or increases in afterload. Although not currently Food and Drug Administration (FDA)-approved for the pediatric population, findings have shown dexmedetomidine to be effective in various clinical scenarios of patients with CHD including sedation during mechanical ventilation, prevention of procedure-related anxiety, prevention of emergence delirium and shivering after anesthesia, and treatment of withdrawal. Although dexmedetomidine may have limited utility for painful or invasive procedures, preliminary data suggest that the addition of ketamine to the regimen may offer benefits. When used during the perioperative period, additional benefits include blunting of the sympathetic stress response with a reduction of endogenous catecholamine release, a decrease in intraoperative anesthetic requirements, and a limitation of postoperative opioid requirements.

Evaluation of the Hypnotic and Hemodynamic Effects of Dexmedetomidine on Propofol-Sedated Swine

This study examined the sedative effect of, and hemodynamic response to dexmedetomidine administration in propofol-sedated swine. Sixteen swine were subjects. After anesthetic induction and preparation, the propofol infusion rate was adjusted to maintain a bispectral index (BIS) value between 55 and 65 (i.e., baseline). With the propofol infusion rate fixed at the baseline rate, dexmedetomidine was infused continuously at a rate of 0.2, 0.4, and 0.7 microg.kg(-1).h(-1) for one hour at each rate. The BIS value and hemodynamic parameters were recorded at each step. Dexmedetomidine decreased the BIS value, mean arterial blood pressure, heart rate, cardiac output, and mixed venous oxygen saturation in a dose-dependent manner. The systemic vascular resistance (SVR) did not change, but the pulmonary vascular resistance (PVR) increased. Oxygen delivery (DO(2)) and oxygen consumption (VO(2)) decreased. A small dose of dexmedetomidine (0.2 microg.kg(-1).h(-1)) greatly enhanced the sedative effects of propofol with only small changes in hemodynamics and systemic oxygen balance, suggesting it may be useful in reducing the propofol dose requirement. However, dexmedetomidine 0.4 microg.kg(-1).h (-1) suppressed cardiac contractility, and 0.7 microg.kg(-1).h(-1) induced hemodynamic instability and further systemic oxygen imbalance while the additional sedative effect was limited. A lower dose of dexmedetomidine may be recommended when using it in combination with propofol.

Analgesic, Sedative and Hemodynamic Effects of Dexmedetomidine Following Major Abdominal Surgeries: A Randomized, Double- Blinded Comparative Study with Morphine

This was a randomized double-blinded study; in which 60 ASAI-II adult patients scheduled for major abdominal surgeries (colostomy, radical cystectomy, major gynecological surgery, and abdominal vascular surgery) were received standard general anesthesia. Twenty minutes before the anticipated end of surgery, patients were randomized into two equal groups: dexmedetomidine group (group D) and morphine group (group M). Group D received dexmedetomidine IV infusion 4μg/kg/h for 15 minutes (1μg/Kg) followed by 0.4μg/kg/h for 3h. Group M received morphine sulfate IV (0.07mg/kg). All patients were given a morphine patient controlled analgesia (PCA) pump in the post anesthesia care unit (PACU), delivering IV morphine 2mg with a lockout time of 5 minutes if pain score assessed through visual analog scale (VAS) was more than 5 at any given 5-min assessment. During the PACU recovery period, morphine consumption; pain and sedation scores; hemodynamic variables (heart rate, mean arterial blood pressure, oxygen saturation and respiratory rate); and postoperative nausea, retching and vomiting (PONV) were recorded every 30 min for 3h (study period) by a member of staff blinded to the treatment. The study demonstrated that the use of dexmedetomidine led to significant decrease in the total amount of morphine consumed throughout the entire PACU recovery period (P<0.05). This was associated with reasonable pain and sedation scores; significant slowing in heart rate (P