Pro: dexmedetomidine should be used for infants and children undergoing cardiac surgery

Why do We Use the Concepts of Adult Anesthesia Pharmacology in Developing Brains? Will It Have an Impact on Outcomes? Challenges in Neuromonitoring and Pharmacology in Pediatric Anesthesia

BACKGROUND

Pediatric sedation and anesthesia techniques have plenty of difficulties and challenges. Data on the pharmacologic, electroencephalographic, and neurologic response to anesthesia at different brain development times are only partially known. New data in neuroscience, pharmacology, and intraoperative neuromonitoring will impact changing concepts and clinical practice. In this article, we develop a conversation to guide the debate and search for a view more attuned to the updated knowledge in neurodevelopment, electroencephalography, and clinical pharmacology for the anesthesiologic practice in the pediatric population.

Cardiac Preconditioning Effect of Ketamine-Dexmedetomidine versus Fentanyl-Propofol during Arrested Heart Revascularization

Background

Myocardial damage due to ischemia and reperfusion is still unavoidable during coronary surgery. Anesthetic agents have myocardial preconditioning effect. Ketamine has sympathomimetic effect, while dexmedetomidine has a sympatholytic effect in addition to anesthetic, analgesic, and anti-inflammatory properties of both the drugs. This study was carried out to compare ketamine-dexmedetomidine (KD) combination with fentanyl-propofol (FP) combination on the release of cardiac troponin T (cTnT) and outcome after coronary artery bypass graft.

Patients and Methods

Ninety adult patients who underwent coronary artery bypass grafting (CABG) were assigned to receive either KD base anesthesia (KD group) or FP anesthesia (FP group). Trends of high-sensitive cTnT, CK-MB, and serum cortisol were followed in the first postoperative 24 h. Other outcomes were vital signs, weaning from cardiopulmonary bypass, tracheal extubation time, and echocardiographic findings.

Results

There was a significant lower release of cTnT in KD group than FP group during its peak values at 6 h after aortic unclamping (92.01 ± 7.332 in KD versus 96.73 ± 12.532 ng.L^-1 P = 0.032). significant lower levels of serum cortisol levels were noted KD group than in FP group at 6 and 12 h after aortic unclamping P < 0.001. As regard tracheal extubation time, patients assigned to KD group extubated earlier than whom in FP group 202.22 ± 28.674 versus 304.67 ± 40.598 min respectively P < 0.001.

Conclusion

The use of KD during on-pump CABG confers better myocardial protective and anti-inflammatory effect than fentanyl propofol.

Fast tracking after repair of congenital heart defects

Fast tracking after repair of congenital heart defects (CHD) is a process involving the reduction of perioperative period by timely admission, early extubation after surgery, short intensive care unit (ICU) stay, early mobilisation, and faster hospital discharge. It requires a coordinated multidisciplinary team involvement. In the last 2 decades, many centres have adopted the fast tracking strategy in paediatric cardiac population, safely and successfully extubating patients in the OR with reported benefits in terms of reduced morbidity and ICU/hospital stay. In this manuscript, we will review the literature available on early extubation after repair of CHD and share our experience with this approach.

Implementation of On-table Extubation After Pediatric Cardiac Surgery in the Developing World

In the recent years there has been increasing trend towards the practice of on-table extubation after pediatric cardiac surgery among practitioner in European and non-European countries. In this article we share our experience with on-table extubation among children after cardiac surgery in the developing world supported with the currently available literature.

An evolving anesthetic protocol fosters fast tracking in pediatric cardiac surgery: A comparison of two anesthetic techniques

Background:

The past two decades have seen rapid development of new surgical techniques for repair as well as palliation of complex congenital heart diseases. For a better patient outcome, minimal postoperative ventilation remains one of the most important endpoints of an effectual perioperative management.

Aims and Objectives:

The aim of this randomized open-label trial was to compare postoperative extubation time and intensive care unit (ICU) stay when two different anesthetic regimens, comprising of induction with ketamine and low-dose fentanyl versus high-dose fentanyl, are used, in pediatric patients undergoing corrective/palliative surgery.

Materials and Methods:

Patients with congenital cardiac defects, under 14 years of age undergoing cardiac surgery under cardiopulmonary bypass (CPB) and epidural analgesia, were enrolled into two groups – Group K (ketamine with low-dose fentanyl) and Group F (high-dose fentanyl) – over a period of 10 months, starting from January 2018. The effect of both these drugs on postoperative extubation time and ICU stay was compared using Mann–Whitney U-test.

Results:

A total of 70 patients were assessed with equal distribution in both the groups. In Group K, 32 of 35 patients were extubated in the operation room, whereas extubation time in Group F was18.1 ± 11 h. Total ICU stay in Group K and Group F was 45.2 ± 30.1 and 60.1 ± 24.5 h, respectively (P = 0.02). Systolic blood pressure was significantly higher in Group K.

Conclusion:

Ketamine along with low-dose fentanyl, when used for anesthetic induction, in comparison to high-dose fentanyl, reduces postoperative extubation time and ICU stay, in pediatric patients undergoing corrective/palliative surgery under CPB and epidural analgesia for congenital cardiac defects.

Use of dexmedetomidine in pediatric cardiac anesthesia

PURPOSE OF REVIEW

In recent years, ultrafast-track anesthesia with on-table extubation and concepts of accelerated postoperative care have gained increasing support in pediatric congenital cardiac surgery. It is believed that such approaches might ideally combine economic benefits with a striving for continuous improvement of patient outcomes. The present review summarizes the role of dexmedetomidine (DEX) in this setting.

RECENT FINDINGS

DEX is a clinical multipurpose drug that mediates its diverse responses through the activation of α2-adrenoreceptors. In pediatric cardiac surgery it has various applications. Used as a premedication, DEX provides arousable sedation and anxiolysis. As an intraoperative adjunctive agent of balanced general anesthesia the primary objectives for its administration are attenuation of the neuro-humoral stress response and facilitation of early extubation. During ICU treatment DEX spares opioids, prevents the risk of postoperative delirium or emergence agitation and impacts on important patient-centered outcomes, such as duration of mechanical ventilation, restart of enteral nutrition or length of ICU stay.

SUMMARY

Due to a favorable mix of beneficial physiologic actions and a limited adverse effect profile, DEX is established in the perioperative pediatric cardiac surgery setting. However, evidence from high-quality randomized controlled trials on the effects of supplemental DEX on meaningful patient outcomes is scarce, and research on the role of DEX in providing cardioprotection, neuroprotection, or renoprotection is still at its beginning. DEX has developed to one of the main agents in the armamentarium of cardiac anesthesiologists and pediatric intensivists, but it should not be regarded as the new 'magic bullet'.

Noncardiac Challenges in the Cardiac ICU: Feeding, Growth and Gastrointestinal Complications, Anticoagulation, and Analgesia

Outcomes following cardiac intensive care unit (CICU) admission are influenced by many factors including initial cardiac diagnosis, surgical complexity, and burden of critical illness. Additionally, the presence of noncardiac issues may have a significant impact on outcomes and the patient experience during and following an intensive care unit stay. This review focuses on three common noncardiac areas which impact outcomes and patient experience in and beyond the CICU: feeding and growth, pain and analgesia, and anticoagulation. Growth failure and feeding dysfunction are commonly encountered in infants requiring cardiac surgery and have been associated with worse surgical and developmental outcomes. Recent studies most notably in the single ventricle population have demonstrated improved weight gain and outcomes when feeding protocols are implemented. Children undergoing cardiac surgery may experience both acute and chronic pain. Emerging research is investigating the impact of sedatives and analgesics on neurodevelopmental outcomes and quality of life. Improved pain scores and standardized management of pain and withdrawal may improve the patient experience and outcomes. Effective anticoagulation is a critical component of perioperative care but may be complicated by inflammation, multiorgan dysfunction, and patient factors. Advances in monitoring of anticoagulation and emerging therapies are reviewed.

Dexmedetomidine utilisation and outcomes of children with trisomy 21 undergoing congenital heart disease surgery

INTRODUCTION

The diagnosis of trisomy 21 in children has been associated with failed extubation after CHD surgery. Dexmedetomidine may be a useful agent to improve postoperative outcomes in these patients, such as ventilator time, ICU length of stay, or hospital length of stay.

MATERIALS AND METHODS

The Pediatric Health Information System database was queried from January, 2008 to December, 2010 for patients with trisomy 21 who underwent CHD surgery. Patients who received dexmedetomidine were matched to patients who did not by propensity score. The primary outcome was ventilator days charged, and secondary outcomes included ICU and hospital length of stay.

RESULTS

A total of 1088 patients (544 matched pairs) met inclusion criteria. Patient characteristics were similar, with the exception of more patients in the dexmedetomidine group undergoing repair of complete atrioventricular canal and fewer undergoing mechanical valve replacement (p<0.01). More patients in the dexmedetomidine group were administered milrinone, epinephrine, vasopressin, benzodiazepines, opiates, and adjunct pain and sedative medications (p<0.01). The dexmedetomidine group had greater time on the ventilator [7 (4.5-11) versus 6 (4-10) days (median, interquartile range) p<0.01] and similar ICU length of stay, hospital length of stay, and mortality compared with controls. Mixed-effects modelling clustered on institution did not show beneficial effect of dexmedetomidine on ventilator time, ICU stay, or hospital length of stay.

CONCLUSIONS

The use of dexmedetomidine was not associated with the decreased ventilatory time. Routine use of dexmedetomidine is not warranted in this patient population.

Total intravenous anesthesia will supercede inhalational anesthesia in pediatric anesthetic practice

Inhalational anesthesia has dominated the practice of pediatric anesthesia. However, as the introduction of agents such as propofol, short-acting opioids, midazolam, and dexmedetomidine a monumental change has occurred. With increasing use, the overwhelming advantages of total intravenous anesthesia (TIVA) have emerged and driven change in practice. These advantages, outlined in this review, will justify why TIVA will supercede inhalational anesthesia in future pediatric anesthetic practice.

Dexmedetomidine attenuates hypoxemia during palliative reconstruction of the right ventricular outflow tract in pediatric patients

The objective of this study was to investigate whether the α agonist dexmedetomidine has the ability to attenuate hypoxemia in pediatric patients undergoing palliative pulmonary artery reconstruction.From January 2009 to January 2013, a total of 25 pediatric patients with Tetralogy of Fallot, pulmonary atresia (ventricular septal defect), or persistent truncus arteriosus (I) were enrolled in our study. Due to hypoplastic pulmonary arteries, all patients received palliative pulmonary artery reconstruction. During the perioperative period, they were allocated to receive either dexmedetomidine (bolus dose of 0.3 μg/kg followed by an infusion of 0.2-0.3 μg/kg/h, n = 15) or control drug (n = 10) intravenously. Any desaturation was recorded. Heart rate, mean arterial pressure, pulse oximetry, and arterial blood gas parameters were measured during the perioperative period.There were no significant differences between the groups in hemodynamic variables. The arterial oxygen saturation and arterial blood gas parameters increased in the dexmedetomidine groups (P < 0.05).These findings suggest that the injection of dexmedetomidine can attenuate hypoxemia during palliative pulmonary artery reconstruction in pediatric patients.

Patient and procedural characteristics for successful and failed immediate tracheal extubation in the operating room following cardiac surgery in infancy

BACKGROUND

Immediate extubation in the operating room after congenital heart surgery is practiced with rising frequency at many cardiac institutions to decrease costs and complications. Infants less than one year of age are also increasingly selected for this 'fast track'. However, factors for patient selection, success, or failure of this practice have not been well defined in this population, yet are critical for patient safety.

OBJECTIVE

To identify selection criteria, patient and procedural characteristics for successful or failed very early endotracheal extubation in the operating room immediately following infant heart surgery.

METHODS

A retrospective analysis was performed for 326 consecutive patients undergoing neonatal and infant heart surgery from 2009 to 2012. Extubation and reintubation data were taken from the institutional Society of Thoracic Surgeons database and patients' charts. Patient characteristics were derived using multivariable logistic regression models.

RESULTS

Very early extubation in the operating room was performed for 130 of 326 neonates and infants (40%). Weight >4 kg, lesser procedural complexity, and absence of trisomy 21 were identified as significant predictors for attempted very early extubation. Of these patients, 12% required reintubation within 48 h following surgery, predominantly due to respiratory failure or for mediastinal re-exploration. Greater procedural complexity was associated with failed extubations. Reintubation was associated with prolonged hospitalization.

CONCLUSIONS

Extubation immediately after infant heart surgery in the operating room can be safely achieved. However, our data suggest that patients undergoing more complex procedures should be selected more conservatively for immediate early extubation.

A phase II/III, multicenter, safety, efficacy, and pharmacokinetic study of dexmedetomidine in preterm and term neonates

OBJECTIVE

To investigate the safety, efficacy, and pharmacokinetic profile of dexmedetomidine in preterm and full-term neonates ≥ 28 to ≤ 44 weeks gestational age.

STUDY DESIGN

Forty-two intubated, mechanically ventilated patients (n = 42) were grouped by gestational age into group I (n = 18), ≥ 28 to <36 weeks, and group II (n = 24), ≥ 36 to ≤ 44 weeks. Within each age group, there were 3 escalating dose levels, including a loading dose (LD, μg/kg) followed by a maintenance dose (MD, μg · kg(-1) · h(-1)) for 6-24 hours: level 1, 0.05 LD/MD; level 2, 0.1 LD/MD; and level 3, 0.2 LD/MD. The primary endpoint was the number of patients requiring sedation as determined by the Neonatal Pain, Agitation, Sedation Scale.

RESULTS

During dexmedetomidine infusion, 5% of Neonatal Pain, Agitation, Sedation Scale scores were >3, indicating agitation/pain, with 4 patients (10%) requiring more sedation and 17 (40%) requiring more analgesia. Though there was significant variability in pharmacokinetic variables, group I appeared to have lower weight-adjusted plasma clearance (0.3 vs 0.9 L · h(-1) · kg(-1)) and increased elimination half-life (7.6 vs 3.2 hours) compared with group II. Fifty-six adverse events (AEs) were reported in 26 patients (62%); only 3 AEs (5%) were related to dexmedetomidine. There were no serious AEs and no AEs or hemodynamic changes requiring dexmedetomidine discontinuation.

CONCLUSION

Dexmedetomidine is effective for sedating preterm and full-term neonates and is well-tolerated without significant AEs. Preterm neonates had decreased plasma clearance and longer elimination half-life.

Endocrinopathies in the cardiac ICU

The past several years have seen an increased appreciation of the potential role of the endocrine system in the recovery process following surgery for congenital heart disease. Many of the hormonal changes following cardiac surgery are adaptive and necessary, whereas activation of proinflammatory cytokine and chemokine responses and some of the metabolic changes following surgery are likely mediators leading to detrimental outcomes. Additionally, other hormonal perturbations may contribute to adverse outcomes. This review examines the pain and the stress response, thyroid function and hyperglycemia following cardiopulmonary bypass (CPB), and the potential role of corticosteroids in the pediatric cardiac critical care unit.

[Dexmedetomidine and clonidine: a review of their pharmacodynamy to define their role for sedation in intensive care patients]

Alpha-2 adrenergic agonists ("alpha-2 agonists") present multiple pharmacodynamic effects: rousable sedation, decreased incidence of delirium in the setting of critical care, preservation of respiratory drive, decreased whole body oxygen consumption, decreased systemic and pulmonary arterial impedance, improved left ventricular systolic and diastolic function, preserved vascular reactivity to exogenous catecholamines, preserved vasomotor baroreflex with lowered set point, preserved kidney function, decreased protein catabolism. These pharmacodynamic effects explain the interest for these drugs in the critical care setting. However, their exact role for sedation in critically ill-patients remains open for further studies. Given the few double-blind randomized multicentric trials available, the present non exhaustive analysis of the literature aims at presenting the utilization of alpha-2 agonists as potential first-line sedative agents, in the critical care setting. Suggestions regarding the use of alpha-2 agonists as sedatives are detailed.

Comparison of the Effects of Ketamine-Dexmedetomidine and Sevoflurane-Sufentanil Anesthesia on Cardiac Biomarkers After Cardiac Surgery: An Observational Study

Inhalational anesthetics have demonstrated cardioprotective effects against myocardial ischemia-reperfusion injury. Clinical studies in cardiac surgery have supported these findings, although not with the consistency demonstrated in experimental studies. Recent investigations have questioned the advantages of inhalational over intravenous anesthetics with respect to cardiac protection. Ketamine has been shown to be comparable with sufentanil, and has even demonstrated anti-inflammatory properties. Dexmedetomidine has been established as a sedative/anesthetic drug with analgesic properties, and has also demonstrated myocardial protective effects. In this retrospective observational study, the influence of ketamine-dexmedetomidine-based anesthesia (KET-DEX group; n=17) on the release of cardiac biomarkers was compared with that of sevoflurane-sufentanil-based anesthesia (SEVO group; n=21) in patients undergoing elective coronary artery bypass grafting. Compared with the SEVO group, the KET-DEX group exhibited significantly reduced cardiac troponin I (2.22±1.73 vs. 3.63±2.37 µg/l; P=0.02) and myocardial fraction of creatine kinase (CK-MB) levels (12.4±10.4 vs. 20.3±11.2 µg/l; P=0.01) on the morning of the first postoperative day. Furthermore, cardiac troponin I release, evaluated as the area under the curve, was significantly reduced in the KET-DEX group (32.1±20.1 vs. 50.6±23.2; P=0.01). These results demonstrate the cardioprotective effects of ketamine-dexmedetomidine anesthesia compared with those of sevoflurane-sufentanil anesthesia.

Hemodynamic effects of the combination of dexmedetomidine-fentanyl versus midazolam-fentanyl in children undergoing cardiac surgery with cardiopulmonary bypass

BACKGROUND AND OBJECTIVES

To evaluate the efficacy of the combined infusion of dexmedetomidine and fentanyl on the hemodynamic response during cardiac surgery with cardiopulmonary bypass (CPB) in children.

METHODS

Thirty-two children, ages 1 month to 10 years, scheduled for cardiac surgery with cardiopulmonary bypass were randomly divided in two groups: the MDZ Group received midazolam 0.2 mg.kg(-1).h(-1), while the DEX group received dexmedetomidine 1 microg.kg(-1).h(-1) during one hour followed be a reduction by half in the rate of infusion in both groups. Both groups received fentanyl 10 microg.kg(-1), midazolam 0.2 mg.h(-1), and vecuronium 0.2 mg.kg(-1) for anesthesia induction. The same doses of fentanyl and vecuronium used during induction were infused during the first hour after induction, followed by a reduction to half. Infusions were initiated immediately after induction and maintained until the end of the surgery. Isoflurane was administered for a short time to control the hyperdynamic response to incision and sternotomy.

RESULTS

In both groups, systolic blood pressure and heart rate reduced significantly after one hour of anesthetic infusion, but the increase in systolic and diastolic pressure and heart rate to skin incision were significantly lower in the DEX Group. A significantly lower number of patients demanded supplementation with isoflurane in the DEX Group. After CPB, patients in both groups had similar hemodynamic responses.

CONCLUSIONS

Infusion of dexmedetomidine without bolus seems to be an effective adjuvant to fentanyl on the promotion of sedation and control of hemodynamic responses during surgery for congenital cardiopathies in children.

Effects of Dexmedetomidine-Fentanyl Infusion on Blood Pressure and Heart Rate during Cardiac Surgery in Children

Background. The purpose of this study was to access the effects of dexmedetomidine-fentanyl infusion on blood pressure (BP) and heart rate (HR) before surgical stimulation, on their changes to skin incision, and on isoflurane requirement during cardiac surgery in children. Methods. This study had a prospective, randomized, and open-label design. Thirty-two children aged 1 month to 10 years undergoing surgery for repair congenital heart disease (CHD) with CPB were randomly allocated into two groups: group MDZ received midazolam 0.2 mg·kg⁻¹·h⁻¹ and group DEX received dexmedetomidine 1 μg·kg⁻¹·h⁻¹ during the first hour followed by half of these rates of infusions thereafter. Both group received fentanyl 10 μg·kg⁻¹, midazolam 0.2 mg·kg⁻¹ and vecuronium 0.2 mg·kg⁻¹ for induction. These same doses of fentanyl and vecuronium were infused during the first hour then reduced to half. The infusions started after induction and maintained until the end of surgery. Isoflurane was given briefly to control hyperdynamic response to skin incision and sternotomy. Results. In both groups, systolic blood pressure (sBP) and heart rate (HR) decreased significantly after one hour of infusion of the anesthetic solutions, but there were significantly less increase in diastolic blood pressure, sBP, and HR, and less patients required isoflurane supplementation to skin incision in the patients of the DEX group. Discussion. Dexmedetomidine infusion without a bolus appears to be an effective adjunct to fentanyl anesthesia in control of hemodynamic responses to surgery for repair of CHD in children.

Dexmedetomidine sedation for pediatric post-Fontan procedure patients

OBJECTIVE

The hemodynamic, respiratory, and sedative effects of dexmedetomidine (DEX) for pediatric patients post-Fontan surgery.

DESIGN

Retrospective.

SETTING

Single institutional intensive care unit.

PARTICIPANTS

Fourteen patients undergoing Fontan-type surgery.

RESULT

A retrospective review was conducted on 14 pediatric patients who had undergone a Fontan procedure for congenital heart disease. A vital component of postoperative management of these patients is to prevent an increase in pulmonary vascular resistance (PVR) that may lead to a serious reduction in cardiac output. DEX an alpha-2 adrenergic receptor agonist might offer an advantage over current sedation methods in preventing a rise in PVR. Nine patients received sedation with DEX and five patients in a control group were administered standard regimens of sedation and analgesia. The DEX group exhibited no evidence of an increased partial pressure of arterial carbon dioxide postoperatively as opposed to the control group. This lack of respiratory depression made the DEX group less likely to increase their PVR. However, the DEX group did experience a significant incidence of bradycardia that required the use of a cardiac pacemaker.

CONCLUSIONS

The results of this retrospective review of the role of DEX in the management of the post-Fontan surgical pediatric patient indicate some potential advantages.