Association of preoperative coronavirus disease 2019 with mortality, respiratory morbidity and extrapulmonary complications after elective, noncardiac surgery: An observational cohort study.

Study Objective: To assess the impact of preoperative infection with the contemporary strain of severe acute respiratory coronavirus 2 (SARS-CoV-2) on postoperative mortality, respiratory morbidity and extrapulmonary complications after elective, noncardiac surgery.

Design: An ambidirectional observational cohort study.

Setting: A tertiary and teaching hospital in Shanghai, China.

Anesthesia and Sedation Exposure and Neurodevelopmental Outcomes in Infants Undergoing Congenital Cardiac Surgery: A Retrospective Cohort Study.

Background: Children undergoing complex cardiac surgery are exposed to substantial cumulative doses of sedative medications and volatile anesthetics and are more frequently anesthetized with ketamine, compared with healthy children. This study hypothesized that greater exposure to sedation and anesthesia in this population is associated with lower neurodevelopmental scores at 18 months of age.

Methods: A secondary analysis was conducted of infants with congenital heart disease who participated in a prospective observational study of environmental exposures and neurodevelopmental outcomes to assess the impact of cumulative volatile anesthetic agents and sedative medications.

Effect of dexmedetomidine on sevoflurane-induced neurodegeneration in neonatal rats.

Background: Structural brain abnormalities in newborn animals after prolonged exposure to all routinely used general anaesthetics have raised substantial concerns for similar effects occurring in millions of children undergoing surgeries annually. Combining a general anaesthetic with non-injurious sedatives may provide a safer anaesthetic technique. We tested dexmedetomidine as a mitigating therapy in a sevoflurane dose-sparing approach.

Standards for preclinical research and publications in developmental anaesthetic neurotoxicity: expert opinion statement from the SmartTots preclinical working group.

In March 2019, SmartTots, a public-private partnership between the US Food and Drug Administration and the International Anesthesia Research Society, hosted a meeting attended by research experts, anaesthesia journal editors, and government agency representatives to discuss the continued need for rigorous preclinical research and the importance of establishing reporting standards for the field of anaesthetic perinatal neurotoxicity. This group affirmed the importance of preclinical research in the field, and welcomed novel and mechanistic approaches to answer some of the field's largest questions. The attendees concluded that summarising the benefits and disadvantages of specific model systems, and providing guidance for reporting results, would be helpful for designing new experiments and interpreting results across laboratories.

Immature murine hippocampal neurones do not develop long-term structural changes after a single isoflurane exposure.

Background: Studies in developing animals show that a clinically relevant anaesthesia exposure increases neuronal death and alters brain structure. In the hippocampal dentate gyrus, the anaesthetic isoflurane induces selective apoptosis among roughly 10% of 2-week-old hippocampal granule cells in 21-day-old mice. In this work, we queried whether the 90% of granule cells surviving the exposure might be 'injured' and integrate abnormally into the brain.

Defining the Vulnerability Window of Anesthesia-Induced Neuroapoptosis in Developing Dentate Gyrus Granule Cells - A Transgenic Approach Utilizing POMC-EGFP Mice.

Exposure to commonly used anesthetics is associated with widespread neuroapoptosis in neonatal animals. Vulnerability of developing hippocampal dentate gyrus granule cells to anesthetic neurotoxicity peaks approximately 2 weeks after cell birth, as measured by bromodeoxyuridine birth dating, regardless of the age of the animal. The present study examined whether the vulnerable window can be further characterized by utilizing a transgenic approach.

Anesthesia and the developing brain: A way forward for laboratory and clinical research.

All commonly used general anesthetics have been shown to cause neurotoxicity in animal models, including nonhuman primates. Opinion, however, remains divided over how cumulative evidence from preclinical and human studies in this field should be interpreted and its translation to current practices in pediatric anesthesia and surgery. A group of international experts in laboratory and clinical sciences recently convened in Genoa, Italy, to evaluate the current state of both laboratory and clinical research and discuss future directions for basic, translational, and clinical studies in this field.

Does pediatric anesthesia cause brain damage? - Addressing parental and provider concerns in light of compelling animal studies and seemingly ambivalent human data.

Anesthesia facilitates surgery in millions of young children every year. Structural brain abnormalities and functional impairment observed in animals have created substantial concerns among clinicians, parents, and government regulators. Clinical studies seemed ambivalent; it remains unclear whether differential species effects exist towards anesthetic exposure.

Comparison of Intranasal Dexmedetomidine and Oral Pentobarbital Sedation for Transthoracic Echocardiography in Infants and Toddlers: A Prospective, Randomized, Double-Blind Trial.

Background: Acquisition of transthoracic echocardiographic (TTEcho) images in children often requires sedation. The optimal sedative for TTEcho has not been determined. Children with congenital heart disease are repeatedly exposed to sedatives and anesthetics that may affect brain development.

Sedation methods for transthoracic echocardiography in children with Trisomy 21-a retrospective study.

Background: Many children with Trisomy 21 have neurologic or behavioral problems that make it difficult for them to remain still during noninvasive imaging studies, such as transthoracic echocardiograms (TTEcho). Recently, intranasal dexmedetomidine sedation has been introduced for this purpose. However, dexmedetomidine has been associated with bradycardia.

Do anesthetics harm the developing human brain? An integrative analysis of animal and human studies.

Anesthetics that permit surgical procedures and stressful interventions have been found to cause structural brain abnormalities and functional impairment in immature animals, generating extensive concerns among clinicians, parents, and government regulators regarding the safe use of these drugs in young children. Critically important questions remain, such as the exact age at which the developing brain is most vulnerable to the effects of anesthetic exposure, whether a particular age exists beyond which anesthetics are devoid of long-term effects on the brain, and whether any specific exposure duration exists that does not lead to deleterious effects. Accordingly, the present analysis attempts to put the growing body of animal studies, which we identified to include >440 laboratory studies to date, into a translational context, by integrating the preclinical data on brain structure and function with clinical results attained from human neurocognitive studies, which currently exceed 30 studies.

Long-term Fate Mapping to Assess the Impact of Postnatal Isoflurane Exposure on Hippocampal Progenitor Cell Productivity.

Background: Exposure to isoflurane increases apoptosis among postnatally generated hippocampal dentate granule cells. These neurons play important roles in cognition and behavior, so their permanent loss could explain deficits after surgical procedures.

Methods: To determine whether developmental anesthesia exposure leads to persistent deficits in granule cell numbers, a genetic fate-mapping approach to label a cohort of postnatally generated granule cells in Gli1-CreER::GFP bitransgenic mice was utilized.

Biomarkers, Genetics, and Epigenetic Studies to Explore the Neurocognitive Effects of Anesthesia in Children.

Exposure to commonly used anesthetic agents causes widespread neuronal degeneration in the developing mammalian brain and has been shown to impair neurodevelopment in a variety of newborn vertebrate animal species. Although retrospective studies have suggested an association between anesthesia exposure in childhood and subsequent neurodevelopmental abnormalities, a causal relationship in humans has yet to be demonstrated. Unfortunately, translation of findings from bench to bedside is limited by several factors and histologic assessment in healthy children following exposure to anesthesia is not possible.

Dosing and efficacy of intranasal dexmedetomidine sedation for pediatric transthoracic echocardiography: a retrospective study.

Purpose: We designed this retrospective observational study on the use of α2-agonist dexmedetomidine to determine the optimum intranasal dose to achieve sedation for pediatric transthoracic echocardiography and to identify any dose-related adverse effects.

Methods: Outpatient children aged three months to three years with diverse diagnoses of congenital heart disease, including cyanotic cardiac defects, underwent transthoracic echocardiography under dexmedetomidine sedation. Aerosolized intranasal dexmedetomidine was administered with initial doses ranging from 1-3 µg·kg(-1).

Cognition and Brain Structure Following Early Childhood Surgery With Anesthesia.

Background: Anesthetics induce widespread cell death, permanent neuronal deletion, and neurocognitive impairment in immature animals, raising substantial concerns about similar effects occurring in young children. Epidemiologic studies have been unable to sufficiently address this concern, in part due to reliance on group-administered achievement tests, inability to assess brain structure, and limited control for confounders.

Methods: We compared healthy participants of a language development study at age 5 to 18 years who had undergone surgery with anesthesia before 4 years of age (n = 53) with unexposed peers (n = 53) who were matched for age, gender, handedness, and socioeconomic status.

Developmental stage-dependent impact of midazolam on calbindin, calretinin and parvalbumin expression in the immature rat medial prefrontal cortex during the brain growth spurt.

Background: Human epidemiological data suggest a link between anesthesia exposure in early postnatal life and subsequent lasting neurocognitive alterations. Understanding the underlying mechanisms of this potential association is of paramount importance in an attempt to develop protective strategies. While general anesthetics are powerful modulators of GABAergic neurotransmission, little is known about the impact of these drugs on developing GABAergic networks.

Clinical research into anesthetic neurotoxicity: does anesthesia cause neurological abnormalities in humans?

General anesthetics mitigate distress and exaggerated hemodynamic responses to pain and stressful stimulation, allowing surgery and diagnostic procedures to be performed worldwide in millions of children every year. Emerging studies, mainly carried out in early postnatal laboratory animals, demonstrate widespread neuronal elimination, alteration in neuronal circuitry, and long-term neurological disabilities following exposure to all commonly used sedatives and anesthetics. These findings have raised concerns among parents, anesthesiologists, neuroscientists, and government regulators about the safety of anesthetic drugs in children, especially infants.

A combination of mild hypothermia and sevoflurane affords long-term protection in a modified neonatal mouse model of cerebral hypoxia-ischemia.

Background: Infant brain injury from hypoxia-ischemia (HI) can lead to life-long impairment, but protective strategies are lacking. Short-term but not long-term protection has been demonstrated in the Rice-Vannucci neonatal brain ischemia model (RVM) by volatile anesthetic administration before HI, while exposure during HI has not been tested. In the current study, we evaluated a combination of sevoflurane and mild hypothermia as a protective approach during HI, both short- and long-term, by introducing intubation and mechanical ventilation to the RVM.

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.

Anesthetic neurotoxicity.

All routinely utilized sedatives and anesthetics have been found neurotoxic in a wide variety of animal species, including non-human primates. Neurotoxic effects observed in animals include histologic evidence for apoptotic neuronal cell death and subsequent learning and memory impairment. Several cohort studies in neonates with significant comorbidities requiring surgical procedures early in life have also demonstrated abnormal neurodevelopmental outcomes.