Correspondence
References 1 Hansen TG. Anesthesia-related neurotoxicity and the developing animal brain is not a significant problem in children. Pediatr Anesth 2014; 25: 65–72. 2 Hansen TG, Pedersen JK, Henneberg SW et al. Neurosurgical conditions and procedures in infancy are associated with mortality and academic performances
in adolescence: a nationwide cohort study. Pediatr Anesth 2015; 25: 186–192. 3 Wilder RT, Flick RP, Sprung J et al. Early exposure to anesthesia and learning disabilities in a population-based birth cohort. Anesthesiology 2009; 110: 796–804.
4 Hansen TG, Flick R. Anesthetic effects on the developing brain: insights from epidemiology. Anesthesiology 2009; 110: 1–3. 5 Flick RP, Warner DO. A users’ guide to interpreting observational studies of pediatric anesthetic neurotoxicity: the lessons of Sir Bradford Hill. Anesthesiology 2012; 117: 459–462.
Effects of anesthesia on the developing brain: can the underlying disease be ignored? SIR—Very few issues (if any) within pediatric anesthesia have created so much concern and emotional gravity than the possibility that general anesthetics might be neurotoxic in the developing brain. Fortunately, contrary to the plethora of positive animal studies, it has proven rather difficult to demonstrate a human corollary to this phenomenon. Consequently, if it exists in humans, anesthesia-related neurotoxicity must be vague or present only in a subset of (genetically?) susceptible infants, otherwise it would have been easy to demonstrate and it would most likely have been suspected many years ago. In two nationwide, unselected followup studies of the Danish birth cohorts 1986–1990 from our group comprising (the largest samples published so far) neonates and infants undergoing inguinal hernia repair in infancy and pyloric stenosis repair before the age of 3 months, academic achievements in 9th grade (aged 15–16 years) were similar to a 5% randomly selected control sample when adjusted for confounding factors (e.g., age, gender, congenital malformations, maternal age, and parental level of education) (1,2). However, exposed children had a slightly higher nonattainment rate (compatible with the existence of a susceptible subgroup?). Interestingly, the above-mentioned confounders more strongly affected academic achievements than anesthesia and surgical exposure. This was the background for my recent review article on this topic (3). The review article was a commissioned paper for the themed January 2015 issue of Pediatric Anesthesia containing various review articles on challenging orthodoxy in pediatric anesthesia many of which had predetermined and bombastic titles such as mine. Of course, my review article was meant as a “provocative” input into the current debate on this topic. However, if one reads the manuscript in full, the reader would
436
acknowledge that the situation is a bit more complicated. I completely concur with Drs. Warner and Flick’s conclusion of their letter (4) addressing my review article that: Although anesthesia-related neurotoxicity may be a minor problem, the jury is still out there. In their letter, Drs. Warner and Flick also question the conclusion drawn in our recent cohort study comprising all children undergoing neurosurgical procedures in Denmark during 1986–1990, that “. . ..pooling of data from multiple surgeries (and diagnosis) in studies on anesthesia-related neurotoxicity and the developing brain is not a legitimate approach. . ...” (5). In Denmark, later academic outcomes (9th grade) in infants undergoing inguinal and pyloric stenosis repair are comparable to the background population (1,2) and much better than in infants undergoing neurosurgeries (5). Additionally, contrary to children undergoing, e.g., inguinal hernia and pyloric stenosis repair, it is very common for children undergoing neurosurgeries to have additional anesthetic and surgical exposures in our Danish registers. Thus, when pooling data from different surgeries and diagnosis in anesthesia-related neurotoxicity cohort studies, this will impact the results obtained. Moreover, in an ongoing study from our group comprising children undergoing oral cleft surgery (a somewhat minor surgery and presumably a more homogeneous group), we found important differences in outcomes (mortality and academic achievements in 9th grade) depending on whether the child had undergone cleft lip, cleft palate, or both cleft lip and palate repair. Therefore, I will maintain that stratification according to diagnosis/surgery is indeed necessary when conducting human cohort studies on the association between anesthesia/surgery exposure in early life and later cognitive outcome.
© 2015 John Wiley & Sons Ltd Pediatric Anesthesia 25 (2015) 431–439
Correspondence
Tom G. Hansen1,2 Department of Anaesthesia and Intensive Care – Pediatric Section, Odense University Hospital, Odense C, Denmark 2 Clinical Institute – Anesthesiology, University of Southern Denmark, Odense C, Denmark Email: [email protected]
Conflicts of interest
1
No conflicts of interest declared.
doi:10.1111/pan.12632
References 1 Hansen TG, Pedersen JK, Henneberg SW et al. Academic performance in adolescence after inguinal hernia repair in infancy: a nationwide cohort study. Anesthesiology 2011; 114: 1076–1085. 2 Hansen TG, Pedersen JK, Henneberg SW et al. Educational outcome following pyloric stenosis repair before 3 months of age: a
nationwide cohort study. Pediatr Anesth 2013; 23: 883–890. 3 Hansen TG. Anesthesia-related neurotoxicity and the developing animal brain is not a significant problem in children. Pediatr Anesth 2015; 25: 65–72. 4 Warner DO, Flick RP. Effects of anesthesia and surgery on the developing brain: prob-
lem solved? Pediatr Anesth 2015; 25: 435– 436. 5 Hansen TG, Pedersen JK, Henneberg SW et al. Neurosurgical conditions and procedures in infancy are associated with mortality and academic performances in adolescence: a nationwide cohort study. Pediatr Anesth 2015; 25: 186–192.
It’s not about the endotracheal tube: reply to editorial on our paper “Endotracheal intubation in the pediatric emergency department” SIR—We thank Lerman, Sharma, and Heard for their valuable comments on our article, and agree that nonoperating room intubations, both in adults and in children, are in need of CPR (1). We also agree that minimum thresholds for proficiency at tracheal intubation should be established as a standard of care, and that a mean first pass success rate of 90% is too low. Furthermore, we feel that the aim of nonoperating room intubations should be zero iatrogenic harm. In response to the suggestion that the primary problem resulting in a high rate of adverse events during Emergency Department (ED) intubations relates to nonanesthetic trainees deficits in knowledge and procedural proficiency, we would like to highlight two points. Firstly, the adverse event rate observed in our study was independent of the specialty or seniority of the intubator. Anesthetic trainees had the same adverse event rate as nonanesthetic trainees. Secondly, none of the patients intubated in our ED over a 1-year period had difficult Cormack and Lehane grade laryngoscopy. The requirement for multiple intubation attempts and the high adverse event rate were due critical illness, not difficult airways. As such, we believe that improving the safety of nonoperating room intubations cannot be addressed entirely by focussing on the knowledge and procedural proficiency of the intubator, as suggested by Lerman et al. The “nontechnical” factors, such as teamwork, leadership and followership, communication, and avoid© 2015 John Wiley & Sons Ltd Pediatric Anesthesia 25 (2015) 431–439
ance of fixation are equally important, and require different training modalities. We have introduced a quality improvement program to improve the safety of nonoperating room intubations that includes a hospital-wide difficult intubation algorithm, clear pathways for airway escalation, standardized hospital-wide equipment available in all critical care areas using identical airway carts, and multidisciplinary education and training to address both the technical and nontechnical aspects of nonoperating room airway management. We recognize that no single educational tool has been shown to improve patient-centered airway outcomes (2). We aim to monitor our first pass success and adverse event rates to see if the afore-mentioned interventions improve the safety of nonoperating room intubations in our institution. Ethics approval Not applicable. Funding The study received no external funding. Conflict of interest The authors report no conflict of interest. 437
Copyright of Pediatric Anesthesia is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
References 1 Hansen TG. Anesthesia-related neurotoxicity and the developing animal brain is not a significant problem in children. Pediatr Anesth 2014; 25: 65–72. 2 Hansen TG, Pedersen JK, Henneberg SW et al. Neurosurgical conditions and procedures in infancy are associated with mortality and academic performances
in adolescence: a nationwide cohort study. Pediatr Anesth 2015; 25: 186–192. 3 Wilder RT, Flick RP, Sprung J et al. Early exposure to anesthesia and learning disabilities in a population-based birth cohort. Anesthesiology 2009; 110: 796–804.
4 Hansen TG, Flick R. Anesthetic effects on the developing brain: insights from epidemiology. Anesthesiology 2009; 110: 1–3. 5 Flick RP, Warner DO. A users’ guide to interpreting observational studies of pediatric anesthetic neurotoxicity: the lessons of Sir Bradford Hill. Anesthesiology 2012; 117: 459–462.
Effects of anesthesia on the developing brain: can the underlying disease be ignored? SIR—Very few issues (if any) within pediatric anesthesia have created so much concern and emotional gravity than the possibility that general anesthetics might be neurotoxic in the developing brain. Fortunately, contrary to the plethora of positive animal studies, it has proven rather difficult to demonstrate a human corollary to this phenomenon. Consequently, if it exists in humans, anesthesia-related neurotoxicity must be vague or present only in a subset of (genetically?) susceptible infants, otherwise it would have been easy to demonstrate and it would most likely have been suspected many years ago. In two nationwide, unselected followup studies of the Danish birth cohorts 1986–1990 from our group comprising (the largest samples published so far) neonates and infants undergoing inguinal hernia repair in infancy and pyloric stenosis repair before the age of 3 months, academic achievements in 9th grade (aged 15–16 years) were similar to a 5% randomly selected control sample when adjusted for confounding factors (e.g., age, gender, congenital malformations, maternal age, and parental level of education) (1,2). However, exposed children had a slightly higher nonattainment rate (compatible with the existence of a susceptible subgroup?). Interestingly, the above-mentioned confounders more strongly affected academic achievements than anesthesia and surgical exposure. This was the background for my recent review article on this topic (3). The review article was a commissioned paper for the themed January 2015 issue of Pediatric Anesthesia containing various review articles on challenging orthodoxy in pediatric anesthesia many of which had predetermined and bombastic titles such as mine. Of course, my review article was meant as a “provocative” input into the current debate on this topic. However, if one reads the manuscript in full, the reader would
436
acknowledge that the situation is a bit more complicated. I completely concur with Drs. Warner and Flick’s conclusion of their letter (4) addressing my review article that: Although anesthesia-related neurotoxicity may be a minor problem, the jury is still out there. In their letter, Drs. Warner and Flick also question the conclusion drawn in our recent cohort study comprising all children undergoing neurosurgical procedures in Denmark during 1986–1990, that “. . ..pooling of data from multiple surgeries (and diagnosis) in studies on anesthesia-related neurotoxicity and the developing brain is not a legitimate approach. . ...” (5). In Denmark, later academic outcomes (9th grade) in infants undergoing inguinal and pyloric stenosis repair are comparable to the background population (1,2) and much better than in infants undergoing neurosurgeries (5). Additionally, contrary to children undergoing, e.g., inguinal hernia and pyloric stenosis repair, it is very common for children undergoing neurosurgeries to have additional anesthetic and surgical exposures in our Danish registers. Thus, when pooling data from different surgeries and diagnosis in anesthesia-related neurotoxicity cohort studies, this will impact the results obtained. Moreover, in an ongoing study from our group comprising children undergoing oral cleft surgery (a somewhat minor surgery and presumably a more homogeneous group), we found important differences in outcomes (mortality and academic achievements in 9th grade) depending on whether the child had undergone cleft lip, cleft palate, or both cleft lip and palate repair. Therefore, I will maintain that stratification according to diagnosis/surgery is indeed necessary when conducting human cohort studies on the association between anesthesia/surgery exposure in early life and later cognitive outcome.
© 2015 John Wiley & Sons Ltd Pediatric Anesthesia 25 (2015) 431–439
Correspondence
Tom G. Hansen1,2 Department of Anaesthesia and Intensive Care – Pediatric Section, Odense University Hospital, Odense C, Denmark 2 Clinical Institute – Anesthesiology, University of Southern Denmark, Odense C, Denmark Email: [email protected]
Conflicts of interest
1
No conflicts of interest declared.
doi:10.1111/pan.12632
References 1 Hansen TG, Pedersen JK, Henneberg SW et al. Academic performance in adolescence after inguinal hernia repair in infancy: a nationwide cohort study. Anesthesiology 2011; 114: 1076–1085. 2 Hansen TG, Pedersen JK, Henneberg SW et al. Educational outcome following pyloric stenosis repair before 3 months of age: a
nationwide cohort study. Pediatr Anesth 2013; 23: 883–890. 3 Hansen TG. Anesthesia-related neurotoxicity and the developing animal brain is not a significant problem in children. Pediatr Anesth 2015; 25: 65–72. 4 Warner DO, Flick RP. Effects of anesthesia and surgery on the developing brain: prob-
lem solved? Pediatr Anesth 2015; 25: 435– 436. 5 Hansen TG, Pedersen JK, Henneberg SW et al. Neurosurgical conditions and procedures in infancy are associated with mortality and academic performances in adolescence: a nationwide cohort study. Pediatr Anesth 2015; 25: 186–192.
It’s not about the endotracheal tube: reply to editorial on our paper “Endotracheal intubation in the pediatric emergency department” SIR—We thank Lerman, Sharma, and Heard for their valuable comments on our article, and agree that nonoperating room intubations, both in adults and in children, are in need of CPR (1). We also agree that minimum thresholds for proficiency at tracheal intubation should be established as a standard of care, and that a mean first pass success rate of 90% is too low. Furthermore, we feel that the aim of nonoperating room intubations should be zero iatrogenic harm. In response to the suggestion that the primary problem resulting in a high rate of adverse events during Emergency Department (ED) intubations relates to nonanesthetic trainees deficits in knowledge and procedural proficiency, we would like to highlight two points. Firstly, the adverse event rate observed in our study was independent of the specialty or seniority of the intubator. Anesthetic trainees had the same adverse event rate as nonanesthetic trainees. Secondly, none of the patients intubated in our ED over a 1-year period had difficult Cormack and Lehane grade laryngoscopy. The requirement for multiple intubation attempts and the high adverse event rate were due critical illness, not difficult airways. As such, we believe that improving the safety of nonoperating room intubations cannot be addressed entirely by focussing on the knowledge and procedural proficiency of the intubator, as suggested by Lerman et al. The “nontechnical” factors, such as teamwork, leadership and followership, communication, and avoid© 2015 John Wiley & Sons Ltd Pediatric Anesthesia 25 (2015) 431–439
ance of fixation are equally important, and require different training modalities. We have introduced a quality improvement program to improve the safety of nonoperating room intubations that includes a hospital-wide difficult intubation algorithm, clear pathways for airway escalation, standardized hospital-wide equipment available in all critical care areas using identical airway carts, and multidisciplinary education and training to address both the technical and nontechnical aspects of nonoperating room airway management. We recognize that no single educational tool has been shown to improve patient-centered airway outcomes (2). We aim to monitor our first pass success and adverse event rates to see if the afore-mentioned interventions improve the safety of nonoperating room intubations in our institution. Ethics approval Not applicable. Funding The study received no external funding. Conflict of interest The authors report no conflict of interest. 437
Copyright of Pediatric Anesthesia is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
