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BACKGROUND: Intraoperative controlled hypotension improves surgical field visibility by reducing blood loss (efficacy) but poses potential risks linked to organ hypoperfusion (safety). The use of controlled hypotension persists despite increasing evidence of associations between intraoperative inadvertent hypotension and adverse outcomes. Therefore, we tested the hypothesis that the focus and results of intraoperative controlled hypertension research differ across anaesthesia and surgery investigators because of differing priorities. METHODS: We systematically reviewed randomised trials comparing controlled hypotension with usual care with trials categorised by investigators' affiliation. RESULTS: We identified 48 eligible trials, of which 37 were conducted by anaesthesia investigators and 11 by surgery investigators. For the primary outcome, 54% of the anaesthesia-led trials focused on safety, whereas all (100%) surgery-led trials focused on efficacy (P=0.004). Compared with usual care, mean arterial pressure in controlled hypotension was 23% (95% confidence interval [CI] 17-29%) lower in anaesthesia trials and 30% (95% CI 14-37%) lower in surgery trials; estimated blood loss was 44% (95% CI 30-55%) less in anaesthesia trials and 38% (95% CI 30-49%) less in surgery trials. Overall, blood loss was reduced by 43% (95% CI 32-53%), and trial sequential analysis supported an efficacy conclusion. Mean arterial pressure and estimated blood loss reductions were associated (R2=0.41, P=0.002). All trials were underpowered for safety outcomes, and none adequately evaluated myocardial or renal injury. CONCLUSIONS: Anaesthesia researchers prioritised safety outcomes, whereas surgery researchers emphasised efficacy in controlled hypotension trials. Controlled hypotension significantly reduces blood loss. In contrast, safety outcomes were poorly studied. Given increasing observational evidence linking inadvertent hypotension to myocardial and renal injury, the safety of controlled hypotension remains to be addressed. SYSTEMATIC REVIEW PROTOCOL: PROSPERO (CRD42023450397).
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BACKGROUND: Postoperative delirium remains prevalent despite extensive research through randomised trials aimed at reducing its incidence. Understanding trial characteristics associated with interventions' effectiveness facilitates data interpretation. METHODS: Trial characteristics were extracted from eligible trials identified through two systematic literature searches. Multivariable meta-regression was used to investigate trial characteristics associated with effectiveness estimated using odds ratios. Meta-analysis was used to investigate pooled effectiveness. RESULTS: We identified 201 eligible trials. Compared with China, trials from the USA/Canada (ratio of odds ratio, 1.89; 95% confidence interval, 1.45-2.45) and Europe/Australia/New Zealand (1.67; 1.29-2.18) had an 89% and 67% higher odds ratio, respectively, suggesting reduced effectiveness. The effectiveness was enhanced when the incidence of postoperative delirium increased (0.85; 0.79-0.92, per 10% increase). Trials with concerns related to deviations from intended interventions reported increased effectiveness compared with those at low risk (0.69; 0.53-0.90). Compared with usual care, certain interventions appeared to have reduced the incidence of postoperative delirium in low-risk trials with low-to-moderate certainty of evidence. However, these findings should be considered inconclusive because of challenges in grouping heterogeneous interventions, the limited number of eligible trials, the prevalence of small-scale studies, and potential publication bias. CONCLUSIONS: The effectiveness of postoperative delirium trials varied based on the region of trial origin, the incidence of delirium, and the risk of bias. The limitations caution against drawing definitive conclusions from different bodies of evidence. These findings highlight the imperative need to improve the quality of research on a global scale. SYSTEMATIC REVIEW PROTOCOL: PROSPERO (CRD42023413984).
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Complicaciones Posoperatorias , Ensayos Clínicos Controlados Aleatorios como Asunto , Humanos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/prevención & control , Delirio/prevención & control , Delirio/epidemiología , Delirio del Despertar/prevención & control , Delirio del Despertar/epidemiologíaRESUMEN
BACKGROUND: Noradrenaline is a standard treatment for hypotension in acute care. The precise effects of noradrenaline on cerebral blood flow in health and disease remain unclear. METHODS: We systematically reviewed and synthesised data from studies examining changes in cerebral blood flow in healthy participants and patients with traumatic brain injury and critical illness. RESULTS: Twenty-eight eligible studies were included. In healthy subjects and patients without critical illness or traumatic brain injury, noradrenaline did not significantly change cerebral blood flow velocity (-1.7%, 95%CI -4.7-1.3%) despite a 24.1% (95%CI 19.4-28.7%) increase in mean arterial pressure. In patients with traumatic brain injury, noradrenaline significantly increased cerebral blood flow velocity (21.5%, 95%CI 11.0-32.0%), along with a 33.8% (95%CI 14.7-52.9%) increase in mean arterial pressure. In patients who were critically ill, noradrenaline significantly increased cerebral blood flow velocity (20.0%, 95%CI 9.7-30.3%), along with a 32.4% (95%CI 25.0-39.9%) increase in mean arterial pressure. Our analyses suggest intact cerebral autoregulation in healthy subjects and patients without critical illness or traumatic brain injury., and impaired cerebral autoregulation in patients with traumatic brain injury and who were critically ill. The extent of mean arterial pressure changes and the pre-treatment blood pressure levels may affect the magnitude of cerebral blood flow changes. Studies assessing cerebral blood flow using non-transcranial Doppler methods were inadequate and heterogeneous in enabling meaningful meta-analysis. CONCLUSIONS: Noradrenaline significantly increases cerebral blood flow in humans with impaired, not intact, cerebral autoregulation, with the extent of changes related to the severity of functional impairment, the extent of mean arterial pressure changes and pre-treatment blood pressure levels.
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Lesiones Traumáticas del Encéfalo , Circulación Cerebrovascular , Enfermedad Crítica , Norepinefrina , Vasoconstrictores , Humanos , Lesiones Traumáticas del Encéfalo/fisiopatología , Norepinefrina/uso terapéutico , Norepinefrina/farmacología , Circulación Cerebrovascular/efectos de los fármacos , Circulación Cerebrovascular/fisiología , Vasoconstrictores/uso terapéutico , Vasoconstrictores/farmacología , Velocidad del Flujo Sanguíneo/efectos de los fármacos , Velocidad del Flujo Sanguíneo/fisiologíaRESUMEN
BACKGROUND: Electroencephalogram (EEG) discontinuity can occur at high concentrations of anesthetic drugs, reflecting suppression of electrocortical activity. This EEG pattern has been reported in children and reflects a deep state of anesthesia. Isoelectric events on the EEG, a more extreme degree of voltage suppression, have been shown to be associated with worse long-term neurologic outcomes in neonates undergoing cardiac surgery. However, the clinical significance of EEG discontinuities during pediatric anesthesia for noncardiac surgery is not yet known and merits further research. In this study, we assessed the incidence of EEG discontinuity during anesthesia induction in neurologically normal infants and the clinical factors associated with its development. We hypothesized that EEG discontinuity would be associated with sevoflurane-induced alpha (8-12 Hz) power during the period of anesthesia induction in infants. METHODS: We prospectively recorded 26 channels of EEG during anesthesia induction in an observational cohort of 54 infants (median age, 7.6 months; interquartile range [IQR] [4.9-9.8 months]). We identified EEG discontinuity, defined as voltage amplitude <25 microvolts for >2 seconds, and assessed its association with sevoflurane-induced alpha power using spectral analysis and multivariable logistic regression adjusting for clinically important variables. RESULTS: EEG discontinuity was observed in 20 of 54 subjects (37%), with a total of 25 discrete events. Sevoflurane-induced alpha power in the posterior regions of the head (eg, parietal or occipital regions) was significantly lower in the EEG discontinuity group (midline parietal channel on the electroencephalogram, International 10-20 System [Pz]; 8.3 vs 11.2 decibels [dBs]; P = .004), and this association remained after multivariable adjustment (adjusted odds ratio [aOR] = 0.51 per dB increase in alpha power [95% CI, 0.30-0.89]; P = .02). There were no differences in the baseline (unanesthetized) EEG between groups in alpha power or power in any other frequency band. CONCLUSIONS: We demonstrate that EEG discontinuity is common during anesthesia induction and is related to the level of sevoflurane-induced posterior alpha power, a putative marker of cortical-thalamic circuit development in the first year of life. This association persisted even after adjusting for age and propofol coadministration. The fact that this difference was only observed during anesthesia and not in the baseline EEG suggests that otherwise hidden brain circuit properties are unmasked by general anesthesia. These neurophysiologic markers observed during anesthesia may be useful in identifying patients who may have a greater chance of developing discontinuity.
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Anestésicos , Propofol , Lactante , Recién Nacido , Niño , Humanos , Sevoflurano/efectos adversos , Electroencefalografía , Anestesia General/efectos adversosRESUMEN
Seizures and interictal epileptiform discharges (IEDs) have been described during sevoflurane. We prospectively estimated their incidence in 54 otherwise neurologically healthy infants by obtaining the full-head video electroencephalogram (EEG). No infants had clinical seizures, but 1 had an electrographic seizure; 3 others had focal IEDs (7.4%; 95% confidence interval [CI], 2.1%-17.9%). We detected no differences in demographic or clinical characteristics between normal and abnormal EEG groups. Diffuse slowing was the most common initial EEG change followed by fast (α, ß) activity in all head leads. Larger studies with more statistical power are needed to further investigate the hypotheses generated with this research.
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Anestésicos por Inhalación/administración & dosificación , Ondas Encefálicas/efectos de los fármacos , Encéfalo/efectos de los fármacos , Electroencefalografía , Movimiento/efectos de los fármacos , Sevoflurano/administración & dosificación , Anestésicos por Inhalación/efectos adversos , Encéfalo/fisiopatología , Preescolar , Femenino , Humanos , Lactante , Masculino , Valor Predictivo de las Pruebas , Estudios Prospectivos , Convulsiones/inducido químicamente , Convulsiones/diagnóstico , Convulsiones/fisiopatología , Sevoflurano/efectos adversos , Factores de Tiempo , Grabación en VideoRESUMEN
BACKGROUND: Increasing awareness of scientific misconduct has prompted various fields of medicine, including orthopedic surgery, neurosurgery, and dentistry to characterize the reasons for article retraction. The purpose of this review was to evaluate the reasons for and the rate of article retraction in the field of anesthesia within the last 30 years. METHODS: Based on a reproducible search strategy, two independent reviewers searched MEDLINE, EMBASE, and the Retraction Watch website to identify retracted anesthesiology articles. Extracted data included: author names, year of publication, year of the retracted article, journal name, journal five-year impact factor, research type (clinical, basic science, or review), reason for article retraction, number of citations, and presence of a watermark indicating article retraction. RESULTS: Three hundred and fifty articles were included for data extraction. Reasons for article retraction could be grouped into six broad categories. The most common reason for retraction was fraud (data fabrication or manipulation), which accounted for nearly half (49.4%) of all retractions, followed by lack of appropriate ethical approval (28%). Other reasons for retraction included publication issues (e.g., duplicate publications), plagiarism, and studies with methodologic or other non-fraud data issues. Four authors were associated with most of the retracted articles (59%). The majority (69%) of publications utilized a watermark on the original article to indicate that the article was retracted. Journal Citation Reports journal impact factors ranged from 0.9 to 48.1 (median [interquartile range (IQR)], 3.6 [2.5-4.0]), and the most cited article was referenced 197 times (median [IQR], 13 [5-26]). Most retracted articles (66%) were cited at least once by other journal articles after having been withdrawn. CONCLUSIONS: Most retracted articles in anesthesiology literature were retracted because of research misconduct. Limited information is available in the retraction notices, unless explicitly stated, so it is challenging to distinguish between an honest error and research misconduct. Therefore, a standardized reporting process with structured retraction notices is desired.
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Anestesiología , Neurocirugia , Mala Conducta Científica , Humanos , Factor de Impacto de la Revista , PlagioRESUMEN
BACKGROUND AND OBJECTIVE: In vivo evaluation of the microstructural differences between asthmatic and non-asthmatic airways and their functional consequences is relevant to understanding and, potentially, treating asthma. In this study, we use endobronchial optical coherence tomography to investigate how allergic airways with asthma differ from allergic non-asthmatic airways in baseline microstructure and in response to allergen challenge. METHODS: A total of 45 subjects completed the study, including 20 allergic, mildly asthmatic individuals, 22 non-asthmatic allergic controls and 3 healthy controls. A 3-cm airway segment in the right middle and right upper lobe were imaged in each subject immediately before and 24 h following segmental allergen challenge to the right middle lobe. Relationships between optical airway measurements (epithelial and mucosal thicknesses, mucosal buckling and mucus) and airway obstruction (FEV1 /FVC (forced expiratory volume in 1 s/forced vital capacity) and FEV1 % (FEV1 as a percentage of predictive value)) were investigated. RESULTS: Significant increases at baseline and in response to allergen were observed for all four of our imaging metrics in the asthmatic airways compared to the non-asthmatic airways. Epithelial thickness and mucosal buckling exhibited a significant relationship to FEV1 /FVC in the asthmatic group. CONCLUSION: Simultaneous assessments of airway microstructure, buckling and mucus revealed both structural and functional differences between the mildly asthmatic and control groups, with airway buckling seeming to be the most relevant factor. The results of this study demonstrate that a comprehensive, microstructural approach to assessing the airways may be important in future asthma studies as well as in the monitoring and treatment of asthma.
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Remodelación de las Vías Aéreas (Respiratorias) , Alérgenos/inmunología , Asma , Pulmón , Hipersensibilidad Respiratoria , Tomografía de Coherencia Óptica/métodos , Adulto , Asma/diagnóstico , Asma/inmunología , Asma/fisiopatología , Pruebas de Provocación Bronquial/métodos , Broncoscopía/métodos , Femenino , Humanos , Pulmón/diagnóstico por imagen , Pulmón/fisiopatología , Masculino , Pruebas de Función Respiratoria/métodos , Hipersensibilidad Respiratoria/diagnóstico , Hipersensibilidad Respiratoria/inmunología , Hipersensibilidad Respiratoria/fisiopatologíaRESUMEN
Fiber-based polarization-sensitive optical coherence tomography (PS-OCT) that utilizes a rotationally-scanning catheter has a variety of potential biomedical applications in luminal organ systems due to its ability to provide intrinsic contrast for birefringent tissue. Incorporating the optic axis (OA) of the tissue greatly enhances this potential by also permitting information about the orientation of the tissue to be extracted; however, measurement distortion that occurs has up to this point made it impossible to obtain accurate sample OA measurements. In this paper we present a straightforward calibration technique that allows the sample OA to be recovered. This technique requires no hardware modifications making it generally applicable, and as a result has tremendous potential in improving the utility of endoscopic PS-OCT image data.
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As the transgender patient population continues to grow, health care providers will need to become aware of elements unique to the transgender community in order to provide the highest quality of care. Neuromuscular blockade with succinylcholine is routinely administered to patients undergoing electroconvulsive therapy (ECT). Decreased amounts or activity of pseudocholinesterase in serum can lead to prolonged duration of muscle paralysis. Causes of reduced action by pseudocholinesterase include genetically abnormal enzymes, reduced hepatic production, pregnancy, and various drug interactions. Estrogen supplementation taken by transitioning patients may affect the duration of neuromuscular blockade.This is a case of a 32-year-old male-to-female transgender patient with prolonged apnea following ECT treatment for severe, refractory depression. Further investigation revealed the patient was on estrogen therapy as a part of her transition and laboratory testing demonstrated reduced serum pseudocholinesterase activity. Further laboratory testing demonstrated reduced serum pseudocholinesterase activity. Succinylcholine dosing was titrated to an appropriate level to avoid prolonged apnea in subsequent ECT treatments. Physicians and other health care providers are faced with a unique population in the transgender community and must be aware of distinctive circumstances when providing care to this group. Of specific interest, many transitioning and transitioned patients can be on chronic estrogen supplementation. Neuromuscular blockade in those patients require attention from the anesthesiology care team as estrogen compounds may decrease pseudocholinesterase levels and lead to prolonged muscle paralysis from succinylcholine.
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Terapia Electroconvulsiva/métodos , Personas Transgénero , Adulto , Androstanoles/antagonistas & inhibidores , Apnea/fisiopatología , Butirilcolinesterasa/sangre , Trastorno Depresivo Resistente al Tratamiento/psicología , Trastorno Depresivo Resistente al Tratamiento/terapia , Interacciones Farmacológicas , Estrógenos/uso terapéutico , Femenino , Humanos , Masculino , Fármacos Neuromusculares Despolarizantes/antagonistas & inhibidores , Rocuronio , Procedimientos de Reasignación de Sexo , Succinilcolina/antagonistas & inhibidores , Sugammadex , gamma-CiclodextrinasRESUMEN
BACKGROUND: Observational studies on pediatric anesthesia neurotoxicity have been unable to distinguish long-term effects of general anesthesia (GA) from factors associated with the need for surgery. A recent study on elementary school children who had received a single GA during the first year of life demonstrated an association in otherwise healthy children between the duration of anesthesia and diminished test scores and also revealed a subgroup of children with "very poor academic achievement" (VPAA), scoring below the fifth percentile on standardized testing. Analysis of postoperative cognitive function in a similar cohort of children anesthetized with an alternative to GA may help to begin to separate the effects of anesthesia from other confounders. METHODS: We used a novel methodology to construct a combined medical and educational database to search for these effects in a similar cohort of children receiving spinal anesthesia (SA) for the same procedures. We compared former patients with a control population of students matched by grade, gender, year of testing, and socioeconomic status. RESULTS: Vermont Department of Education records were analyzed for 265 students who had a single exposure to SA during infancy for circumcision, pyloromyotomy, or inguinal hernia repair. Exposure to SA and surgery had no significant effect on the odds of children having VPAA. (mathematics: P = 0.18; odds ratio 1.50, confidence interval (CI), 0.83-2.68; reading: P = 0.55; odds ratio = 1.19, CI, 0.67-2.1). There was no relationship between duration of exposure to SA and surgery and performance on mathematics (P = 0.73) or reading (P = 0.57) standardized testing. There was a small but statistically significant decrease in reading and math scores in the exposed group (mathematics: P = 0.03; reading: P = 0.02). CONCLUSIONS: We found no link between duration of surgery with infant SA and scores on academic achievement testing in elementary school. We also found no relationship between infant SA and surgery with VPAA on elementary school testing, although the CIs were wide.
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Anestesia Raquidea/efectos adversos , Anestesia Raquidea/psicología , Cognición/fisiología , Procedimientos Quirúrgicos Operativos/efectos adversos , Procedimientos Quirúrgicos Operativos/psicología , Factores de Edad , Anestesia/efectos adversos , Anestesia/estadística & datos numéricos , Enfermedades del Sistema Nervioso Central/complicaciones , Enfermedades del Sistema Nervioso Central/psicología , Niño , Preescolar , Sedación Consciente/efectos adversos , Sedación Consciente/estadística & datos numéricos , Interpretación Estadística de Datos , Bases de Datos Factuales , Escolaridad , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Matemática , Pruebas Neuropsicológicas , Lectura , Respiración Artificial/efectos adversos , Respiración Artificial/estadística & datos numéricos , Instituciones Académicas , Factores Socioeconómicos , Resultado del TratamientoAsunto(s)
Fibrosis Pulmonar Idiopática/diagnóstico por imagen , Tomografía de Coherencia Óptica/métodos , Anciano , Bronquios/diagnóstico por imagen , Bronquios/patología , Femenino , Humanos , Fibrosis Pulmonar Idiopática/patología , Imagenología Tridimensional/métodos , Masculino , Persona de Mediana Edad , Proyectos PilotoAsunto(s)
Anestesiólogos/psicología , Anestesiólogos/normas , Agotamiento Profesional/prevención & control , Agotamiento Profesional/psicología , Anestesiólogos/economía , Agotamiento Profesional/economía , Ahorro de Costo/economía , Ahorro de Costo/normas , Humanos , Médicos/economía , Médicos/psicología , Médicos/normasRESUMEN
We demonstrate strong coupling between a surface plasmon and intersublevel transitions in self-assembled InAs quantum dots. The surface plasmon mode exists at the interface between the semiconductor emitter structure and a periodic array of holes perforating a metallic Pd/Ge/Au film that also serves as the top electrical contact for the emitters. Spectrally narrowed quantum-dot electroluminescence was observed for devices with varying subwavelength hole spacing. Devices designed for 9, 10, and 11 µm wavelength emission also exhibit a significant spectral splitting. The association of the splitting with quantum-dot Rabi oscillation is consistent with results from a calculation of spontaneous emission from an interacting plasmonic field and quantum-dot ensemble. The fact that this Rabi oscillation can be observed in an incoherently excited, highly inhomogeneously broadened system demonstrates the utility of intersublevel transitions in quantum dots for investigations of coherent transient and quantum coherence phenomena.
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Arsenicales/química , Arsenicales/efectos de la radiación , Indio/química , Indio/efectos de la radiación , Mediciones Luminiscentes/instrumentación , Puntos Cuánticos , Resonancia por Plasmón de Superficie/instrumentación , Conductividad Eléctrica , Campos Electromagnéticos , Diseño de Equipo , Análisis de Falla de Equipo , Luz , Dispersión de RadiaciónRESUMEN
The incorporation of polarization sensitivity into optical coherence tomography (PS-OCT) imaging can greatly enhance utility by allowing differentiation via intrinsic contrast of many types of tissue. In fiber-based OCT systems such as those employing endoscopic imaging probes, however, polarization mode dispersion (PMD) can significantly impact the ability to obtain accurate polarization data unless valuable axial resolution is sacrificed. In this work we present a new technique for compensating for PMD in endoscopic PS-OCT with minimal impact on axial resolution and without requiring mutually coherent polarization inputs, needing only a birefringent structure with known orientation in view (such as the catheter sheath). We then demonstrate the advantages of this technique by comparing it against the current state of the art approach.
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From March to June of 2020, Montefiore Medical Center faced one of the most acute surges in hospital admissions and critical illness ever experienced in the United States due to the severe acute respiratory syndrome coronavirus 2 pandemic. The pandemic had not yet spread to most of the country, and there was a relative deficit of knowledge regarding treatments, prognosis, and prevention of the virus, making this experience relatively unique and challenging. As part of a surge plan, our institution converted nonclinical spaces, such as conference rooms, to inpatient care settings and placed elective surgeries on hold to free up resources. A central deployment office suspended anesthesiology resident rotations and instead assigned them to intensive care settings based on need. For the Montefiore Medical Center Department of Anesthesiology, preserving its academic mission and commitment to Graduate Medical Education was essential. Adaptations included changing the residency rotation structure to biweekly, converting didactics online, ensuring adequate case numbers for graduating residents, actively pursuing wellness interventions, and prioritizing the safety of the residents caring for patients with coronavirus disease 2019 (COVID-19). In this brief report, the authors discuss solutions devised to maintain the quality of anesthesiology resident education and training as much as possible during the COVID-19 surge.
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The novel SARS-CoV-2 pandemic starting in 2019 profoundly changed the world, and thousands of residents of New York City were affected, leading to one of the most acute surges in regional hospital capacity. As the largest academic medical center in the Bronx, Montefiore Medical Center was immediately impacted, and the entire hospital was mobilized to address the needs of its community. In this article, we describe our experiences as a large academic anesthesiology department during this pandemic. Our goals were to maximize our staff's expertise, maintain our commitment to wellness and safety, and preserve the quality of patient care. Lessons learned include the importance of critical care training presence and leadership, the challenges of converting an ambulatory surgery center to an intensive care unit (ICU), and the management of effective communication. Lastly, we provide suggestions for institutions facing an acute surge, or subsequent waves of COVID-19, based on a single center's experiences.
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Centros Médicos Académicos/tendencias , Anestesiología/tendencias , COVID-19/epidemiología , Cuidados Críticos/tendencias , Reestructuración Hospitalaria/tendencias , Admisión y Programación de Personal/tendencias , Centros Médicos Académicos/normas , Anestesiología/normas , COVID-19/terapia , Cuidados Críticos/normas , Personal de Salud/normas , Personal de Salud/tendencias , Reestructuración Hospitalaria/normas , Humanos , Ciudad de Nueva York , Pandemias , Admisión y Programación de Personal/normasRESUMEN
The inability to assess and measure changes to the airway smooth muscle (ASM) in vivo is a major challenge to evaluating asthma and its clinical outcomes. Bronchial thermoplasty (BT) is a therapy for asthma that aims to reduce the severity of excessive bronchoconstriction by ablating ASM. Although multiple long-term clinical studies of BT have produced encouraging results, the outcomes of BT treatment in practice have been variable, and questions remain regarding the selection of patients. Previously, we have demonstrated an imaging platform called orientation-resolved optical coherence tomography that can assess ASM endoscopically using an imaging catheter compatible with bronchoscopy. In this work, we present results obtained from a longitudinal BT study performed using a canine model (n = 8) and with the goal of investigating the use of orientation-resolved optical coherence tomography (OR-OCT) for measuring the effects of BT on ASM. We demonstrate that we are capable of accurately assessing ASM both before and in the weeks following the BT procedure using blinded matching to histological samples stained with Masson's trichrome (P < 0.0001, r2 = 0.79). Analysis of volumetric ASM distributions revealed significant decreases in ASM in treated airways (average cross-sectional ASM area: 0.245 ± 0.145 mm2 pre-BT and 0.166 ± 0.112 mm2 6 wk following BT). These results demonstrate that OR-OCT can provide clinicians with the feedback necessary to better evaluate ASM and its response to BT, and may potentially play an important role in phenotyping asthma and predicting which patients are most likely to respond to BT treatment.NEW & NOTEWORTHY The inability to assess ASM in vivo is a significant hurdle in advancing our understanding of airway diseases such as asthma, as well as evaluating potential treatments and therapies. In this study, we demonstrate that endoscopic OR-OCT can be used to accurately measure changes to ASM structure following BT. Our results demonstrate how this technology could occupy an important role in asthma treatments targeting ASM.