Three-dimensional pelvis computed tomography-assisted Taylor approach for spinal anesthesia in hip arthroplasty: a retrospective study

BACKGROUND

Needle insertion for spinal anesthesia using the Taylor approach is challenging as the L5-S1 space is difficult to locate from the surface anatomy. In this study, we suggest the use of three-dimensional (3D) pelvis computed tomography (CT) to assist anesthesiologists in locating the needle insertion point. By comparing the success rate of 3D pelvis CT-assisted Taylor approach to that of other approaches in the existing literatures, we suggest this technique as an alternative method for subarachnoid block in the L5-S1 space.

METHODS

In this retrospective observational study, we reviewed the records of hip arthroplasty using the 3D pelvis CT-assisted Taylor approach. An imaginary guidance line was created from the intersection point of the midline and intercristal line on the posterior view of the 3D pelvis CT to the ideal skin insertion point for Taylor approach. The primary outcome was the success rate. The secondary outcomes included the angle between the intercristal line and the guidance line, and the length of the guidance line and the distance between the ideal needle insertion point and the L5-S1 space.

RESULTS

We reviewed the records of the 276 patients who underwent hip arthroplasty using 3D CT-assisted Taylor approach. In this cohort, the 3D CT-assisted Taylor approach in L5-S1 subarachnoid block failed in only 25/276 patients. The success rate of 3D CT-assisted Taylor approach was 90.9%.

CONCLUSIONS

A 3D pelvis CT-assisted Taylor approach of spinal anesthesia can be an alternative method for subarachnoid block in the L5-S1 space with an acceptable success rate.

Longitudinal asthma exacerbation phenotypes in the Korean childhood asthma study cohort

BACKGROUND

Asthma exacerbation (AE) leads to social and economic costs and long-term adverse outcomes. We aimed to predict exacerbation-prone asthma (EPA) in children.

METHODS

The Korean childhood Asthma Study (KAS) is a prospective nationwide pediatric asthma cohort of children aged 5-15 years followed every 6 months. Patients with AE during the 6 months prior to all three visits, with AE prior to one or two visits, and without AE prior to any visit were defined as having EPA, exacerbation-intermittent asthma (EIA), and exacerbation-resistant asthma (ERA), respectively. Risk factors and prediction models of EPA were explored.

RESULTS

Of the 497 patients who completed three visits, 42%, 18%, and 15% had exacerbations prior to visits 1, 2, and 3 and 5%, 47%, and 48% had EPA, EIA, and ERA, respectively. Univariate and multivariable logistic regression revealed forced expiratory volume in 1 s (FEV1) z-score, forced vital capacity (FVC) z-score, white blood cell (WBC) count, and asthma control test (ACT) score as relevant EPA risk factors. The EPA prediction model comprised FVC z-score, WBC count, ACT score, sex, and parental education level (area under the receiver operating characteristic curve [AUROC] 0.841 [95% confidence interval (CI): 0.728-0.954]).

CONCLUSION

With appropriate management, AE decreases over time, but persistent AEs may occur. Apart from asthma control level, baseline lung function and WBC count predicted EPA.

Associated Factors for Asthma Severity in Korean Children: A Korean Childhood Asthma Study

Purpose

Childhood asthma has a considerable social impact and economic burden, especially in severe asthma. This study aimed to identify the proportion of childhood asthma severity and to evaluate associated factors for greater asthma severity.

Methods

This study was performed on 667 children aged 5–15 years with asthma from the nationwide 19 hospitals in the Korean childhood Asthma Study (KAS). Asthma was classified as mild intermittent, mild persistent, and moderate/severe persistent groups according to the National Asthma Education and Prevention Program recommendations. Multinomial logistic regression models were used to identify the associated factors for greater asthma severity.

Results

Mild persistent asthma was most prevalent (39.0%), followed by mild intermittent (37.6%), moderate persistent (22.8%), and severe persistent asthma (0.6%). Onset later than 6 years of age (adjusted odds ratio [aOR], 1.69 for mild persistent asthma; aOR, 1.92 for moderate/severe persistent asthma) tended to increase asthma severity. Exposure to environmental tobacco smoke (aOR, 1.53 for mild persistent asthma; aOR, 1.85 for moderate/severe persistent asthma), and current dog ownership with sensitization to dog dander (aOR, 5.86 for mild persistent asthma; aOR, 6.90 for moderate/severe persistent asthma) showed increasing trends with greater asthma severity. Lower maternal education levels (aOR, 2.32) and no usage of an air purifier in exposure to high levels of outdoor air pollution (aOR, 1.76) were associated with moderate/severe persistent asthma.

Conclusions

Modification of identified environmental factors associated with greater asthma severity might help better control childhood asthma, thereby reducing the disease burden due to childhood asthma.

Asthma control test reflects not only lung function but also airway inflammation in children with stable asthma

Objective: Various numerical asthma control tools have been developed to distinguish different levels of symptom control. We aimed to examine whether the asthma control test (ACT) is reflective of objective findings such as lung function, fractional exhaled nitric oxide (FeNO) and laboratory data in patients with stable asthma.Methods: We included patients who were enrolled in the Korean Childhood Asthma Study. ACT, spirometry, blood tests and FeNO were performed in patients after stabilization of their asthma. We examined differences among spirometry parameters, blood tests and FeNO according to control status as determined by ACT and investigated for any significant correlations.Results: The study population consisted of 441 subjects. Spirometry showed that forced expiratory volume in one second (FEV₁), forced expiratory flow between 25% and 75% of forced vital capacity and FEV₁/forced vital capacity were all significantly higher in the controlled asthma group. Likewise, FeNO and percent-change in FEV₁ were both significantly lower in the controlled asthma group. In blood tests, the eosinophil fraction was significantly lower in the controlled asthma group while white blood cell count was significantly higher in the controlled asthma group. Lastly, among the various factors analyzed, only provocative concentration of methacholine causing a 20% fall in FEV₁ significantly correlated with ACT score.Conclusion: ACT is useful as part of the routine evaluation of asthmatic children and should be used as a complement to existing tools such as spirometry and FeNO measurement.

Korean childhood asthma study (KAS): a prospective, observational cohort of Korean asthmatic children

Background

Asthma is a syndrome composed of heterogeneous disease entities. Although it is agreed that proper asthma endo-typing and appropriate type-specific interventions are crucial in the management of asthma, little data are available regarding pediatric asthma.

Methods

We designed a cluster-based, prospective, observational cohort study of asthmatic children in Korea (Korean childhood Asthma Study [KAS]). A total of 1000 Korean asthmatic children, aged from 5 to 15 years, will be enrolled at the allergy clinics of the 19 regional tertiary hospitals from August 2016 to December 2018. Physicians will verify the relevant histories of asthma and comorbid diseases, as well as airway lability from the results of spirometry and bronchial provocation tests. Questionnaires regarding subjects’ baseline characteristics and their environment, self-rating of asthma control, and laboratory tests for allergy and airway inflammation will be collected at the time of enrollment. Follow-up data regarding asthma control, lung function, and environmental questionnaires will be collected at least every 6 months to assess outcome and exacerbation-related aggravating factors. In a subgroup of subjects, peak expiratory flow rate will be monitored by communication through a mobile application during the overall study period. Cluster analysis of the initial data will be used to classify Korean pediatric asthma patients into several clusters; the exacerbation and progression of asthma will be assessed and compared among these clusters. In a subgroup of patients, big data-based deep learning analysis will be applied to predict asthma exacerbation.

Discussion

Based on the assumption that asthma is heterogeneous and each subject exhibits a different subset of risk factors for asthma exacerbation, as well as a different disease progression, the KAS aims to identify several asthma clusters and their essential determinants, which are more suitable for Korean asthmatic children. Thereafter we may suggest cluster-specific strategies by focusing on subjects’ personalized aggravating factors during each exacerbation episode and by focusing on disease progression. The KAS will provide a good academic background with respect to each interventional strategy to achieve better asthma control and prognosis.