Pulse oximetry in acute asthma

How Schools Can Help Address Social Determinants of Health in Asthma Management

Schools are in a unique position to address social determinants of health (SDOHs) in pediatric asthma management because of their potential to provide resources and facilitate collaboration with health care providers and services for children at risk within their community. SDOHs include economic factors, educational attainment and health literacy, neighborhood factors and the built environment, social and community aspects including discrimination and racism, and health care access and quality. These factors have a significant impact on asthma health in children, and certain populations such as minoritzed populations and those living in high-poverty environments have been shown to be at greater risk for adverse effects of SDOHs on asthma outcomes. School-based asthma programs address several SDOHs including health literacy, the built environment, and health care quality and access and have been shown to improve asthma outcomes. Key components include connection between the school and the health care team, self-management education, and directly observed therapy. School nurses play a key role in directing and managing effective programs because they can evaluate and support a student's health while considering the effect of SDOHs at interpersonal, institutional, community, and policy levels.

Initial ED oxygen saturation ≤90% increases the risk of a complicated hospital course in pediatric asthmatics requiring admission

Emergency physicians are responsible for admitting children with asthma who do not respond to initial therapy. We examined the hypothesis that an initial room air pulse oximetry ≤90% elevates the risk of a complicated hospital course in children who require admission with acute asthma.

METHODS

Charts of all patients ages 2 years-17 years admitted for asthma from January 2017 to December 2017 were reviewed. An explicit chart review was performed by trained data extractors using a standardized form.

RESULTS

A total of 244 children meeting inclusion criteria were admitted for asthma from the ED during the study period. All patients had an initial room air pulse oximetry documented. Sixty-five were admitted to PICU status (27%), and 179 (73%) were admitted to floor status. The relative risk of a complicated course in those patients presenting with a saturation of ≤90% was 11.3 (95% CI 3.9-32.6). The mean initial pulse oximetry on patients with a complicated course was 85% versus 93% for those without a complicated course (p < 0.005).

CONCLUSION

Our data suggest that in pediatric asthmatics that require admission from the ED, those with pulse oximetry readings less than or equal to 90% on presentation are at higher risk of a complicated hospital course.

Clinical respiratory scales: which one should we use?

INTRODUCTION

There are countless clinical respiratory scales for acute dyspnoea. Most healthcare professionals choose one based on previous personal experience or following local practice, unaware of the implications of their choice. The lack of critical comparisons between those different tools has been a widespread problem that only recently has begun to be addressed via score validation studies. Here we try to assess and compare the quality criteria of measurement properties of acute dyspnoea scores. Areas covered: A literature review was conducted by searching the PubMed database. Forty-five documents were deemed eligible as they reported the use or building of clinical scales, using at least two parameters, and applied these to an acute episode of respiratory dyspnoea. Our primary focus was the description of the validity, reliability and utility of 41 suitable scoring instruments. Differences in sample selection, study design, rater profiles and potential methodological shortcomings were also addressed. Expert commentary: All acute dyspnoea scores lack complete validation. In particular, the areas of measurement error and interpretability have not been addressed correctly by any of the tools reviewed. Frequent modification of pre-existing scores (in items composition and/or name), differences in study design and discrepancies in reviewed sources also hinder the search for an adequate tool.

Modification of an Established Pediatric Asthma Pathway Improves Evidence-Based, Efficient Care

OBJECTIVE

In September 2011, an established pediatric asthma pathway at a tertiary care children's hospital underwent significant revision. Modifications included simplification of the visual layout, addition of evidence-based recommendations regarding medication use, and implementation of standardized admission criteria. The objective of this study was to determine the impact of the modified asthma pathway on pathway adherence, percentage of patients receiving evidence-based care, length of stay, and cost.

METHODS

Cases were identified by using International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes. Data were analyzed for 24 months before and after pathway modification. Statistical process control was used to examine changes in processes of care, and interrupted time series was used to examine outcome measures, including length of stay and cost in the premodification and postmodification periods.

RESULTS

A total of 5584 patients were included (2928 premodification; 2656 postmodification). Pathway adherence was high (79%-88%) throughout the study period. The percentage of patients receiving evidence-based care improved after pathway modification, and the results were sustained for 2 years. There was also improved efficiency, with a 30-minute (10%) decrease in emergency department length of stay for patients admitted with asthma (P = .006). There was a nominal (<10%) increase in costs of asthma care for patients in the emergency department (P = .04) and no change for those admitted to the hospital.

CONCLUSIONS

Modification of an existing pediatric asthma pathway led to sustained improvement in provision of evidence-based care and patient flow without adversely affecting costs. Our results suggest that continuous re-evaluation of established clinical pathways can lead to changes in provider practices and improvements in patient care.

Standardized Asthma Admission Criteria Reduce Length of Stay in a Pediatric Emergency Department

OBJECTIVES

Asthma is the most common chronic illness in children and accounts for > 600,000 emergency department (ED) visits each year. Reducing ED length of stay (LOS) for moderate to severe asthmatics improves ED throughput and patient care for this high-risk population. The objective of this study was to determine the impact of adding standardized, respiratory score-based admission criteria to an asthma pathway on ED LOS for admitted patients, time to bed request, overall percentage of admitted asthmatics, inpatient LOS, and percentage of pediatric intensive care unit (PICU) admissions.

METHODS

This was a retrospective study of a quality improvement intervention. Statistical process control methodologies were used to analyze measures 15 months before and after implementation of a modified asthma pathway (June 2010 to December 2012; pathway modification September 2011).

RESULTS

A total of 3,688 patients aged 1 through 18 years who presented to the ED with an asthma exacerbation during the study period were included. Patients were excluded if they were not eligible for the asthma pathway. Patient characteristics were similar before and after the intervention. Mean ED LOS and time to bed request for admitted asthmatics both decreased by 30 minutes. There was no change in percentage of asthma admissions (34%), mean inpatient LOS (1.4 days), or percentage of PICU admissions (2%).

CONCLUSIONS

Standardizing care for asthma patients to include objective admission criteria early in the ED course may optimize patient care and improve ED flow.

Predicting need for hospitalization in acute pediatric asthma

OBJECTIVES

To develop and validate predictive models to determine the need for hospitalization in children treated for acute asthma in the emergency department (ED).

METHODS

Prospective cohort study of children aged 2 years and older treated at 2 pediatric EDs for acute asthma. The primary outcome was successful ED discharge, defined as actual discharge from the ED and no readmission for asthma within 7 days, versus need for extended care. Among those defined as requiring extended care, a secondary outcome of inpatient care (>24 hours) or short-stay care (<24 hours) was defined. Logistic regression and recursive partitioning were used to create predictive models based on historical and clinical data from the ED visit. Models were developed with data from 1 ED and validated in the other.

RESULTS

There were 852 subjects in the derivation group and 369 in the validation group. A model including clinical score (Pediatric Asthma Severity Score) and number of albuterol treatments in the ED distinguished successful discharge from need for extended care with an area under the receiver-operator characteristic curve of 0.89 (95% confidence interval [CI], 0.87-0.92) in the derivation group and 0.92 (95% CI, 0.89-0.95) in the validation group. Using a score of 5 or more as a cutoff, the likelihood ratio positive was 5.2 (95% CI, 4.2-6.5), and the likelihood ratio negative was 0.22 (95% CI, 0.17-0.28). Among those predicted to need extended care, a classification tree using number of treatments in the ED, clinical score at end of ED treatment, and initial pulse oximetry correctly classified 63% (95% CI, 56-70) of the derivation group as short stay or inpatient, and 62% (95% CI, 55-68) of the validation group.

CONCLUSIONS

Successful discharge from the ED for children with acute asthma can be predicted accurately using a simple clinical model, potentially improving disposition decisions. However, predicting correct placement of patients requiring extended care is problematic.

Decision making in asthma exacerbation: a clinical judgement analysis

BACKGROUND

Clinical decisions which impact directly on patient safety and quality of care are made during acute asthma attacks by individual doctors based on their knowledge and experience. Decisions include administration of systemic corticosteroids (CS) and oral antibiotics, and admission to hospital. Clinical judgement analysis provides a methodology for comparing decisions between practitioners with different training and experience, and improving decision making.

METHODS

Stepwise linear regression was used to select clinical cues based on visual analogue scale assessments of the propensity of 62 clinicians to prescribe a short course of oral CS (decision 1), a course of antibiotics (decision 2), and/or admit to hospital (decision 3) for 60 "paper" patients.

RESULTS

When compared by specialty, paediatricians' models for decision 1 were more likely to include level of alertness as a cue (54% vs 16%); for decision 2 they were more likely to include presence of crepitations (49% vs 16%) and less likely to include inhaled CS (8% vs 40%), respiratory rate (0% vs 24%) and air entry (70% vs 100%). When compared to other grades, the models derived for decision 3 by consultants/general practitioners were more likely to include wheeze severity as a cue (39% vs 6%).

CONCLUSIONS

Clinicians differed in their use of individual cues and the number included in their models. Patient safety and quality of care will benefit from clarification of decision-making strategies as general learning points during medical training, in the development of guidelines and care pathways, and by clinicians developing self-awareness of their own preferences.

Oxygen saturation as a predictor of prolonged, frequent bronchodilator therapy in children with acute asthma

OBJECTIVES

To examine if the initial oxygen saturation (SaO2) in the Emergency Department is a useful predictor of prolonged frequent bronchodilator therapy (FBT) in children with acute asthma.

STUDY DESIGN

Prospective cohort study of 273 children, 1 to 17 years of age, requiring systemic corticosteroids. Patients were categorized as needing FBT for >4 hours (n=166) versus >4 hours (n=107) and >12 hours (n=79) versus >12 hours (n=194). Multiple logistic regression determined the association between SaO2 and these outcomes.

RESULTS

Baseline SaO2 remains a significant independent predictor of FBT for >4 hours (OR=0.81) and >12 hours (OR=0.84); 91% of patients with SaO2 of 90% to 91% had FBT >4 hours and 80% of patients with SaO2 of < or =89% had FBT >12 hours. Children with SaO2 of < or =91% are 14.7 and 12.0 times more likely to require FBT for >4 hours and >12 hours, respectively, than those with SaO2 of 98% to 100%. The interval likelihood ratios for FBT >4 hours were 12.3 for SaO2 of < or =89%, 6.5 for 90% to 91%, but only 1.8 for 92% to 93%. The likelihood ratios for FBT >12 hours decreased from 9.8 for SaO2 of < or =89% to 3.5 for SaO2 of 90% to 91%.

CONCLUSIONS

SaO2 is a useful predictor of FBT >4 hours if it is < or =91% and of FBT >12 hours if it is < or =89%.

Accident and emergency departments are still failing to assess asthma severity

OBJECTIVES

To quantify the documentation of vital signs in children attending accident and emergency (A&E) for asthma and to assess whether indicators of severity were used appropriately.

METHODS

Records of all children aged 3 to 14 attending A&E for the treatment of asthma in four London hospitals over a three month period were examined for documentation of heart rate, respiratory rate, peak expiratory flow rate, oxygen saturation, and fraction of inspired oxygen. The relation between severity indicators and whether the child was admitted or not was examined.

RESULTS

There were 255 attendances in 229 children. Heart rate, respiratory rate, and oxygen saturation were recorded on most attendances (94.5%, 85.5%, and 96.8%) but fraction of inspired oxygen and peak flow were recorded in few children (48.6% and 48.5%). Heart rate and respiratory rate were higher and oxygen saturation lower in children who were admitted compared with those who were not.

CONCLUSIONS

Assessment of airways obstruction is inadequate in children but when measured may be used appropriately to guide admission. There is a need for interventions to improve assessment of children attending A&E for asthma.

Initial oxygen saturation as a predictor of admission in children presenting to the emergency department with acute asthma

BACKGROUND

Previous studies have looked at the relationship between initial oxygen saturation (SaO (2)) and the need for admission in children presenting with an acute asthma exacerbation. If initial SaO (2) value is indeed predictive of admission, then the admission process could be initiated sooner, and time spent in the emergency department could be potentially lessened.

STUDY OBJECTIVE

The objective of the current study was to examine whether initial room air SaO (2) in children presenting to the ED with acute asthma is a reliable predictor of hospital admission.

METHODS

This was a prospective multicenter study during 1997 and 1998 at 44 North American EDs as part of the Multicenter Airway Research Collaboration. Inclusion criteria were physician diagnosis of acute asthma and age between 2 and 17 years. The association between hospital admission and SaO (2) was examined by using logistic regression. Likelihood ratios were used to assess the diagnostic value of SaO (2).

RESULTS

Of the 1,184 children enrolled in the current study, 1,040 (88%) had a documented initial SaO (2) value on room air. The mean age of the cohort was 8+/-4 years, with a mean initial SaO (2) of 95%+/-4%. Overall, 241 (23%) children were admitted to the hospital. The mean SaO (2) value of children admitted to the hospital was 93%+/-5% versus 96%+/-3% for those not admitted (P <.001). The admission rate decreased with increasing SaO (2); 73% (30/41) of children with an SaO (2) value of 88% or less were admitted versus 8% (7/88) with an SaO (2) value of 100%. In the logistic regression model, children with an SaO (2) value of 88% or less were 32 (95% confidence interval 11 to 89) times more likely to be admitted than those with an SaO (2) value of 100%. The likelihood ratio for admission was 12 for children with an SaO (2) value of 88% or less (42/1,040) but decreased to 4.6 for children with an SaO (2) value of 91% or less (130/1,040) and 2.7 for children with an SaO (2) value of 94% or less (333/1,040).

CONCLUSION

This large, clinical multicenter study does not support earlier findings that SaO (2) alone is a clinically useful predictor of hospital admission in children who present to the ED with acute asthma.

Contemporary approach to the emergency department management of pediatric asthma

Asthma continues to be an enormous health problem and economic burden in US society. EDs probably will continue to provide a substantial amount of care for those affected by the disease. Pediatric asthma patients frequently are encountered in EDs. Emergency physicians must remain current in their approach to providing expert care while the management of acute asthma exacerbations continues to evolve, older therapies are challenged and new therapies are developed, tested, and implemented.

Nordic consensus report on asthma management. Nordic Asthma Consensus Group

The work with the Nordic consensus report on asthma management started some years ago. The Nordic countries have common socioeconomic conditions. We acknowledge the international as well as other European guidelines providing valuable recommendations. Nevertheless, we felt the need to combine the common Nordic experiences in order to have a local statement of asthma and asthma care, based upon Nordic clinical science and tradition. The work has been rewarding and we acknowledge many valuable contributions from paediatricians, allergologists and lung physicians in all Nordic countries. The response has so far been positive and we feel that the present material reflects the main opinion of Nordic physicians taking care of asthma patients of all ages. However, the asthma and allergy research field is rapidly developing. Thus, this document should merely be regarded as a time-limited contribution to the continuing scientific discussion of this fascinating field.

Validation of a predictive model for asthma admission in children: how accurate is it for predicting admissions?

We studied 364 index presentations to the Emergency Department of a children's hospital with a diagnosis of asthma. The admission rate for this group of children was about 31%. We developed a parsimonious multiple logistic regression model to predict asthma hospital admission based on asthma severity indicators. We then evaluated the model's predictive ability using two methods of cross-validation, using the same sample that was used for the predictive model, and using data from a split sample. The logistic regression model had a predictive accuracy of 90% (95% confidence interval 85-95%). The sensitivity and specificity were 86% and 88%, respectively. Cross-validation models confirmed that the predictive ability of the model was stable. In studies with limited sample sizes, it is possible to validate a model without setting aside a split sample for cross-validation.

Pulse oximetry in the evaluation of the severity of acute asthma and/or wheezing in children

We evaluated 174 children with acute asthma and/or wheezing attending two different settings, the allergy clinic (AC) and the emergency room (ER), and compared clinical symptoms and spirometric findings with arterial oxygen saturation as measured by pulse oximetry (SpO2). Seventy-four children (4 months to 15 years old) seen at the AC and 100 children (2 months to 14 years old) seen at the ER for the treatment of acute asthma and/or wheezing were evaluated and a clinical score was attributed on the basis of their symptoms. In addition, the heart rate (HR) was recorded and SpO2 was measured. Among the children seen at the AC, 58 were able to perform pulmonary function tests, and the forced respiratory volume in 1 sec (FEV1) and forced expiratory flow between 25% and 75% of the forced vital capacity (FEF(25-75)) were determined. Children from both groups underwent treatment with a nebulized beta2-agonist (Fenoterol 0.5% solution, 0.08 mg/kg/dose, maximum 2.5 mg) and were re-evaluated after 30 min. Our results showed a significant correlation between decrease in clinical scores and increase of SpO2 following treatment with bronchodilator in both groups of children. SpO2 levels correlated positively with FEV1 and FEF(25-75) values, and negatively with clinical scores and heart rate. The data revealed that a clinical score greater than 3 and an SpO2 < 94% were associated with increased severity of the asthma attack. In addition, SpO2 levels < or = 92% were associated with a 6.3-fold greater relative risk for requiring additional treatment. We concluded that determination of oxygen saturation by pulse oximetry is helpful in monitoring the severity of an acute exacerbation of asthma and/or wheezing, and has a prognostic value.

Evaluation of pre- and posttreatment pulse oximetry in acute childhood asthma

OBJECTIVE

To evaluate the utility of pre- and posttreatment O2 saturation (SpO2) for prediction of admission or relapse after ED release in acute asthma exacerbations using a standardized treatment protocol.

DESIGN

A prospective, double-blind, observational study was performed at a pediatric ED. Children with acute asthma were enrolled upon ED presentation. SpO2 was measured prior to treatment and after disposition decision. Two experienced physicians determined disposition based on history and physical examination alone, while blinded to SpO2. Relapse of released patients was determined by telephone follow-up.

RESULTS

A pretreatment room-air SpO2 of < or = 91% had a sensitivity of 0.24, a specificity of 0.86, and a likelihood ratio of 1.77 to predict admission/relapse. A posttreatment room-air SpO2 of < or = 91% had a sensitivity of 0.34, a specificity of 0.98, and a likelihood ratio of 16.43 to predict admission/relapse.

CONCLUSIONS

As opposed to some previous studies, this study found pretreatment SpO2 to be a relatively poor predictor of admission. A posttreatment SpO2 of < or = 91% occurred in a minority (32%) of patients, but increased the odds of admission 16-fold and may be used as an adjunct to objectively confirm the need for admission.

The prediction of hospital admission in children with acute asthma

OBJECTIVE

To determine whether a single assessment of children at the time of presentation to the emergency department would discriminate accurately between those requiring admission and those who could be managed at home and to examine the appropriateness of these decisions.

METHODOLOGY

Fifty-three children were assessed using a table recommended by Australian and New Zealand respiratory paediatricians, which categorizes children as probably being able to manage at home (group 1), may need admission to hospital (group 2) and certainly need admission to hospital (group 3) on the basis of oximetry, presence of wheeze and pulsus paradoxus.

RESULTS

Nine out of 11 children assigned to group 1 were managed at home and 15/17 who were predicted to require admission were admitted. No individual component of the assessment dominated the decision made. Of the 25 children allocated to group 2, 18 were admitted.

CONCLUSIONS

The method employed was highly predictive of outcome for half of the children who presented with asthma. However, 25/53 (47%) were assigned by the table to a recommendation for further assessment; this limits its usefulness.

Development of a clinical asthma score for use in hospitalized children between 1 and 5 years of age

The objective of this study was to develop a clinical asthma score (CAS) for use in hospitalized children between 1 and 5 years of age. Formal approaches to item selection and reduction, reliability, discriminatory power, validity, and responsiveness were used. The final CAS consisted of five clinical characteristics: respiratory rate, wheezing, indrawing, observed dyspnea, and inspiratory-to-expiratory ratio. Interrater reliability was high (weighted kappa = 0.82), and the CAS was discriminatory (Ferguson's delta = 0.92). The CAS was valid, with a strong correlation with length of hospital stay (Spearman's correlation = 0.47, p < 0.05) and drug dosing interval (Spearman's correlation = -0.58, p < 0.01). The CAS was responsive, with a significant change in CAS from admission to discharge (Wilcoxon signed rank test, p < 0.01). This score, for use in hospitalized preschool children, is reliable, discriminatory, valid, and responsive.

Clinical scores for acute asthma in pre-school children. A review of the literature

The objective of this paper was to evaluate the applicability in research and clinical practice of clinical scores for acute asthma in pre-school children. All instruments were reviewed according to a standardized set of criteria: purpose of the score, suitability for use in children, inter-observer agreement, validity and responsiveness. A Medline literature research resulted in 16 different clinical asthma scores, which have been developed to assess the severity of acute asthma, to predict the outcome of an attack, or to evaluate the response to treatment. Most asthma scores could be easily obtained in children. Three scores have been modified to facilitate application in a younger age-category. Inter-observer agreement has received little attention, although all scores contained items that require subjective judgement. The predictive validity was insufficient to justify the application of clinical scores as a decision rule for the admission or discharge of children with acute asthma. Asthma scores seem to be useful for assessing the severity of an attack and evaluating the response to therapy, but as yet there is insufficient information on the performance of the scores to justify a preference. Wheezing and retractions appear to be important items of any useful score for acute asthma.

Use of pulse oximetry in the hospital management of acute asthma in childhood

Oxyhemoglobin saturation values were recorded before and 10 minutes after 5 mg of nebulized salbutamol in 75 children (age, 1.5-14.6 years) admitted to hospital with acute asthma. Other assessments included heart rate, respiratory rate, peak expiratory flow rate, pulsus paradoxus, and an asthma severity score. All assessments were performed by the same observer (GC) and subsequent hospital care was transferred to the on-call pediatricians, who were not told the initial saturation values. Six children required intravenous therapy after hospital admission when their symptoms were not improved after nebulized salbutamol. Cutoff points for each continuous variable were selected so that they identified at least 5 of these 6 children (i.e., with a sensitivity of at least 83 percent). The resulting specificities and positive predictive values were calculated for each variable before and after nebulized therapy. A postnebulizer saturation of less than 91% had a sensitivity of 100% [95% confidence interval (CI), (54-100] with a specificity of 98% (95% CI, 92-100) and a positive predictive value of 86%. This was the best predictor of the need for intravenous (IV) therapy. Correlation coefficients were calculated for the 75 admissions and 2 others who required immediate IV treatment to determine how closely saturation values were related to the other recorded clinical variables. Saturation values were significantly, though weakly, correlated with asthma severity scores and prenebulizer heart rate, but they were not associated with any of the other variables. These results highlight the difficulties encountered when assessing acute asthma in a hospital population with a large number of preschool children.(ABSTRACT TRUNCATED AT 250 WORDS)

Continuous pulse oximetry during emergency endotracheal intubation

STUDY OBJECTIVE

To determine whether continuous pulse oximetry improves the recognition and management of hypoxemia during emergency endotracheal intubation.

DESIGN

A prospective, serial 14-month study.

SETTING

Emergency department, Level I trauma center.

TYPE OF PARTICIPANTS

All adult patients requiring emergency intubation for whom data collection would not compromise patient care.

INTERVENTIONS

All samples were obtained from a finger site at a five-second sampling interval and stored in computer memory. Patients were intubated by the nasotracheal or orotracheal route.

MEASUREMENTS AND MAIN RESULTS

One hundred ninety-one consecutive adult patients qualified for the study and 211 intubation attempts were analyzed. Hypoxemia (O2 saturation, less than 90%) occurred during an intubation attempt in 30 of 111 nonmonitored versus 15 of 100 monitored attempts (P < .05), and the duration of severe hypoxemia (O2 saturation, less than 85%) was significantly greater for nonmonitored attempts (P < .05).

CONCLUSION

Continuous pulse oximetry monitoring reduces the frequency and duration of hypoxemia associated with emergency intubation attempts.

Pulse oximetry and peak flow as indicators of wheezing severity in children and improvement following bronchodilator treatments

This study examined the changes from the initial peak flows and oxygen saturations (OSAT) of wheezing children at presentation to the emergency department through their treatment in the emergency department. Data was collected prospectively on 785 patients 5 to 20 years of age during an 11-month period from November 1, 1990, to September 30, 1991. Both the initial OSAT and peak flows were correlated with the number of bronchodilator treatments required in the emergency department and with the need for hospitalization. Both the initial OSAT and the peak flows had a limited ability to predict the need for hospitalization. Oxygen saturation appears to be a valid measure of wheezing severity and is more easily obtained in children of all ages. Following bronchodilator treatment, peak flow results in a larger quantitative improvement than OSAT; however, this difference does not appear to have any significant advantage. Aerosolized albuterol and subcutaneous epinephrine resulted in a similar degree of improvement as measured by peak flow and by oxygen saturation, with clinically similar changes in heart rate.

Oxygen saturation changes during the pediatric emergency department treatment of wheezing

This study examined the oxygen saturation (OSAT) changes measured by pulse oximetry during emergency department (ED) bronchodilator treatment of wheezing patients. Data were collected prospectively on two cohorts (November 1987 to November 1988, 2,468 patients; and December 1988 to October 1990, 4,913 patients) presenting to a pediatric ED with wheezing-associated respiratory illnesses. Initial, posttreatment, and discharge OSAT was recorded in many of these patients. Improvement in OSAT following ED bronchodilator administration was noted in most patient groups. Initial OSAT was indicative of severity as measured by the need for hospitalization and the number of bronchodilator treatments administered in the ED. Subcutaneous epinephrine and aerosolized albuterol were compared in OSAT improvement and side effects. Aerosolized albuterol was not shown to be superior to epinephrine. Improvements in OSAT following bronchodilator administration documents the presence of relative preexisting hypoxemia which is reversed to some degree with bronchodilators. Pulse oximetry is an objective means of assessing asthma severity.

Pulse oximetry in acute asthma

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Evaluation of the properties and reliability of a clinical severity scale for acute asthma in children

The inter-observer agreement (reliability) and validity of a clinical asthma severity scale (ASS) derived from separate scores of wheeze, heart rate and accessory muscle use (each on a 4-point scale) were studied in 60 children aged between 6 months and 17 years (mean 5.4 years). Independent assessments of these clinical parameters were made by two paediatricians, and they also rated patients as having a mild, moderate, severe or very severe acute episode (clinical judgement rating, CJR). Oxygen saturation (SaO2) was measured concurrently by a Biox 3700 pulse oximeter and readings were categorized as mild (SaO2 greater than or equal to 94%), moderate (91-93%) and severe (less than 91%). Agreement between clinicians was assessed by the weighted kappa statistic (kappa W). Agreement for the ASS score compared to the severity grade obtained from SaO2 was slight (kappa W = 0.34) and compared to CJR the kappa W was 0.55. An ASS score of moderate or worse (greater than 3) had sensitivity of 97% and specificity of 50% for prediction of admission. The maximum frequency and duration of nebulizer therapy following admission were significantly greater for severe patients than for moderate patients. Length of hospital stay did not reflect the ASS score in the emergency department but total duration of functional disability increased with ASS score. The substitution of an adjusted heart rate score for the raw heart rate score used in ASS detracted from scale performance. The ASS is an imprecise but reasonable quantitative measure of the severity of an acute episode of asthma.(ABSTRACT TRUNCATED AT 250 WORDS)