The Editor's Choice for November is a study evaluating a respiratory therapist (RT)-driven protocol in pediatric asthma. Miller and others performed a before and after trial of aprotocol guided by assessment of the modified pulmonaryindex score. They demonstrated an increased use of high-flownasal cannula (HFNC) and noninvasive ventilation (NIV)during the intervention period, as well as shorter pediatricintensive care unit (PICU) length of stay, shorter duration ofcontinuous albuterol treatment, and shorter hospitalization. Myers pens an accompanying editorial reviewing the historyof RT-driven protocols in pediatric asthma and concludes thatprotocolized therapy should be a standard of care.
Zemach and others describe the use of HFNC outside the ICU. To date, HFNC has typically been reserved forhigher intensity care environments. This study evaluateddyspnea scores and changes in cardiorespiratory variables,as well as ICU admission. Subjects experienced a decreasein dyspnea scores, a reduction in breathing frequency, andimproved oxygen saturation. A third of subjects had do-not-resuscitate orders and a resultant high in-hospital mortality. The ROX index ([SpO2/FIO2]/breathing frequency) was theonly independent predictor of HFNC success. Messika andRicard contribute an editorial reviewing the improvementsin outcomes associated with HFNC. They suggest caution inHFNC use outside of appropriately monitored environmentsto assure safety.
Osborn et al and Villalba et al contribute two papers onthe use of pulse oximetry to monitor anemia (SpHb) andcarboxyhemoglobin in the emergency department (ED).Osborn et al studied a convenience sample of 350 subjectsand determined limits of agreement for Hb of –3.3 to 2.5 g/dLcompared to standard laboratory measurements using venousblood. They suggest that pulse oximetry can be useful toscreen for anemia in the ED. Villalba et al used pulse oximetryto screen for CO exposure in the ED. Using data from 126subjects, they compared SpCO to standard blood co-oximetry. An SpCO of ≥10% was defined as positive. Fourteen of 23subjects had a positive SpCO. However, limits of agreementwere –10.3% and +8.1% compared to blood CO measurements. Hogan and McMullan cogently argue that implementation ofa screening program should offer a meaningful interventionupon detection of a true positive result, while assuring that alarge proportion of afflicted patients do not escape detection. They suggest that screening for anemia and CO exposure inthe ED using oximetry technology doesn't meet this standard.
Maue and colleagues report on an RT-driven protocolfor continuous albuterol delivery in the PICU. This singlecenter trial used an interdisciplinary team to create a protocolfor continuous albuterol treatment based on the Pediatric Asthma Severity Score. Using before and after methodology,the authors demonstrated no difference in the duration of continuous albuterol administration or adverse events. Theyconclude that the RT-driven protocol was as safe as physician-ordered treatment.
Berlinski and Velasco evaluated albuterol delivery in apediatric model of NIV using a single-limb circuit. Theystudied vibrating mesh nebulizers (VMNs) and jet nebulizersat various positions in the circuit. The highest deliveryefficiency was seen with the VMN placed after the exhalationport. VMNs were superior to jet nebulizers regardless ofposition in the circuit.
Impaired cough results in respiratory compromise in ahost of pulmonary diseases and monitoring cough peak flow (CPF) helps identify patients at risk. Norisue et al evaluatedCPF and ultrasound evaluation of diaphragmatic excursionin a group of healthy subjects. They demonstrated thatcephalic excursion during cough predicted CPF. The utilityof ultrasound evaluation of the diaphragm needs validationin patients.
Ntoumenopoulos and colleagues describe a study evaluatinga number of common and advanced techniques for determiningthe need for airway clearance. This included acoustic monitoring as well as breath sounds and the presence of a ‘sawtooth’ pattern in the expiratory flow waveform. The bestpredictive model of the volume of airway secretions removedwere the presence of the sawtooth waveform and ventilatortubing fremitus on expiration. They concluded that simpleclinical assessments are superior to advanced technology.
Home oxygen therapy improves outcomes in COPD andresting hypoxemia. Stulce et al evaluated oxidative stressin COPD subjects and a control group using exhaled breathcondensate. They reported that exposure to inspired oxygenconcentrations of ≤ 0.36 did not appear to induce oxidativestress.
Cani and colleagues evaluated the impact of home oxygentherapy on physical activities of daily living in COPDsubjects. COPD subjects using home oxygen were comparedto COPD subjects not requiring oxygen therapy. Subjectsrequiring home oxygen spent less time in all aspects ofphysical activity. Oxygen therapy time in hours per day wasthe strongest predictor of reduced physical activity.
Rantala et al report on a retrospective study of COPDsubjects requiring home oxygen therapy evaluating predictorsof survival. The study evaluated 195 subjects over a 3-yperiod. The most frequent reasons for home oxygen therapywere COPD and interstitial lung diseases (ILD). Most of thesubjects (69%) died during the study, and the median survivaltime was 2.2 y. ILD subjects had shorter survival comparedto COPD subjects. Needing assistance with activities of dailyliving predicted short survival.
Dadlez and others evaluated HFNC in children with bronchiolitis outside the ICU. This was a retrospectivereview of HFNC use over 2 y. In a sample of 80 subjects,intubation was not required and there were no reportedbarotrauma events. The authors suggest that at flow < 10 L/min, HFNC may be safely used outside the ICU inpatients with less severe illness.
Macedo et al evaluated the performance of NIV masksin a lung model of COPD. They measured end tidal carbondioxide concentration (EtCO2), mask leakage, tidal volume,trigger time, time to achieve 90% of the inspiratory targetduring inspiration, and excess inspiratory time. They studiedtwo sizes of oronasal masks and a full-face mask. They did notfind any impact on EtCO2 washout or on synchrony variables.
Elnaggar and others evaluated different physiotherapytechniques in children with asthma. This included diaphragmatic release technique and thoracic lymphatic pumptechnique compared to conventional respiratory re-training. They measured the impact of each technique on forced vitalcapacity and diaphragmatic mobility. All three interventionsresulted in improved lung function.
Zayed et al contribute a systematic review of noninvasive oxygenation strategies in subjects with hypoxemic respiratory failure. This review evaluates HFNC, NIV, and conventional oxygen therapy on outcomes, including intubation rates and mortality.
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