Ventilatory Ratio is a Valuable Prognostic Indicator in a Representative Observational Cohort of Patients with Acute Respiratory Distress Syndrome

Background Estimating mortality risk is essential for prognostic enrichment. How various indices specific to respiratory compromise contribute to prognostication in patients with acute respiratory distress syndrome (ARDS) is not well-characterized in general clinical populations. The primary objective of this study was to identify variables specific to respiratory failure that add prognostic value to indicators of systemic illness severity. We tested the added benefit of respiratory variables in a representative observational cohort of patients with ARDS.Methods 50 patients with ARDS were enrolled in a single-center, prospective, observational cohort. We tested the contribution of respiratory variables (oxygenation index, ventilatory ratio [VR], and the radiographic assessment of lung edema score) to logistic regression models of 28-day mortality adjusted for indicators of systemic illness severity (the Acute Physiology and Chronic Health Evaluation [APACHE] III score or severity of shock as measured by the number of vasopressors required at baseline). We also compared a model utilizing APACHE III with one including baseline number of vasopressors using the areas under their receiver operating curves.ResultsVR significantly improved model performance by likelihood ratio testing when added to APACHE III (p = 0.04) or vasopressor number at baseline (p = 0.01). Adjusted for APACHE III, each 0.5-unit change in VR was associated with an odds ratio for 28-day mortality of 1.78 (95% CI = 0.78-3.23). The number of vasopressors required at baseline had similar prognostic discrimination to the multi-component APACHE III. A model including the number of vasopressors and VR (area under the receiver operating curve [AUROC] 0.77, 95% CI 0.64-0.90) was comparable to a model including APACHE III and VR (AUROC 0.81 (95% CI 0.68 – 0.93), p value for comparison = 0.58.) ConclusionsIn this observational cohort of patients with ARDS, the ventilatory ratio significantly improved discrimination for mortality when combined with indicators of severe systemic illness. Additionally, the number of vasopressors required at baseline and APACHE III had similar discrimination for mortality when combined with VR. The ventilatory ratio is easily obtained at the bedside and offers promise for both clinical prognostication and enriching clinical trial populations.

802 Seizure-Associated Central Respiratory Events: What’s Sleep Go To Do With It?

Introduction Seizure-related respiratory dysfunction has been reported in patients with epilepsy(PWE) on scalp EEG. We assessed this in Stereo-EEG(SEEG) recordings in patients with pharmacoresistant focal epilepsy. Methods PWE undergoing SEEG wore temperature/pressure-based airflow,RIP belts, SpO2, and EtCO2/TcpCO2. Interpretable recordings required SpO2 and at least one airflow and effort channel. Respiratory events including apneas, hypopneas(3%) and central pauses (5 to<10sec). Respiratory events, respiratory rate(RR), SpO2 nadir, total desaturation time, Peak EtCO2/TcpCO2, and hypercapnia duration were analyzed surrounding seizures. Frequency and duration of central events were compared in sleep-onset and awake seizures. Linear mixed-effects models evaluated relationships between respiratory variables and the frequency and duration of central events associated with seizures and compared respiratory variables between seizures with and without events. Results 44 seizures were recorded in 23 patients. Seizures were focal-onset in 79.5%(n=35), GTC in 20.5%(9). Respiratory events accompanied 61.4%(27) of the seizures with median duration/seizure duration of 0.40(IQR: 0.27, 0.61). Of the 47 respiratory events, 42 were central events, and 66.6%(28) were central apneas. Respiratory events occurred during the seizure in 73.8%, postictal in 26.2%; median SpO2 nadir was 90%(77.0, 93.0), total desaturation duration 104.3(50.3, 195.0)sec, peak TcpCO2 41.3(38.7, 44.8) mmHg, hypercapnia duration 157.6(51.0, 367.9) sec, and ictal-postictal RR change 3.3 ± 4.0bpm. For every 1 sec duration increase in central event duration, there was a significant increase in peak TcpCO2 0.35(95%CI [0.09,0.62],p=0.015) and TcpCO2 change 0.25(95%CI [0.02,0.49],p=0.037). Presence of central events were associated with increased peak TcpCO2(9.82[3.77,15.9], p=0.006). Seizures with central events trended greater changes in RR, SpO2, and EtCO2/TcpCO2, desaturation and hypercapnia time, with negative changes in SpO2 nadir. No significant difference on central event frequency was found between sleep-onset and awake seizures. Conclusion Central events including apneas and pauses are common in focal seizures arising from sleep and wake and are associated with hypercapnia. In addition to the significant association between TcpCO2 and the frequency and duration of central events, there is a positive trend of association of other respiratory dysfunction parameters. These findings suggest that central events may lead to a cascade of respiratory disturbance that may participate in the pathophysiology of sudden unexplained death in epilepsy. Support (if any):

Association of Maternal, Obstetric and Neonatal Variables on the Use of Bronchial Hygiene Maneuvers and Impact on Morbidity, Mortality and Survival in Neonatal Intensive Care Unit

Objective: To analyze whether maternal, obstetric, anthropometric data of the neonate and respiratory variables influence the use of BHMs in neonates admitted to the NICU. In addition, to evaluate the impact of the applicability of this type of technique on the morbidity, mortality and survival of these neonates. Methods: Retrospective, quantitative study with descriptive and inferential analysis. Initially, the sample consisted of 599 medical records. The study involved newborns of both sexes admitted to the Neonatal Intensive Care Unit (NICU) of the tertiary referral hospital at maternal and child health, during 2017. The respiratory variables, maternal, obstetric, data of the neonate, morbidity and mortality were selected. Results: BHMs were associated with neonates whose mothers had a number of pregnancies ≥ 3 or newborns who had cephalic presentation at the time of delivery. In addition, there are particularities among neonates who receive this intervention, such as higher capillary glycemia, lower head circumference and occurrence of jaundice. The technique was not related to prematurity factors, such as pregnancy time ≤ 24 weeks, or respiratory factors, such as apnea, flapping of the nose wing, cyanosis and intercostal retraction. However, the use of the BHMs increases neonatal survival and reduces the mortality. Conclusion: The BHMs use is determined by maternal, obstetric and neonatal variables, being determinant to reduce the risk of death and increase the survival in NICU. RESUMO Objetivo: Analisar se dados maternos, obstétricos, antropométricos e variáveis respiratórias influenciam o uso de BHMs em neonatos internados em UTIN. Além disso, avaliar o impacto da aplicabilidade desse tipo de técnica na morbimortalidade e sobrevida desses neonatos. Métodos: Estudo retrospectivo, quantitativo com análise descritiva e inferencial. Inicialmente, a amostra era composta por 599 prontuários. O estudo envolveu recém-nascidos de ambos os sexos internados na Unidade de Terapia Intensiva Neonatal (UTIN) do hospital terciário de referência em saúde materno-infantil, durante 2017. Foram selecionadas as variáveis respiratórias, maternas, obstétricas, dados do neonato, morbimortalidade.Resultados: os BHMs foram associados a neonatos cujas mães tiveram um número de gestações ≥ 3 ou recém-nascidos que apresentaram apresentação cefálica no momento do parto. Além disso, existem particularidades entre os neonatos que recebem essa intervenção, como aumento da glicemia capilar, menor perímetro cefálico e ocorrência de icterícia. A técnica não foi relacionada a fatores de prematuridade, como tempo de gestação ≤ 24 semanas, ou fatores respiratórios, como apneia, batimento da asa nasal, cianose e retração intercostal. Porém, o uso dos BHMs aumenta a sobrevida neonatal e reduz a mortalidade. Conclusão: O uso de BHMs é determinado por variáveis maternas, obstétricas e neonatais, sendo determinante para reduzir o risco de óbito e aumentar a sobrevida em UTIN.

Second generation laryngeal mask airway during laparoscopic living liver donor hepatectomy: a randomized controlled trial

The second-generation laryngeal mask airway (LMA) provides a higher sealing pressure than classical LMA and can insert the gastric drainage tube. We investigated the difference in respiratory variables according to the use of second-generation LMA and endotracheal tube (ETT) in laparoscopic living liver donor hepatectomy (LLDH). In this single-blind randomized controlled trial, intraoperative arterial carbon dioxide partial pressure at 2 h after the airway devices insertion (PaCO2_2h) was compared as a primary outcome. Participants were randomly assigned to the following groups: Group LMA (n = 45, used Protector LMA), or Group ETT (n = 43, used cuffed ETT). Intraoperative hemodynamic and respiratory variables including mean blood pressure (MBP), heart rate (HR), and peak inspiratory pressure (PIP) were compared. Postoperative sore throat, hoarseness, postoperative nausea and vomiting (PONV), and pulmonary aspiration were recorded. The PaCO2_2h were equally effective between two groups (mean difference: 0.99 mmHg, P = 0.003; 90% confidence limits: − 0.22, 2.19). The intraoperative change in MBP, HR, and PIP were differed over time between two groups (P < 0.001, P = 0.015, and P = 0.039, respectively). There were no differences of the incidence of postoperative complications at 24 h following LLDH (sore throat and hoarseness: P > 0.99, PONV: P > 0.99, and P = 0.65, respectively). No case showed pulmonary aspiration in both groups. Compared with endotracheal tube, second-generation LMA is equally efficient during LLDH. The second-generation LMA can be considered as the effective airway devices for securing airway in patients undergoing prolonged laparoscopic surgery. Trial Registration This study was registered at the Clinical Trial Registry of Korea (https://cris.nih.go.kr. CRiS No. KCT0003711).