Number Of Desaturation Events Research Articles

Interdisciplinary collaborative eye examinations to protect preterm infant neurodevelopment: a quality improvement project.

Infants born <31 weeks gestational age with birth weight ≤ 1,500 grams receive routine eye examinations to screen for Retinopathy of Prematurity (ROP) while in the Neonatal Intensive Care Unit (NICU) to help prevent vision threatening complications; however, preterm infants' sensory systems are underdeveloped, and repeated exposure to painful stimuli is associated with worse developmental outcomes. An interdisciplinary NICU team designed a collaborative eye exam model (CEEM) incorporating best practice recommendations for infant pain control during exams. Pain scores and vital signs were recorded before, during, and after exams. Two sets of mixed-effects regression models with a random intercept on infants were established to investigate relationships between the intervention, birth gestational age (BGA), postmenstrual age (PMA), and outcomes associated with painful stimuli. Survey feedback was elicited from NICU stakeholders about the CEEM. Thirty standard of care (SC) and 35 CEEM exams of 37 infants were included in final analysis. In infants of the same BGA, the number of desaturation events was significantly reduced in the CEEM group (p = 0.003) and became 1.53 times smaller with each additional week of BGA (p = 0.009). Probability of heart rate recovery within 15 min lowered significantly in the CEEM group (p = 0.04). In SC or CEEM or between infants of the same PMA, no differences were observed for bradycardia, heart rate range, chance of heart rate recovery, or pain scores. Increases in tachycardia (p < 0.001) events and desaturations p = 0.006 were discovered in the CEEM group. When considering interaction effects, the CEEM appeared to reduce the number of desaturations to a greater degree for infants at earliest BGAs with attenuation of this effect with greater BGA. Regarding PMA, bradycardia and tachycardia events were reduced for infants across PMAs in the CEEM, but the effect for tachycardia improves with age, while the effect for bradycardia diminishes with age. Stakeholders agreed that the infant's eye exam experience and the staff experience was "very much" improved by the CEEM. Despite variable findings in selected outcome measures, the CEEM was positively viewed by staff. Infants may benefit from the CEEM differently based on BGA and PMA.

Dexmedetomidine versus propofol sedation in flexible bronchoscopy: a randomized controlled trial

BackgroundDexmedetomidine (DEX), is a highly selective alpha2 adrenoceptor (α2-AR) agonist, successfully used in various procedures including flexible bronchoscopy. Randomized controlled trials (RCTs) evaluating DEX sedation during bronchoscopy report equivocal results regarding respiratory and hemodynamic outcomes.MethodsWe conducted an RCT to evaluate the efficacy and safety of dexmedetomidine compared to propofol for sedation during bronchoscopy. The primary outcome was the number of desaturation events, secondary outcomes were transcutaneous Pco2 level, hemodynamic adverse events and physician and patient satisfaction.ResultsOverall, 63 patients were included, 30 and 33 in the DEX and propofol groups, respectively. The number of desaturation events was similar between groups, median (IQR) 1 (0–1) and 1 (0–2) in the DEX and control groups, respectively (P = 0.29). Median desaturation time was 1 (0–2) and 1 (0–3) minutes in the DEX and control groups, respectively (P = 0.48). Adverse events included hypotension, 33% vs 21.1% in intervention and control groups, respectively (P = 0.04), bradycardia, cough, and delayed recovery from sedation. Total adverse events were 22 and 7 in DEX and propofol groups, respectively (P = 0.009).ConclusionDexmedetomidine sedation during bronchoscopy did not show differences in oxygen saturation and transcutaneous CO2 level in comparison to propofol. Moreover, DEX sedation required a significantly higher number of rescue boluses, due to inadequate sedation and was associated with a higher rate of adverse events.Trial registration NCT04211298, registration date: 26.12.2019.

Predicting outcome of velopharyngeal surgery in drug-induced sleep endoscopy by traction velum.

Outcomes of surgical management of obstructive sleep apnea-hypopnea syndrome (OSAHS) can be difficult to predict preoperatively. To study the effect of applying traction to the velum during drug-induced sleep endoscopy (DISE) in OSAHS patients, and to describe the use of traction velum in predicting surgical success. 41 adult surgical patients with OSA (Friedman tongue position II and III) were evaluated by DISE. All patients subsequently underwent velopharyngeal surgery in the form of uvulopalatopharyngoplasty with tonsillectomy plus barbed reposition pharyngoplasty. Surgical responders (n = 26, 63.4%) and nonresponders (n = 15, 36.6%) demonstrated no significant differences with regard to preoperative AHI, age, sex, body mass index, and mean/lowest O2 saturation. Responders had a marked decrease in desaturation events (2.96 vs 0.03, p < 0.001) and percentage change in number of desaturation events before/after traction velum (56.7 vs 4.5, p < 0.001). Regression analysis revealed that reduction in mean desaturation events, with traction velum, by a percentage > 26.8% (odds ratio [OR] 1.046; 95% confidence interval [CI] 1.018-1.075; p = 0.001) was the only independent predictor of surgery success. OSAHS patients' velopharyngeal surgical outcome can be predicted by measuring the percentage change in the number of oxygen desaturation events before and after traction velum in DISE.

Model-based PEEP titration versus standard practice in mechanical ventilation: a randomised controlled trial

BackgroundPositive end-expiratory pressure (PEEP) at minimum respiratory elastance during mechanical ventilation (MV) in patients with acute respiratory distress syndrome (ARDS) may improve patient care and outcome. The Clinical utilisation of respiratory elastance (CURE) trial is a two-arm, randomised controlled trial (RCT) investigating the performance of PEEP selected at an objective, model-based minimal respiratory system elastance in patients with ARDS.Methods and designThe CURE RCT compares two groups of patients requiring invasive MV with a partial pressure of arterial oxygen/fraction of inspired oxygen (PaO2/FiO2) ratio ≤ 200; one criterion of the Berlin consensus definition of moderate (≤ 200) or severe (≤ 100) ARDS. All patients are ventilated using pressure controlled (bi-level) ventilation with tidal volume = 6–8 ml/kg. Patients randomised to the control group will have PEEP selected per standard practice (SPV). Patients randomised to the intervention will have PEEP selected based on a minimal elastance using a model-based computerised method. The CURE RCT is a single-centre trial in the intensive care unit (ICU) of Christchurch hospital, New Zealand, with a target sample size of 320 patients over a maximum of 3 years. The primary outcome is the area under the curve (AUC) ratio of arterial blood oxygenation to the fraction of inspired oxygen over time. Secondary outcomes include length of time of MV, ventilator-free days (VFD) up to 28 days, ICU and hospital length of stay, AUC of oxygen saturation (SpO2)/FiO2 during MV, number of desaturation events (SpO2 < 88%), changes in respiratory mechanics and chest x-ray index scores, rescue therapies (prone positioning, nitric oxide use, extracorporeal membrane oxygenation) and hospital and 90-day mortality.DiscussionThe CURE RCT is the first trial comparing significant clinical outcomes in patients with ARDS in whom PEEP is selected at minimum elastance using an objective model-based method able to quantify and consider both inter-patient and intra-patient variability. CURE aims to demonstrate the hypothesized benefit of patient-specific PEEP and attest to the significance of real-time monitoring and decision-support for MV in the critical care environment.Trial registrationAustralian New Zealand Clinical Trial Registry, ACTRN12614001069640. Registered on 22 September 2014.(https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=366838&isReview=true) The CURE RCT clinical protocol and data usage has been granted by the New Zealand South Regional Ethics Committee (Reference number: 14/STH/132).

SERUM LIPOPROTEIN-ASSOCIATED PHOSPHOLIPASE A2 IN MALES WITH METABOLIC SYNDROME AND OBSTRUCTIVE SLEEP APNEA.

Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a novel biomarker for cardiovascular diseases (CVD) risk estimation with high specificity for vascular inflammation. Few studies have investigated Lp-PLA2 levels in patients with metabolic syndrome (MetS) and obstructive sleep apnea syndrome (OSAS). This study aimed to evaluate the role of Lp-PLA2 levels as a marker of vascular inflammation that contributes to cardiometabolic dysfunction in patients with MetS and OSAS. This is a prospective case-control study. 83 men were enrolled. Following anthropometric measurements, laboratory analysis and overnight sleep study, patients were divided into three groups: MetS, OSAS with/without MetS. Serum Lp-PLA2 levels were determined by ELISA method. Serum Lp-PLA2 levels were statistically significant among the three groups and were higher in OSAS with MetS group than those without MetS. A significant positive relationship between increased Lp-PLA2 level and CRP (C-reactive protein) and apnea-hypopnea index (AHI) was found. Average oxygen saturation (AvO2) and the lowest oxygen saturation were negatively correlated with Lp-PLA2. The number of desaturation events, oxygen desaturation index, AvO2, AHI and CRP were significant predictors of Lp-PLA2. Lp-PLA2 levels are associated with OSAS severity and might play an important role in predicting CVD in OSAS with/without MetS.

Human factors in the emergency department: Is physician perception of time to intubation and desaturation rate accurate?

The main objective of the present study was to examine the perceived versus actual time to intubation (TTI) as an indication to help determine the situational awareness of Emergency Physicians during rapid sequence intubation and, additionally, to determine the physician's perception of desaturation events. A timed, observation prospective cohort study was conducted. A post-intubation survey was administered to the intubating physician. Each step of the procedure was timed by an observer in order to determine actual TTI. The number of desaturation events was also recorded. One hundred individual intubations were included. The provider perceived TTI was significantly different and underestimated when compared with the actual TTI (23 s, 95% confidence interval (CI) 20.4-25.49 vs 45.5 s, 95% CI 40.2-50.7, P < 0.001, respectively). Pearson correlation coefficient of perceived TTI to actual TTI was r(2) = 0.39 (95% CI 0.21-0.54, P < 0.001). The provider perceived desaturation rate was also significantly different from actual desaturation rate (13, 95% CI 3-12 vs 23, 95% CI 13-29, P = 0.05, respectively). The overall time to desaturation was 65.1 s. Our findings have shown that provider's perception of TTI occurs sooner than actually observed. Also, the providers were less aware of desaturation during the procedure.

Analysis of nocturnal pulse oximetry in sleep medicine

Oxygen saturation obtained from nocturnal pulse oximetry is a significant evaluation parameter for sleep related breathing disorders, especially in the diagnosis of the obstructive sleep apnea syndrome (OSA). Today clinical interpretation relies mainly on the number of desaturation events per hour (oxygen desaturation index, ODI). In this study various alternatives were established and their applicability for OSA screening was evaluated. The discussed methods include time-based approaches (Δ-index), non-linear analysis (central tendency measure, approximate entropy), and spectral methods (Welch transform, wavelet transform). When applied to 192 data sets (132 male, 60 female, 47.9±15.5 years, BMI 27.4±6.5 kg/m(2)) these methods showed good correlation with clinical findings. When discriminating between non-OSA and OSA patients the approaches under investigation yield sensitivity values between 96.6% and 100% and specificity values between 97.4% and 100%. Particularly spectral methods could provide parameters for an optimized OSA screening based on nocturnal pulse oximetry.

Use of Ambulatory Overnight Oximetry to Investigate Sleep Apnea in a General Internal Medicine Practice

To examine how clinical factors and results from ambulatory overnight oximetry related to recommendations for further sleep evaluation in patients with clinically suspected obstructive sleep apnea syndrome. We reviewed 100 medical records selected randomly from 375 consecutive patients for whom ambulatory overnight oximetry had been ordered by internists and completed between September 1, 2001, and May 1, 2002. We analyzed relationships among clinical Information, oximetry results, resultant recommendations, and patient follow-up data. Only 21 of 100 patients had normal results from ambulatory overnight oximetry; 5 were referred for further sleep consultation. Abnormal results from ambulatory overnight oximetry were seen in 79 patients, but only 51 were referred for further sleep evaluation. Abnormal results from ambulatory overnight oximetry were associated with only a small increased likelihood of referral (likelihood ratio, 2.7; confidence interval, 1.2-6.0). Those with an oxygen desaturation index (number of desaturation events per hour of recording time) of greater than 15 received sleep consultation at a median of 8 days after completion of oximetry, whereas those with an oxygen desaturation index of 6 to 10 were evaluated in a median of 42 days (P=.60). All 17 patients who had minimum oxygen saturation of less than 80% were referred for further evaluation. Abnormal results from ambulatory overnight oximetry per se may not substantially influence internist referral of patients with clinically suspected sleep apnea for further sleep evaluation. Rather, severity of oximetry abnormalities is used along with other patient-related factors and sleep study accessibility to prioritize the need and urgency of further evaluation.

Occurrence of oxygen desaturation events during preterm infant bottle feeding near discharge.

The purpose of this study was to examine the occurrence, severity, pattern, and moderators of oxygen desaturation during preterm infant bottle feeding near the time of discharge from the neonatal intensive care unit (NICU) when fed by mothers. Twenty-two very low birthweight (VLBW) infants [birthweight 1155+/-293 g, gestational age (GA) 28.1+/-2.0, postconceptional age (PCA) 36.5+/-1.6 weeks] were videotaped being bottle-fed by their mothers. Most infants (86%) were discharged within 6 days of the study. Oxygen saturation was continuously monitored and infant feeding behaviors were coded. Oxygen desaturation events (SpO(2)<90%) were identified and analyzed. Infants averaged 10.8 events during feeding (range 1-28, S.D. 8.9) and spent, on average, 20% of their feeding time (range 0-70%, S.D. 17.98%) with oxygen levels below 90%. One hundred forty of the desaturation events (59%) were classified as mild (SpO(2) 85-89), 47 events (20%) were classified as moderate (SpO(2) 81-84), and 51 events (21%) were classified as severe (SpO(2)</=80). Events were evenly distributed across infants' feeding time. Receiving supplemental oxygen, beginning the feeding with a higher baseline SpO(2), and being of older PCA predicted lower percentage of feeding time with SpO(2) below 90% (R(2)=0.57). Receiving supplemental oxygen and beginning the feeding with a higher baseline SpO(2) predicted less number of desaturation events during the feeding (R(2)=0.44). Despite similar baseline SpO(2) levels, infants who were on supplemental oxygen had 50% less oxygen desaturation events and spent 33% less time with SpO(2) less than 90%. VLBW infants continue to have desaturation events during feeding when fed by their mothers near the time of discharge. Further research is needed to understand the effect of hypoxemia on the preterm infant's development of oral feeding skills, to study the effects of supplemental oxygen during feeding, and to further develop interventions to minimize desaturation during feeding.

Nocturnal periodic breathing and the development of acute high altitude illness.

We tested the hypothesis that periodic breathing (PB) at high altitude is more frequent and arterial oxygen desaturation more severe during sleep in subjects developing high altitude pulmonary edema (HAPE) or acute mountain sickness (AMS) compared with subjects remaining healthy. We registered thoraco-abdominal movement, electro-encephalogram and oxygen saturation by pulse oximeter (pSao2) in 21 subjects during the first night spent at the altitude of 4,559 m. During the subsequent stay at 4,559 m, eight subjects remained well (controls), five subjects developed AMS and eight subjects developed HAPE. PB was found in all sleep stages and the percentage PB in any sleep stage was not significantly different between groups. There was a trend towards more PB in the HAPE vs. AMS and control group lasting 80 +/- 5 (mean +/- SE), 58 +/- 7, 57 +/- 9% of analyzable time, respectively (p = 0.09). The mean nocturnal decrease of pSao2 for these groups was 8.7 +/- 1.9, 5.4 +/- 2.1, 4.8 +/- 1.2%; (p = 0.36) and the median nocturnal pSao2 was 49 +/- 3, 63 +/- 3, and 63 +/- 4% (p = 0.02). Arterial blood gas analysis before and after sleep recordings indicate that the significantly lower Sao2 in the HAPE group is secondary to gas exchange rather than ventilation. The nocturnal decrease of pSao2 did not correlate with the time of PB nor the number of desaturation events > or = 4%. These findings suggest that more frequent PB in the HAPE group is a consequence of lower Sao2 due to impairment of gas exchange.

Sleep-Disordered Breathing and Poor Functional Outcome After Stroke

We objectively evaluated patients with recent stroke to determine the prevalence of sleep-disordered breathing (SDB) and whether SDB was associated with unfavorable clinical outcomes. Forty-seven patients with recent ischemic stroke (median, 13 days) were studied with computerized overnight oximetry for evidence of arterial oxyhemoglobin desaturation (SaO2). Polysomnography was also performed on 19 patients. Medical history, sleep history, location of stroke, and severity of neurological deficit were recorded, and patients were observed by staff for evidence of snoring and excessive daytime sleepiness. Functional abilities were measured with the use of the Barthel Index (BI). Outcome variables included ability to return home at discharge, continued residence at home at 3 and 12 months, BI at discharge, BI at 3 and 12 months, and death from any cause at 12 months. Mean SaO2 during oximetry was 94.0 +/- 1.7%, and percentage of recording time spent at < 90% SaO2 was 4.3 +/- 5.7%. The number of desaturation events per hour of recording time (desaturation index [DI]) was 9.5 +/- 9.67, with 15 of 47 (32%) having DI > 10 and 6 of 47 (13%) having DI > 20. Oximetry measures of SDB correlated with lower BI scores at discharge and lower BI at 3- and 12-month follow-ups (P < or = .05, Pearson coefficients). Oximetry measures correlated with return home after discharge, but the association between oximetry measures and living at home was lost at 12 months. Two oximetry variables correlated with death at 1 year. Brain stem location correlated with higher DI and time at < 90% SaO2, but patients with hemispheric stroke and oximetry abnormalities also had worse functional outcome. No correlation was found between oximetry values and sex, age, preexisting medical conditions (except previous stroke), or severity of neurological deficit. Oximetry abnormalities were associated with a history of snoring. Polysomnography on 19 patients confirmed oximetry evidence of severe SDB. Eighteen of 19 patients (95%) had an apnea-hypopnea index (AHI) of > 10 events per hour of recording, 13 of 19 (68%) had an AHI > 20, and 10 of 19 (53%) had an AHI > 30. Desaturation events were largely due to obstructive apneas. SDB accompanied by arterial oxyhemoglobin desaturation is common in patients undergoing rehabilitation after stroke and is associated with higher mortality at 1 year and lower BI scores at discharge and at 3 and 12 months after stroke. SDB may be an independent predictor of worse functional outcome. Obstructive sleep apnea appeared to be the most common form of SDB, and the frequent history of snoring suggests that SDB preceded the stroke in most patients.