Decrease In SpO2 Research Articles

Transient hypoxemia induced by cortical electrical stimulation: A mapping study in 75 patients.

To identify which cortical regions are associated with direct electrical stimulation (DES)-induced alteration of breathing significant enough to impair pulse oximetry (SpO2). Evolution of SpO2 after 1,352 DES was analyzed in 75 patients with refractory focal epilepsy who underwent stereo-EEG recordings. For each DES, we assessed the change in SpO2 from 30 seconds prior to DES onset to 120 seconds following the end of the DES. The primary outcome was occurrence of stimulation-induced transient hypoxemia as defined by decrease of SpO2 ≥5% within 60 seconds after stimulation onset as compared to pre-DES SpO2 or SpO2 nadir <90% during at least 5 seconds. Localization of the stimulated contacts was defined according to MarsAtlas brain parcellation and Freesurfer segmentation. A stimulation-induced transient hypoxemia was observed after 16 DES (1.2%) in 10 patients (13%), including 6 in whom SpO2 nadir was <90%. Among these 16 DES, 7 (44%) were localized within the perisylvian cortex. After correction for individual effects and the varying number of DES contributed by each person, significant decrease of SpO2 was significantly associated with the localization of DES (p = 0.019). Though rare, a significant decrease of SpO2 could be elicited by cortical direct electrical stimulation outside the temporo-limbic structures, most commonly after stimulation of the perisylvian cortex.

Vibration Does Not Affect Short Term Outcomes Following Traumatic Brain Injury in a Porcine Model

Abstract Introduction Traumatic brain injury (TBI) has become increasingly prevalent among the injuries sustained in the military. Many wounded warriors require emergency medical evacuation via helicopter and subsequently fixed wing transport. During aeromedical evacuation, both pilots and patients experience whole body vibration due to engine, rotor, and propeller rotation. The impact of posttraumatic vibration and hypoxia exposure characteristic of the aeromedical evacuation environment on TBI is currently unknown. Methods A swine TBI model of controlled cortical impact was utilized. The pigs first underwent TBI or sham injury and were subsequently exposed to vibration or no vibration and hypoxia or normoxia for 2 hours. They were monitored for an additional 4 hours following vibration/hypoxia and blood was drawn at hourly intervals for cytokine and serum biomarker analysis. Continuous physiologic and neurologic monitoring were utilized. Prior to the conclusion of the experiment, the animals underwent brain magnetic resonance imaging. At the end of the study, the brain was extracted for histologic analysis. Results Physiologic parameters except for peripheral capillary oxygen saturation (SpO2) were similar between all groups. The hypoxia groups demonstrated the expected decrease in SpO2 and pO2 during the hypoxic period, and this was sustained throughout the study period. The pH, pCO2 and electrolytes were similar among all groups. Neuron specific enolase was increased over time in the TBI group, however it was similar to the sham TBI group at all time points. There were no differences in IL-1β, IL-6, IL-8, TNFα, GFAP, HIF1α, syndecan-1, or S100β serum levels between groups. The mean ICP during cortical impact in the TBI group was 279.8 ± 56.2 mmHg. However, the postinjury ICP was not different between groups at any subsequent time point. Brain tissue oxygenation and perfusion were similar between all groups. Conclusion In this novel study evaluating the effect of vibration on short-term outcomes following TBI, we demonstrate that the moderate vibration and hypoxia simulating aeromedical evacuation do not impact short term outcomes following TBI.

Neonatal respiratory inhibition causes repeated severe hypoxemia

Objective The goal of this study was to verify the details of neonatal respiratory inhibition (NRI) in healthy infants. Methods We screened for NRI in 521 infants who weighed at least 2000 g and who were born at a gestational age of at least 36 weeks. Respiratory inhibition was defined as severe hypoxemia, accompanied by clinical manifestations of central cyanosis and a decrease in SpO2 to less than 70%. NRI consists of feeding hypoxemia, respiratory inhibition after crying (RIAC), and respiratory inhibition after gastroesophageal reflux (RIGER). The subjects were monitored continuously via pulse oximetry from birth until discharge. To identify the details of NRI, we analyzed detailed notes taken by both parents and medical staff during monitoring using specific software designed to interpret pulse oximetry measurements. The mothers of infants with feeding hypoxemia received nursing guidance. Results NRI was observed in 268 (51.4%) infants (feeding hypoxemia in 227 (43.6%); RIAC in 121 (23.2%); and RIGER in 12 (2.3%)). Among perinatal factors, NRI was related to diabetes mellitus (p = .008; odds ratio = 3.290; 95% CI: 1.371–7.895), twin pregnancy (p = .032; odds ratio = 2.061; 95% CI: 1.062–3.998), and cesarean section (p = .036; odds ratio = 1.537; 95% CI: 1.027–2.299) using multiple logistic regression analysis. Almost all infants with RIAC and RIGER, even those with severe cases, recovered until discharge. However, 93 (41.0%) infants with feeding hypoxemia needed additional feeding control after being discharged. Despite the provision of nursing guidance in feeding control, 143 (63.0%) infants experienced feeding hypoxemia continuously. The more frequently the infants experienced feeding hypoxemia, the more severe the degree of feeding hypoxemia became. Breastfeeding reduced the frequency and degree of feeding hypoxemia compared to bottle-feeding. Conclusions NRI was often observed in healthy infants. Breastfeeding and careful feeding control should be recommended to mothers of infants with repeated feeding hypoxemia.

Cardiorespiratory Response during the 1-min Sit-to-Stand Test in Chronic Obstructive Pulmonary Disease.

This study aimed to assess the cardiorespiratory response during a 1-min sit-to-stand test (1STS) in comparison with cycling cardiopulmonary exercise test (CPET) in people with chronic obstructive pulmonary disease (COPD) and in healthy subjects and to evaluate whether 1STS may induce leg fatigue in these individuals. Fourteen people with severe COPD and 12 healthy subjects performed a 1STS and a CPET during which cardiorespiratory response, perception of dyspnea, and leg fatigue were assessed. Quadriceps strength was assessed before and after 1STS, and contractile fatigue was defined as a postexercise fall in quadriceps twitch force greater than 15% of resting values. In COPD, peak V˙O2, V˙E, and HR achieved during 1STS reached 113%, 103%, and 93% of the corresponding values during CPET, respectively. Decrease in SpO2 from preexercise to peak exercise and the magnitude of dynamic hyperinflation were similar between 1STS and CPET. Borg dyspnea and leg fatigue scores were higher for CPET than 1STS. In healthy subjects, peak cardiorespiratory demand and symptom scores were higher during CPET compared with 1STS. A V˙O2 overshoot during recovery was observed only in people with COPD. After 1STS, the V˙O2 half-time recovery of COPD was 152 ± 25 s compared with 74 ± 18 in healthy subjects (P < 0.01). Ten people with COPD and five healthy subjects were considered as fatiguers. The 1STS induced a similar cardiorespiratory stress to that of CPET and was associated with contractile quadriceps fatigue in people with severe COPD. The V˙O2 overshoot and slower recovery time of cardiorespiratory variables seen in COPD demonstrate the clinical relevance of monitoring the recovery phase of exercise.

Total and differential leukocyte count and oxygen saturation of hemoglobin changes in healthy smokers and non-smokers

Background: Inflammatory markers are altered in smokers and smoking has been proved as one of the main causative factors for cardiovascular diseases (CVDs), inflammatory diseases, and oxidative stress stimulation. An alteration in hematological parameters and oxygen saturation of hemoglobin is expected with smoking tobacco. Aim and Objective: This study has been planned with the aim to evaluate the changes associated with the extent of adverse effects of tobacco smoking in total and differential leukocyte count (DLC) and oxygen saturation of hemoglobin in healthy smokers and non-smokers. Materials and Methods: A total of 150 healthy adults were participated in this cross-sectional study. Anthropometric measurements such as height, weight, and body mass index were taken, and information of smoking habits were obtained by a questionnaire. Blood samples were taken for the estimation of total and DLC using MS-9 automated hematology cell counter. Oxygen saturation of hemoglobin was done using fingertip pulse oximeter Nidek Medical 5300. Results: Our results showed a statistically significant rise in the total leukocyte count (TLC) (P < 0.001), lymphocyte count (P < 0.001), granulocyte count (P < 0.01), and monocyte count (P < 0.02) and showed a statistically significant decrease in SpO2 (P < 0.04) in smokers as compared to non-smokers. Conclusion: The study has shown that altered values of TLC and DLC and oxygen saturation of hemoglobin in smokers should be considered during diagnosis, interpretation of result, and treatment of patients. A high TLC and DLCs exhibited in this research may be responsible for chronic inflammation and subsequent high risk of CVD in smokers. Therefore, quitting smoking should be encouraged for better health.

Are current wireless monitoring systems capable of detecting adverse events in high-risk surgical patients? A descriptive study

BackgroundAdverse events are common in high-risk surgical patients, but early detection is difficult. Recent innovations have resulted in wireless and ‘wearable’ sensors, which may capture patient deterioration at an early stage, but little is known regarding their ability to timely detect events. The objective of this study is to describe the ability of currently available wireless sensors to detect adverse events in high-risk patients. MethodsA descriptive analysis was performed of all vital signs trend data obtained during an observational comparison study of wearable sensors for vital signs monitoring in high-risk surgical patients during the initial days of recovery at a surgical step-down unit (SDU) and subsequent traumatology or surgical oncology ward. Heart rate (HR), respiratory rate (RR) and oxygen saturation (SpO2) were continuously recorded. Vital sign trend patterns of patients that developed adverse events were described and compared to vital sign recordings of patients without occurrence of adverse events. Two wearable patch sensors were used (SensiumVitals and HealthPatch), a bed-based mattress sensor (EarlySense) and a patient-worn monitor (Masimo Radius-7). ResultsTwenty adverse events occurred in 11 of the 31 patients included. Atrial fibrillation (AF) was most common (20%). The onset of AF was recognizable as a sudden increase in HR in all recordings, and all patients with new-onset AF after esophagectomy developed other postoperative complications. Patients who developed respiratory insufficiency showed an increase in RR and a decrease in SpO2, but an increase in HR was not always visible. In patients without adverse events, temporary periods of high HR and RR are observed as well, but these were transient and less frequent. ConclusionsCurrent systems for remote wireless patient monitoring on the ward are capable of detecting abnormalities in vital sign patterns in patients who develop adverse events. Remote patient monitoring may have potential to improve patient safety by generating early warnings for deterioration to nursing staff.

Cerebral Oxygenation During Respiratory Events in Children with Sleep-Disordered Breathing and Associated Disorders

To evaluate changes in cerebral oxygenation by means of near-infrared spectroscopy during respiratory events in children with sleep-disordered breathing (SDB) and associated disorders. Sixty-five children suspected of having SDB underwent a respiratory polygraphy with simultaneous recording of cerebral oxygenation indices. Respiratory events were analyzed by type of event, duration, variations of pulse oximetry (oxygen saturation [SpO2]), cerebral tissue oxygenation index (TOI), and heart rate. Data were categorized according to the severity of SDB and age. There were 540 obstructive and mixed apneas, 172 central apneas, and 393 obstructive hypopneas analyzed. The mean decreases in SpO2 and TOI were 4.1±3.1% and 3.4±2.8%, respectively. The mean TOI decrease was significantly smaller for obstructive hypopnea compared with apneas. The TOI decrease was significantly less in children with mild SDB as compared with those with moderate-to-severe SDB and in children >7years as compared with those <7years old. TOI decreases correlated significantly with SpO2 decreases, duration of event, and age, regardless of the type of event. In a multivariable regression model, predictive factors of TOI decreases were the type of respiratory event, SpO2 decrease, apnea-hypopnea index, and age. In children with SDB and associated disorders, cerebral oxygenation variations depend on the type of respiratory event, severity of SDB, and age.

Clinical, functional and hemodynamic profile of patients with Eisenmenger syndrome in comparison with the group of idiopathic pulmonary hypertension, features of starting specific therapy choice

Aim. To conduct a comprehensive analysis of the clinical, functional, hemodynamic profile of patients with pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD) and Eisenmenger syndrome, as compared with the group of idiopathic pulmonary hypertension (IPAH) according to the Russian Registry, and also to study the features of drug therapy. Materials and methods. The study involved 20 patients with PAH-CHD and Eisenmenger syndrome and 20 patients with IPAH over 18 years old. All patients had been entered in the Russian registry (NCT03707561). A comparative analysis of clinical, functional, hemodynamic parameters was held. The diagnosis was established in accordance with the algorithm proposed in the Russian guidelines the diagnosis and treatment of PH (2016). Results. In this study, 20 patients with PAH-CHD (16 women and 4 men) and Eisenmenger syndrome and 20 patients with IPAH (18 women and 2 men) were analyzed. Patients were comparable in age and sex. The time from the onset of symptoms to the final diagnosis in the PAH-CHD group was significantly longer: on average, it took three years to establish the diagnosis, whereas in patients with IPAH, on average, after 10.5 months, the correct diagnosis was made (p=0,0006). In the group of patients with Eisenmenger syndrome, there was a significant decrease in SpO2 both at rest and under exertion and averaged 86.5±9.7% at rest and 70±12.3% after exercise (p=0,0002). Conclusions. Patients with Eisenmenger syndrome compared with the IPAH group are characterized by a longer duration of symptoms until the diagnosis, and lower oxygen saturation. When estimating the parameters of pressure in the pulmonary artery (sPAP, dPAP, mPAP), according to the data of right heart catheterization and echo, significantly higher values of pressure in the pulmonary artery and lower values of SpO2 were detected.

Revised threshold values for neonatal oxygen saturation at mild and moderate altitudes.

The aim of this study was to determine reference values for oxygen saturation (SpO2 ) in neonates at mild and moderate altitudes. Our study included 41097 consecutively born, asymptomatic neonates from 35 hospitals, located in Yunnan, China, with altitudes ranging from 267 to 2202m. Pre-and post-ductal SpO2 of each neonate was measured at 24hours of age and before hospital discharge. All study participants, according to the altitude of birth, were categorised into three groups: low (0-500m), mild (500-1500m) and moderate altitude (1500-2500m). Every 1000-m increase in altitude was associated with a 1.54 per cent decrease in mean SpO2 . The means of pre-ductal SpO2 at low, mild and moderate groups were 97.9%, 96.4% and 95.5%, respectively. We used the 2.5th percentile of SpO2 distribution as the cut-off for neonatal SpO2 screening and defined new cut-off values of ≤93% for mild altitudes, ≤92% for moderate altitudes and no adjustment for low altitudes. We recommend revised cut-off values for neonatal SpO2 at mild and moderate altitudes and provide new values for paediatricians to refer to when screening neonates for severe congenital heart or lung diseases.

Immobilization of captive Persian fallow deer (Dama dama mesopotamica) using medetomidine–ketamine or medetomidine–midazolam

ObjectiveTo establish and compare the effectiveness of two medetomidine-based immobilization protocols in Persian fallow deer (Dama dama mesopotamica). Study designProspective, randomized, blinded clinical study. AnimalsA group of 31 captive Persian fallow deer. MethodsDeer scheduled for translocation were immobilized with a combination of medetomidine (76 ± 11 μg kg−1) and ketamine (1.0 ± 0.2 mg kg−1) (MK; n = 15) or medetomidine (77 ± 11 μg kg−1) and midazolam (0.10 ± 0.01 mg kg−1) (MM; n = 16) administered intramuscularly. An observer unaware of group assignments recorded times to immobilization and recovery, monitored physiologic variables and scored the quality of induction, immobilization and recovery (scale 1–5: 1, poor; 5, excellent). Atipamezole was administered for reversal. Data analysis was performed using the t test, the Mann–Whitney U test, the chi-square test and the Fisher's exact test. Significance was set at p < 0.05. ResultsData are presented as mean ± standard deviation or median (range). Time to induce immobilization was 9 ± 4 and 10 ± 4 minutes in the MK and MM groups, respectively. Immobilization quality score was 5 (1–5) following both combinations. Hemoglobin oxygen saturation (SpO2) was significantly lower in the MK (80 ± 8%) than in the MM group (87 ± 8%) although respiratory frequency did not differ between MK and MM (11 ± 5 and 10 ± 2 breaths minute−1, respectively). Recovery times were 13 ± 6 (MK) and 14 ± 7 minutes (MM) and did not differ between groups. No morbidities or mortalities were recorded during 1 month after immobilization. Conclusions and clinical relevanceThe MK and MM combinations produced sufficient immobilization in captive Persian fallow deer for short nonpainful procedures. Based on the SpO2 values, the MM combination may be associated with less respiratory depression; nevertheless, both combinations may result in a decrease in SpO2.

Desaturation during Physical Exercise in COPD Patients - a Stable-over-time Phenomenon.

Exercise-induced desaturation is a common finding in patients with moderate and severe COPD. It is an important marker in the course of disease that has a prognostic value for mortality risk. To monitor over time COPD patients with and without desaturation during 6-minute walking test (6MWT) and to assess the stability of that phenomenon. A 6MWT was administered to 70 patients with COPD which ranged in severity from stage 2A to stage 4D (GOLD 2011); the patients had a mean age of 64.5±10.1, mean pack-years - 38.8±21, FEV1% = 46.4%±15.7%, FVC% = 73.7%±1.3%, MRC = 2.31±0.84, CAT = 20.8±6.6. Oxygen saturation was monitored during the test; indications for desaturation were a decrease of SpO2 by ≥4% and a fall in SpO2 to ≤88% for at least 3 min. The patients were followed-up for mean 40.9±22.3 months and tests were repeated. Patients were divided into two groups based on the decrease in SpO2: Group A included patients with desaturation (n=35) and Group B - patients with no desaturation (n=35). In 66 of the patients the desaturation profile was stable over time. Only two patients, who did not desaturated at baseline, experienced desaturation in the follow-up 6MWT and another two patients, who desaturated at baseline, did not have it later in the follow-up. Desaturation is a phenomenon that is persistent over time. Based on the results, it could be concluded that exercise-induced desaturation is a major marker of a particular COPD phenotype.

Laparoscopy in infants: close intraoperative hemodynamic monitoring for patient safety

BackgroundHemodynamic changes during laparoscopy have not been well defined in very young children. In this study, intraoperative monitoring of hemodynamic parameters and oxygenation was evaluated during laparoscopy in infants weighing < 10 kg.Patients and methodsThirty infants (5.07 ± 2.51 kg), undergoing laparoscopy (LAP Group, n = 15) or open surgery (Open Group, n = 15), were enrolled. Cerebral regional (crScO2), renal regional oxygenation (rrScO2), peripheral oxygen saturation (SpO2), heart rate (HR), blood pressure, transcutaneous CO2 (TcCO2), end-tidal CO2 (EtCO2), and core temperature (TC) were analyzed at five intervals: T0 = basal; T1 = anesthesia induction; T2 = CO2 PP insufflation in the LAP group; T3 = intraoperative; T4 = cessation of CO2 PP in the LAP group; and T5 = before extubation.ResultsThe LAP group showed differences in crScO2 at T1, T3, and T4 compared with T0 (p < 0.05) and in rrScO2 from T1 to T4 versus T0 (p < 0.05), without hypoxemia. In addition, in the LAP group, an increase in TcCO2 from T2 to T5 versus T0 (p < 0.01) was related to anesthesia time (p = 0.01) and sex (p = 0.03). The SpO2 values were not different during laparoscopy; on the contrary, the OPEN group exhibited a decrease in SpO2 at T4 (p < 0.001) and an increase at T5 versus T0 (p = 0.001) compared with T0. HR and TC changes were detected in both groups (p < 0.01). No significant variations were recorded in blood pressure or end-tidal CO2.ConclusionLimited effects on oxygenation, cardiac output, and thermoregulation were detected in infants during laparoscopy. Many factors, including the child’s age, may play different roles in the regulation of these parameters. Close monitoring is essential to guarantee the infant’s safety.

Effect of Dexamethasone on Nocturnal Oxygenation in Lowlanders With Chronic Obstructive Pulmonary Disease Traveling to 3100 Meters

During mountain travel, patients with chronic obstructive pulmonary disease (COPD) are at risk of experiencing severe hypoxemia, in particular, during sleep. To evaluate whether preventive dexamethasone treatment improves nocturnal oxygenation in lowlanders with COPD at 3100 m. A randomized, placebo-controlled, double-blind, parallel trial was performed from May 1 to August 31, 2015, in 118 patients with COPD (forced expiratory volume in the first second of expiration [FEV1] >50% predicted, pulse oximetry at 760 m ≥92%) who were living at altitudes below 800 m. The study was conducted at a university hospital (760 m) and high-altitude clinic (3100 m) in Tuja-Ashu, Kyrgyz Republic. Patients underwent baseline evaluation at 760 m, were taken by bus to the clinic at 3100 m, and remained at the clinic for 2 days and nights. Participants were randomized 1:1 to receive either dexamethasone, 4 mg, orally twice daily or placebo starting 24 hours before ascent and while staying at 3100 m. Data analysis was performed from September 1, 2015, to December 31, 2016. Dexamethasone, 4 mg, orally twice daily (dexamethasone total daily dose, 8 mg) or placebo starting 24 hours before ascent and while staying at 3100 m. Difference in altitude-induced change in nocturnal mean oxygen saturation measured by pulse oximetry (Spo2) during night 1 at 3100 m between patients receiving dexamethasone and those receiving placebo was the primary outcome and was analyzed according to the intention-to-treat principle. Other outcomes were apnea/hypopnea index (AHI) (mean number of apneas/hypopneas per hour of time in bed), subjective sleep quality measured by a visual analog scale (range, 0 [extremely bad] to 100 [excellent]), and clinical evaluations. Among the 118 patients included, 18 (15.3%) were women; the median (interquartile range [IQR]) age was 58 (52-63) years; and FEV1 was 91% predicted (IQR, 73%-103%). In 58 patients receiving placebo, median nocturnal Spo2 at 760 m was 92% (IQR, 91%-93%) and AHI was 20.5 events/h (IQR, 12.3-48.1); during night 1 at 3100 m, Spo2 was 84% (IQR, 83%-85%) and AHI was 39.4 events/h (IQR, 19.3-66.2) (P < .001 both comparisons vs 760 m). In 60 patients receiving dexamethasone, Spo2 at 760 m was 92% (IQR, 91%-93%) and AHI was 25.9 events/h (IQR, 16.3-37.1); during night 1 at 3100 m, Spo2 was 86% (IQR, 84%-88%) (P < .001 vs 760 m) and AHI was 24.7 events/h (IQR, 13.2-33.7) (P = .99 vs 760 m). Altitude-induced decreases in Spo2 during night 1 were mitigated by dexamethasone vs placebo by a mean of 3% (95% CI, 2%-3%), and increases in AHI were reduced by 18.7 events/h (95% CI, 12.0-25.3). Similar effects were observed during night 2. Subjective sleep quality was improved with dexamethasone during night 2 by 12% (95% CI, 0%-23%). Sixteen (27.6%) patients using dexamethasone had asymptomatic hyperglycemia. In lowlanders in Central Asia with COPD traveling to a high altitude, preventive dexamethasone treatment improved nocturnal oxygen saturation, sleep apnea, and subjective sleep quality. ClinicalTrials.gov Identifier: NCT02450994.

Dry-EEG Manifestations of Acute and Insidious Hypoxia During Simulated Flight

INTRODUCTION: Recently, portable dry electroencephalographs (dry-EEGs) have indexed cognitive workload, fatigue, and drowsiness in operational environments. Using this technology this project assessed whether significant changes in brainwave frequency power occurred in response to hypoxic exposures as experienced in military aviation.METHODS: There were 60 (30 women, 30 men) student Naval Aviators or Flight Officers who were exposed to an intense (acute) high-altitude (25,000 ft) normobaric hypoxic exposure, and 20 min later, more gradual (insidious) normobaric hypoxic exposure up to 20,000 ft while flying a fixed-wing flight simulation and monitored with a dry-EEG system. Using MATLAB, EEG frequencies and power were quantified and analyzed. Cognitive performance was also assessed with a cognitive task validated under hypoxia. Normobaric hypoxia and O₂ saturation (Spo₂) were produced and monitored using the Reduced Oxygen Breathing Device (ROBD2).RESULTS: Significant Spo₂ decreases were recorded at acute 25K and insidious 20K simulated altitudes. Significant power decreases were recorded in all frequencies (alpha, beta, gamma, and theta) and all channels with acute 25K exposures. Gamma, beta, and theta frequency power were significantly decreased with insidious 20K exposures at most of the channels. The frequency power decreases corresponded to significant decreases in cognitive performance and flight performance. Most importantly, frequency power suppressions occurred despite 42% of the volunteers not perceiving they were hypoxic in the acute phase, nor 20% in the insidious phase.DISCUSSION: Results suggest EEG suppression during acute/insidious hypoxia can index performance decrements. These findings have promising implications in the development of biosensors that mitigate potential in-flight hypoxic physiological episodes.Rice GM, Snider D, Drollinger S, Greil C, Bogni F, Phillips J, Raj A, Marco K, Linnville S. Dry-EEG manifestations of acute and insidious hypoxia during simulated flight. Aerosp Med Hum Perform. 2019; 90(2):92-100.

Apnea within the first year of life in premature infants with bronchopulmonary displasia and pulmonary hypertension

Infants with severe and moderate bronchopulmonary dysplasia (BPD) are characterized by long-term persistence of apnea of prematurity and often have a pulmonary hypertension (PH). Respiratory pauses, accompanied by intermittent hypoxia, do not clinically manifest themselves, therefore cardiorespiratory monitoring (CRM) is required. We hypothesized that the persistent of apnea, as the cause of hypoxemia episodes, may be associated with the persistence of PH in infants with BPD.&#x0D; The aim of the study was to evaluate the dynamics of cardiorespiratory parameters and to study the relationship between obstructive apnea and PH during the first year of life of premature infants with BPD + PH.&#x0D; Materials and methods. CRM was performed in 58 infants were born at 26 0/7-31 0/7 weeks gestation and with birth weight less than 1500 grams, before discharge from the hospital (35-44 weeks of post menstrual age). 14 infants did not have BPD (group without BPD). 44 infants had BPD and 17 of them had a complication of this disease PH (BLD + PH group). Other infants with BPD did not have PH (BLD-PH group). Eight infants with BPD also underwent a study at home (aged 9 to 10 months of life).&#x0D; Results. Preterm infants with BPD + PH were more significant decrease in the average SpO2, higher desaturation index and more a number of desaturation episodes of &lt;10% compared to infants with BPD-PH and without BPD. There was no difference in the apnea/hypopnea index and frequency of occurrence of different types of apnea between groups. There was no difference in cardiorespiratory performance in infants with BPD+PH compared to infants with BPD-PH in 9-10 months of life.&#x0D; Conclusions. There was a positive dynamics of cardiorespiratory parameters in infants with BPD+PH in 9-10 months after discharge from the hospital. The number of infants with an index of OA&gt; 1/hour is higher in the group BPD+LH.

Sleep apnea syndrome caused lowering of cerebral oxygenation in a hemodialysis patient: a case report and literature review

BackgroundSleep apnea syndrome (SAS) is a sleep disturbance, which is frequently comorbid in dialysis patients. SAS induces hypoxia, and therefore, systemic and cerebral oxygenation would be low. Near-infrared spectroscopy (NIRS) has recently been used to measure regional saturation of oxygen (rSO2), as a marker of tissue oxygenation. Although cerebral rSO2 was measured in patients in various clinical settings, few reports have previously shown the associations of changes in cerebral rSO2 and systemic oxygenation using measurement of peripheral arterial oxygen saturation (SpO2) in patients undergoing hemodialysis (HD) with SAS. We herein report a first HD case with SAS-induced reduction in cerebral oxygenation during sleep.Case presentationA 74-year-old woman underwent HD therapy for 1 month, because of advanced CKD caused by hypertension and obesity. In addition, she was diagnosed with obstructive sleep apnea with polysomnography about 4 years prior. Her apnea-hypopnea index (AHI) was 77.5 per hour, and therefore, continuous positive airway pressure (CPAP) was started. Thereafter, her AHI was improved to 3 to 6 per hour. However, she discontinued CPAP therapy at HD initiation. Since her oxygenation without CPAP would deteriorate, we evaluated her SpO2 and cerebral rSO2 by NIRS monitoring during sleep. We confirmed the deterioration in cerebral rSO2 according to the SpO2 decrease, and furthermore, the improvement in cerebral rSO2 was apparently delayed even after the improvement in her SpO2. The patient’s cerebral oxygenation under CPAP therapy could not be evaluated because she refused to receive CPAP therapy after HD initiation. Therefore, as a comparison, we evaluated a 69-year-old male HD patient without SAS and found that in contrast to a patient with SAS, his SpO2 and cerebral rSO2 were maintained throughout sleep.ConclusionWe observed deterioration in cerebral oxygenation during sleep in addition to a decrease in systemic oxygenation in a patient with SAS undergoing HD. Real-time cerebral NIRS monitoring during sleep might be a useful method for detection of SAS.

Comparison of analgesia provided by lidocaine or morphine delivered epidurally in rabbits undergoing hindlimb orthopedic surgery

The aim of the study was to compare anaesthesia protocol utilizing combination ketamine/ medetomidine with epidural lidocaine or morphine to orthopaedic surgery in rabbits. All rabbits received intramuscularly medetomidine (0.5 mg/kg) and ketamine (20 mg/kg). In group L (n=13) epidural injection was performed with lidocaine (3 mg/kg) and in group M (n=13) with morphine (0.1 mg/kg) diluted with sterile saline to 0.6 ml. Rabbits underwent bilateral mosaicplasty surgery. Heart rate (HR), systolic (SBP), diastolic (DBP) and mean arterial blood pressure (MAP), arte- rial oxygen saturation (SpO2) and respiratory rate (RR) were measured every 5 minute during surgical procedure. Duration of sensory blockade was measured based on toe pinch reflex and recorded. Hemodynamic parameters were comparable at baseline in both groups. We did not observe significant differences in HR, RR, SBP, DBP, MAP between group L and M. Intragroup statistical analysis revealed differences at different time points in group M in terms of HR, SBP, DBP, MAP. In rabbits in group M blood pressure dropped while HR increased over time. In both groups a decrease in SpO2 was observed. Mean duration of loss of the toe pinch reflex was similar between group L and M, and amounted to 72.79±34.48 and 82.80±17.85 minutes, respectively.

Effect of rewarming in oxygenation and respiratory condition after neonatal exposure to moderate therapeutic hypothermia

BackgroundTo assess changes in clinical condition and oxygenation in neonates after rewarming following moderate therapeutic hypothermia (MTH) for neonatal encephalopathy. MethodsRetrospective study of 28 neonates receiving MTH in a tertiary neonatal intensive care unit in Israel. We compared pre-and 24 h post-rewarming arterial oxygen saturation (SaO2) as measured by the blood gases analyzer, pulse-oximetry saturation (SpO2), and cardio-respiratory condition. ResultsThe SpO2 declined from 96.9% (±2.9) before rewarming to 95.2% (±2.6) after rewarming (p < 0.001). Twelve neonates (42.9%) had clinical respiratory impairment (needing higher respiratory support or had new onset desaturations). In 16 neonates (57.1%) with no change in respiratory support after rewarming, SpO2 decreased from 98.3 ± 1.9% to 95.6 ± 3.0% (p < 0.001) and SaO2 decreased from 97.1 ± 1.7% to 96.0 ± 2.3% (p = 0.002). The mean SpO2 decrease was greater than mean SaO2 decrease (2.63 ± 1.8 and 1.1 ± 1.3 respectively, p = 0.021). ConclusionNeonates who underwent MTH showed reduction in oxygenation after rewarming either by decreasing SpO2 or increasing FiO2 requirements. The SpO2 decline was larger than the SaO2 decline. We suggest careful monitoring of neonates after rewarming.

The prognosis of infants with neonatal respiratory inhibition syndrome

Objective: The goal of this study was to investigate the prognosis of infants with neonatal respiratory inhibition syndrome (NRIS).Methods: Infants with a gestational age of at least 36 weeks and a birth weight of at least 2000 g who were born at Nara Prefecture General Medical Center, in Nara, Japan, between March 2013 and June 2016 were screened for NRIS using our established method. NRIS was defined as severe hypoxemia caused by respiratory inhibition immediately after crying (RIAC) or gastroesophageal reflux (RIGER) or as a respiratory pause during feeding (feeding hypoxemia), accompanied clinically by central cyanosis and a decrease in SpO2 to less than 70%. All infants were monitored using pulse oximetry immediately after birth. Diagnosis of RIAC, feeding hypoxemia, and RIGER are based on observation by both parents and medical staff as well as on on-screen computer analysis using specific software. All infants were examined at a one-month check-up. Parents of the infants who experienced one or more episodes of NRIS accompanied by a decrease in SpO2 to less than 70% for more than approximately 60 s received a questionnaire by mail about their child’s development. We conducted a logistic regression analysis with developmental problems as the dependent variable.Results: NRIS was observed in 362 (28.5%) infants; 216 (17.0%) infants showed RIAC, 254 (20.0%) infants showed feeding hypoxemia, and 54 (4.2%) infants showed RIGER. Although all infants were monitored in the maternity ward nursery, 184 (85.2%) infants with RIAC and 111 (43.7%) infants with feeding hypoxemia were overlooked. All infants with NRIS were found to have successfully recovered at one month after birth. Sixty-two cases were examined in the follow-up study by the mailed questionnaire. The median age of the subjects at time of study was 22 months. Fourteen cases (22.6%) exhibited developmental problems including delayed speech development, stereotyped interests and behaviors, sensory disturbance, hyperactivity, delayed motor development, and short stature. Developmental problems tended to relate to shorter gestational age (odds ratio, 0.622; p = .068; 95% CI, 0.373–1.036), smaller birth weight (odds ratio, 0.998; p = .069; 95% CI, 0.997–1.000), and maximum duration of SpO2 to less than 70% by RIAC (odds ratio, 1.009; p = .086; 95% CI, 0.999–1.020). All cases had experienced severe hypoxemia accompanied by a decrease in SpO2 to less than 60%. Seven cases had experienced prolonged hypoxemia accompanied by a decrease in SpO2 to less than 70% for at least 2 min. Among the subjects, 19 infants were examined closely, and their natural course of NRIS was observed in the neonatal intensive care unit. No cases demonstrated abnormal findings with blood examinations, chest-abdominal X-ray, echocardiogram, laryngoendoscopy, hearing loss screening, or mass screening. Only one case had a small intracranial hemorrhage as evidenced in a magnetic resonance imaging of the head.Conclusions: The infants with severe NRIS tended to have developmental problems. Spreading knowledge about NRIS worldwide is thought to be very important.

Twenty-Five Percent Dextrose and EBM in Pain Relief During Heel Lance in Late Preterm Babies Using the PIPP Score: A Randomized Controlled Trial

Objective: To compare the analgesic effect of 25% dextrose and expressed breast milk (EBM) in pain relief during heel lance in late preterm babies using the premature infant pain profile (PIPP) score. Study Design: Prospective, double blind, randomized controlled trial. Setting: The neonatal intensive care unit of Jaipur Golden Hospital, Rohini, Delhi. Participants: One-hundred eleven late preterm babies who required heel lancing for glycemic control and who were on oral feeds and were hemodynamically stable. Methodology: The babies were randomized into 2 intervention groups (25% dextrose and EBM) and control group (sterile water). The test solution of 2mL was given to baby 2 minutes before heel lancing. The facial response to pain (brow bulge, eye squeeze, and nasolabial furrow) was analyzed from the video. Maximum heart rate (HR) and minimum blood oxygen saturation (SpO2) were also recorded at 30 seconds, 1 minute, 1.5 minutes, and 2.5 minutes after heel lancing by another camera. Outcome Variable: PIPP score, HR, SpO2 at 30 seconds, 1 minute, 1.5 minutes, and 2.5 minutes after heel lancing. Results: A total of 63 babies were considered for final analysis with 21 each in the 25% dextrose, EBM, and sterile water groups. The mean PIPP score in the 25% dextrose, EBM, and control groups at 30 seconds were 4.52, 6.86, and 10.14, respectively ( P &lt; .001). At 1 minute, the PIPP scores were 3.24, 5.14, and 8.24, respectively, for the 25% dextrose, EBM, and control groups ( P &lt; .001). Twenty-five percent dextrose gave better pain relief than EBM. Mean difference between the PIPP score in the 25% dextrose and EBM groups was –2.34 and –1.9 at 30 seconds and 1 minute, respectively, after the painful procedure ( P = .001). Babies in intervention groups had less increase in HR and less decrease in SpO2. Conclusions: Twenty-five percent dextrose and EBM significantly reduced procedural pain in neonates, though pain relief was better in the 25% dextrose group as compared to the EBM group.