Search Results (245)

Intraoperative anaesthetic monitoring is essential in rabbits due to their high perioperative morbidity and mortality and the limited availability of species-specific evidence, despite their increasing role as companion animals. This narrative review summarises the available scientific literature on intraoperative monitoring in anaesthetised rabbits, focusing on central nervous system assessment, cardiovascular and respiratory monitoring, and temperature management during general anaesthesia. Findings indicate that anaesthetic depth assessment based solely on ocular reflexes is unreliable and should be integrated with jaw tone, reflex responses, and respiratory patterns. Cardiovascular monitoring relies on heart rate, electrocardiography, and arterial pressure measurement, although invasive and non-invasive techniques have limitations in accuracy and practicability in small-size patients. Pulse oximetry and capnography assess oxygenation and ventilation but may be affected by peripheral perfusion, equipment dead space, and technical limitations. Temperature monitoring is critical due to high risk of hypothermia, with continuous or frequent measurements recommended. Overall, multimodal monitoring improves detection of physiological disturbances and supports safer anaesthetic management. Full article

Background: The COVID-19 pandemic exposed critical gaps in pandemic preparedness and highlighted the need for vaccine platforms capable of rapid adaptation. Outer membrane vesicle (OMV)-based platforms utilizing vesicles derived from genetically detoxified Neisseria meningitidis serogroup B (Nm-nOMV) represent a promising plug-and-play approach. Methods: This Phase I, first-in-human, randomized, double-blind, placebo- and OMV-controlled trial, evaluated safety, tolerability, and immunogenicity of intranasally administered OMVs combined with SARS-CoV-2 Spike protein in healthy SARS-CoV-2 seropositive adults aged 18–55 years. Forty participants were enrolled across two cohorts: a low-dose cohort receiving 140 μg OMV/70 μg Spike (OMV + Spike, n = 13; OMV alone, n= 3; Placebo, n = 5) and a high-dose cohort receiving 280 μg of OMV/140 μg of Spike (OMV + Spike, n = 13; OMV alone, n = 3; Placebo, n = 3), administered on Days 1 and 22. Safety was assessed through adverse events, vital signs, laboratory parameters, ECG, and pulse oximetry. Immunogenicity was evaluated via systemic SARS-CoV-2 neutralizing antibodies, antigen-specific antibodies (IgG and IgA), and mucosal antibodies (IgA in nasal wash). Results: Intranasal administration of OMVs combined with SARS-CoV-2 Spike protein was safe, well-tolerated, and immunogenic. No serious adverse events were reported, and adverse events were predominantly mild and transient. Dose-dependent increases in systemic and mucosal immune responses were observed, with statistically significant enhanced serum IgG and nasal wash IgA antibodies in the high-dose group. Conclusions: The current clinical data confirm key aspects of the preclinical profile, which demonstrate the potential of the Nm-nOMV platform as a strong adjuvant for mucosal vaccines. These findings support the broader application of the Nm-nOMV vaccine platform in pandemic preparedness. Full article

Background: Needle-related procedures such as venipuncture can be distressing for children and may trigger severe fear and behavioral dysregulation, particularly in those with previous traumatic experiences. Trauma-informed care (TIC) is a framework that recognizes the widespread impact of trauma and integrates this knowledge into clinical practice to prevent re-traumatization and support emotional regulation during medical procedures. Methods: This before-and-after study included 135 children aged 4–8 years who had previously shown severe distress during venipuncture, including escape attempts, shouting, or self/other-directed aggressive behaviors. Before venipuncture, children and their families received a TIC-based intervention delivered by a psychological counselor in a dedicated preparation room. Fear, behavioral responses during venipuncture, procedural pain, and heart rate were evaluated before and after the intervention using parent reports, the Children’s Fear Scale, the Wong–Baker FACES Pain Rating Scale, and pulse oximetry. Results: Following the TIC intervention, significant pre–post reduction were observed in distress-related behaviors during venipuncture, including escape attempts, shouting/crying, and self-/other-directed harmful behaviors. The proportion of children rated as experiencing high levels of fear decreased from 96.2% before the intervention to 15.5% after. Among the 85 children with complete heart-rate measurements available, mean heart rate decreased from 113.6 ± 10.1 beats/min to 87.3 ± 8.43 beats/min. Many families reported a more positive venipuncture experience compared with previous procedures. Conclusions: A trauma-informed care intervention delivered before venipuncture is associated with meaningful reductions in behavioral distress, fear, and physiological arousal in children with prior needle-related traumatic experiences. These pre–post associations support the feasibility and potential value of the TIC model, though controlled studies are needed to confirm these findings without confounding clinical effects. Full article

Pulse oximetry is an essential standard monitor in modern anesthetic practice, enabling continuous noninvasive assessment of arterial oxygen saturation and pulse rate throughout the perioperative period. Since its introduction into clinical medicine, pulse oximetry has significantly improved patient safety by facilitating early detection of hypoxemia and physiologic deterioration. Despite its widespread use, clinicians may underrecognize the technical principles, physiologic assumptions, and limitations that influence measurement accuracy. This review provides a perioperative perspective on pulse oximetry, including the physics of photoplethysmography, sensor technologies, and practical considerations for optimal probe placement and signal acquisition. Sources of inaccuracy such as motion artifact, low perfusion states, dyshemoglobinemias, ambient light interference, skin pigmentation, and venous pulsation are discussed in detail. The review further examines perioperative applications across preoperative evaluation, intraoperative monitoring, and postoperative recovery, while also exploring advanced parameters including perfusion index (PI) and pleth variability index (PVI). Emerging innovations such as multi-wavelength systems and artificial intelligence (AI)-enhanced signal analysis are also highlighted. A comprehensive understanding of pulse oximetry allows anesthesiologists to appropriately interpret monitor data, recognize device limitations, and optimize perioperative patient care. Full article

Maropitant has been proposed as an adjunct for pain relief in dogs undergoing surgeries like ovariohysterectomy (OVH), but its effectiveness has not yet been definitively proven. This study aimed to assess the intraoperative analgesic effect of intravenously administered maropitant citrate at a constant rate infusion through monitoring parasympathetic tone activity in female dogs undergoing OVH. Thirty healthy females of various breeds, with an average age of 3.8 ± 2.7 years, an average weight of 16.75 ± 10.68 kg, were randomly assigned to two treatment groups. The group receiving maropitant (G_Maro, n = 15) was given a 1 mg kg⁻¹ maropitant bolus intravenously (IV), followed by a continuous infusion of 100 mcg kg⁻¹ min⁻¹. The lidocaine group (G_Lido, n = 15) received a 2 mg/kg lidocaine IV bolus, with subsequent infusion at 50 mcg kg⁻¹ min⁻¹. Cardiorespiratory variables and the PTA index were evaluated at 11 anesthetic time points. Overall, cardiovascular variables such as Heart Rate (HR) and systolic arterial pressure (SAP) significantly decreased during anesthesia induction in the G_Maro (p = 0.0001; p = 0.01, respectively) and in G_Lido (p = 0.01). Differences between groups during induction were observed in HR (p = 0.03), SAP (p = 0.04), and mean arterial pressure (MAP) (p = 0.03). MAP showed significant changes from baseline at the start of surgery and during clamping in both G_Maro (p = 0.03) and G_Lido (p = 0.003). Regarding ventilatory variables—pulse oximetry (SpO₂), respiratory rate (RR), inspired oxygen fraction (FiO₂), end-tidal CO₂ (EtCO₂)—no group differences were found, but RR (G_Maro; p = 0.001, G_Lido; p = 0.0001) and SpO₂ (G_Maro; p = 0.004, G_Lido; p = 0.04) differed significantly from baseline due to the controlled clinical setting. During anesthesia maintenance, end-tidal isoflurane (ET_Iso) increased significantly in the G_Lido (p = 0.009), with no difference between groups (p = 0.94). Finally, only the PTA energy variable showed a significant decrease in the G_Maro (p = 0.0006), and a significant difference in this parameter was observed during right ovarian pedicle manipulation between groups (p = 0.02). In conclusion, continuous intravenous infusion of maropitant citrate at 100 mcg kg⁻¹ h⁻¹ effectively reduced the sympathetic response related to nociception, similar to lidocaine, in healthy female dogs undergoing OVH. Full article

Background: Rocuronium onset time shows interindividual variability, yet its hemodynamic determinants remain incompletely characterized. The peripheral perfusion index (PI), derived non-invasively from pulse oximetry, reflects integrated cardiac output and peripheral vascular tone. We hypothesized that early PI dynamics during anesthesia induction are associated with rocuronium onset time. Methods: This single-center retrospective observational cohort study included 1377 adults who received rocuronium 0.6 mg/kg under a standardized induction protocol with quantitative electromyographic train-of-four monitoring. Baseline PI was categorized as low-PI (PI < 0.7), intermediate-PI (0.7 ≤ PI < 1.4), or normal-PI (PI ≥ 1.4), and patients were further stratified by anesthetic method (TIVA or volatile anesthesia), yielding six subgroups. The 60 s PI change after propofol bolus (ΔPI₆₀) was selected as the primary dynamic variable and classified into equal-frequency tertiles (Slow-Rise, Mid-Rise, Fast-Rise). Sequential multivariable linear regression model was used to quantify independent contributions of induction-phase variables on onset time. Results: In the overall cohort, onset time differed significantly across baseline PI groups (p = 0.033), though this was not replicated within either anesthetic subgroup (TIVA: p = 0.200; volatile: p = 0.137). In contrast, ΔPI₆₀ tertile was significantly associated with onset time in both subgroups (both p < 0.001), with median onset times of 211, 183, and 170 s in the Slow-Rise, Mid-Rise, and Fast-Rise groups, respectively. In the regression model, ΔPI₆₀ tertile produced the largest single increment in model fit (adjusted R² Δ0.060, p < 0.001); Slow-Rise and Mid-Rise groups had 32.7% and 18.8% longer onset times relative to Fast-Rise, respectively. Conclusions: ΔPI₆₀ was most strongly associated with rocuronium onset time among the variables examined, independent of baseline characteristics and anesthetic method. These findings provide hypothesis-generating evidence that induction-phase PI dynamics may serve as a physiologically grounded, non-invasive marker of rocuronium delivery conditions, warranting prospective validation. Full article

Background: The ratio of arterial partial pressure of oxygen to fraction of inspired oxygen (PaO₂/FiO₂) is central to the classification of acute respiratory distress syndrome (ARDS). However, its assessment requires arterial blood gas analysis, which may be limited by availability, cost, and invasiveness. Consequently, the ratio of peripheral oxygen saturation to fraction of inspired oxygen (SpO₂/FiO₂) has been proposed as a non-invasive surrogate for estimating the degree of oxygenation impairment. Methods: A retrospective cross-sectional study was conducted in adult patients with COVID-19 admitted to the intensive care unit at an altitude of 2600 m above sea level (m.a.s.l.). Spearman correlation coefficients were calculated to assess the association between the SpO₂/FiO₂ and PaO₂/FiO₂ ratios and their corresponding imputation models. A generalized linear model was applied, and the diagnostic performance of the SpO₂/FiO₂ ratio and the imputation models for detecting severe and non-severe hypoxemia (PaO₂/FiO₂ cutoff value of 150) was evaluated using the area under the receiver operating characteristic curve (AUC). Results: A total of 473 patients receiving invasive mechanical ventilation were included, with a mean age of 62.4 years (SD 14.1), and a predominance of males (67.2%). An SpO₂/FiO₂ ratio cutoff value of ≥206 demonstrated excellent diagnostic performance, with an AUC of 0.983 (95% CI 0.97–0.99), high sensitivity (90.6%), high specificity (96.7%), and an overall correct classification rate of 93.9%. This performance remained consistent across multiple clinical scenarios. In patients with positive end-expiratory pressure > 10 cmH₂O, the AUC was 0.982, with a specificity of 97.7%. In the presence of hyperbilirubinemia (total bilirubin ≥ 3 mg/dL), the AUC was 0.951. Among patients with hemoglobin levels < 10 g/dL, sensitivity reached 100%, although specificity was reduced. In the subgroup with arterial partial pressure of carbon dioxide > 35 mmHg, an SpO₂/FiO₂ ratio ≥ 206 showed near-perfect specificity (99.4%) and a positive likelihood ratio of 120.9. Conclusions: The SpO₂/FiO₂ ratio is a reliable and non-invasive surrogate of the PaO₂/FiO₂ ratio in mechanically ventilated patients with COVID-19 living at high altitude, particularly for the identification of non-severe hypoxemia. Full article

Background: Blood flow restriction (BFR) training induces morphological and neuromuscular adaptations using low-intensity exercise (20–40% 1RM), offering a reduced mechanical load alternative to traditional high-load resistance training. Safe and effective implementation, however, requires a clear understanding of physiological mechanisms, contraindications, and pressure determination methodologies. In this three-part series, we provide a comprehensive review of BFR for athletic populations and provide strength and conditioning coaches with a structured framework for screening, safety, and methodological considerations to support BFR integration in high-performance settings. Methods: A narrative review of the literature examining BFR safety, contraindication screening, adverse event reporting, and occlusion pressure determination was conducted using a PubMed and MEDLINE search. Search terms included combinations of (“blood flow restriction” OR “BFR” OR “occlusion training” OR “KAATSU”) AND (“safety” OR “contraindications” OR “risk stratification”) AND (“arterial occlusion pressure” OR “limb occlusion pressure” OR “occlusion pressure” OR “Doppler” OR “handheld Doppler” OR “pulse oximetry” OR “cuff width” OR “capillary refill time” OR “monitoring”). Studies examining contraindication screening systems, arterial occlusion pressure calculation methods, and real-time monitoring protocols were evaluated. Primary considerations included risk stratification frameworks, pressure determination accuracy, and control parameter validation for ensuring vascular safety during application. Results: Risk stratification systems can effectively identify absolute and relative contraindications requiring medical clearance prior to BFR use. Epidemiological data indicate that adverse events are transient and non-serious, while serious events appear rare when evidence-informed protocols are applied. Doppler-based assessment remains a criterion approach for determining inflation pressure, although validated estimation methods using limb circumference and systolic blood pressure offer a pragmatic and comparable alternative for applied environments. Inflation pressures of 50–80% arterial occlusion, adjusted for cuff width, produce effective and safe stimulus. Real-time monitoring through capillary refill time, pulse strength palpation, and skin coloration can support iterative pressure optimization and help identify excessive restriction pressures. Conclusions: BFR implementation in athletic populations requires systematic screening protocols, individualized inflation pressure determination using validated methods, and real-time monitoring parameters. These foundations provide the essential safety infrastructure required before progressing to specific training applications across resistance, cardiovascular, and other performance and rehabilitation modalities. Full article

Hemorrhagic shock remains a leading cause of preventable death in trauma, yet traditional vital signs may fail to reflect early blood loss before physiological compensatory mechanisms are no longer able to maintain hemodynamic stability. The Compensatory Reserve Measurement (CRM) algorithm offers early detection capability using physiological waveforms but requires testing with emerging wearable sensor technologies for operational deployment. This study tested the Epicore Epidermal Patch for Imperceptible Care (EPIC) wearable healthcare device (WHD) for CRM-based hemodynamic monitoring during progressive central hypovolemia induced by lower-body negative pressure (LBNP) to simulate hemorrhage. Twenty participants underwent progressive LBNP while photoplethysmography (PPG) signals were recorded from EPIC sensors placed at the clavicle and triceps alongside a clinical-grade finger pulse oximeter for reference. Signal quality, heart-rate accuracy, and CRM predictions were evaluated across multiple filtering approaches. The triceps placement achieved signal quality comparable to the pulse oximeter reference when Chebyshev Type II filtering was applied, as well as high heart-rate accuracy. CRM derived from the EPIC sensor placed at the triceps tracked compensatory trends during progressive hypovolemia, but prediction magnitudes were inaccurate compared to calculated CRM values. In contrast, the clavicle placement consistently performed poorly across all measurements, regardless of the signal-processing approach. These findings support the feasibility of soft, flexible wearable sensors for continuous hemorrhage monitoring at the triceps location in operational environments where traditional finger-based pulse oximetry is impractical. Full article

Introduction: Congenital central hypoventilation syndrome (CCHS) is a rare disorder characterized by an impaired ventilatory response to hypercapnia and hypoxia, particularly during sleep, and frequently associated with autonomic dysfunction. It is caused by pathogenic variants in the PHOX2B gene. Although CCHS is typically diagnosed in the neonatal period, milder forms may present later in infancy or childhood, often triggered by respiratory infections. Case presentation: We report the case of 16-month-old male diagnosed with CCHS following an episode of hypoxemic–hypercapnic respiratory failure during respiratory syncytial virus (RSV) infection. His medical history included neonatal respiratory distress requiring oxygen therapy and recurrent wheezing. At 15 months, he developed acute respiratory distress with severe hypercapnia (PaCO₂ 70 mmHg), requiring admission to the Pediatric Intensive Care Unit and invasive mechanical ventilation. Persistent sleep-related hypercapnia and hypoxemia prompted evaluation for central hypoventilation, confirmed by means of transcutaneous capnography and nocturnal pulse oximetry. Genetic testing revealed a de novo nonsense mutation in exon 1 of PHOX2B (p.Tyr14Ter). Brain magnetic resonance imaging showed diffuse white matter changes suggestive of gliosis. Further investigations identified early-onset systemic hypertension, requiring antihypertensive therapy. The patient was discharged on nocturnal non-invasive ventilation and enrolled in a neurodevelopmental rehabilitation program. Conclusions: This case highlights the phenotypic variability of CCHS and the importance of considering this diagnosis in children presenting with unexplained hypercapnia and sleep-related hypoxemia. It underscores the need for comprehensive autonomic evaluation, including blood pressure monitoring. The p.Tyr14Ter variant may allow partial protein function, potentially accounting for the relatively mild phenotype. Full article

Background: Pulse oximetry is widely used to estimate arterial oxygen saturation, yet accuracy may vary for a number of reasons. Data on children with functionally univentricular circulation are limited. The primary aim of this study was to evaluate the agreement between arterial oxygen saturation measured by blood gas and pulse oximetry in children with functionally univentricular circulations. Methods: A retrospective analysis was performed of paired arterial blood gas and pulse oximetry oxygen saturation measurements following Norwood, Glenn, or Fontan procedures. Signed difference was defined as arterial oxygen saturation by blood gas—arterial oxygen saturation by pulse oximetry. Bland–Altman analyses, multivariable regressions, and generalized additive modeling were performed. Results: Mean bias was −4.9 percentage points, indicating pulse oximetry overestimated arterial saturation. The 95% limits of agreement were wide, from −20.7 to 10.8. The agreement was similar in Black and White patients. Fontan physiology demonstrated reduced overestimation by pulse oximetry by multivariable regression. Nonlinear modeling demonstrated more bias in agreement at lower arterial oxygen saturation levels, with arterial oxygen saturation levels explaining 50% of the variance. Conclusions: In functionally univentricular patients, pulse oximetry using the Nellcor MAXN-NS pulse oximeter (Medtronic, Dublin, Ireland) systematically overestimates arterial saturation, particularly in the setting of hypoxemia. Saturation level, rather than race, was the dominant determinant of bias. Full article

Background: Sudden unexpected death in epilepsy (SUDEP) causes significant mortality, affecting approximately 1 in 1000 people with epilepsy. Clinical and preclinical studies have identified severe seizures, bradycardia, apnea, severe postictal hypoxia, and sleep deficiency that emerge prior to SUDEP and thus may represent temporal biomarkers. The metabolic ketogenic diet (KD) therapy increases longevity in preclinical SUDEP models. Here, the hypothesis that KD therapy would determine whether the emergent sleep deficiency, bradycardia, apnea and/or hypoxemia persist as temporal biomarkers in preclinical SUDEP was tested. Methods: Kv1.1 knockout (KO) mice, a preclinical SUDEP model, and wild-type littermates were weaned onto a standard diet (SD) or treated with KD. In separate cohorts, approximately every 10 days, seizures and sleep architecture were recorded with electroencephalography–electromyography (EEG-EMG), heart rate was measured with noninvasive ECGenie, apnea was assessed with noninvasive airway mechanics, and blood O₂ saturation was measured with pulse oximetry. Data were aligned from the day of sudden death and analyzed retrospectively. Results: KD treatment significantly increased longevity and reduced seizures, reproducing previous studies. Using retrospective analyses from the day of death, KD treatment attenuated the emergence of (i) interictal intermittent bradycardia in the last 20 days of life, (ii) apnea, and (iii) intermittent hypoxemia in the last 10 days of life. In contrast, (iv) KD treatment did not rescue REM and NREM sleep deficiencies during the last 10 days of life. Conclusions: Our findings provide novel preclinical support for KD as a candidate therapy to attenuate seizure frequency and burden, bradycardia, apnea, and hypoxemia in SUDEP. In addition, sleep deficiency persisted as a potential temporal biomarker of preclinical SUDEP; however, causality will need to be tested in future studies. Full article

Critical congenital heart disease (CCHD) is a major cause of neonatal morbidity and mortality. Pulse oximetry screening enables early detection, potentially reducing complications and improving outcomes. This study evaluated pediatric residents’ knowledge, attitudes, and practices (KAP) related to CCHD screening in Saudi Arabia. A cross-sectional survey was distributed to pediatric residents across Saudi Arabia. The questionnaire assessed knowledge, attitude, and practice regarding CCHD screening. A total of 123 pediatric residents in training were included in the study. Of these, 57 (46.3%) were male, and 66 (53.7%) were female. A progressive increase in mean scores was observed with advancing training years (p = 0.010). A significant difference was observed in knowledge scores based on completion of a cardiology rotation (p = 0.006). A progressive increase in attitude scores was observed with each successive year of training. Current year in training showed a statistically significant association with attitude scores (p < 0.001). Completion of a newborn nursery or NICU rotation was also significantly associated with higher attitude scores (p = 0.027). Similarly, attitude scores were significantly higher among those who had completed a cardiology rotation (mean = 12.99, SD = 1.52) compared to those who had not (mean = 11.60, SD = 1.84; p < 0.001). While practice scores were not statistically different across most groups, senior residents demonstrated better adherence to screening. Residents exhibit increasing awareness and positive attitudes with experience; however, practical implementation remains inconsistent. Targeted education and standardized protocols are necessary to improve outcomes. A positive correlation was observed between knowledge and attitude scores (r = 0.346, p < 0.001). Full article

Background: Continuous non-invasive hemoglobin monitoring (SpHb) may provide real-time information during surgery, but its accuracy in neurosurgery remains uncertain. We evaluated the agreement, trending ability, and diagnostic performance of SpHb compared with arterial blood gas hemoglobin during elective intracranial neurosurgery. Methods: In this prospective observational study, 60 adults undergoing elective neurosurgery with invasive arterial monitoring were included. SpHb (Masimo Radical-7) was compared with paired arterial hemoglobin values. Agreement was assessed using repeated-measures Bland–Altman analysis and mixed-effects modeling. Trending ability was evaluated using four-quadrant concordance with an exclusion zone of ±0.5 g/dL. Discrimination for severe anemia (Hb < 8 g/dL) was assessed using ROC analysis with patient-level cluster bootstrapping. Results: A total of 190 paired measurements were analyzed. Mean bias was +0.23 g/dL, with wide limits of agreement (−3.26 to +3.72 g/dL). Agreement was worse under low-perfusion-index conditions. Trending performance was preserved, with an overall concordance rate of 85.5%. SpHb showed moderate discrimination for severe anemia (AUC 0.78; 95% CI 0.61–0.93), although severe anemia events were infrequent. Conclusions: SpHb showed limited reliability for absolute hemoglobin quantification during neurosurgery but provided useful trend information. SpHb should not replace invasive hemoglobin measurements for clinical decision-making. Full article