scholarly journals Assessment of perioperative minute ventilation in obese versus non-obese patients with a non-invasive respiratory volume monitor

2017 ◽  
Vol 17 (1) ◽  
Author(s):  
Jaideep H. Mehta ◽  
Davide Cattano ◽  
Jordan B. Brayanov ◽  
Edward E. George
Keyword(s):  
Minute Ventilation ◽  
Obese Patients ◽  
Respiratory Volume ◽  
Non Invasive

Abstract 19116: Assessment of Perioperative Minute Ventilation in Obese versus Non-Obese Patient Using a Non-Invasive Respiratory Volume Monitor

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Christopher Voscopoulos ◽  
Jenny Freeman ◽  
Kathleen Campbell ◽  
Edward George
Keyword(s):  
Minute Ventilation ◽  
Obese Patients ◽  
Metabolic Demand ◽  
Respiratory Volume ◽  
Non Invasive ◽  
Indirect Measures ◽  
Obesity Status ◽  
Treatment Plans ◽  
Orthopedic Patients ◽  
Direct Measures

Introduction: Adequate respiration is critical to survival and can be influenced by opioids, sedatives and apnea. Direct monitoring of ventilation has previously not been available for non-intubated patients. Reliance on indirect measures (SpO2, RR) may delay needed interventions and obese patients may be at further risk. A non-invasive respiratory volume monitor (RVM) providing real-time direct measures of MV, TV & RR in non-intubated patients is used to assess respiratory status in obese and non-obese patients. Methods: Data collected from an impedance-based RVM (ExSpiron-1Xi, Respiratory Motion, Waltham, MA) in 62 orthopedic patients (65.4 ±12.0 yrs, BMI: 30.8 ±6.0 kg/m 2 ) before, during & after surgery (PACU arrival & discharge) were compared to predicted MV (MV PRED ) based on IBW. Ventilator MV (Apollo, Draeger, Telford, PA) during GA was assumed to be adjusted to maintain appropriate end-tidalCO 2 . Patients were stratified based on obesity status (cutoff BMI=30). The distributions of MV at various times were compared (non-obese vs obese) using an un-paired 1-sided t-test & a 2-sample F-test. Results: Despite similar MV PRED in both groups (6.2±0.2; 6.1±0.2 L/min, p>0.3) obese patients were managed at a higher MV during surgery (6.1±0.2; 5.3±0.2 L/min, p<0.01). MV differences were far greater preoperatively (9.7±0.4 vs. 6.7±0.3 L/min), at PACU arrival (11.4 ±1.2; 6.8±0.7 L/min) & discharge (7.7±0.5; 5.0±0.6 L/min, p<0.01 all, Fig 1). Patient-to-patient variability in MV was similar in both groups pre-op, but larger in obese patients. Even with the large average MV in obese patients, 6% of them left the PACU with MV<40% MV PRED . Conclusions: On average, obese patients have greater MV than predicted by IBW formula, likely due to greater metabolic demand. Post-op, obese patients have greater variability in ventilation when treated with standard opioid doses & may be at greater risk for hypoventilation. RVM can provide data for individualized treatment plans.

Low minute ventilation episodes during anesthesia recovery following intraperitoneal surgery as detected by a non-invasive respiratory volume monitor

2017 ◽  
Vol 32 (5) ◽  
pp. 929-935 ◽  
Author(s):  
Alexandre N. Cavalcante ◽  
Yvette N. Martin ◽  
Juraj Sprung ◽  
Jasmin Imsirovic ◽  
Toby N. Weingarten
Keyword(s):  
Minute Ventilation ◽  
Respiratory Volume ◽  
Non Invasive

scholarly journals Respiratory Volume Monitoring: A Machine-Learning Approach to the Non-Invasive Prediction of Tidal Volume and Minute Ventilation

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 227936-227944
Author(s):  
Daniel E. Hurtado ◽  
Javier A. P. Chavez ◽  
Roberto Mansilla ◽  
Roberto Lopez ◽  
Angel Abusleme
Keyword(s):  
Machine Learning ◽  
Tidal Volume ◽  
Minute Ventilation ◽  
Learning Approach ◽  
Respiratory Volume ◽  
Non Invasive ◽  
Machine Learning Approach

Abstract 16248: Comparison of a Non-Invasive Respiratory Volume Monitor to End-Tidal CO2 in Measuring Changes in Minute Ventilation

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
George Williams ◽  
Eamon Fleming ◽  
Christopher Voscopoulos
Keyword(s):  
Minute Ventilation ◽  
Fold Increase ◽  
False Alarms ◽  
Systematic Bias ◽  
Experimental Conditions ◽  
Strong Negative Correlation ◽  
Respiratory Volume ◽  
Delay In Diagnosis ◽  
Non Invasive ◽  
End Tidal

Introduction: Monitoring respiratory performance is a challenge. Use of secondary indicators like oxygen saturation (SpO 2 ) and capnography (EtCO 2 ) have introduced delay in diagnosis and can produce false alarms. EtCO 2 in non-intubated patients has been problematic. We compared performance of an EtCO 2 monitor to a respiratory volume monitor (RVM), which provides accurate (error <10%) measurements of minute ventilation (MV), tidal volume & respiratory rate, to assess changes in respiratory status in non-intubated subjects. Methods: Continuous RVM (ExSpiron, Respiratory Motion, Waltham, MA) and capnography data (Capnostream 20, SmartCapnoLine Plus & Filterline Set, Covidien, Mansfield, MA) were collected from 39 subjects. The relationship between EtCO 2 & MV for each patient was quantified & EtCO 2 sensitivity to MV changes and mean EtCO 2 values were compared across the two EtCO 2 sampling techniques (paired t-test). Results: A strong negative correlation between MV changes and EtCO 2 changes was found (similar between nasal sampling (NS) and in-line sampling (IS) ( -0.6 ±0.1 v -0.7±0.1 mmHg/(L/min), p>0.1, Fig 1A)). IS readings were higher than NS for each patient. In the same patients (normal breathing) the average IS EtCO 2 was 36.7 ±0.7 vs 33.7±0.6 mmHg for NS (p<0.01) despite larger MV (8.74 ±0.5 vs 7.0±0.5 L/min). Similar disparity was present during hypo & hyperventilation (Fig 1B&C). Regardless of sampling methodology, EtCO 2 displayed poor resolution in response to large swings in MV (13 & 14 mmHg in response to 17 & 21 fold increase in MV; IS & NS, respectively). Conclusions: Under controlled experimental conditions & with an in-line sensor capable of capturing 100% of exhaled air, EtCO 2 did not report large swings in MV with fidelity. Commonly used nasal sampling introduced a systematic bias that could further delay informing clinicians of dangerously low MV. RVM provides a direct measure of MV, eliminating the lag between a change in MV and secondary measurements.

Non-Invasive Assessment of Steatosis and Liver Fibrosis in Overweight and Obese Patients

2016 ◽  
Vol 64 (2) ◽  
pp. S500
Author(s):  
T. Broquetas ◽  
M. Puigvehí ◽  
S. Coll ◽  
M. García-Retortillo ◽  
N. Cañete ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Obese Patients ◽  
Non Invasive

scholarly journals Effectiveness of non-invasive ventilation in acute respiratory failure of obese patients: a brief narrative review

2018 ◽  
Vol 12 (1) ◽  
pp. 5
Author(s):  
Maurizio Alessandro Cavalleri ◽  
Elena Barbagelata ◽  
Marco Scudeletti ◽  
Antonello Nicolini
Keyword(s):  
Respiratory Failure ◽  
Acute Respiratory Failure ◽  
Obese Patients ◽  
Invasive Ventilation ◽  
Acute Setting ◽  
Non Invasive ◽  
High Severity ◽  
Non Invasive Ventilation ◽  
Hypoventilation Syndrome ◽  
High Severity Score

Non-invasive ventilation (NIV) has been used successfully for the management of acute respiratory failure (ARF) more often in the last two decades compared to prior decades; nevertheless, NIV can have failure rates ranging from 5% to 50%. However, there are particular groups of patients that are more likely to benefit from NIV. One of these groups is patients with hypoventilation syndrome (OHS). The aim of this review is to seek evaluation of the effectiveness of NIV in acute setting. Only a few studies have investigated NIV success or failure in OHS patients. More than 30% of them were diagnosed when hospitalized for ARF. NIV rarely failed in reversing ARF. OHS patients who exhibited early NIV failure had a high severity score and a low HCO3 level at admission; more than half of hypercapnic patients with decompensated OHS exhibited a delayed but successful response to NIV. Patients with decompensation of OHS have a better prognosis and response to NIV than other hypercapnic patients. They require more aggressive NIV settings, a longer time to reduce PaCO2 levels, and more frequently a delayed but successful response to NIV.

scholarly journals Evaluation of NAFLD and fibrosis in obese patients – a comparison of histological and clinical scoring systems

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Sophia Marie-Therese Schmitz ◽  
Andreas Kroh ◽  
Tom Florian Ulmer ◽  
Julia Andruszkow ◽  
Tom Luedde ◽  
...  
Keyword(s):  
Scoring System ◽  
High Sensitivity ◽  
Scoring Systems ◽  
Obese Patients ◽  
Alcoholic Fatty Liver ◽  
Non Invasive ◽  
Nafld Fibrosis Score ◽  
Histologic Evaluation ◽  
Clinical Scoring ◽  
Nas Score

Abstract Background Non-alcoholic fatty liver disease (NAFLD) is a frequent condition in obese patients and regularly progresses to non-alcoholic steatohepatitis (NASH) and subsequent cirrhosis. Histologic evaluation is the gold standard for grading and staging, but invasive biopsies are associated with obvious risks. The aim of this study was to evaluate different non-invasive tools for screening of NAFLD and fibrosis in obese patients. Methods In a prospective cohort study liver specimens of 141 patients were taken during bariatric surgery. Serological parameters and clinical data were collected and the following scores calculated: NASH clinical scoring system (NCS), aspartate aminotransferase to platelet ratio index (APRI), FIB-4 as well as NAFLD fibrosis score (NFS). Liver function capacity was measured preoperatively by LiMAx test (enzymatic capacity of cytochrome P450 1A2). Intraoperative liver biopsies were classified using NAFLD activity score (NAS) and steatosis, activity and fibrosis (SAF) score. Results APRI was able to differentiate between not NASH and definite NASH with a sensitivity of 74% and specificity of 67% (AUROC 0.76). LiMAx and NCS also showed significant differences between not NASH and definite NASH. No significant differences were found for NFS and Fib-4. APRI had a high sensitivity (83%) and specificity (76%) in distinguishing fibrosis from no fibrosis (AUROC = 0.81). NCS and Fib-4 also revealed high AUROCs (0.85 and 0.67), whereas LiMAx and NFS did not show statistically significant differences between fibrosis stages. Out of the patients with borderline NASH in the histologic NAS score, 48% were classified as NASH by SAF score. Conclusions APRI allows screening of NAFLD as well as fibrosis in obese patients. This score is easy to calculate and affordable, while conveniently only using routine clinical parameters. Using the NAS histologic scoring system bears the risk of underdiagnosing NASH in comparison to SAF score.

scholarly journals 1260 High Tidal Volume Non-invasive Ventilation Required to Treat Obesity Hypoventilation

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A479-A480
Author(s):  
Talayeh Rezayat ◽  
Abigail Beggs ◽  
Alon Y Avidan ◽  
Shahrokh Javaheri
Keyword(s):  
Tidal Volume ◽  
Upper Airway ◽  
Morbidly Obese ◽  
Obese Patients ◽  
Invasive Ventilation ◽  
Class Iii ◽  
Non Invasive ◽  
Non Invasive Ventilation ◽  
Patient Reported ◽  
Obesity Hypoventilation

Abstract Introduction Current guidelines recommend CPAP or non-invasive ventilation with tidal volume (VT) &lt;10ml/kg of ideal body weight (IBW) for the treatment of obesity hypoventilation. However, in select patients with significant obesity hypoventilation, this recommendation may not be sufficient to resolve nocturnal hypoventilation. Report of Case A 35 y/o male with hypertension and class III obesity (BMI 58 kg/m2) was referred for evaluation of acute respiratory failure with hypoxia and hypercapnia. ABG demonstrated daytime PCO2 of 71 mmHg. Patient reported sleep fragmentation, snoring, choke awakenings, poor concentration, depression and sleep attacks. PSG demonstrated severe OSA, with an AHI of 154 events/hour, persistent hypoxia and hypercapnia with a SpO2 nadir of 50% and ET-CO2 of 83 mmHg during REM sleep. Respiratory events persisted with CPAP and bilevel, up to a setting of 25/16. Average volume assured pressure support (AVAPS) S/T titration study was performed and resolved sleep apnea at settings of IPAP 24-30, EPAP 4-15, VT 790 (10 mL/kg IBW), 0.5 LPM O2, rate 16. The patient reported having had the best sleep of his life at the end of this study and has since been started on treatment. Conclusion Treatment of OHS should be individualized and may require use of tidal volumes above 10ml/kg for effective treatment. We suggest that in super morbidly obese patients, with extremely noncompliant respiratory system, larger than recommended tidal volume is necessary to ventilate the patient and improve gas exchange. The sustained higher pressures achieved by AVAPS to impose the augmented tidal volume more effectively ameliorate OSA, by keeping the upper airway open. Higher pressures achieved also could elevate FRC, not only increasing oxygen stores, but also contributing to maintenance of open upper airway through its tethering effect. Further physiological studies are needed in super morbidly obese patients comparing low and high tidal volumes.

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