scholarly journals Model-based neuro-fuzzy control of FiO2 for intensive care mechanical ventilation

Critical Care ◽  
2001 ◽  
Vol 5 (Suppl 1) ◽  
pp. P002
Author(s):  
HF Kwok ◽  
GH Mills ◽  
M Mahfouf ◽  
DA Linkens
Keyword(s):  
Mechanical Ventilation ◽  
Intensive Care ◽  
Fuzzy Control ◽  
Model Based ◽  
Neuro Fuzzy

scholarly journals Product of driving pressure and respiratory rate for predicting weaning outcomes

2021 ◽  
Vol 49 (5) ◽  
pp. 030006052110100
Author(s):  
Ju Gong ◽  
Bibo Zhang ◽  
Xiaowen Huang ◽  
Bin Li ◽  
Jian Huang
Keyword(s):  
Mechanical Ventilation ◽  
Respiratory Rate ◽  
Spontaneous Breathing ◽  
Spontaneous Breathing Trial ◽  
Plateau Pressure ◽  
Driving Pressure ◽  
Failure Group ◽  
Rapid Shallow Breathing Index ◽  
Weaning Failure ◽  
Shallow Breathing

Objective Clinicians cannot precisely determine the time for withdrawal of ventilation. We aimed to evaluate the performance of driving pressure (DP)×respiratory rate (RR) to predict the outcome of weaning. Methods Plateau pressure (Pplat) and total positive end-expiratory pressure (PEEPtot) were measured during mechanical ventilation with brief deep sedation and on volume-controlled mechanical ventilation with a tidal volume of 6 mL/kg and a PEEP of 0 cmH2O. Pplat and PEEPtot were measured by patients holding their breath for 2 s after inhalation and exhalation, respectively. DP was determined as Pplat minus PEEPtot. The rapid shallow breathing index was measured from the ventilator. The highest RR was recorded within 3 minutes during a spontaneous breathing trial. Patients who tolerated a spontaneous breathing trial for 1 hour were extubated. Results Among the 105 patients studied, 44 failed weaning. During ventilation withdrawal, DP×RR was 136.7±35.2 cmH2O breaths/minute in the success group and 230.2±52.2 cmH2O breaths/minute in the failure group. A DP×RR index >170.8 cmH2O breaths/minute had a sensitivity of 93.2% and specificity of 88.5% to predict failure of weaning. Conclusions Measurement of DP×RR during withdrawal of ventilation may help predict the weaning outcome. A high DP×RR increases the likelihood of weaning failure. Statement: This manuscript was previously posted as a preprint on Research Square with the following link: https://www.researchsquare.com/article/rs-15065/v3 and DOI: 10.21203/rs.2.24506/v3

scholarly journals Vagal feedback in the entrainment of respiration to mechanical ventilation in sleeping humans

2000 ◽  
Vol 89 (2) ◽  
pp. 760-769 ◽  
Author(s):  
Peggy M. Simon ◽  
Alfred M. Habel ◽  
J. Andrew Daubenspeck ◽  
J. C. Leiter
Keyword(s):  
Mechanical Ventilation ◽  
Respiratory Rate ◽  
Eye Movement ◽  
Lung Transplant ◽  
Respiratory Activity ◽  
Nrem Sleep ◽  
Normal Subjects ◽  
The Other ◽  
Absolute Requirement ◽  
Striking Contrast

We studied the capacity of four “normal” and six lung transplant subjects to entrain neural respiratory activity to mechanical ventilation. Two transplant subjects were studied during wakefulness and demonstrated entrainment indistinguishable from that of normal awake subjects. We studied four normal subjects and four lung transplant subjects during non-rapid eye movement (NREM) sleep. Normal subjects entrained to mechanical ventilation over a range of ventilator frequencies that were within ±3–5 breaths of the spontaneous respiratory rate of each subject. After lung transplantation, during which the vagi were cut, subjects did demonstrate entrainment during NREM sleep; however, entrainment only occurred at ventilator frequencies at or above each subject's spontaneous respiratory rate, and entrainment was less effective. We conclude that there is no absolute requirement for vagal feedback to induce entrainment in subjects, which is in striking contrast to anesthetized animals in which vagotomy uniformly abolishes entrainment. On the other hand, vagal feedback clearly enhances the fidelity of entrainment and extends the range of mechanical frequencies over which entrainment can occur.

Use of High-Flow Nasal Cannula in Patients With Pneumonia and Hypoxemic Respiratory Failure at Altitudes Above 2600 m: What Is the Best Predictor of Success?

2021 ◽  
pp. 088506662110575
Author(s):  
Molano Franco Daniel ◽  
Gómez Duque Mario ◽  
Beltrán Edgar ◽  
Villabon Mario ◽  
Hurtado Alejandra ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Respiratory Failure ◽  
Respiratory Rate ◽  
High Flow ◽  
Nasal Cannula ◽  
High Flow Nasal Cannula ◽  
Multicenter Cohort Study ◽  
Hypoxemic Respiratory Failure ◽  
Severity Scores ◽  
High Flow Oxygen

Introduction: The use of high-flow nasal cannulas (HFNC) in patients with hypoxemic ventilatory failure reduces the need for mechanical ventilation and does not increase mortality when intubation is promptly applied. The aim of the study is to describe the behavior of HFNC in patients who live at high altitudes, and the performance of predictors of success/failure of this strategy. Methods: Prospective multicenter cohort study, with patients aged over 18 years recruited for 12 months in 2020 to 21. All had a diagnosis of hypoxemic respiratory failure secondary to pneumonia, were admitted to intensive care units, and were receiving initial management with a high-flow nasal cannula. The variables assessed included need for intubation, mortality in ICU, and the validation of SaO2, respiratory rate (RR) and ROX index (IROX) as predictors of HFNC success / failure. Results: One hundred and six patients were recruited, with a mean age of 59 years and a success rate of 74.5%. Patients with treatment failure were more likely to be obese (BMI 27.2 vs 25.5; OR: 1.03; 95% CI: .95-1.1) and had higher severity scores at admission (APACHE II 12 vs 20; OR 1.15; 95% CI: 1.06-1.24). Respiratory rates after 12 (AUC .81 CI: .70-.92) and 18 h (AUC .85 CI: .72-0.90) of HFNC use were the best predictors of failure, performing better than those that included oxygenation. ICU mortality was higher in the failure group (6% vs 29%; OR 8.8; 95% CI:1.75-44.7). Conclusions: High-flow oxygen cannula therapy in patients with hypoxemic respiratory failure living at altitudes above 2600 m is associated with low rates of therapy failure and a reduced need for mechanical ventilation in the ICU. The geographical conditions and secondary physiological changes influence the performance of the traditionally validated predictors of therapy success. Respiratory rate <30 proved to be the best indicator of early success of the device at 12 h of use.

Decreased respiratory rate variability during mechanical ventilation is associated with increased mortality

2013 ◽  
Vol 39 (8) ◽  
pp. 1359-1367 ◽  
Author(s):  
Guillermo Gutierrez ◽  
Aparna Das ◽  
Guillermo Ballarino ◽  
Arshan Beyzaei-Arani ◽  
Hülya Türkan ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Respiratory Rate ◽  
Respiratory Rate Variability

Apnea after normocapnic mechanical ventilation during NREM sleep

1994 ◽  
Vol 77 (5) ◽  
pp. 2079-2085 ◽  
Author(s):  
A. M. Leevers ◽  
P. M. Simon ◽  
J. A. Dempsey
Keyword(s):  
Mechanical Ventilation ◽  
Nrem Sleep ◽  
Inspiratory Effort ◽  
Control Mechanical Ventilation ◽  
Inhibitory Effects ◽  
Inspiratory Motor ◽  
Ventilator Mode ◽  
Controlled Mechanical Ventilation ◽  
The Subject ◽  
End Tidal

We determined whether normocapnic mechanical ventilation at high tidal volume (VT) and breathing frequency (f) during non-rapid-eye-movement (NREM) sleep would cause apnea. Seven normal sleeping subjects were placed on assist-control mechanical ventilation (i.e., subject initiates inspiration) and VT was gradually increased to 2.1 times eupneic VT (1.17 +/- 0.04 liters). This high VT was maintained for 5 min, the ventilator mode was switched to controlled mechanical ventilation, and f was increased gradually from 9.5 +/- 1.0 (during assist-control mechanical ventilation) to 14.0 +/- 0.7 breaths/min. Normocapnia (end-tidal PCO2 = 44 +/- 1.2 Torr) was maintained throughout the trials. Inspiratory effort was completely inhibited during the period of sustained high VT and f, and apnea occurred immediately after cessation of the passive mechanical ventilation. The duration of the apnea preceding the first inspiratory effort was 20.3 +/- 2.3 s or 7.1 times the eupneic expiratory duration and 5 times the expiratory duration chosen by the subject during assist-control mechanical ventilation. We conclude that inhibition of inspiratory motor output occurs during and after normocapnic mechanical ventilation at high VT and f during NREM sleep. These neuromechanical inhibitory effects may serve to initiate and prolong apnea.

scholarly journals Prone Position after Liberation from Prolonged Mechanical Ventilation in COVID-19 Respiratory Failure

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Andrei Karpov ◽  
Anish R. Mitra ◽  
Sarah Crowe ◽  
Gregory Haljan
Keyword(s):  
Intensive Care Unit ◽  
Mechanical Ventilation ◽  
Intensive Care ◽  
Respiratory Failure ◽  
Respiratory Rate ◽  
Prolonged Mechanical Ventilation ◽  
Case Series ◽  
Prone Positioning ◽  
Retrospective Case ◽  
Number Of Patients

Objective and Rationale. Prone positioning of nonintubated patients has prevented intubation and mechanical ventilation in patients with respiratory failure from coronavirus disease 2019 (COVID-19). A number of patients in a recently published cohort have undergone postextubation prone positioning (PEPP) following liberation from prolonged mechanical ventilation in attempt to prevent reintubation. The objective of this study is to systematically search the literature for reports of PEPP as well as describe the feasibility and outcomes of PEPP in patients with COVID-19 respiratory failure. Design. This is a retrospective case series describing the feasibility and tolerability of postextubation prone positioning (PEPP) and its impact on physiologic parameters in a tertiary intensive care unit during the COVID-19 pandemic. Setting and Patients. This study was conducted on patients with COVID-19 respiratory failure hospitalized in a tertiary Intensive Care Unit at Surrey Memorial Hospital during the COVID-19 pandemic. Measurements and Results. We did not find prior reports of PEPP following prolonged intubation in the literature. Four patients underwent a total of 13 PEPP sessions following liberation from prolonged mechanical ventilation. Each patient underwent a median of 3 prone sessions (IQR: 2, 4.25) lasting a median of 1.5 hours (IQR: 1.2, 2.1). PEPP sessions were associated with a reduction in median oxygen requirements, patient respiratory rate, and reintubation rate. The sessions were well tolerated by patients, nursing, and the allied health team. Conclusions. The novel practice of PEPP after liberation from prolonged mechanical ventilation in patients with COVID-19 respiratory failure is feasible and well tolerated, and may be associated with favourable clinical outcomes including improvement in oxygenation and respiratory rate and a low rate of reintubation. Larger prospective studies of PEPP are warranted.

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