Lower inflection point and recruitment with PEEP in ventilated patients with acute respiratory failure

2001 ◽  
Vol 91 (1) ◽  
pp. 441-450 ◽  
Author(s):  
M. Mergoni ◽  
A. Volpi ◽  
C. Bricchi ◽  
A. Rossi
Keyword(s):  
Respiratory Failure ◽  
Acute Respiratory Failure ◽  
Respiratory System ◽  
Inflection Point ◽  
Simple Method ◽  
Lower Inflection Point ◽  
Pressure Method ◽  
System Pressure ◽  
System P ◽  
Significant Difference

The lower inflection point (LIP) on the total respiratory system pressure-volume (P-V) curve is widely used to set positive end-expiratory pressure (PEEP) in patients with acute respiratory failure (ARF) on the assumption that LIP represents alveolar recruitment. The aims of this work were to study the relationship between LIP and recruited volume (RV) and to propose a simple method to quantify the RV. In 23 patients with ARF, respiratory system P-V curves were obtained by means of both constant-flow and rapid occlusion technique at four different levels of PEEP and were superimposed on the same P-V plot. The RV was measured as the volume difference at a pressure of 20 cmH2O. A third measurement of the RV was done by comparing the exhaled volumes after the same distending pressure of 20 cmH2O was applied (equal pressure method). RV increased with PEEP ( P < 0.0001); the equal pressure method compares favorably with the other methods ( P = 0.0001 by correlation), although individual data cannot be superimposed. No significant difference was found when RV was compared with PEEP in the group of patients with a LIP ≤5 cmH2O and the group with a LIP >5 cmH2O (76.9 ± 94.3 vs. 61.2 ± 51.3, 267.7 ± 109.9 vs. 209.6 ± 73.9, and 428.2 ± 216.3 vs. 375.8 ± 145.3 ml with PEEP of 5, 10, and 15 cmH2O, respectively). A RV was found even when a LIP was not present. We conclude that the recruitment phenomenon is not closely related to the presence of a LIP and that a simple method can be used to measure RV.

Comparative study between noninvasive positive pressure ventilation and invasive mechanical ventilation in patients with respiratory failure

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Mohammed N Al Shafi'i ◽  
Doaa M. Kamal El-din ◽  
Mohammed A. Abdulnaiem Ismaiel ◽  
Hesham M Abotiba
Keyword(s):  
Intensive Care Unit ◽  
Mechanical Ventilation ◽  
Intensive Care ◽  
Respiratory Failure ◽  
Acute Respiratory Failure ◽  
Positive Pressure Ventilation ◽  
Invasive Mechanical Ventilation ◽  
Noninvasive Positive Pressure Ventilation ◽  
Positive Pressure ◽  
Significant Difference

Abstract Background Noninvasive positive pressure ventilation (NIPPV) has been increasingly used in the management of respiratory failure in intensive care unit (ICU). Aim of the Work is to compare the efficacy and resource consumption of NIPPMV delivered through face mask against invasive mechanical ventilation (IMV) delivered by endotracheal tube in the management of patients with acute respiratory failure (ARF). Patients and Methods This prospective randomized controlled study included 78 adults with acute respiratory failure who were admitted to the intensive care unit. The enrolled patients were randomly allocated to receive either noninvasive ventilation or conventional mechanical ventilation (CMV). Results Severity of illness, measured by the simplified acute physiologic score 3 (SAPS 3), were comparable between the two patient groups with no significant difference between them. Both study groups showed a comparable steady improvement in PaO2:FiO2 values, indicating that NIPPV is as effective as CMV in improving the oxygenation of patients with ARF. The PaCO2 and pH values gradually improved in both groups during the 48 hours of ventilation. 12 hours after ventilation, NIPPMV group showed significantly more improvement in PaCO2 and pH than the CMV group. The respiratory acidosis was corrected in the NIPPV group after 24 hours of ventilation compared with 36 hours in the CMV group. NIPPV in this study was associated with a lower frequency of complications than CMV, including ventilator acquired pneumonia (VAP), sepsis, renal failure, pulmonary embolism, and pancreatitis. However, only VAP showed a statistically significant difference. Patients who underwent NIPPV in this study had lower mortality, and lower ventilation time and length of ICU stay, compared with patients on CMV. Intubation was required for less than a third of patients who initially underwent NIV. Conclusion Based on our study findings, NIPPV appears to be a potentially effective and safe therapeutic modality for managing patients with ARF.

Performing concurrent operations in academic vascular neurosurgery does not affect patient outcomes

2017 ◽  
Vol 127 (5) ◽  
pp. 1089-1095 ◽  
Author(s):  
Corinna C. Zygourakis ◽  
Janelle Lee ◽  
Julio Barba ◽  
Errol Lobo ◽  
Michael T. Lawton
Keyword(s):  
Severe Sepsis ◽  
Respiratory Failure ◽  
Acute Respiratory Failure ◽  
Odds Ratio ◽  
Aneurysm Rupture ◽  
Clinical Indicators ◽  
Patient Demographics ◽  
Postoperative Stroke ◽  
Significant Difference ◽  
Procedure Type

OBJECTIVEConcurrent surgeries, also known as “running two rooms” or simultaneous/overlapping operations, have recently come under intense scrutiny. The goal of this study was to evaluate the operative time and outcomes of concurrent versus nonconcurrent vascular neurosurgical procedures.METHODSThe authors retrospectively reviewed 1219 procedures performed by 1 vascular neurosurgeon from 2012 to 2015 at the University of California, San Francisco. Data were collected on patient age, sex, severity of illness, risk of mortality, American Society of Anesthesiologists (ASA) status, procedure type, admission type, insurance, transfer source, procedure time, presence of resident or fellow in operating room (OR), number of co-surgeons, estimated blood loss (EBL), concurrent vs nonconcurrent case, severe sepsis, acute respiratory failure, postoperative stroke causing neurological deficit, unplanned return to OR, 30-day mortality, and 30-day unplanned readmission. For aneurysm clipping cases, data were also obtained on intraoperative aneurysm rupture and postoperative residual aneurysm. Chi-square and t-tests were performed to compare concurrent versus nonconcurrent cases, and then mixed-effects models were created to adjust for different procedure types, patient demographics, and clinical indicators between the 2 groups.RESULTSThere was a significant difference in procedure type for concurrent (n = 828) versus nonconcurrent (n = 391) cases. Concurrent cases were more likely to be routine/elective admissions (53% vs 35%, p < 0.001) and physician referrals (59% vs 38%, p < 0.001). This difference in patient/case type was also reflected in the lower severity of illness, risk of death, and ASA class in the concurrent versus nonconcurrent cases (p < 0.01). Concurrent cases had significantly longer procedural times (243 vs 213 minutes) and more unplanned 30-day readmissions (5.7% vs 3.1%), but shorter mean length of hospital stay (11.2 vs 13.7 days), higher rates of discharge to home (66% vs 51%), lower 30-day mortality rates (3.1% vs 6.1%), lower rates of acute respiratory failure (4.3% vs 8.2%), and decreased 30-day unplanned returns to the OR (3.3% vs 6.9%; all p < 0.05). Rates of severe sepsis, postoperative stroke, intraoperative aneurysm rupture, and postoperative aneurysm residual were equivalent between the concurrent and nonconcurrent groups (all p values nonsignificant). Mixed-effects models showed that after controlling for procedure type, patient demographics, and clinical indicators, there was no significant difference in acute respiratory failure, severe sepsis, 30-day readmission, postoperative stroke, EBL, length of stay, discharge status, or intraoperative aneurysm rupture between concurrent and nonconcurrent cases. Unplanned return to the OR and 30-day mortality were significantly lower in concurrent cases (odds ratio 0.55, 95% confidence interval 0.31–0.98, p = 0.0431, and odds ratio 0.81, p < 0.001, respectively), but concurrent cases had significantly longer procedure durations (odds ratio 21.73; p < 0.001).CONCLUSIONSOverall, there was a significant difference in the types of concurrent versus nonconcurrent cases, with more routine/elective cases for less sick patients scheduled in an overlapping fashion. After adjusting for patient demographics, procedure type, and clinical indicators, concurrent cases had longer procedure times, but equivalent patient outcomes, as compared with nonconcurrent vascular neurosurgical procedures.

scholarly journals Association Between Basal Platelet Count and All-cause Mortality in Critically Ill Patients With Acute Respiratory Failure: a Secondary Analysis From the eICU Collaborative Research Database

2021 ◽  
Author(s):  
Chuan Xiao ◽  
Zuoan Qin ◽  
Jingjing Xiao ◽  
Yumei Cheng ◽  
Qing Li ◽  
...  
Keyword(s):  
Platelet Count ◽  
Respiratory Failure ◽  
Acute Respiratory Failure ◽  
Critically Ill ◽  
Critically Ill Patients ◽  
Collaborative Research ◽  
Inflection Point ◽  
Research Database ◽  
Negatively Associated ◽  
All Cause Mortality

Abstract Background: There is limited evidence on the correlation between platelet counts and all-cause mortality in critically ill patients with acute respiratory failure (ARF). The aim was to evaluate whether platelet count was associated with all-cause mortality in critical patients with ARF by using the eICU Collaborative Research Database.Methods: Using a retrospective multicenter cohort dataset, data of 26961 patients with ARF in ICU between 2014 and 2015 were collected. The independent variable was log2 basal platelet count, and the dependent variables were all-cause mortality in hospital and in ICU. Covariates included demographic data, Acute Physiology and Chronic Health Evaluation (APACHE) IV score, supportive treatment, and comorbidities.Results: In fully adjusted model, log2 basal platelet count was negatively associated with all-cause mortality both in hospital [ RR:0.87, 95% CI: 0.84 - 0.91] or in ICU [RR: 0.87, 95% CI:0.83, 0.92]. By nonlinearity test, the relationship between log2 basal platelet count and all-cause mortality in hospital and in ICU were nonlinear. The inflection point we got was 6.83 and 6.86 (after inverse log2 logarithmic conversion, the platelet count are 114×109/L and 116×109/L). There was no a correlation between blood platelets and all-cause mortality in hospital on the right side of the inflection point, (RR:0.96, 95% CI: 0.88-1.03) and in ICU (RR:0.97, 95% CI: 0.91-1.04).Conclusions: For patients with ARF in ICU, platelet count was negatively associated with all-cause mortality in hospital and in ICU when platelet count is less than 114 ×109/L and 116 ×109/L respectively, but when the platelet count was higher, we failed to observe a correlation between them. The safe ranges of platelet count we detected were 78×109/L -145×109/L and 89×109/L -147×109/L respectively.

Sigmoidal equation for lung and chest wall volume-pressure curves in acute respiratory failure

2003 ◽  
Vol 95 (5) ◽  
pp. 2064-2071 ◽  
Author(s):  
Cécile Pereira ◽  
Julien Bohé ◽  
Sylvaine Rosselli ◽  
Emmanuel Combourieu ◽  
Christian Pommier ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Chest Wall ◽  
Respiratory System ◽  
Inflection Point ◽  
Significant Contribution ◽  
Esophageal Pressure ◽  
Constant Flow ◽  
Lower Inflection Point ◽  
Mechanically Ventilated ◽  
Volume Pressure Curves

To assess incidence and magnitude of the “lower inflection point” of the chest wall, the sigmoidal equation was used in 36 consecutive patients intubated and mechanically ventilated with acute lung injury (ALI). They were 21 primary and 5 secondary ALI, 6 unilateral pneumonia, and 4 cardiogenic pulmonary edema. The lower inflection point was estimated as the point of maximal compliance increase. The low constant flow inflation method and esophageal pressure were used to partition the volume-pressure curves into their chest wall and lung components on zero end-expiratory pressure. The sigmoidal equation had an excellent fit with coefficients of determination >0.90 in all instances. The point of maximal compliance increase of the chest wall ranged from 0 to 8.3 cmH2O (median 1 cmH2O) with no difference between ALI groups. The chest wall significantly contributed to the lower inflection point of the respiratory system in eight patients only. The occurrence of a significant contribution of the chest wall to the lower inflection point of the respiratory system is lower than anticipated. The sigmoidal equation is able to determine precisely the point of the maximal compliance increase of lung and chest wall.

Respiratory system mechanics in the early phase of acute respiratory failure due to severe kyphoscoliosis

1997 ◽  
Vol 23 (5) ◽  
pp. 539-544 ◽  
Author(s):  
G. Conti ◽  
M. Rocco ◽  
M. Antonelli ◽  
M. Bufi ◽  
S. Tarquini ◽  
...  
Keyword(s):  
Respiratory Failure ◽  
Acute Respiratory Failure ◽  
Respiratory System ◽  
Early Phase ◽  
Respiratory System Mechanics

scholarly journals Goal-Directed Mechanical Ventilation: Are We Aiming at the Right Goals? A Proposal for an Alternative Approach Aiming at Optimal Lung Compliance, Guided by Esophageal Pressure in Acute Respiratory Failure

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Arie Soroksky ◽  
Antonio Esquinas
Keyword(s):  
Mechanical Ventilation ◽  
Respiratory Failure ◽  
Acute Respiratory Failure ◽  
Chest Wall ◽  
Respiratory System ◽  
Transpulmonary Pressure ◽  
Esophageal Pressure ◽  
Plateau Pressure ◽  
Lung Compliance ◽  
Inspiratory Pressure

Patients with acute respiratory failure and decreased respiratory system compliance due to ARDS frequently present a formidable challenge. These patients are often subjected to high inspiratory pressure, and in severe cases in order to improve oxygenation and preserve life, we may need to resort to unconventional measures. The currently accepted ARDSNet guidelines are characterized by a generalized approach in which an algorithm for PEEP application and limited plateau pressure are applied to all mechanically ventilated patients. These guidelines do not make any distinction between patients, who may have different chest wall mechanics with diverse pathologies and different mechanical properties of their respiratory system. The ability of assessing pleural pressure by measuring esophageal pressure allows us to partition the respiratory system into its main components of lungs and chest wall. Thus, identifying the dominant factor affecting respiratory system may better direct and optimize mechanical ventilation. Instead of limiting inspiratory pressure by plateau pressure, PEEP and inspiratory pressure adjustment would be individualized specifically for each patient's lung compliance as indicated by transpulmonary pressure. The main goal of this approach is to specifically target transpulmonary pressure instead of plateau pressure, and therefore achieve the best lung compliance with the least transpulmonary pressure possible.

scholarly journals Role of advanced respiratory support in acute respiratory failure in clinically frail patients with COVID-19

2021 ◽  
Author(s):  
Iftikhar Nadeem ◽  
Louise Jordon ◽  
Masood Ur Rasool ◽  
Noor Mahdi ◽  
Ritesh Kumar ◽  
...  
Keyword(s):  
Respiratory Failure ◽  
Acute Respiratory Failure ◽  
Survival Rates ◽  
Respiratory Support ◽  
Single Center Study ◽  
Significant Difference ◽  
Different Types ◽  
The Impact ◽  
Frailty Score

Background: The main aim of this study was to assess the efficacy of advanced respiratory support (ARS) for acute respiratory failure in do-not-attempt cardiopulmonary resuscitation order (DNACPR) COVID-19 patients. Methods: In this single-center study, the impact of different types of ARS modality, PaO2/FiO2 (PF) ratio, clinical frailty score (CFS) and 4C score on mortality was evaluated. Results: There was no significant difference in age, type of ARS modality, PF ratio and 4C scores between those who died and those who survived. Overall survival rates/hospital discharge of patients still requiring ARS at 5 and 7 days post admission were 20 and 17%, respectively. Conclusion: Our study showed that ARS can be a useful tool in frail, elderly and high-risk COVID-19 patients irrespective of high 4C mortality score.

scholarly journals Failure of non-invasive respiratory support after 6 hours from initiation is associated with ICU mortality

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0251030
Author(s):  
Mitsuaki Nishikimi ◽  
Kazuki Nishida ◽  
Yuichiro Shindo ◽  
Muhammad Shoaib ◽  
Daisuke Kasugai ◽  
...  
Keyword(s):  
Respiratory Failure ◽  
Acute Respiratory Failure ◽  
Lung Diseases ◽  
Ventilatory Support ◽  
Respiratory Support ◽  
Positive Pressure ◽  
Icu Mortality ◽  
Failure Group ◽  
Non Invasive ◽  
Significant Difference

A previous study has shown that late failure (> 48 hours) of high-flow nasal cannula (HFNC) was associated with intensive care unit (ICU) mortality. The aim of this study was to investigate whether failure of non-invasive respiratory support, including HFNC and non-invasive positive pressure ventilation (NPPV), was also associated with the risk of mortality even if it occurs in the earlier phase. We retrospectively analyzed 59 intubated patients for acute respiratory failure due to lung diseases between April 2014 and June 2018. We divided the patients into 2 groups according to the time from starting non-invasive ventilatory support until their intubation: ≤ 6 hours failure and > 6 hours failure group. We evaluated the differences in the ICU mortality between these two groups. The multivariate logistic regression analysis showed the highest mortality in the > 6 hours failure group as compared to the ≤ 6 hours failure group, with a statistically significant difference (p < 0.01). It was also associated with a statistically significant increased 30-day mortality and decreased ventilator weaning rate. The ICU mortality in patients with acute respiratory failure caused by lung diseases was increased if the time until failure of HFNC and NPPV was more than 6 hours.

Sign in / Sign up

Export Citation Format

Share Document