Institution Of Positive Pressure Ventilation Research Articles

Con: The Best Induction Agent for the Physiologically Difficult Airway Is Ketamine-Propofol Admixture (“Ketofol”)

Tracheal intubation (TI) is a high-risk procedure commonly performed in critically ill patients. A significant proportion of these patients tend to have a physiologically difficult airway, wherein the patients’ physiologic perturbations predispose them to a higher risk of cardiovascular and other complications with TI and institution of positive pressure ventilation.1 These derangements predominantly drive the risks with intubation and often lead to complications despite a successful first attempt. Although many physiological derangements may be associated with a physiologically difficult airway, the ones most commonly encountered are hypotension, hypoxia, severe metabolic acidosis, and right ventricular dysfunction.1

Pneumothorax in Critically Ill COVID-19 Patients in the Indian Subcontinent.

To explore the incidence and risk factors, as well as mortality, in critically ill COVID-19 patients who developed pneumothorax (PTX) and/or pneumomediastinum (PNM). A retrospective cohort study was undertaken to analyse data of all patients with moderate to severe COVID-19 disease who were either RTPCR positive or had a clinico-radiological diagnosis. The exposure group consisted of COVID-19 patients who presented with PTX/PNM, whereas the non-exposure group consisted of patients who did not develop PTX and/or PNM during the stay. Incidence of PTX/PNM was observed to be 1.9% among critically ill COVID-19 patients. 94.4% (17/18) of patients in the PTX group received positive pressure ventilation (PPV); the majority of these patients were on non-invasive ventilation when they developed PTX/PNM; only one patient was receiving conventional oxygen therapy. COVID-19 patients who developed PTX/PNM had 2.7 times higher mortality. A mortality rate of 72.2% was observed in COVID-19 patients who developed PTX/PNM. Development of PTX/PNM in critically ill COVID-19 patients is associated with more severe disease involvement, and institution of PPV is an additional risk factor. Significantly high mortality was observed following PTX/PNM in critically ill COVID-19 patients and is an independent marker of poor prognosis in COVID-19 disease.

Team-based model for non-operating room airway management: validation using a simulation-based study

BackgroundNon-operating room (non-OR) airway management has previously been identified as an area of concern because it carries a significant risk for complications. One reason for this could be attributed to the independent practice of residents in these situations. The aim of the present study was to ascertain whether differences in performance exist between residents working alone vs with a resident partner when encountering simulated non-OR airway management scenarios. MethodsThirty-six anaesthesia residents were randomized into two groups. Each group experienced three separate scenarios (two scenarios initially and then a third 6 weeks later). The scenarios consisted of one control scenario and two critical event scenarios [i.e. asystole during laryngoscopy and pulseless electrical activity (PEA) upon post-intubation institution of positive pressure ventilation]. One group experienced the simulated non-OR scenarios alone (Solo group). The other group consisted of resident pairs, participating in the same three scenarios (Team group). ResultsAlthough the time to intubation did not differ between the Solo and Team groups, there were several differences in performance. The Team group received better overall performance ratings for the asystole (8.5 vs 5.5 out of 10; P<0.001) and PEA (8.5 vs 5.8 out of 10; P<0.001) scenarios. The Team group was also able to recognize asystole and PEA conditions faster than the Solo group [10.1 vs 23.5 s (P<0.001) and 13.3 vs 36.0 s (P<0.001), respectively]. ConclusionsResidents who performed a simulated intubation with a second trained provider had better overall performance than those who practised independently. The residents who practised in a group were also faster to diagnose serious complications, including peri-intubation asystole and PEA. Given these data, it is reasonable that training programmes consider performing all non-OR airway management with a team-based method.

Noninvasive ventilation in acute respiratory failure.

After the institution of positive-pressure ventilation, the use of noninvasive ventilation (NIV) through an interface substantially increased. The first technique was continuous positive airway pressure; but, after the introduction of pressure support ventilation at the end of the 20th century, this became the main modality. Both techniques, and some others that have been recently introduced and which integrate some technological innovations, have extensively demonstrated a faster improvement of acute respiratory failure in different patient populations, avoiding endotracheal intubation and facilitating the release of conventional invasive mechanical ventilation. In acute settings, NIV is currently the first-line treatment for moderate-to-severe chronic obstructive pulmonary disease exacerbation as well as for acute cardiogenic pulmonary edema and should be considered in immunocompromised patients with acute respiratory insufficiency, in difficult weaning, and in the prevention of postextubation failure. Alternatively, it can also be used in the postoperative period and in cases of pneumonia and asthma or as a palliative treatment. NIV is currently used in a wide range of acute settings, such as critical care and emergency departments, hospital wards, palliative or pediatric units, and in pre-hospital care. It is also used as a home care therapy in patients with chronic pulmonary or sleep disorders. The appropriate selection of patients and the adaptation to the technique are the keys to success. This review essentially analyzes the evidence of benefits of NIV in different populations with acute respiratory failure and describes the main modalities, new devices, and some practical aspects of the use of this technique.

Intraoperative Pneumothorax Identified with Transthoracic Ultrasound

Intraoperative Pneumothorax Identified with Transthoracic Ultrasound

Diabetic Cardiomyopathy and Anesthesia

Diabetic Cardiomyopathy and Anesthesia

Biological markers of lung injury before and after the institution of positive pressure ventilation in patients with acute lung injury

BackgroundSeveral biological markers of lung injury are predictors of morbidity and mortality in patients with acute lung injury (ALI). The low tidal volume lung-protective ventilation strategy is associated with a significant decrease in plasma biomarker levels compared to the high tidal volume ventilation strategy. The primary objective of this study was to test whether the institution of lung-protective positive pressure ventilation in spontaneously ventilating patients with ALI exacerbates pre-existing lung injury by using measurements of biomarkers of lung injury before and after intubation.Materials and methodsA prospective observational cohort study was conducted in the intensive care unit of a tertiary care university hospital. Twenty-five intubated, mechanically ventilated patients with ALI were enrolled. Physiologic data and serum samples were collected within 6 hours before intubation and at two different time points within the first 24 hours after intubation to measure the concentration of interleukin (IL)-6, IL-8, intercellular adhesion molecule 1 (ICAM-1), and von Willebrand factor (vWF). The differences in biomarker levels before and after intubation were analysed using repeated measures analysis of variance and a paired t test with correction for multiple comparisons.ResultsBefore endotracheal intubation, all of the biological markers (IL-8, IL-6, ICAM-1, and vWF) were elevated in the spontaneously breathing patients with ALI. After intubation and the institution of positive pressure ventilation (tidal volume 7 to 8 ml/kg per ideal body weight), none of the biological markers was significantly increased at either an early (3 ± 2 hours) or later (21 ± 5 hours) time point. However, the levels of IL-8 were significantly decreased at the later time point (21 ± 5 hours) after intubation. During the 24-hour period after intubation, the PaO2/FiO2 (partial pressure of arterial oxygen/fraction of the inspired oxygen) ratio significantly increased and the plateau airway pressure significantly decreased.ConclusionLevels of IL-8, IL-6, vWF, and ICAM-1 are elevated in spontaneously ventilating patients with ALI prior to endotracheal intubation. The institution of a lung-protective ventilation strategy with positive pressure ventilation does not further increase the levels of biological markers of lung injury. The results suggest that the institution of a lung-protective positive pressure ventilation strategy does not worsen the pre-existing lung injury in most patients with ALI.

Anaesthetic management of congenital lobar emphysema: A report of two cases

Congenital lobar emphysema (CLE) is a rare cause of sudden respiratory distress in the newborn and infants [1]. Hyperinflation and air trapping cause expansion of the affected lobe along with the compression of other lung tissue, mediastinal shifting and impaired venous return. Anaesthesia for CLE, is challenging, as often children are sick and the laid down principles of anaesthesia such as keeping the airway pressures low, cannot be adhered to. Attempts to maintain spontaneous respiration may not be successful and institution of positive pressure ventilation has the potential of worsening the condition. The aim of this paper is to present two case reports with unusual clinical features, each highlighting two different aspects of the disease. The first case had a short history, rapid downhill course with features of life threatening mediastinal shift whereas the second case had an eventful induction of anaesthesia. Anaesthetic management of cases with CLE is outlined and the relevant literature is discussed briefly.

Delayed Bronchial Stenosis After Blunt Chest Trauma

Delayed Bronchial Stenosis After Blunt Chest Trauma

Effect of Positive Pressure Ventilation on Impedance Plethysmography

It has been stated that positive pressure ventilation (PPV) may cause false positive impedance plethysmography (IPG) results because PPV can decrease venous outflow. We studied 36 patients who were being weaned from mechanical ventilation to determine the effect of PPV on IPG. Patients had IPGs performed during spontaneous ventilation and while receiving mechanical ventilation in the assist/control (A/C) mode without positive end expiratory pressure (PEEP) and with 10 cm H2O PEEP. No patient developed a positive IPG with institution of PPV (mean airway pressure = 6.8 cm H2O), or with PEEP (mean airway pressure = 14.9 cm H2O). The IPG values for venous capacitance and venous outflow did not change during either mode of mechanical ventilation. There also was no tendency for positive pressure ventilation to move IPG results in the direction of a positive test. In summary, PPV does not cause IPG results to be false positive, nor does it move IPG results toward the discriminant line that separates normal from abnormal results.

General anaesthesia and undrained pneumothorax

A patient who required pleurectomy had a 30% pneumothorax when she was presented for anaesthesia. She had refused to have this drained, and it had not responded to conservative management. She was anaesthetised using a computer-controlled propofol infusion system, without the use of nitrous oxide, and a chest drain was inserted before the institution of positive pressure ventilation. This technique reduces the hazards associated with general anaesthesia in the presence of an undrained pneumothorax. It may be a safe alternative method of induction of anaesthesia in other conditions in which positive pressure ventilation must be avoided, such as bronchopleural fistula.

A STREAMLINED ANAESTHETIC SYSTEM

A streamlined modification of the combined Mapleson D & E systems has been described. The main advantages of this circuit are that it is light in weight, adaptable to both adult and paediatric anaesthesia, allows complete airway control at all times, and permits the institution of positive pressure ventilation, The circuit is easily adaptable for pollution control.

A streamlined anaesthetic system.

A streamlined modification of the combined Mapleson D & E systems has been described. The main advantages of this circuit are that it is light in weight, adaptable to both adult and paediatric anaesthesia, allows complete airway control at all times, and permits the institution of positive pressure ventilation, The circuit is easily adaptable for pollution control.