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Concept: Positive pressure ventilation


Many penetrating trauma patients in severe hemorrhagic shock receive positive pressure ventilation (PPV) upon transport to definitive care, either by intubation (INT) or bag-valve mask (BVM). Using a swine hemorrhagic shock model that simulates penetrating trauma, we proposed that severely injured patients may have better outcomes with “permissive hypoventilation,” where manual breaths are not given and oxygen is administrated passively via face mask (FM). We hypothesized that PPV has harmful physiologic effects in severe low-flow states and that permissive hypoventilation would result in better outcomes.

Concepts: Intensive care medicine, Medical emergencies, Mechanical ventilation, Physical trauma, Firefighting, Penetrating trauma, Positive pressure ventilation, Bag valve mask



Ultrasound assessment of the inferior vena cava (IVC) has gained favour in aiding fluid management decisions for controlled, mechanically ventilated patients as well as in non-mechanically ventilated, spontaneously breathing patients. Its utility in spontaneously breathing patients during positive pressure non-invasive ventilation has not yet been determined. The use of the axillary vein, as an alternative option to the IVC due to its ease of accessibility and independence from intra-abdominal pressure, has also not been evaluated. The aim of this study was to assess respiratory variation in IVC and axillary vein diameters in spontaneously breathing participants (Collapsibility Index) and with the application of increasing positive end-expiratory pressure (PEEP) via positive pressure non-invasive ventilation (Distensibility Index).

Concepts: Pulmonology, Evaluation, Intensive care medicine, Assessment, Inferior vena cava, Superior vena cava, Axillary vein, Positive pressure ventilation


The effects of high flow nasal cannula (HFNC) on adult patients after extubation remain controversial. We aimed to further determine the effectiveness of HFNC in comparison to noninvasive positive pressure ventilation (NIPPV) and conventional oxygen therapy (COT).

Concepts: Oxygen, Effect, Effectiveness, Firefighting, Oxygen therapy, Nasal cannula, Positive pressure ventilation


The safety of transbronchial lung biopsy (TBLB) on positive pressure mechanical ventilation has been controversial due to a presumed risk of pneumothorax. Data are especially limited on TBLB with elective intubation and mechanical ventilation. In this study, we compared complications of TBLB in patients who were electively mechanically ventilated for the procedure to those who were not.

Concepts: Pulmonology, Lung, Mechanical ventilation, Pneumothorax, Mechanical, Positive pressure ventilation


Cerebral autoregulation (CA) is the mechanism that maintains constancy of cerebral blood flow (CBF) despite variations in blood pressure (BP). Patients with attenuated CA have been shown to have an increased incidence of peri-operative stroke. Studies of CA in anaesthetized subjects are rare, because a simple and non-invasive method to quantify the integrity of CA is not available. In this study, we set out to improve non-invasive quantification of CA during surgery. For this purpose, we introduce a novel method to amplify spontaneous BP fluctuations during surgery by imposing mechanical positive pressure ventilation at three different frequencies and quantify CA from the resulting BP oscillations.

Concepts: Myocardial infarction, Thermodynamics, Hematology, Cultural studies, Cerebral blood flow, Positive pressure ventilation, Autoregulation, Resperate


Sedation and/or analgesia can relieve the patient-ventilator asynchrony. However, whether sedation and/or analgesia can benefit the clinical outcome of the patients with interface intolerance is still unclear.

Concepts: Firefighting, Positive pressure ventilation


Objective To determine the risks of bleeding and other complications in pediatric patients who require noninvasive positive pressure ventilation (PPV) in the immediate posttonsillectomy period. Study Design Case series with chart review. Setting Single tertiary pediatric hospital. Subjects and Methods Sixty-nine patients who had undergone tonsillectomy from July 2007 through December 2013 and required postoperative PPV were reviewed. Data collected included age, sex, medical history, preoperative polysomnogram parameters, length of use and type of noninvasive ventilatory support, and postoperative complications. Bleeding rate was calculated. Results Sixty-nine children met inclusion criteria for the study. Most had comorbid conditions. The mean age of these patients was 6.4 years. The postoperative bleeding rate of children who required operative intervention for control was 5.97%. Patients did not experience other complications. Conclusion This is the largest study in the literature investigating bleeding in pediatric patients undergoing tonsillectomy who required postoperative noninvasive PPV. Some hesitation may exist in using this form of ventilation when open pharyngeal wounds are exposed to pressure, but this study suggests that it can be used as a suitable alternative to invasive ventilation.

Concepts: Medicine, Hospital, Physician, Pediatrics, Comorbidity, Invasive, Children's hospital, Positive pressure ventilation


A breath-synchronized nebulization option that could potentially improve drug delivery during noninvasive positive pressure ventilation (NIPPV) is currently not available on single-limb circuit bilevel ventilators. The aim of this study was to compare urinary excretion of amikacin following aerosol delivery with a vibrating mesh nebulizer coupled to a single-limb circuit bilevel ventilator, using conventional continuous (Conti-Neb) and experimental inspiratory synchronized (Inspi-Neb) nebulization modes.

Concepts: Lung, Mechanical ventilation, Medical ventilator, Respiratory therapy, Nebulizer, Positive pressure ventilation, Bag valve mask


The use of flexible laryngeal mask airway (FLMA) in elective ear, nose and throat (ENT) surgery offers significant advantages, but is frequently considered inferior to tracheal intubation (TI) for ventilation and airway protection. We investigated the safety and success rate of intraoperative FLMA use with positive pressure ventilation (PPV), and the factors responsible for FLMA failure.

Concepts: Endotracheal tube, Respiratory system, Intubation, Laryngeal mask airway, Positive pressure ventilation