Randomized controlled trial of low vs high oxygen during neonatal anesthesia: Oxygenation, feasibility, and oxidative stress.

Background: To reduce risk for intermittent hypoxia a high fraction of inspired oxygen is routinely used during anesthesia induction. This differs from the cautious dosing of oxygen during neonatal resuscitation and intensive care and may result in significant hyperoxia.

Aim: In a randomized controlled trial, we evaluated oxygenation during general anesthesia with a low (23%) vs a high (80% during induction and recovery, and 40% during maintenance) fraction of inspired oxygen, in newborn infants undergoing surgery.

Limitations of the ARDS criteria during high-flow oxygen or non-invasive ventilation: evidence from critically ill COVID-19 patients.

Background: The ratio of partial pressure of arterial oxygen to inspired oxygen fraction (PaO/FO) during invasive mechanical ventilation (MV) is used as criteria to grade the severity of respiratory failure in acute respiratory distress syndrome (ARDS). During the SARS-CoV2 pandemic, the use of PaO/FO ratio has been increasingly used in non-invasive respiratory support such as high-flow nasal cannula (HFNC) and non-invasive ventilation (NIV). The grading of hypoxemia in non-invasively ventilated patients is uncertain.

A proof-of-concept study on mortality prediction with machine learning algorithms using burn intensive care data.

Introduction: Burn injuries are a common traumatic injury. Large burns have high mortality requiring intensive care and accurate mortality predictions. To assess if machine learning (ML) could improve predictions, ML algorithms were tested and compared with the original and revised Baux score.

Intranasal dexmedetomidine and rectal ketamine for young children undergoing burn wound procedures.

Background: Safe and effective methods for sedation and analgesia in pediatric burn patients are strongly warranted. This retrospective study of electronic health care records aims to evaluate the safety and efficacy of intranasal dexmedetomidine combined with rectal ketamine as procedural sedation for young children undergoing dressing changes and debridement of burn wounds.

Methods: Documentation was analyzed from 90 procedures in 58 pediatric patients aged <5 years.

Expiratory Resistances Prevent Expiratory Diaphragm Contraction, Flow Limitation, and Lung Collapse.

Tidal expiratory flow limitation (tidal-EFL) is not completely avoidable by applying positive end-expiratory pressure and may cause respiratory and hemodynamic complications in ventilated patients with lungs prone to collapse. During spontaneous breathing, expiratory diaphragmatic contraction counteracts tidal-EFL. We hypothesized that during both spontaneous breathing and controlled mechanical ventilation, external expiratory resistances reduce tidal-EFL.

The time-course of the inflammatory response to major burn injury and its relation to organ failure and outcome.

Burn injury causes major inflammatory activation and cytokine release, however, the temporal resolution of the acute and sub-acute inflammatory response has not yet been fully delineated. To this end, we have quantified 20 inflammatory mediators in plasma from 44 adult patients 0-21 days after burn injury and related the time course of these mediators to % total body surface area (TBSA) burned, clinical parameters, organ failure and outcome. Of the cytokines analyzed in these patients, interleukin 6 (IL-6), IL-8, IL-10 and monocyte chemoattractant protein 1 (MCP-1) correlated to the size of the injury at 24-48h after burn injury.

Optimal PEEP during one-lung ventilation with capnothorax: An experimental study.

Background: One-lung ventilation (OLV) with induced capnothorax carries the risk of severely impaired ventilation and circulation. Optimal PEEP may mitigate the physiological perturbations during these conditions.

Methods: Right-sided OLV with capnothorax (16 cm H O) on the left side was initiated in eight anesthetized, muscle-relaxed piglets.

Altered adrenal and gonadal steroids biosynthesis in patients with burn injury.

Introduction: Burn injury inevitably leads to changes in the endogenous production of cytokines, as well as adrenal and gonadal steroids. Previous studies have reported gender-related differences in outcome following burn injury, which suggests that gonadal steroids may play a role. The aim of this study was to assess alterations in concentration of endogenous steroids in patients with burn injury.

Matrix metalloproteinases -8 and -9 and tissue inhibitor of metalloproteinase-1 in burn patients. A prospective observational study.

Introduction: Matrix metalloproteinases (MMPs) -8 and -9 are released from neutrophils in acute inflammation and may contribute to permeability changes in burn injury. In retrospective studies on sepsis, levels of MMP-8, MMP-9, and tissue inhibitor of metalloproteinase-1 (TIMP-1) differed from those of healthy controls, and TIMP-1 showed an association with outcome. Our objective was to investigate the relationship between these proteins and disease severity and outcome in burn patients.

Hypercapnic acidosis transiently weakens hypoxic pulmonary vasoconstriction without affecting endogenous pulmonary nitric oxide production.

Purpose: Hypercapnic acidosis often occurs in critically ill patients and during protective mechanical ventilation; however, the effect of hypercapnic acidosis on endogenous nitric oxide (NO) production and hypoxic pulmonary vasoconstriction (HPV) presents conflicting results. The aim of this study is to test the hypothesis that hypercapnic acidosis augments HPV without changing endogenous NO production in both hyperoxic and hypoxic lung regions in pigs.

Methods: Sixteen healthy anesthetized pigs were separately ventilated with hypoxic gas to the left lower lobe (LLL) and hyperoxic gas to the rest of the lung.

Prevention of atelectasis in morbidly obese patients during general anesthesia and paralysis: a computerized tomography study.

Background: Morbidly obese patients show impaired pulmonary function during anesthesia and paralysis, partly due to formation of atelectasis. This study analyzed the effect of general anesthesia and three different ventilatory strategies to reduce the amount of atelectasis and improve respiratory function.

Methods: Thirty patients (body mass index 45 +/- 4 kg/m) scheduled for gastric bypass surgery were prospectively randomized into three groups: (1) positive end-expiratory pressure of 10 cm H2O (PEEP), (2) a recruitment maneuver with 55 cm H2O for 10 s followed by zero end-expiratory pressure, (3) a recruitment maneuver followed by PEEP.

Distant effects of nitric oxide inhalation in endotoxemic pigs.

Objective: Inhalation of nitric oxide (INO) has distant effects. By a blood- borne factor, INO down-regulates endogenous nitric oxide production in healthy pig lungs, resulting in vasoconstriction in lung regions not directly reached by INO. The aim of this study was to investigate whether INO has distant effects in endotoxemic pig lungs.

Central hemodynamics during lung recruitment maneuvers at hypovolemia, normovolemia and hypervolemia. A study by echocardiography and continuous pulmonary artery flow measurements in lung-injured pigs.

Objective: The impact of lung-recruitment maneuvers on heart function at different volemic levels has not been studied in detail. We therefore investigated the effect on central hemodynamics of lung recruitment maneuvers at hypovolemia, normovolemia and hypervolemia in experimental lung injury.

Design: Randomized, controlled, cross-over experimental study.