Impact of Adrenal Function on Hemostasis/Endothelial Function in Patients Undergoing Surgery.

Context: Glucocorticoids regulate hemostatic and endothelial function, and they are critical for adaptive functions during surgery. No data regarding the impact of adrenal function on hemostasis and endothelial function in the perioperative setting are available.

Objective: We assessed the association of adrenal response to adrenocorticotropic hormone (ACTH) and markers of endothelial/hemostatic function in surgical patients.

One too many diabetes: the combination of hyperglycaemic hyperosmolar state and central diabetes insipidus.

Unlabelled: The combination of hyperosmolar hyperglycaemic state and central diabetes insipidus is unusual and poses unique diagnostic and therapeutic challenges for clinicians. In a patient with diabetes mellitus presenting with polyuria and polydipsia, poor glycaemic control is usually the first aetiology that is considered, and achieving glycaemic control remains the first course of action. However, severe hypernatraemia, hyperglycaemia and discordance between urine-specific gravity and urine osmolality suggest concurrent symptomatic diabetes insipidus.

An Unexpected Case of Black Mamba () Bite in Switzerland.

Mambas (genus ) are among the most feared venomous African snakes. Without medical treatment, mamba bites are frequently fatal. First-aid treatment includes lymphatic retardation with the pressure immobilization technique.

Neural control of ventilation prevents both over-distension and de-recruitment of experimentally injured lungs.

Background: Endogenous pulmonary reflexes may protect the lungs during mechanical ventilation. We aimed to assess integration of continuous neurally adjusted ventilatory assist (cNAVA), delivering assist in proportion to diaphragm's electrical activity during inspiration and expiration, and Hering-Breuer inflation and deflation reflexes on lung recruitment, distension, and aeration before and after acute lung injury (ALI).

Methods: In 7 anesthetised rabbits with bilateral pneumothoraces, we identified adequate cNAVA level (cNAVA) at the plateau in peak ventilator pressure during titration procedures before (healthy lungs with endotracheal tube, [HL]) and after ALI (endotracheal tube [ALI] and during non-invasive ventilation [ALI]).

Esophageal versus surface recording of diaphragm compound muscle action potential.

Introduction: Repeated diaphragm compound muscle action potential (CMAP) recordings may help to understand the pathophysiology of respiratory muscle weakness. Neurally adjusted ventilator assist (NAVA) uses esophageal EMG electrodes to drive the ventilator. We evaluated the feasibility of CMAP recordings using these electrodes and established normal values.

Heart-lung interactions during neurally adjusted ventilatory assist.

Introduction: Assist in unison to the patient's inspiratory neural effort and feedback-controlled limitation of lung distension with neurally adjusted ventilatory assist (NAVA) may reduce the negative effects of mechanical ventilation on right ventricular function.

Methods: Heart-lung interaction was evaluated in 10 intubated patients with impaired cardiac function using esophageal balloons, pulmonary artery catheters and echocardiography. Adequate NAVA level identified by a titration procedure to breathing pattern (NAVAal), 50% NAVAal, and 200% NAVAal and adequate pressure support (PSVal, defined clinically), 50% PSVal, and 150% PSVal were implemented at constant positive end-expiratory pressure for 20 minutes each.

Early changes of muscle membrane properties in porcine faecal peritonitis.

Introduction: Sepsis-induced myopathy and critical illness myopathy (CIM) are possible causes of muscle weakness in intensive care patients. They have been attributed to muscle membrane dysfunction. The aim of this study was to investigate membrane properties in the early stage of experimental sepsis by evaluating muscle excitability.

Cumulative lactate and hospital mortality in ICU patients.

Background: Both hyperlactatemia and persistence of hyperlactatemia have been associated with bad outcome. We compared lactate and lactate-derived variables in outcome prediction.

Methods: Retrospective observational study.

Effects of cardiac preload reduction and dobutamine on hepatosplanchnic blood flow regulation in porcine endotoxemia.

Insufficient cardiac preload and impaired contractility are frequent in early sepsis. We explored the effects of acute cardiac preload reduction and dobutamine on hepatic arterial (Qha) and portal venous (Qpv) blood flows during endotoxin infusion. We hypothesized that the hepatic arterial buffer response (HABR) is absent during preload reduction and reduced by dobutamine.

Neurally adjusted ventilatory assist in patients with critical illness-associated polyneuromyopathy.

Purpose: Diaphragmatic electrical activity (EA(di)), reflecting respiratory drive, and its feedback control might be impaired in critical illness-associated polyneuromyopathy (CIPM). We aimed to evaluate whether titration and prolonged application of neurally adjusted ventilatory assist (NAVA), which delivers pressure (P (aw)) in proportion to EA(di), is feasible in CIPM patients.

Methods: Peripheral and phrenic nerve electrophysiology studies were performed in 15 patients with clinically suspected CIPM and in 14 healthy volunteers.

Identification of adequate neurally adjusted ventilatory assist (NAVA) during systematic increases in the NAVA level.

Neurally adjusted ventilatory assist (NAVA) delivers airway pressure (P(aw)) in proportion to the electrical activity of the diaphragm (EAdi) using an adjustable proportionality constant (NAVA level, cm·H(2)O/μV). During systematic increases in the NAVA level, feedback-controlled down-regulation of the EAdi results in a characteristic two-phased response in P(aw) and tidal volume (Vt). The transition from the 1st to the 2nd response phase allows identification of adequate unloading of the respiratory muscles with NAVA (NAVA(AL)).

Effects of catecholamines on hepatic and skeletal muscle mitochondrial respiration after prolonged exposure to faecal peritonitis in pigs.

Use of norepinephrine to increase blood pressure in septic animals has been associated with increased efficiency of hepatic mitochondrial respiration. The aim of this study was to evaluate whether the same effect could be reproduced in isolated hepatic mitochondria after prolonged in vivo exposure to faecal peritonitis. Eighteen pigs were randomized to 27 h of faecal peritonitis and to a control condition (n = 9 each group).

Physiologic response to changing positive end-expiratory pressure during neurally adjusted ventilatory assist in sedated, critically ill adults.

Background: Neurally adjusted ventilatory assist (NAVA) delivers airway pressure (Paw) in proportion to neural inspiratory drive as reflected by electrical activity of the diaphragm (EAdi). Changing positive end-expiratory pressure (PEEP) impacts respiratory muscle load and function and, hence, EAdi. We aimed to evaluate how PEEP affects the breathing pattern and neuroventilatory efficiency during NAVA.

Neurally adjusted ventilatory assist decreases ventilator-induced lung injury and non-pulmonary organ dysfunction in rabbits with acute lung injury.

Objective: To determine if neurally adjusted ventilatory assist (NAVA) that delivers pressure in proportion to diaphragm electrical activity is as protective to acutely injured lungs (ALI) and non-pulmonary organs as volume controlled (VC), low tidal volume (Vt), high positive end-expiratory pressure (PEEP) ventilation.

Design: Prospective, randomized, laboratory animal study.

Subjects: Twenty-seven male New Zealand white rabbits.

Peri-operative adrenocortical response to low-dose (1 microg) ACTH and relation to postoperative complications in patients undergoing elective abdominal surgery.

Background: To test the hypothesis that reduced responsiveness to adrenocorticotropin (ACTH) stimulation before elective major abdominal surgery is associated with an increased incidence of postoperative complications.

Methods: A low-dose (1 microg) ACTH test was performed the day before surgery, during the operation, on the first postoperative day, and before discharge from the hospital in 77 patients undergoing major abdominal surgery (age 62 [47;69] yrs [median, quartiles]; 30 female). Thirty-one patients undergoing minor, non-abdominal surgery (mostly inguinal hernia repair) (age 57 [40;66] yrs; 14 female) served as controls with minor surgical stress.

Physiological response to increasing levels of neurally adjusted ventilatory assist (NAVA).

This study evaluated the response to increasing levels of neurally adjusted ventilatory assist (NAVA), a mode converting electrical activity of the diaphragm (EAdi) into pressure, regulated by a proportionality constant called the NAVA level. Fourteen rabbits were studied during baseline, resistive loading and ramp increases of the NAVA level. EAdi, airway (Paw) and esophageal pressure (Pes), Pes pressure time product (PTPes), breathing pattern, and blood gases were measured.

Titration and implementation of neurally adjusted ventilatory assist in critically ill patients.

Background: Neurally adjusted ventilatory assist (NAVA) delivers assist in proportion to the patient's respiratory drive as reflected by the diaphragm electrical activity (EAdi). We examined to what extent NAVA can unload inspiratory muscles, and whether unloading is sustainable when implementing a NAVA level identified as adequate (NAVAal) during a titration procedure.

Methods: Fifteen adult, critically ill patients with a Pao(2)/fraction of inspired oxygen (Fio(2)) ratio < 300 mm Hg were studied.

Subject-ventilator synchrony during neural versus pneumatically triggered non-invasive helmet ventilation.

Objective: Patient-ventilator synchrony during non-invasive pressure support ventilation with the helmet device is often compromised when conventional pneumatic triggering and cycling-off were used. A possible solution to this shortcoming is to replace the pneumatic triggering with neural triggering and cycling-off-using the diaphragm electrical activity (EA(di)). This signal is insensitive to leaks and to the compliance of the ventilator circuit.

Non-invasive neurally adjusted ventilatory assist in rabbits with acute lung injury.

Objective: Neurally adjusted ventilatory assist uses the electrical activity of the diaphragm (EAdi)--a pneumatically-independent signal--to control the timing and pressure of the ventilation delivered, and should not be affected by leaks. The aim of this study was to evaluate whether NAVA can deliver assist in synchrony and proportionally to EAdi after extubation, with a leaky non-invasive interface.

Design And Setting: Prospective, controlled experimental study in an animal laboratory.

Improved synchrony and respiratory unloading by neurally adjusted ventilatory assist (NAVA) in lung-injured rabbits.

With increasing pressure support ventilation (PSV), a form of pneumatically triggered ventilation, there can be an increase in wasted inspiratory efforts (neural inspiratory efforts that fail to trigger the ventilator). With neurally adjusted ventilatory assist (NAVA), a mode of ventilation controlled by the electrical activity of the diaphragm (EAdi), synchrony should be maintained at high levels of assist. The aim of this study was to evaluate the response to increasing levels of PSV and NAVA on synchrony and diaphragm unloading in lung-injured rabbits.

Influence of neurally adjusted ventilatory assist and positive end-expiratory pressure on breathing pattern in rabbits with acute lung injury.

Objective: To evaluate the influence of neurally adjusted ventilatory assist (NAVA) and positive end-expiratory pressure (PEEP) on the control of breathing in rabbits with acute lung injury.

Design: Prospective animal study.

Setting: Experimental laboratory in a university hospital.

Membrane microdialysis: Evaluation of a new method to assess splanchnic tissue metabolism.

Objective: Measuring peritoneal lactate concentrations could be useful for detecting splanchnic hypoperfusion. The aims of this study were to evaluate the properties of a new membrane-based microdialyzer in vitro and to assess the ability of the dialyzer to detect a clinically relevant decrease in splanchnic blood flow in vivo.

Design: A membrane-based microdialyzer was first validated in vitro.

Effects of low abdominal blood flow and dobutamine on blood flow distribution and on the hepatic arterial buffer response in anaesthetized pigs.

Low cardiac output impairs the hepatic arterial buffer response (HABR). Whether this is due to low abdominal blood flow per se is not known. Dobutamine is commonly used to increase cardiac output, and it may further modify hepatosplanchnic and renal vasoregulation.