Jan Schumacher

Guy's and St Thomas' NHS Foundation Trust · Department of Anaesthetics

Background The COVID-19 pandemic has highlighted the importance of respiratory protective equipment for clinicians performing airway management. Aim To evaluate the impact of powered air-purifying respirators, full-face air-purifying respirators and filtering facepieces on specially trained anaesthesiologists performing difficult airway procedures...

Introduction This study was designed to determine whether improvised respirators based on modified full-face snorkel masks are able to pass a standard qualitative fit test. Methods This is a prospective crossover study conducted in 16 staff. Fit-tests were conducted on masks mated to (1) an anaesthetic breathing circuit heat and moisture exchange...

Introduction This study was designed to determine the respiratory safety of improvised respirators based on modified full-face snorkel masks, making comparisons with a purpose-designed mask Methods This is a prospective crossover study conducted on ten recruits. Volunteers wore snorkel masks mated to an anaesthetic heat and moisture exchange filte...

The current international coronavirus disease 19 health crisis underlines the importance of adequate and suitable personal protective equipment for clinical staff during acute airway management. This study compares the impacts of standard air purifying respirators and powered air purifying respirators during simulated difficult airway scenarios. Tw...

Introduction Recent terror attacks and assassinations involving highly toxic chemical weapons have stressed the importance of sufficient respiratory protection of medical first responders and receivers. As full-face respirators cause perceptual-motor impairment, they not only impair vision but also significantly reduce speech intelligibility. The r...

A 52-year-old patient was scheduled for a cystoscopy. Anesthesia was induced by intravenous injection of fentanyl and propofol. After administration of atracurium, he became bradycardic and suffered a cardiac arrest. Despite prolonged cardiopulmonary resuscitation, the patient could not be revived. Electrolytes and hemoglobin levels were normal, an...

Recent incidents involving chemical, biological, radiological and nuclear substances have stressed the importance of sufficient personal protection equipment for medical first-responders. Modern lightweight, battery-independent, suit ensembles may prove superior to the current protective suit used in the UK. This study compared the powered respirat...

We read with great interest the study of Schroeder et al and found it a valuable contribution to a very contemporary topic in emergency and disaster medicine. We would however raise two concerns regarding the study design and research governance. The authors state that the participants were using the gastight ISOTEMP-4000 chemical protection overa...

Introduction An adequate level of personal protective equipment (PPE) is necessary when treating patients with highly infectious diseases or those contaminated with hazardous substances. Following National Institute for Health Research's Research Centre (London, United Kingdom) approval, the authors of this study conducted a survey of specialist re...

We conducted a survey to assess clinicians' knowledge of personal protective equipment (PPE) requirements for infectious diseases and biochemical warfare agents. A safe level of PPE is essential when treating patients with highly infectious diseases or those contaminated with hazardous substances. The recent Ebola virus disease (EVD) outbreak in We...

Introduction Emergency pediatric life support (EPLS) of children infected with transmissible respiratory diseases requires adequate respiratory protection for medical first responders. Conventional air-purifying respirators (APR) and modern loose-fitting powered air-purifying respirator-hoods (PAPR-hood) may have a different impact during pediatric...

The threat of mass casualties caused by an unconventional terrorist attack is a challenge for the public health system, with special implications for emergency medicine, anesthesia, and intensive care. Advanced life support of patients injured by chemical or biological warfare agents requires an adequate level of personal protection. The aim of thi...

Bag-valve-mask ventilation is a key component of life support, but only one handheld resuscitator is designed to operate in contaminated or toxic atmospheres. After Institutional Review Board approval, the efficacy of this device was evaluated. The distal trachea of a Laerdal Airway Management Trainer was connected to a mechanical Draeger Volumeter...

Advanced life support of patients contaminated with chemical, biological, radiological or nuclear (CBRN) substances requires adequate respiratory protection for medical first responders. Conventional and powered air-purifying respirators may exert a different impact during resuscitation and therefore require evaluation. This will help to improve ma...

Fluid therapy in cardiac surgery patients should be managed according to predefined target parameters. In case infusions of crystalloid solutions are applied, full-electrolytes preparations should be preferred. Both, HES and gelatin products - under certain conditions human albumin as well - may be used as colloid solutions. At present, existing li...

Bag-valve-mask ventilation is a key component of life support, but only one handheld resuscitator is designed to operate in contaminated or toxic atmospheres. Following Institutional Review Board approval we determined the efficacy of this device. Twenty anaesthetists ventilated a modified manikin, either with or without a combination filter attach...

Emergency room personnel are threatened by secondary poisoning when treating victims affected by chemical warfare agents. Therefore, resuscitation skills practised with respiratory protection equipment in place require evaluation. We investigated the influence of wearing air-purifying respirators on the simulated resuscitation of chemical warfare a...

The modified algorithm for the non-invasive determination of cardiac output (CO) by electrical bioimpedance-electrical velocimetry (EV)-has been reported to give reliable results in comparison with echocardiography and pulmonary arterial thermodilution (PA-TD) in patients either before or after cardiac surgery. The present study was designed to det...

Medical first responders and emergency room personnel potentially are threatened by exposure to primary or secondary intoxication by chemical, biological, radiological or nuclear (CBRN) substances. The impact of personal respiratory protection by air-purifying respirators on the performance of resuscitation requires evaluation. This will help to im...

To counteract the contribution of angiotensin II to shock-induced ischaemic organ damage pharmacologic blockade of the renin-angiotensin-system (RAS) is currently under investigation. To evaluate potential side-effects of RAS blockade regarding capillary leak, we studied alterations in microvascular permeability in various organs during haemorrhagi...

Lübeck, Univ., Habil.-Schr., 2003. Department of Anaesthesiology, University of Luebeck, Germany,

To investigate the time course of fluid extravasation during cardiopulmonary bypass (CPB), we measured the peripheral tissue thickness (TT) by A-mode ultra-sound in 34 patients undergoing elective cardiac surgery. TT of the forehead was determined by a handheld A-mode ultrasound device and 10 MHz Transducer at nine defined intervals, from the night...

Shock-induced enhanced capillary permeability is associated with alterations in the interstitial matrix composition and contributes to organ damage. This study was designed to evaluate albumin extravasation in various organ tissues during severe, hemorrhagic shock without fluid resuscitation and reperfusion. Target value of hemorrhagic shock was a...

Respiratory depression and apnoea during anaesthesia may lead to hypoxia and myocardial ischaemia. A self-inflating miniature bag-mask device was assembled combining characteristics from the Ambu-bag and the Kuhn-system. This bag-mask device permitted ventilation during anaesthesia-induced apnoea in rats until a safe airway by tracheotomy was achie...

Postoperative acute lung injury (ALI) contributes to the morbidity and mortality following cardiopulmonary bypass (CPB). To determine whether the presence of matrix metalloproteinases (MMPs) is associated with ALI after CPB, MMP-2 and MMP-9 activities in bronchoalveolar lavage fluid (BALF) were compared with parameters indicating impaired gas excha...

Proper oxygenation is critical to prevent hypoxia and myocardial ischemia in animals during pharmacological sedation. The authors compared the efficacy of two oxygen delivery masks during sedation and spinal anesthesia for knee surgery in sheep.

Implications: This case report shows that atelectasis of the left lung-induced by extrinsic compression of the left main bronchus by an aortic aneurysm and persisting despite aggressive conservative treatment-may be effectively treated by bronchial stenting and high-frequency percussive ventilation.

While point-of-care testing (POCT) is being used increasingly as a basis for deciding on perioperative erythrocyte transfusion, no valid standards currently exist concerning the accuracy of Hb concentration measurements. For clinical employment, however, the confidence limits (+/-2 SD) of these measurements should lie close to 5 g/l. The aim of the...

Objective.Measurement of functional residual capacity (FRC) is of considerable interest for monitoring ventilated patients in ICUs. However, the lack of instruments that can be used in the clinical setting has so far impeded the routine application of this measurement. It was the aim of our study to evaluate the accuracy and the reproducibility of...

The (patho-)physiological role of human urotensin II (hU-II) - the most potent endogenous vasoconstrictor yet described - remains to be defined [1]. Preliminary evidence suggests that hU-II levels during cardiac surgery are increased in patients with myocardial dysfunction [2]. However, it is not known, if hU-II plasma concentrations are related to...

Previous studies demonstrated a biphasic time course with post-operative dissociation of blood levels of cortisol and ACTH in patients undergoing major surgery and critically ill patients. A possible role of endothelin and atrial natriuretic peptide (ANP) in the dissociation of concentrations of cortisol and ACTH in critically ill patients has been...

The cardiovascular effects of volatile anesthetics during sepsis sets patients at high risk for hemodynamic deterioration. We compared the microcirculatory alterations in skeletal muscle under anesthesia with isoflurane, enflurane, and halothane in an endotoxemic rat preparation. Twenty-one Sprague-Dawley rats under continuous hemodynamic monitorin...

The authors considered three protocols for spinal anesthesia using sheep as a model. An appropriate spinal anesthesia method would obviate the need for general anesthesia in certain surgical approaches.

Measurement of functional residual capacity (FRC) is of considerable interest for monitoring ventilated patients in ICUs. However, the lack of instruments that can be used in the clinical setting has so far impeded the routine application of this measurement. It was the aim of our study to evaluate the accuracy and the reproducibility of a simplifi...

We evaluated the changes of tissue layer thickness in circumscribed superficial tissue areas with a 10-MHz A-mode and a 20-MHz B-mode ultrasound device under alterations in body posture and plasma volume to detect fluid shifts between the different compartments. In 20 male volunteers, we measured tissue thickness by A mode and corium and subcutis t...

The diuretic effects of atrial natriuretic peptide (ANP) are known to be reduced if renin-angiotensin-aldosteron system (RAAS) activity is increased. Studies of ANP-effects in intact organisms are hampered by the vasodilating action of this hormone, decreasing arterial blood pressure and thereby the diuretic activity of ANP itself. To investigate w...

The rate of intercompartmental fluid volume changes during hemodialysis (HD) is a major determinant of dialysis-induced hypotension and lacks direct monitoring. The aim of the study was to evaluate the feasibility of tissue thickness (TT) measurement in monitoring the mobilization of interstitial fluids during HD. We studied the intradialytic chang...

The findings about mechanisms regulating production and excretion of urodilatin [ANP-(95-126)], a member of the atrial natriuretic peptide (ANP) family, are controversial. To elucidate a possible relationship between arterial blood pressure and renal urodilatin excretion, we studied the effects of different perfusion pressures on urine flow (UV), u...

The findings about mechanisms regulating production and excretion of urodilatin [ANP-(95–126)], a member of the atrial natriuretic peptide (ANP) family, are controversial. To elucidate a possible relationship between arterial blood pressure and renal urodilatin excretion, we studied the effects of different perfusion pressures on urine flow (UV), u...