Gerald Ihra

Tubeless combined high-frequency jet ventilation for laryngotracheal laser surgery in paediatric anaesthesia.

Background: High‐frequency jet ventilation (HFJV) is an alternative ventilatory approach in airway surgery and for facilitating gas exchange in patients with pulmonary insufficiency. We have developed a new technique of combined HFJV utilising two superimposed jet streams. In this study we describe the application of tubeless supralaryngeal HFJV during laryngotracheal laser surgery in infants and children.

Near-fatal paradoxical gas embolism during gynecological laparoscopy

Laparoscopy is an established procedure of minimally invasive surgery. Although risks and complications during laparoscopy are rare, complications arise from hemorrhage or intestinal perforation, and hemodynamic compromise may result from extensive pneumoperitoneum. Massive gas embolism is a potentially life threatening complication (1–5). We report an incident of severe paradoxical CO2 embolism verified by an intraoperative transesophageal echocardiogram.

High-frequency ventilation for management of respiratory complications after trauma and major orthopaedic surgery

Patients with severe pulmonary insufficiency after trauma or major orthopaedic surgery challenge intensive care medicine with special problems. Impaired respiratory function due to shock, aspiration of gastric contents, infection. bronchopleural fistulae and massive transfusion necessitates increased ventilatory support, especially in patients with pre-existing severe skeletal deformity of the spine presenting with markedly increased chest wall stifkess and/or a highly restrictive lung pattern. Severe thoracic distortion is correlated with considerable reduction of vital capacity to below 25% ofnormal at Cobb angles between 30 and 60%. In patients developing adult respiratory distress syndrome, conventional mechanical respirator therapy has been associated with ventilator-induced lung injury arising fiom overdistension and damage to the remaining functional alveolar units [l]. Morphological changes of alveolar compartments with increased lung sfiess in these patients have been shown to be dismbuted non-homogeneously over the lungs, resulting in different airfilling conditions within particular lung segments. The remaining functional alveoli with preserved normal elasticity are predisposed to volume and barotrauma when airway pressures increase to improve impeded gas exchange. In patients with bronchopled fistulae the &action of tidal volume lost will be proportional to the airway pressure and inversely proportional to the compliance of the lungs. Delivering large tidal volumes requires high inspiratoq pressures and prolonged impiratov time and otien becomes ineffective in paaenB with respiratory fiilure. Consequently. intentional hypoventilation, reduction of peak inspintory pressures and extracorporal CO, removal have been introduced to limit alveolar overdistention. Alternative ventilation strategies have been developed and used to minimise airway pressure, to improve oxygenation at the lowest attainable F,o,. and to reduce mortality. These respiratory modalities include forms of highfiequency (HF) vendation, such as highfiequency jet-vendation (HFJV) and high-frequency percussive ventilation (HFPV). Here we consider the theoretical and technical aspects. ofhighfrequency ventilation, new techca l developments and report our clinical experience with HFJV and HFPV in patients with pulmonary insufficiency afier trauma or major orthopaedic surgery.

Transesophageal echocardiographic assessment of right heart hemodynamics during high-frequency jet ventilation

STUDY OBJECTIVE To evaluate right ventricular dimensions and function by echocardiography in anesthetized patients during superimposed high-frequency jet ventilation (HFJV). DESIGN Prospective clinical study. SETTING University hospital operating room. PATIENTS 20 ASA physical status I patients undergoing elective minor otorhinolaryngological surgery, and undergoing conventional mechanical ventilation with subsequent superimposed HFJV. INTERVENTIONS Two-dimensional transesophageal echocardiography with a 5-MHz multiplane transducer to determine right ventricular dimensions and function from a mid-esophageal view. Insertion of a radial artery catheter for monitoring blood pressure and blood gases. MEASUREMENTS AND MAIN RESULTS Heart rate, mean arterial blood pressure, and right ventricular end-diastolic and end-systolic volumes determined by echocardiography, stroke volume, and ejection fraction. Measurements were performed after 10 minutes of conventional positive pressure ventilation (control) and after 10 minutes of subsequent superimposed HFJV at similar peak and positive end-expiratory airway pressures. Right ventricular systolic and diastolic volumes, stroke volume, and ejection fraction did not reveal statistical significant differences after transition to HFJV. Interventricular septum did not show any abnormalities in motion. In contrast, interatrial septum demonstrated momentary mid-systolic bows toward the left atrium in 9 of 17 patients (53%) during conventional ventilation, but in 15 of 17 patients (88%) during jet ventilation. Heart rate and mean arterial blood pressure remained unchanged, but arterial oxygen tension values were higher and arterial carbon dioxide tension values lower during HFJV. CONCLUSION Transesophageal echocardiographic evaluation of right heart hemodynamics did not show any significant difference after transition of ventilation to superimposed HFJV applying similar airway pressures. Furthermore, superimposed HFJV was safe and effective, it improved oxygenation, and it facilitated carbon dioxide elimination.

SHFJV : Jet-Adapter zur Durchführung der Superponierten Hochfrequenz Jet-Ventilation (SHFJV) über einen Tubus in der Intensivmedizin : Eine technische Neuerung

ZusammenfassungDie superponierte Hochfrequenz Jet-Ventilation (SHFJV) wurde als alternative Beatmungstechnik bei Patienten mit Lungenversagen eingesetzt. Um diese Beatmungsform optimal applizieren zu können, wurde ein spezieller Jet-Adapter entwickelt. Methoden: Dieser Jet-Adapter aus Kunststoff besteht aus einem T-Stück mit vier Kunststoffkanülen und kann an jeden handelsüblichen Endotrachealtubus konnektiert werden. Eine Umintubation auf einen speziellen Jet-Tubus vor dem Beginn der SHFJV ist unnötig. Die simultane hoch- und niederfrequente Beatmung erfolgt über zwei Düsen. Zwei weitere Kanülen dienen der kontinuierlichen Messung des Beatmungsdrucks und der Befeuchtung des Atemgases. Über den Querschenkel des T-Stücks wird ein Atemgasquerstrom geleitet. Eine zusätzliche, verschließbare Öffnung im Querschenkel des T-Stücks ermöglicht das Einführen eines Absaugkatheters oder eines Bronchoskops, so daß keine Diskonnektion vom Respirator erforderlich ist. Ergebnisse: Mit dem Jet-Adapter kann 1. die SHFJV angewendet werden, 2. der Beatmungsdruck kontinuierlich gemessen werden, 3. die Befeuchtung und Erwärmung der Atemgase durchgeführt und 4. Medikamente appliziert oder NO zugeleitet werden Schlußfolgerung: Der Jet-Adapter gewährleistet mit der SHFJV eine suffiziente Beatmung, die mit anderen therapeutischen Möglichkeiten kombiniert werden kann.AbstractDespite advances and technical developments in the area of intensive care medicine is has not been possible to lower the mortality of patients with pulmonary insufficiency. Therefore, alternative ventilation strategies have been developed and applied. One of these ventilation techniques is superimposed high-frequency jet ventilation (SHFJV). For optimal application of SHFJV we designed a special jet-adapter. Methods: This jet-adapter made of plastic consists of a T-piece and four central, small-bore cannulas and can be connected to any commercially available endotracheal tube. Therefore, it does not require reintubation with an endotracheal jet tube when beginning SHFJV. The simultaneous high-frequency and low-frequency jet ventilation is performed over two jet-nozzles that have been designed according to optimal flow dynamic measurements. Two further cannulas are used for continuous airway pressure monitoring and humidification of the applied gases. A pre-warmed and humidified bias flow with exactly defined oxygen concentration is led through the cross-part of the T-piece for gas entrainment. Additionally, the cross-part contains a port that can be opened for endotracheal suctioning or bronchoscopy and makes disconnection of the jet adapter from the endotracheal tube for either purpose unnecessary. Conclusion: The jet adapter can be used: (1) to apply SHFJV; (2) to measure airway pressures continuously; (3) to humidify and warm inspired gases; (4) to administer medications or add nitrous oxide by the inspiratory route, enabling combination with new therapeutic possibilities in the management of patients with severe ARDS.

Perioperative pain management at the Department of Orthopaedic Surgery of the Vienna Medical School

SummarySurgical treatment in the skeleton region and its adjacent tissue causes severe pain, demonstrated by the high demand of anaesthetics in the early postoperative phase. In order to offer adequate and individually adapted pain management, the orthopaedic department is working closely with the departments of anaesthesiology and intensive care medicine of the Vienna Medical University at Vienna’s General Hospital. The aim of this cooperation is to start postoperative rehabilitation early, to increase postoperative quality of life and to reduce the length of hospital stay. The surgical spectrum of the orthopaedic department consists of general orthopaedic, paediatric-orthopaedic-, sport- and rheuma-orthopaedic, tumour and spine interventions. The purpose of this review is to describe the cooperation between orthopaedic surgeons and anaesthetists at the Vienna Medical University.ZusammenfassungOperationen im muskuloskeletalen Bereich, vor allem bei Manipulationen am Periost, gehören zu den schmerzhaftesten Eingriffen des gesamten chirurgischen Spektrums. Dies manifestiert sich in einem höheren Analgetikabedarf in der unmittelbar postoperativen Phase. Um den Ansprüchen einer adäquaten Schmerztherapie in der Orthopädie gerecht zu werden, wurden in enger Kooperation zwischen den Universitätskliniken für Orthopädie und Anästhesie und Intensivmedizin I und II der Medizinischen Universität Wien Konzepte erstellt, die den Patienten eine frühzeitige postoperative Rehabilitation ermöglichen. Weitgehende Schmerzreduktion verbessert die Lebensqualität und verkürzt die Aufenthaltsdauer. Das Spektrum der Universitätsklinik für Orthopädie beinhaltet neben allgemein orthopädischen Operationen auch solche aus den Bereichen Knochen- und Weichteiltumoren, Wirbelsäule, Sport-, Kinder- und Rheumaorthopädie. Operationen werden sowohl stationär als auch ambulant durchgeführt. Ziel dieser Arbeit ist es, die aus der Kooperation zwischen Orthopäden und Anästhesisten entwickelten Konzepte zur perioperativen Schmerztherapie darzustellen.

A new scoring system, using Doppler transmitral diastolic measurement, identifies transient myocardial ischaemia

In patients with acute transient myocardial ischaemia, changes in left ventricular filling produce alterations in transmitral diastolic flow velocity and isovolumic relaxation time. In this study a scoring system derived from isovolumic relaxation time and indices from transmitral flow velocity was used to evaluate perioperative transient myocardial ischaemia. Fifty three patients with known coronary artery disease or at risk were studied. Ischaemic events were assessed using Doppler transoesophageal echocardiography midoesophageal left ventricular four-chamber view planes. Diastolic Doppler ratios of peak early to atrial peak (E/A), deceleration time, deceleration rate and isovolumic relaxation time were scored using standard methods. An evaluation of peri-operative ischaemic events could be important for patients with a non-ischaemic cause for abnormal segmental wall motion, as the use of a two-dimensional scoring system has limitations. Acute changes in the Doppler ratio of peak early to atrial peak must be interpreted cautiously during surgery. Diastolic dysfunction commonly occurs during ischaemia and recognition of this may alter the approach to monitoring as well as to treatment.

Neue Aspekte der hämodynamischen Therapie bei schwerer Brandverletzung

ZusammenfassungSchwer verbrannte Patienten sollten so rasch als möglich in spezialisierten Zentren behandelt werden. Traditionelle Konzepte zur hämodynamischen Therapie können zu einer Überinfusion und weiteren Komplikationen führen. Die unkritische Volumengabe in der Akutphase nach alleiniger Formelberechnung entsprechend der verbrannten Körperoberfläche führt zur massiven interstitiellen Ödembildung und der weiteren Verschlechterung der Organfunktionen. Das erweiterte hämodynamische Monitoring ist die Voraussetzung zur Optimierung der Kreislaufsituation mit Infusionslösungen und Katecholaminen. Innerhalb der ersten Stunden nach dem Verbrennungstrauma sollten Normwerte für Herzindex und Sauerstoffversorgung erreicht werden.AbstractSeverely burned patients are characterized by a high morbidity and mortality. Treatment should be performed in specialized centers to reduce the complication rate and costs and to improve the survival rate. Traditional concepts for volume management may lead to over-resuscitation and to further deterioration of organ function. Hemodynamic evaluation of the critically burned patient relies on an optimal monitoring system. Different approaches and basic considerations to guide therapy with volume and catecholamines are discussed in this article. Normalization of cardiac index and tissue oxygenation should be attempted within the first hours of intensive care therapy.

Perioperatives Schmerzmanagement an der Universitätsklinik für Orthopädie Wien

SummarySurgical treatment in the skeleton region and its adjacent tissue causes severe pain, demonstrated by the high demand of anaesthetics in the early postoperative phase. In order to offer adequate and individually adapted pain management, the orthopaedic department is working closely with the departments of anaesthesiology and intensive care medicine of the Vienna Medical University at Vienna’s General Hospital. The aim of this cooperation is to start postoperative rehabilitation early, to increase postoperative quality of life and to reduce the length of hospital stay. The surgical spectrum of the orthopaedic department consists of general orthopaedic, paediatric-orthopaedic-, sport- and rheuma-orthopaedic, tumour and spine interventions. The purpose of this review is to describe the cooperation between orthopaedic surgeons and anaesthetists at the Vienna Medical University.ZusammenfassungOperationen im muskuloskeletalen Bereich, vor allem bei Manipulationen am Periost, gehören zu den schmerzhaftesten Eingriffen des gesamten chirurgischen Spektrums. Dies manifestiert sich in einem höheren Analgetikabedarf in der unmittelbar postoperativen Phase. Um den Ansprüchen einer adäquaten Schmerztherapie in der Orthopädie gerecht zu werden, wurden in enger Kooperation zwischen den Universitätskliniken für Orthopädie und Anästhesie und Intensivmedizin I und II der Medizinischen Universität Wien Konzepte erstellt, die den Patienten eine frühzeitige postoperative Rehabilitation ermöglichen. Weitgehende Schmerzreduktion verbessert die Lebensqualität und verkürzt die Aufenthaltsdauer. Das Spektrum der Universitätsklinik für Orthopädie beinhaltet neben allgemein orthopädischen Operationen auch solche aus den Bereichen Knochen- und Weichteiltumoren, Wirbelsäule, Sport-, Kinder- und Rheumaorthopädie. Operationen werden sowohl stationär als auch ambulant durchgeführt. Ziel dieser Arbeit ist es, die aus der Kooperation zwischen Orthopäden und Anästhesisten entwickelten Konzepte zur perioperativen Schmerztherapie darzustellen.

Perioperative pain management at the Department of Orthopaedic Surgery of the Vienna Medical School@@@Perioperatives Schmerzmanagement an der Universitätsklinik für Orthopädie Wien

SummarySurgical treatment in the skeleton region and its adjacent tissue causes severe pain, demonstrated by the high demand of anaesthetics in the early postoperative phase. In order to offer adequate and individually adapted pain management, the orthopaedic department is working closely with the departments of anaesthesiology and intensive care medicine of the Vienna Medical University at Vienna’s General Hospital. The aim of this cooperation is to start postoperative rehabilitation early, to increase postoperative quality of life and to reduce the length of hospital stay. The surgical spectrum of the orthopaedic department consists of general orthopaedic, paediatric-orthopaedic-, sport- and rheuma-orthopaedic, tumour and spine interventions. The purpose of this review is to describe the cooperation between orthopaedic surgeons and anaesthetists at the Vienna Medical University.ZusammenfassungOperationen im muskuloskeletalen Bereich, vor allem bei Manipulationen am Periost, gehören zu den schmerzhaftesten Eingriffen des gesamten chirurgischen Spektrums. Dies manifestiert sich in einem höheren Analgetikabedarf in der unmittelbar postoperativen Phase. Um den Ansprüchen einer adäquaten Schmerztherapie in der Orthopädie gerecht zu werden, wurden in enger Kooperation zwischen den Universitätskliniken für Orthopädie und Anästhesie und Intensivmedizin I und II der Medizinischen Universität Wien Konzepte erstellt, die den Patienten eine frühzeitige postoperative Rehabilitation ermöglichen. Weitgehende Schmerzreduktion verbessert die Lebensqualität und verkürzt die Aufenthaltsdauer. Das Spektrum der Universitätsklinik für Orthopädie beinhaltet neben allgemein orthopädischen Operationen auch solche aus den Bereichen Knochen- und Weichteiltumoren, Wirbelsäule, Sport-, Kinder- und Rheumaorthopädie. Operationen werden sowohl stationär als auch ambulant durchgeführt. Ziel dieser Arbeit ist es, die aus der Kooperation zwischen Orthopäden und Anästhesisten entwickelten Konzepte zur perioperativen Schmerztherapie darzustellen.