Markus Kredel - Academia.edu (original) (raw)

Papers by Markus Kredel

Critical care (London, England), 2014

Lung protective ventilation is the mainstay of treatment in acute respiratory distress syndrome (... more Lung protective ventilation is the mainstay of treatment in acute respiratory distress syndrome (ARDS). However, in patients who have severe ARDS and who are receiving extracorporeal membrane oxygenation (ECMO), the ventilation strategy might be modified. This was the subject of the review by Schmidt and colleagues [1] in a recent issue of Critical Care. We invited 39 ARDS centers in Germany to participate in a survey about respiratory and adjuvant ARDS therapy. The questionnaire was completed by 25 centers, 22 of which applied ECMO therapy at the specific time point of the survey (2011 to 2012).

BioMed Research International, 2014

Missed or delayed detection of progressive neuronal damage after traumatic brain injury (TBI) may... more Missed or delayed detection of progressive neuronal damage after traumatic brain injury (TBI) may have negative impact on the outcome. We investigated whether routine follow-up CT is beneficial in sedated and mechanically ventilated trauma patients. The study design is a retrospective chart review. A routine follow-up cCT was performed 6 hours after the admission scan. We defined 2 groups of patients, group I: patients with equal or recurrent pathologies and group II: patients with new findings or progression of known pathologies. A progression of intracranial injury was found in 63 patients (42%) and 18 patients (12%) had new findings in cCT 2 (group II). In group II a change in therapy was found in 44 out of 81 patients (54%). 55 patients with progression or new findings on the second cCT had no clinical signs of neurological deterioration. Of those 24 patients (44%) had therapeutic consequences due to the results of the follow-up cCT. We found new diagnosis or progression of intracranial pathology in 54% of the patients. In 54% of patients with new findings and progression of pathology, therapy was changed due to the results of follow-up cCT. In trauma patients who are sedated and ventilated for different reasons a routine follow-up CT is beneficial.

Ultraschall in der Medizin, 2005

We studied the anatomy of the sciatic nerve and its division into the tibial and peroneal part us... more We studied the anatomy of the sciatic nerve and its division into the tibial and peroneal part using handheld ultrasound in adults. We wanted to evaluate the feasibility of ultrasound-guided identification of the sciatic nerve in the popliteal fossa and the correlation of the findings by ultrasound with patients' characteristics. 74 volunteers were randomly selected. Using a handheld ultrasound system with a 5-10 MHz linear array probe the popliteal fossa and the back of the thigh were examined and measured. Using a caliper the distance of the joint line to the nerve division was measured. The sciatic nerve and its division were depicted by ultrasound. We could depict the sciatic nerve in all volunteers and its division in 53 of 74 (72%) volunteers. The position of nerve division showed large anatomic variation. A significant correlation between the width of the knee-joint line and the depth of the nerve division could be demonstrated. We conclude that handheld ultrasound is able to depict the sciatic nerves division. To block the nerve by one injection a more proximal access or visualization by mobile ultrasound is recommended. In addition the surrounding anatomic structures can be depicted as well.

Perfusion, 2006

This prospective large-animal study was performed to evaluate the contribution of arterio-venous ... more This prospective large-animal study was performed to evaluate the contribution of arterio-venous extracorporeal lung assist (AV-ECLA) to pulmonary gas exchange in a porcine lavage-induced acute lung injury model. Fifteen healthy female pigs, weighing 50.39/3.8 kg (mean9/SD), were included. After induction of general anaesthesia and controlled ventilation, an arterial line and a pulmonary artery catheter were inserted. Saline lung lavage was performed until the PaO 2 decreased to 519/16 mmHg. After a stabilization period of 60 min, the femoral artery and vein were cannulated and a low-resistance membrane lung was interposed. Under apnoeic oxygenation, variations of sweep-gas flow were performed every 20 min in order to evaluate the membrane lung's efficacy, in terms of carbon dioxide (CO 2 ) removal and oxygen (O 2 ) uptake. Although AV-ECLA is highly effective in eliminating CO 2 , if combined with apnoeic oxygenation, normocapnia was not achievable. AV-ECLA's contribution to oxygenation during severe hypoxemia was antagonized by a significant increase in the pulmonary shunt fraction. Perfusion (2006) 21, 277 Á 284. Arterio-venous extracorporeal lung assist and gas exchange J Brederlau et al. AV-ECLA, arteriovenous extracorporeal lung assist; AV-ECLA-flow, blood flow through membrane lung; CO, cardiac output; CVP, central venous pressure; HR, heart rate; MAP, mean arterial pressure; MPAP, mean pulmonary artery pressure; PCWP, pulmonary capillary wedge pressure.

BMC Anesthesiology, 2006

To compare the effect of a sustained inflation followed by an incremental mean airway pressure tr... more To compare the effect of a sustained inflation followed by an incremental mean airway pressure trial during conventional and high-frequency oscillatory ventilation on oxygenation and hemodynamics in a large porcine model of early acute respiratory distress syndrome.

BMC Anesthesiology, 2006

Background: This animal study was conducted to assess the combined effects of high frequency osci... more Background: This animal study was conducted to assess the combined effects of high frequency oscillatory ventilation (HFOV) and prone positioning on pulmonary gas exchange and hemodynamics.

Ultraschall in der Medizin, 2008

We examined the feasibility of a newly developed handheld ultrasound device capable of transesoph... more We examined the feasibility of a newly developed handheld ultrasound device capable of transesophageal echocardiography (TEE). Prospective case series in a non-cardiac surgical intensive care unit including 18 deeply sedated and endotracheally intubated critically ill non-cardiac surgical patients. The imaging quality and findings of a newly developed handheld device were compared to those of a cart-based standard TEE system. All patients were examined with both systems in a randomized order by independent examiners performing a structured and complete TEE examination. The imaging quality of the standard cardiac cross sections and spectral Doppler studies of the cardiac valves was assessed on an analog scale from 1 (excellent) to 5 (insufficient). The time requirements for each study were documented. We did not detect significant differences in two-dimensional imaging. Continuous-wave Doppler imaging of the left ventricular outflow tract and pulsed-wave Doppler imaging of the transmitral flow were significantly better (p <0.001) with the standard system. Handheld TEE is a goal-oriented diagnostic tool, which may sufficiently replace a standard cart-based TEE system in unstable critically ill patients when an acute gross diagnosis is required.

Journal of Trauma and Acute Care Surgery, 2012

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) can be used as an "ultima ratio" strategy ... more BACKGROUND: Extracorporeal membrane oxygenation (ECMO) can be used as an "ultima ratio" strategy in multiple injured patients with severe thoracic trauma. However, systemic anticoagulation during ECMO is recommended and thus traumatic brain injury (TBI) and intracranial bleeding are well-accepted contraindications for ECMO therapy.

Perfusion (United Kingdom), 2012

Veterinary Anaesthesia and Analgesia, 2008

Objective To evaluate the feasibility of ultrasound guided vascular access in pigs by comparing c... more Objective To evaluate the feasibility of ultrasound guided vascular access in pigs by comparing central venous and arterial cannulation techniques.

Medical Science Monitor, 2011

Ventilation with high positive end-expiratory pressure (PEEP) can lead to hepatic dysfunction. Th... more Ventilation with high positive end-expiratory pressure (PEEP) can lead to hepatic dysfunction. The aim of this study was to investigate the hepatic effects of strategies using high airway pressures either in pressure-controlled ventilation (PCV) or in high-frequency oscillatory ventilation (HFOV) combined with an arteriovenous extracorporeal lung assist (ECLA).

The Journal of Trauma: Injury, Infection, and Critical Care, 2007

To compare the combined effects of arteriovenous extracorporeal lung assist (AV-ECLA) and high-fr... more To compare the combined effects of arteriovenous extracorporeal lung assist (AV-ECLA) and high-frequency oscillatory ventilation (HFOV) on pulmonary gas exchange, hemodynamics, and respiratory parameters in a lavage-induced porcine lung injury model. A prospective, randomized animal study. Saline lung lavage was performed in 33 healthy female pigs, weighing 52 +/- 4.1 kg (mean +/- SD), until the Pao2 decreased to 53 +/- 8 mm Hg. After a stabilization period of 60 minutes, the animals were randomly assigned to four groups: group 1, pressure-controlled ventilation (PCV) with a tidal volume of 6 mL/kg; group 2, PCV with a tidal volume of 6 mL/kg and AV-ECLA; group 3, HFOV; group 4, HFOV and AV-ECLA. In groups 2 and 4, the femoral artery and vein were cannulated and a low-resistance membrane lung was interposed. After isolated evaluation of AV-ECLA, the mean airway pressure was increased by 3 cm H2O from 16 to 34 cm H2O every 20 minutes, accompanied by blood gas analyses and measurements of respiratory and hemodynamic variables. Only in AV-ECLA-treated animals was normocapnia achieved. No significant increase of Pao2 attributable to AV-ECLA alone was detected. Mean airway pressure augmentation resulted in a significant increase in Pao2 in all groups. Peak inspiratory pressure was significantly lower in HFOV-treated animals. The combination of AV-ECLA and HFOV resulted in normocapnia and comparable Pao2, although a smaller ventilator pressure amplitude was applied. Long-term animal studies are needed to assess whether this approach results in further lung protection.

The Journal of Trauma: Injury, Infection, and Critical Care, 2009

Whole-body multislice helical computed tomography (MSCT) becomes increasingly important as a diag... more Whole-body multislice helical computed tomography (MSCT) becomes increasingly important as a diagnostic tool in patients with multiple injuries. We describe time requirement of two different diagnostic approaches to multiple injuries one with whole-body-MSCT (MSCT Trauma-Protocol) as the sole radiologic procedure and one with conventional use of radiography, combined with abdominal ultrasound and organ focused CT (Conventional-Trauma-Protocol). Observational study with retrospective analysis of time requirements for resuscitation, diagnostic workup and transfer to definitive treatment after changing from conventional to MSCT Trauma-Protocol. Group I: data from trauma patients imaged with whole-body MSCT. Group II: data of trauma patients investigated with conventional trauma protocol before the introduction of MSCT-Trauma-Protocol. The complete diagnostic workup in group I (n = 82) was finished after 23 minutes (17-33 minutes) [median; interquartile range (IQR)] and after 70 minutes (IQR, 56-85) in group II (n = 79). The definitive management plan based on a completed diagnostic workup was devised after 47 minutes (IQR, 37-59) in group I and after 82 minutes (IQR, 66-110) in group II. A whole-body MSCT-based diagnostic approach to multiple injuries might shorten the time interval from arrival in the trauma emergency room until obtaining a final diagnosis and management plan in patients with multiple injuries and might, therefore, contribute to improvements in patient care.

The Journal of Trauma: Injury, Infection, and Critical Care, 2008

ABSTRACT

Journal of PeriAnesthesia Nursing, 2004

Background-Untreated, one third of surgical patients suffer postoperative nausea and vomiting (PO... more Background-Untreated, one third of surgical patients suffer postoperative nausea and vomiting (PONV). The relative benefit of prophylactic interventions remains unknown, as does the efficacy of combining interventions. We therefore compared the efficacy of six antiemetic interventions and their combinations.

Journal of Critical Care, 2012

Elimination of carbon dioxide by an arteriovenous extracorporeal lung assist (av-ECLA) can facili... more Elimination of carbon dioxide by an arteriovenous extracorporeal lung assist (av-ECLA) can facilitate the lung protective capabilities of high-frequency oscillatory ventilation (HFOV). This case series describes patients treated with HFOV because of severe respiratory failure with and without additional av-ECLA. A retrospective analysis of 31 patients regarding patient characteristics, gas exchange, respirator settings, hemodynamics, and outcome. In 18 patients, av-ECLA was started before, together with, or during HFOV. The initial arterial carbon dioxide tension before HFOV and av-ECLA was higher in patients who received av-ECLA compared with patients without (P = .043): 65 (48-84) mm Hg and 50 (44-60) mmHg (median and interquartile range). The initial arterial oxygen tension (Pao(2))/inspiratory oxygen fraction (Fio(2)) index in patients who received av-ECLA was 79 (63-133) mm Hg. The Pao(2)/Fio(2) index immediately before HFOV was 84 (65-124) mm Hg (av-ECLA) and 121 (68-150) mmHg (no av-ECLA) and improved to 149 (89-231) mm Hg and 200 (117-233) mmHg during HFOV. Similarly, the oxygenation index improved. No statistically significant differences among groups were detected for Pao(2)/Fio(2) index, oxygenation index, and arterial carbon dioxide tension immediately before and during HFOV. The hospital mortality was 39% (av-ECLA) and 69% (no av-ECLA). High-frequency oscillatory ventilation improved the oxygenation in patients with severe respiratory failure. Additional av-ECLA may facilitate using lung protective HFOV settings in more severe lung injury and hypercapnia.

Intensive Care Medicine, 2007

High-frequency oscillatory ventilation (HFOV) may reduce ventilator-induced lung injury in experi... more High-frequency oscillatory ventilation (HFOV) may reduce ventilator-induced lung injury in experimental neonatal respiratory distress. However, these data permit no conclusions for large animals or adult patients with acute respiratory distress syndrome (ARDS), because in neonates higher frequencies and lower amplitudes can be used, resulting in lower tidal volumes (VT) and airway pressures. The aim of this study was to compare gas exchange, lung histopathology and inflammatory cytokine expression during lung-protective pressure-controlled ventilation (PCV) and HFOV in a long-term large-animal model of ARDS. Prospective, randomized, controlled pilot study. University animal laboratory. Sixteen female pigs (55.3 +/- 3.9 kg). After induction of ARDS by repeated lavage, the animals were randomly assigned to PCV (VT = 6 ml/kg) and HFOV (6 Hz). After lung injury, a standardised lung recruitment was performed in both groups, and ventilation was continued for 24 h. After lung recruitment sustained improvements in the oxygenation index were observed in both groups. The mean airway pressure (mPaw) was significantly lower in the HFOV group during the experiment (p < 0.01). Histologically, lung inflammation was significantly ameliorated in the HFOV group (p < 0.05). The messenger RNA expression of IL-1-beta in lung tissue was significantly lower in the HFOV-treated animals (p < 0.01). These data suggest that HFOV compared with conventional lung-protective ventilation can reduce lung inflammation in a large-animal 24-h model of ARDS. Furthermore, it was shown that lung recruitment leads to sustained improvements in gas exchange with a significantly lower mPaw when HFOV is used.

Experimental Lung Research, 2013

Oxygenation during high-frequency oscillatory ventilation is secured by a high level of mean airw... more Oxygenation during high-frequency oscillatory ventilation is secured by a high level of mean airway pressure. Our objective was to identify a pressure difference between the airway opening of the respiratory circuit and the trachea during application of different oscillatory frequencies. Six female Pietrain pigs (57.1 ± 3.6 kg) were first ventilated in a conventional mechanical ventilation mode. Subsequently, the animals were switched to high-frequency oscillatory ventilation by setting mean airway opening pressure 5 cmH(2)O above the one measured during controlled mechanical ventilation. Measurements at the airway opening and at tracheal levels were performed in healthy lungs and after induction of acute lung injury by surfactant depletion. During high-frequency oscillatory ventilation, the airway opening pressure was set at a constant level. The pressure amplitude was fixed at 90 cmH(2)O. Starting from an oscillatory frequency of 3 Hz, the frequency was increased in steps of 3 Hz to 15 Hz and then decreased accordingly. At each frequency, measurements were performed in the trachea through a side-lumen of the endotracheal tube and the airway opening pressure was recorded. The pressure difference was calculated. At every oscillatory frequency, a pressure loss towards the trachea could be shown. This pressure difference increased with higher oscillatory frequencies (3 Hz 2.2 ± 2.1 cmH(2)O vs. 15 Hz 7.5 ± 1.8 cmH(2)O). The results for healthy and injured lungs were similar. Tracheal pressures decreased with higher oscillatory frequencies. This may lead to pulmonary derecruitment. This has to be taken into consideration when increasing oscillatory frequencies and differentiated pressure settings are mandatory.

Experimental Lung Research, 2011

The separate effects of positive end-expiratory pressure (PEEP) and intravascular volume administ... more The separate effects of positive end-expiratory pressure (PEEP) and intravascular volume administration on the histopathologic lung injury were not investigated in experimental lung injury previously. The authors hypothesized that high PEEP and a restrictive volume therapy would yield the best oxygenation and the least degree of lung injury. Pigs (52.8 ± 3.4 kg) underwent saline lavage-induced lung injury. The animals were ventilated either with low PEEP (mean PEEP 9 to 12 cm H₂O) and liberal volume therapy using hydroxyethyl starch (LowP/Vol+) or high PEEP (mean PEEP 21 cm H₂O) combined with recruitment maneuvers and liberal (HighP/Vol+) or restrictive volume therapy (HighP/Vol-). After 6.5 hours, lung injury was determined by using a histopathologic score evaluating overdistension, edema, exsudation, and inflammation. When volume therapy was liberal, high PEEP (HighP/Vol+) improved the Pao₂/Fio₂ index (416 ± 80 mm Hg) compared to low PEEP (LowP/Vol+, 189 ± 55 mm Hg; P < .05) but there was no difference in the median (interquartile range) lung injury score: 1.6 (1.2-1.9) and 1.9 (1.4-2.0). High PEEP with restrictive volume therapy (HighP/Vol-) did not further improve oxygenation (400 ± 55 mm Hg) but ameliorated the degree of lung injury: 0.9 (0.8-1.4) (P < .05). In lavage-induced lung injury, high PEEP improved oxygenation, but restrictive volume administration markedly reduced the lung injury score, mainly by reduced edema.

Experimental Lung Research, 2010

In order to optimize the lung-protective potential of high-frequency oscillatory ventilation (HFO... more In order to optimize the lung-protective potential of high-frequency oscillatory ventilation (HFOV), it is currently recommended to maximize oscillatory frequencies. However, very high frequencies may lead to insufficient CO(2) elimination with severe respiratory acidosis. Arteriovenous extracorporeal lung assist (av-ECLA) allows near total CO(2) removal, thereby allowing for maximization of the lung-protective potential of HFOV. The aim of this study was to determine the impact of HFOV and av-ECLA on lung inflammation and function compared to conventional lung-protective ventilation. In a porcine surfactant depletion model of lung injury, the authors randomly assigned 16 female pigs to conventional lung-protective ventilation and HFOV/ECLA. Both strategies were combined with an "open-lung" approach. Gas exchange and hemodynamic parameters were measured at intervals during the 24-hour study period. Postmortem, lung tissue was analyzed to determine histological damage and lung inflammation. The authors found that the combination of HFOV and av-ECLA (1) allows significant reductions in mean and peak airway pressures; and (2) reduces histological signs of lung inflammation in the basal regions of the lung. HFOV/av-ECLA reduces histological signs of lung inflammation compared to conventional lung-protective ventilation strategies. Thus, combination of HFOV and av-ECLA might be a further lung-protective tool if conventional ventilation strategies are failing.

Critical care (London, England), 2014

Lung protective ventilation is the mainstay of treatment in acute respiratory distress syndrome (... more Lung protective ventilation is the mainstay of treatment in acute respiratory distress syndrome (ARDS). However, in patients who have severe ARDS and who are receiving extracorporeal membrane oxygenation (ECMO), the ventilation strategy might be modified. This was the subject of the review by Schmidt and colleagues [1] in a recent issue of Critical Care. We invited 39 ARDS centers in Germany to participate in a survey about respiratory and adjuvant ARDS therapy. The questionnaire was completed by 25 centers, 22 of which applied ECMO therapy at the specific time point of the survey (2011 to 2012).

BioMed Research International, 2014

Missed or delayed detection of progressive neuronal damage after traumatic brain injury (TBI) may... more Missed or delayed detection of progressive neuronal damage after traumatic brain injury (TBI) may have negative impact on the outcome. We investigated whether routine follow-up CT is beneficial in sedated and mechanically ventilated trauma patients. The study design is a retrospective chart review. A routine follow-up cCT was performed 6 hours after the admission scan. We defined 2 groups of patients, group I: patients with equal or recurrent pathologies and group II: patients with new findings or progression of known pathologies. A progression of intracranial injury was found in 63 patients (42%) and 18 patients (12%) had new findings in cCT 2 (group II). In group II a change in therapy was found in 44 out of 81 patients (54%). 55 patients with progression or new findings on the second cCT had no clinical signs of neurological deterioration. Of those 24 patients (44%) had therapeutic consequences due to the results of the follow-up cCT. We found new diagnosis or progression of intracranial pathology in 54% of the patients. In 54% of patients with new findings and progression of pathology, therapy was changed due to the results of follow-up cCT. In trauma patients who are sedated and ventilated for different reasons a routine follow-up CT is beneficial.

Ultraschall in der Medizin, 2005

We studied the anatomy of the sciatic nerve and its division into the tibial and peroneal part us... more We studied the anatomy of the sciatic nerve and its division into the tibial and peroneal part using handheld ultrasound in adults. We wanted to evaluate the feasibility of ultrasound-guided identification of the sciatic nerve in the popliteal fossa and the correlation of the findings by ultrasound with patients' characteristics. 74 volunteers were randomly selected. Using a handheld ultrasound system with a 5-10 MHz linear array probe the popliteal fossa and the back of the thigh were examined and measured. Using a caliper the distance of the joint line to the nerve division was measured. The sciatic nerve and its division were depicted by ultrasound. We could depict the sciatic nerve in all volunteers and its division in 53 of 74 (72%) volunteers. The position of nerve division showed large anatomic variation. A significant correlation between the width of the knee-joint line and the depth of the nerve division could be demonstrated. We conclude that handheld ultrasound is able to depict the sciatic nerves division. To block the nerve by one injection a more proximal access or visualization by mobile ultrasound is recommended. In addition the surrounding anatomic structures can be depicted as well.

Perfusion, 2006

This prospective large-animal study was performed to evaluate the contribution of arterio-venous ... more This prospective large-animal study was performed to evaluate the contribution of arterio-venous extracorporeal lung assist (AV-ECLA) to pulmonary gas exchange in a porcine lavage-induced acute lung injury model. Fifteen healthy female pigs, weighing 50.39/3.8 kg (mean9/SD), were included. After induction of general anaesthesia and controlled ventilation, an arterial line and a pulmonary artery catheter were inserted. Saline lung lavage was performed until the PaO 2 decreased to 519/16 mmHg. After a stabilization period of 60 min, the femoral artery and vein were cannulated and a low-resistance membrane lung was interposed. Under apnoeic oxygenation, variations of sweep-gas flow were performed every 20 min in order to evaluate the membrane lung's efficacy, in terms of carbon dioxide (CO 2 ) removal and oxygen (O 2 ) uptake. Although AV-ECLA is highly effective in eliminating CO 2 , if combined with apnoeic oxygenation, normocapnia was not achievable. AV-ECLA's contribution to oxygenation during severe hypoxemia was antagonized by a significant increase in the pulmonary shunt fraction. Perfusion (2006) 21, 277 Á 284. Arterio-venous extracorporeal lung assist and gas exchange J Brederlau et al. AV-ECLA, arteriovenous extracorporeal lung assist; AV-ECLA-flow, blood flow through membrane lung; CO, cardiac output; CVP, central venous pressure; HR, heart rate; MAP, mean arterial pressure; MPAP, mean pulmonary artery pressure; PCWP, pulmonary capillary wedge pressure.

BMC Anesthesiology, 2006

To compare the effect of a sustained inflation followed by an incremental mean airway pressure tr... more To compare the effect of a sustained inflation followed by an incremental mean airway pressure trial during conventional and high-frequency oscillatory ventilation on oxygenation and hemodynamics in a large porcine model of early acute respiratory distress syndrome.

BMC Anesthesiology, 2006

Background: This animal study was conducted to assess the combined effects of high frequency osci... more Background: This animal study was conducted to assess the combined effects of high frequency oscillatory ventilation (HFOV) and prone positioning on pulmonary gas exchange and hemodynamics.

Ultraschall in der Medizin, 2008

We examined the feasibility of a newly developed handheld ultrasound device capable of transesoph... more We examined the feasibility of a newly developed handheld ultrasound device capable of transesophageal echocardiography (TEE). Prospective case series in a non-cardiac surgical intensive care unit including 18 deeply sedated and endotracheally intubated critically ill non-cardiac surgical patients. The imaging quality and findings of a newly developed handheld device were compared to those of a cart-based standard TEE system. All patients were examined with both systems in a randomized order by independent examiners performing a structured and complete TEE examination. The imaging quality of the standard cardiac cross sections and spectral Doppler studies of the cardiac valves was assessed on an analog scale from 1 (excellent) to 5 (insufficient). The time requirements for each study were documented. We did not detect significant differences in two-dimensional imaging. Continuous-wave Doppler imaging of the left ventricular outflow tract and pulsed-wave Doppler imaging of the transmitral flow were significantly better (p <0.001) with the standard system. Handheld TEE is a goal-oriented diagnostic tool, which may sufficiently replace a standard cart-based TEE system in unstable critically ill patients when an acute gross diagnosis is required.

Journal of Trauma and Acute Care Surgery, 2012

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) can be used as an "ultima ratio" strategy ... more BACKGROUND: Extracorporeal membrane oxygenation (ECMO) can be used as an "ultima ratio" strategy in multiple injured patients with severe thoracic trauma. However, systemic anticoagulation during ECMO is recommended and thus traumatic brain injury (TBI) and intracranial bleeding are well-accepted contraindications for ECMO therapy.

Perfusion (United Kingdom), 2012

Veterinary Anaesthesia and Analgesia, 2008

Objective To evaluate the feasibility of ultrasound guided vascular access in pigs by comparing c... more Objective To evaluate the feasibility of ultrasound guided vascular access in pigs by comparing central venous and arterial cannulation techniques.

Medical Science Monitor, 2011

Ventilation with high positive end-expiratory pressure (PEEP) can lead to hepatic dysfunction. Th... more Ventilation with high positive end-expiratory pressure (PEEP) can lead to hepatic dysfunction. The aim of this study was to investigate the hepatic effects of strategies using high airway pressures either in pressure-controlled ventilation (PCV) or in high-frequency oscillatory ventilation (HFOV) combined with an arteriovenous extracorporeal lung assist (ECLA).

The Journal of Trauma: Injury, Infection, and Critical Care, 2007

To compare the combined effects of arteriovenous extracorporeal lung assist (AV-ECLA) and high-fr... more To compare the combined effects of arteriovenous extracorporeal lung assist (AV-ECLA) and high-frequency oscillatory ventilation (HFOV) on pulmonary gas exchange, hemodynamics, and respiratory parameters in a lavage-induced porcine lung injury model. A prospective, randomized animal study. Saline lung lavage was performed in 33 healthy female pigs, weighing 52 +/- 4.1 kg (mean +/- SD), until the Pao2 decreased to 53 +/- 8 mm Hg. After a stabilization period of 60 minutes, the animals were randomly assigned to four groups: group 1, pressure-controlled ventilation (PCV) with a tidal volume of 6 mL/kg; group 2, PCV with a tidal volume of 6 mL/kg and AV-ECLA; group 3, HFOV; group 4, HFOV and AV-ECLA. In groups 2 and 4, the femoral artery and vein were cannulated and a low-resistance membrane lung was interposed. After isolated evaluation of AV-ECLA, the mean airway pressure was increased by 3 cm H2O from 16 to 34 cm H2O every 20 minutes, accompanied by blood gas analyses and measurements of respiratory and hemodynamic variables. Only in AV-ECLA-treated animals was normocapnia achieved. No significant increase of Pao2 attributable to AV-ECLA alone was detected. Mean airway pressure augmentation resulted in a significant increase in Pao2 in all groups. Peak inspiratory pressure was significantly lower in HFOV-treated animals. The combination of AV-ECLA and HFOV resulted in normocapnia and comparable Pao2, although a smaller ventilator pressure amplitude was applied. Long-term animal studies are needed to assess whether this approach results in further lung protection.

The Journal of Trauma: Injury, Infection, and Critical Care, 2009

Whole-body multislice helical computed tomography (MSCT) becomes increasingly important as a diag... more Whole-body multislice helical computed tomography (MSCT) becomes increasingly important as a diagnostic tool in patients with multiple injuries. We describe time requirement of two different diagnostic approaches to multiple injuries one with whole-body-MSCT (MSCT Trauma-Protocol) as the sole radiologic procedure and one with conventional use of radiography, combined with abdominal ultrasound and organ focused CT (Conventional-Trauma-Protocol). Observational study with retrospective analysis of time requirements for resuscitation, diagnostic workup and transfer to definitive treatment after changing from conventional to MSCT Trauma-Protocol. Group I: data from trauma patients imaged with whole-body MSCT. Group II: data of trauma patients investigated with conventional trauma protocol before the introduction of MSCT-Trauma-Protocol. The complete diagnostic workup in group I (n = 82) was finished after 23 minutes (17-33 minutes) [median; interquartile range (IQR)] and after 70 minutes (IQR, 56-85) in group II (n = 79). The definitive management plan based on a completed diagnostic workup was devised after 47 minutes (IQR, 37-59) in group I and after 82 minutes (IQR, 66-110) in group II. A whole-body MSCT-based diagnostic approach to multiple injuries might shorten the time interval from arrival in the trauma emergency room until obtaining a final diagnosis and management plan in patients with multiple injuries and might, therefore, contribute to improvements in patient care.

The Journal of Trauma: Injury, Infection, and Critical Care, 2008

ABSTRACT

Journal of PeriAnesthesia Nursing, 2004

Background-Untreated, one third of surgical patients suffer postoperative nausea and vomiting (PO... more Background-Untreated, one third of surgical patients suffer postoperative nausea and vomiting (PONV). The relative benefit of prophylactic interventions remains unknown, as does the efficacy of combining interventions. We therefore compared the efficacy of six antiemetic interventions and their combinations.

Journal of Critical Care, 2012

Elimination of carbon dioxide by an arteriovenous extracorporeal lung assist (av-ECLA) can facili... more Elimination of carbon dioxide by an arteriovenous extracorporeal lung assist (av-ECLA) can facilitate the lung protective capabilities of high-frequency oscillatory ventilation (HFOV). This case series describes patients treated with HFOV because of severe respiratory failure with and without additional av-ECLA. A retrospective analysis of 31 patients regarding patient characteristics, gas exchange, respirator settings, hemodynamics, and outcome. In 18 patients, av-ECLA was started before, together with, or during HFOV. The initial arterial carbon dioxide tension before HFOV and av-ECLA was higher in patients who received av-ECLA compared with patients without (P = .043): 65 (48-84) mm Hg and 50 (44-60) mmHg (median and interquartile range). The initial arterial oxygen tension (Pao(2))/inspiratory oxygen fraction (Fio(2)) index in patients who received av-ECLA was 79 (63-133) mm Hg. The Pao(2)/Fio(2) index immediately before HFOV was 84 (65-124) mm Hg (av-ECLA) and 121 (68-150) mmHg (no av-ECLA) and improved to 149 (89-231) mm Hg and 200 (117-233) mmHg during HFOV. Similarly, the oxygenation index improved. No statistically significant differences among groups were detected for Pao(2)/Fio(2) index, oxygenation index, and arterial carbon dioxide tension immediately before and during HFOV. The hospital mortality was 39% (av-ECLA) and 69% (no av-ECLA). High-frequency oscillatory ventilation improved the oxygenation in patients with severe respiratory failure. Additional av-ECLA may facilitate using lung protective HFOV settings in more severe lung injury and hypercapnia.

Intensive Care Medicine, 2007

High-frequency oscillatory ventilation (HFOV) may reduce ventilator-induced lung injury in experi... more High-frequency oscillatory ventilation (HFOV) may reduce ventilator-induced lung injury in experimental neonatal respiratory distress. However, these data permit no conclusions for large animals or adult patients with acute respiratory distress syndrome (ARDS), because in neonates higher frequencies and lower amplitudes can be used, resulting in lower tidal volumes (VT) and airway pressures. The aim of this study was to compare gas exchange, lung histopathology and inflammatory cytokine expression during lung-protective pressure-controlled ventilation (PCV) and HFOV in a long-term large-animal model of ARDS. Prospective, randomized, controlled pilot study. University animal laboratory. Sixteen female pigs (55.3 +/- 3.9 kg). After induction of ARDS by repeated lavage, the animals were randomly assigned to PCV (VT = 6 ml/kg) and HFOV (6 Hz). After lung injury, a standardised lung recruitment was performed in both groups, and ventilation was continued for 24 h. After lung recruitment sustained improvements in the oxygenation index were observed in both groups. The mean airway pressure (mPaw) was significantly lower in the HFOV group during the experiment (p < 0.01). Histologically, lung inflammation was significantly ameliorated in the HFOV group (p < 0.05). The messenger RNA expression of IL-1-beta in lung tissue was significantly lower in the HFOV-treated animals (p < 0.01). These data suggest that HFOV compared with conventional lung-protective ventilation can reduce lung inflammation in a large-animal 24-h model of ARDS. Furthermore, it was shown that lung recruitment leads to sustained improvements in gas exchange with a significantly lower mPaw when HFOV is used.

Experimental Lung Research, 2013

Oxygenation during high-frequency oscillatory ventilation is secured by a high level of mean airw... more Oxygenation during high-frequency oscillatory ventilation is secured by a high level of mean airway pressure. Our objective was to identify a pressure difference between the airway opening of the respiratory circuit and the trachea during application of different oscillatory frequencies. Six female Pietrain pigs (57.1 ± 3.6 kg) were first ventilated in a conventional mechanical ventilation mode. Subsequently, the animals were switched to high-frequency oscillatory ventilation by setting mean airway opening pressure 5 cmH(2)O above the one measured during controlled mechanical ventilation. Measurements at the airway opening and at tracheal levels were performed in healthy lungs and after induction of acute lung injury by surfactant depletion. During high-frequency oscillatory ventilation, the airway opening pressure was set at a constant level. The pressure amplitude was fixed at 90 cmH(2)O. Starting from an oscillatory frequency of 3 Hz, the frequency was increased in steps of 3 Hz to 15 Hz and then decreased accordingly. At each frequency, measurements were performed in the trachea through a side-lumen of the endotracheal tube and the airway opening pressure was recorded. The pressure difference was calculated. At every oscillatory frequency, a pressure loss towards the trachea could be shown. This pressure difference increased with higher oscillatory frequencies (3 Hz 2.2 ± 2.1 cmH(2)O vs. 15 Hz 7.5 ± 1.8 cmH(2)O). The results for healthy and injured lungs were similar. Tracheal pressures decreased with higher oscillatory frequencies. This may lead to pulmonary derecruitment. This has to be taken into consideration when increasing oscillatory frequencies and differentiated pressure settings are mandatory.

Experimental Lung Research, 2011

The separate effects of positive end-expiratory pressure (PEEP) and intravascular volume administ... more The separate effects of positive end-expiratory pressure (PEEP) and intravascular volume administration on the histopathologic lung injury were not investigated in experimental lung injury previously. The authors hypothesized that high PEEP and a restrictive volume therapy would yield the best oxygenation and the least degree of lung injury. Pigs (52.8 ± 3.4 kg) underwent saline lavage-induced lung injury. The animals were ventilated either with low PEEP (mean PEEP 9 to 12 cm H₂O) and liberal volume therapy using hydroxyethyl starch (LowP/Vol+) or high PEEP (mean PEEP 21 cm H₂O) combined with recruitment maneuvers and liberal (HighP/Vol+) or restrictive volume therapy (HighP/Vol-). After 6.5 hours, lung injury was determined by using a histopathologic score evaluating overdistension, edema, exsudation, and inflammation. When volume therapy was liberal, high PEEP (HighP/Vol+) improved the Pao₂/Fio₂ index (416 ± 80 mm Hg) compared to low PEEP (LowP/Vol+, 189 ± 55 mm Hg; P < .05) but there was no difference in the median (interquartile range) lung injury score: 1.6 (1.2-1.9) and 1.9 (1.4-2.0). High PEEP with restrictive volume therapy (HighP/Vol-) did not further improve oxygenation (400 ± 55 mm Hg) but ameliorated the degree of lung injury: 0.9 (0.8-1.4) (P < .05). In lavage-induced lung injury, high PEEP improved oxygenation, but restrictive volume administration markedly reduced the lung injury score, mainly by reduced edema.

Experimental Lung Research, 2010

In order to optimize the lung-protective potential of high-frequency oscillatory ventilation (HFO... more In order to optimize the lung-protective potential of high-frequency oscillatory ventilation (HFOV), it is currently recommended to maximize oscillatory frequencies. However, very high frequencies may lead to insufficient CO(2) elimination with severe respiratory acidosis. Arteriovenous extracorporeal lung assist (av-ECLA) allows near total CO(2) removal, thereby allowing for maximization of the lung-protective potential of HFOV. The aim of this study was to determine the impact of HFOV and av-ECLA on lung inflammation and function compared to conventional lung-protective ventilation. In a porcine surfactant depletion model of lung injury, the authors randomly assigned 16 female pigs to conventional lung-protective ventilation and HFOV/ECLA. Both strategies were combined with an "open-lung" approach. Gas exchange and hemodynamic parameters were measured at intervals during the 24-hour study period. Postmortem, lung tissue was analyzed to determine histological damage and lung inflammation. The authors found that the combination of HFOV and av-ECLA (1) allows significant reductions in mean and peak airway pressures; and (2) reduces histological signs of lung inflammation in the basal regions of the lung. HFOV/av-ECLA reduces histological signs of lung inflammation compared to conventional lung-protective ventilation strategies. Thus, combination of HFOV and av-ECLA might be a further lung-protective tool if conventional ventilation strategies are failing.