[Methemoglobin intoxication by prilocaine in EMLA. Accidental intoxication of an infant with scald injuries]. / Methämoglobinintoxikation durch Prilocain in EMLA. Akzidentelle Intoxikation bei einem Kleinkind mit Verbrühungen.

The case of an infant who had received EMLA(R) for local pain therapy after scalding to 5% of the body surface with boiling water is reported. Due to the application of EMLA(R) on the injured skin and exceeding the recommended doses of prilocaine and lidocaine the child developed symptomatic methemoglobinemia. During surgical wound dressing the boy showed cyanosis, decreased peripheral oxygen saturation and potentially suffered a general seizure. With a symptomatic therapy including mechanical ventilation and anticonvulsive drugs the methemoglobinemia normalized within 9 h. The child recovered without any neurological impairment after wound treatment was completed.

[Percutaneous vertebroplasty -- the role of osseous phlebography]. / Die perkutane Vertebroplastie -- Rolle der ossären Phlebographie.

PURPOSE: To evaluate the usefulness of osseous phlebography preceding percutaneous vertebroplasty. MATERIALS AND METHODS: Seventy-five patients with painful osteoporotic (57) or malignant (18) vertebral fractures were treated by percutaneous vertebroplasty under fluoroscopic control. Prior to cement injection, osseous phlebography was performed, with 247 phlebographic studies included in the retrospective correlation with radiographic and CT images. Clinical results were assessed by standardized questionnaire. RESULTS: In 69/75 (92 %) patients, pain and mobility improved and medication needed for pain control decreased significantly after vertebroplasty. Two clinically apparent complications occurred. The results of osseous phlebography prompted correction of the needle position in 34/247 (14 %) of the procedures and cancellation of the cement injection in 19/247 (8 %). No complications occurred related to osseous phlebography. CT was superior to conventional radiography in detecting extra-osseous cement leakage (106/247 by CT vs. 63/247 by conventional radiography). The cement leakage was asymptomatic in 104/106 (98 %) cases for the duration of follow-up. DISCUSSION: Osseous phlebography prior to percutaneous vertebroplasty had a significant impact on the procedure in our retrospective study and was able to predict the cement distribution in the majority of cases. However, phlebography was unable to foresee and therefore prevent 2 clinically relevant complications. Complications related to phlebography did not occur.

Influence of positioning on ventilation-perfusion relationships in severe adult respiratory distress syndrome.

In 12 patients with severe adult respiratory distress syndrome (ARDS), pulmonary gas exchange and hemodynamics were evaluated before, during, and after a 2-h period of pressure-controlled mechanical ventilation with the patient in the prone position. Ventilation-perfusion relationships (VA/Q) were assessed by a multiple inert gas elimination technique. Pressure-controlled mechanical ventilation in the prone position resulted in an overall increase (p < or = 0.05) of arterial oxygenation after 120 min (98.4 +/- 50.3 to 146.2 +/- 94.9 mm Hg). Whereas eight patients revealed an improvement of PaO2 of more than 10 mm Hg after 30 min in the prone position (responders), four patients reacted to positional changes with a deterioration of arterial oxygenation (nonresponders). Data about the continuous distribution of ventilation-perfusion ratios revealed that in the responder group positioning caused a decrease of shunt perfusion of 11 +/- 5% and a concomitant increase of normal VA/Q by 12 +/- 4% after 30 min. There was no change demonstrable within low VA/Q areas. Returning the patient to the supine position reversed the improvement in gas exchange. The nonresponder group did not show any significant alteration in the distribution of VA/Q during the study. We concluded that improvement of oxygenation during pressure-controlled mechanical ventilation in the prone position is due to a shift of blood flow away from shunt regions, thus increasing areas with normal VA/Q. This redistribution of blood flow is most likely caused by a recruitment of previously ateletatic but nondiseased areas induced by altered gravitational forces.

Efficacy of inhaled nitric oxide in patients with severe ARDS.

STUDY OBJECTIVE: To investigate the initial and long-term effect of nitric oxide (NO) inhalation in patients with severe acute respiratory distress syndrome (ARDS). DESIGN: Retrospective, clinical study. SETTING: University surgical ICU. PATIENTS: Eighty-seven patients with severe ARDS. INTERVENTIONS AND MEASUREMENTS: Thirty of 87 patients with ARDS inhaled low concentrations of NO for more than 48 h in addition to the standard treatment. Initial and long-term effects of NO inhalation on hemodynamics, gas exchange, and methemoglobin formation were determined. Survival of patients treated with inhaled NO was compared with survival in similar patients without NO inhalation. RESULTS: In 83% of the patients, NO increased the ratio of arterial PO2 to the fraction of inspired O2 (PaO2/FIO2) by > or = 10 mm Hg; in 87%, NO reduced venous admixture (QVA/QT) by > or = 10%, and in 63%, NO decreased mean pulmonary artery pressure (PAP) by > or = 3 mm Hg. Daily short interruption of continuous inhalation of NO for a duration of 17 +/- 2.4 days was consistently associated with a decrease in PaO2/FIO2 by 81 +/- 4 mm Hg (p < 0.001). QVA/QT increased by 8.3 +/- 0.4% (p < 0.001) and PAP by 5.3 +/- 0.3 mm Hg (p < 0.001). Over time, we observed neither tachyphylaxis nor a more pronounced effect of inhaled NO. Methemoglobin increased from 0.74 +/- 0.56% to 0.98 +/- 0.02% (p < 0.001). Survival rates in patients treated with NO did not differ from survival rates in patients not treated with NO. CONCLUSION: Beneficial effects of NO inhalation can be observed in most patients with severe ARDS; in some cases, however, it may fail to improve pulmonary gas exchange or to reduce pulmonary hypertension without obvious explanation. To demonstrate a possible increase in survival associated with NO inhalation, large randomized prospective trials are required.

Acute effects of a single dose of porcine surfactant on patients with the adult respiratory distress syndrome.

In an attempt to restore functional surfactant to the lungs of patients with the adult respiratory distress syndrome (ARDS), we have treated six patients within the first 2 days of the onset of ARDS with a single dose of hydrophobic components of porcine surfactant. Surfactant (4 g in 50 ml) delivered via a bronchoscope in aliquots to each of the lobar bronchi was well tolerated and caused a modest transient improvement in gas exchange. No significant changes in chest radiograph or lung compliance were detected. Analysis of bronchoalveolar lavage (BAL) fluid showed no change in albumin, alpha-1-proteinase inhibitor specific activity, or cell count. Bronchoalveolar lavage phospholipid concentrations were elevated 3 h after surfactant administration relative to preadministration levels and fell by 24 h. In addition, in two patients we found reduced inhibition of surfactant function in BAL after surfactant replacement. These observations suggest a role for surfactant replacement in the treatment of patients with ARDS and support the need for continuing investigation.

Continuous monitoring of blood gases during hypercapnia in a patient with severe acute lung failure.

We report about our first experiences with a new device for continuous intra-arterial monitoring of blood gases in a patient with severe acute respiratory failure. This device facilitated continuous monitoring of PaO2, PaCO2 and pH while weaning the patient from extracorporeal membrane oxygenation (ECMO). Although sufficient oxygenation at FIO2 0.45 could be achieved after disconnection from ECMO, carbon dioxide elimination remained inadequate and resulted in severe respiratory acidosis. Within six hours, PaCO2 increased to 95 mmHg. Continuous monitoring of pH and PaCO2 helped to monitor CO2 retention and assisted the decision making process for reinstitution of ECMO.

Long-term inhalation with evaluated low doses of nitric oxide for selective improvement of oxygenation in patients with adult respiratory distress syndrome.

OBJECTIVE: To evaluate the lowest dose of inhaled nitric oxide (NO) in patients with adult respiratory distress syndrome (ARDS), which is able to improve arterial oxygenation more than 30% compared to baseline data. DESIGN: Prospective, clinical study. SETTING: Anesthesiological ICU in a university hospital. PATIENTS: 3 consecutive patients with severe ARDS according to clinical and radiological signs. INTERVENTIONS: Pressure-controlled ventilation with positive end-expiratory pressure of 8-12 cm H2O. Inhalation of NO was performed with a blender system and a Servo 300 ventilator. The lowest effective NO dose was defined by titrating the inspiratory NO dose until reaching a 30% improvement of PaO2/FiO2. This dose was used for the following continuous long-term NO inhalation; controls of efficacy by investigation of hemodynamics and blood gas exchange were performed initially and 2 times per patient after intervals of 3-5 days. MEASUREMENTS AND RESULTS: Initial NO concentrations were found to be effective at 60, 100, and 230 parts per billion (ppb). In all measurements, arterial oxygenation was found to be elevated by NO inhalation with the initially evaluated dose compared to baseline data; in parallel, the venous admixture (Qva/Qt) was reduced. The O2 delivery increased, although O2 consumption and hemodynamics did not change. In 1 patient, interruption of NO inhalation caused remarkable increase of pulmonary resistance. CONCLUSIONS: The improvement of oxygenation by NO inhalation in ARDS does not require reduction of pulmonary resistance and can be performed using low doses in the ppb range, which has to be considered as probably non-toxic.

A new method for P0.1 measurement using standard respiratory equipment.

The airway occlusion pressure, P0.1, is an index for the neuro-muscular activation of the respiratory system. It has been shown to be a very useful indicator for the ability of patients receiving ventilatory support to be weaned from mechanical ventilation. Since the standard measurement technique for P0.1 determination is technically complex, it is not widely available for clinical purposes. For that reason a P0.1 measurement technique was developed as an integrated function in a standard respirator (Evita, Dräger, Lübeck, Germany). This technique is easy to use and does not need any further equipment. We validated this new technique by comparing it to standard P0.1 measurements in a mechanical lung model as well as in ventilated patients. In the lung model we found a correlation between the Evita measurement and standard measurements of r = 0.99. In 6 ventilated patients the correlation was r = 0.78. Since the Evita P0.1 and the standard measurement had to be performed during two different breaths, this little poorer correlation in patients may be due to a significant breath-by-breath variability in P0.1. Comparing the Evita P0.1 and the standard measurement within one breath resulted in a clearly better correlation (r = 0.89). We conclude that this new measurement technique provides an easy and accurate P0.1 measurement using standard respiratory equipment when tested in a lung model. In patient measurements the method is less precise, which is probably due to the variable waveforms of the inspiratory driving pressure seen in patients, for example when intrinsic PEEP is present.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of inhaled nitric oxide on right ventricular function in severe acute respiratory distress syndrome.

OBJECTIVE: To compare the effects of inhaled nitric oxide (NO) and an infusion of prostacyclin (PGI2) on right ventricular function in patients with severe acute respiratory distress syndrome (ARDS). DESIGN: Randomized prospective short-term study. SETTING: Post-surgical ICU in an university hospital. PATIENTS: 10 patients with severe ARDS referred to our hospital for intensive care. INTERVENTIONS: In random sequence the patients inhaled NO at a concentration of 18 parts per million (ppm) followed by 36 ppm, and received an intravenous infusion of PGI2 (4 ng.kg-1.min-1). MEASUREMENTS AND RESULTS: Inhalation of 18 ppm NO reduced the mean (+/- SE) pulmonary artery pressure (PAP) from 33 +/- 2 to 28 +/- 1 mmHg (p = 0.008), increased right ventricular ejection fraction (RVEF), as assessed by thermodilution technique, from 28 +/- 2 to 32 +/- 2% (p = 0.005), decreased right ventricular end-diastolic volume index from 114 +/- 6 to 103 +/- 8 ml.m-2 (p = 0.005) and right ventricular end-systolic volume index from 82 +/- 4 to 70 +/- 5 ml.m-2 (p = 0.009). Mean arterial pressure (MAP) and cardiac index (CI) did not change significantly. The effects of 36 ppm NO were not different from the effects of 18 ppm NO. Infusion of PGI2 reduced PAP from 34 +/- 2 to 30 +/- 2 mmHg (p = 0.02), increased RVEF from 29 +/- 2 to 32 +/- 2% (p = 0.02). Right ventricular end-diastolic and end-systolic volume indices did not change significantly. MAP decreased from 80 +/- 4 to 70 +/- 5 mmHg (p = 0.03), and CI increased from 4.0 +/- 0.5 to 4.5 +/- 0.5 l.min-1.m-2 (p = 0.02). CONCLUSIONS: Using a new approach to selective pulmonary vasodilation by inhalation of NO, we demonstrate in this group of ARDS patients that an increase in RVEF is not necessarily associated with a rise in CI. The increase in CI during PGI2 infusion is probably related to the systemic effect of this substance.

Morphological changes in chest radiographs of patients with acute respiratory distress syndrome (ARDS).

OBJECTIVE: To determine whether the quality of infiltrations in chest radiographs can accurately predict the histological extent of fibrotic change in patients with acute respiratory distress syndrome (ARDS). DESIGN: Retrospective clinical investigation. SETTING: Intensive care unit (ICU) of a university teaching hospital. PATIENTS AND METHODS: Of 47 patients treated with extracorporeal membrane oxygenation (ECMO) for severe ARDS over a 5-year period, 23 patients underwent open lung biopsy at thoracotomy for treatment, mostly of pneumothorax. Chest films obtained by portable chest roentgenography preceding the operation were reviewed retrospectively and compared to the histomorphological results of the lung specimen. RESULTS: Chest radiographs displayed mixed alveolar-reticular opacification in 60.2%, alveolar patterns in 22.9% and reticular opacities in 10.5%. In 0.4% there were no infiltrates, 6% could not be evaluated because of insufficient quality. There was no relevant difference between the right and left lungs. Subdividing patients into two groups according to the histological results of either absent or mild (1) or severe (2) lung fibrosis, we found an alveolar haziness in 12.3% in group 1 compared with 28.2% in group 2, while reticular characteristics were identified in 13% and 11%, respectively. CONCLUSIONS: The most common opacity in chest radiographs of patients with severe ARDS treated with ECMO is mixed alveolar-reticular opacification. Severe lung fibrosis is not positively correlated with a reticular radiographic pattern. ECMO does not lead to specific radiological changes in conventional radiograms, contrary to clinical findings that treatment with ECMO might induce pleural or pulmonic haemorrhage, especially in the earlier days when systemic heparinization had to be used instead of the heparin-coated tube-surfacing.

Effect of N-nitroso-N-methylurethane on gas exchange, lung compliance, and surfactant function of rabbits.

OBJECTIVES: To define the effect of N-nitroso-N-methyl-urethane (NNNMU) on pulmonary gas exchange, compliance and the biochemical and functional properties of the lung surfactant system. DESIGN: Four days after inducing lung injury, gas exchange and pulmonary compliance were studied and a bronchoalveolar lavage was taken. SETTING: Experimental laboratory of a university department of medicine, division of pulmonary and critical care medicine. ANIMALS: Ten rabbits after they had received an injection of NNNMU and five control animals. INTERVENTIONS: Controlled mechanical ventilation and bronchoalveolar lavage. MEASUREMENTS AND RESULTS: Measurements of gas exchange (using the multiple inert gas elimination technique), hemodynamics and pulmonary compliance were performed during ventilatory and hemodynamic steady state. A bronchoalveolar lavage (BAL) was taken after sacrificing the animal. BAL samples were processed for cell count and biochemical and functional surfactant analysis. Animals injected with NNNMU developed mild, but significant reduction in PaO2, while maintaining eucapnia during spontaneous air breathing. V/Q distributions and arterial blood gases were similar in all animals when ventilated mechanically with a fixed tidal volume. Compliance of the lung and phospholipid levels in lavage of NNNMU animals was significantly lower than in control animals (CON). Function of surfactant recovered from animals receiving NNNMU was decreased significantly where compared to CON. Thus, NNNMU resulted in a lowered lavage surfactant phospholipid content, impaired surfactant function, decreased compliance and hypoxemia during spontaneous ventilation. However, gas exchange was similar to that of control animals during mechanical ventilation. CONCLUSION: We conclude that NNNMU-induced gas exchange abnormalities present after 4 days are mild and are reversed by fixed volume mechanical ventilation despite marked alteration in surfactant function and lung compliance. These observations further define properties of a lung injury model that is of value in the study of surfactant replacement.

High survival rate in 122 ARDS patients managed according to a clinical algorithm including extracorporeal membrane oxygenation.

OBJECTIVE: We investigated whether a treatment according to a clinical algorithm could improve the low survival rates in acute respiratory distress syndrome (ARDS). DESIGN: Uncontrolled prospective trial. SETTING: One university hospital intensive care department. PATIENTS AND PARTICIPANTS: 122 patients with ARDS, consecutively admitted to the ICU. INTERVENTIONS: ARDS was treated according to a criteria-defined clinical algorithm. The algorithm distinguished two main treatment groups: The AT-sine-ECMO (advanced treatment without extracorporeal membrane oxygenation) groups (n = 73) received a treatment consisting of a set of advanced non-invasive treatment options, the ECMO treatment group (n = 49) received additional extracorporeal membrane oxygenation (ECMO) using heparin-coated systems. MEASUREMENTS AND RESULTS: The groups differed in both APACHE II (16 +/- 5 vs 18 +/- 5 points, p = 0.01) and Murray scores (3.2 +/- 0.3 vs 3.4 +/- 0.3 points, p = 0.0001), the duration of mechanical ventilation prior to admission (10 +/- 9 vs 13 +/- 9 days, p = 0.0151), and length of ICU stay in Berlin (31 +/- 17 vs 50 +/- 36 days, p = 0.0016). Initial PaO2/FIO2 was 86 +/- 27 mm Hg in AT-sine-ECMO patients that improved to 165 +/- 107 mm Hg on ICU day 1, while ECMO patients showed an initial PaO2/FIO2 of 67 +/- 28 mm Hg and improvement to 160 +/- 102 mm Hg was not reached until ICU day 13. QS/QT was significantly higher in the ECMO-treated group and exceeded 50% during the first 14 ICU days. The overall survival rate in our 122 ARDS patients was 75%. Survival rates were 89% in the AT-sine ECMO group and 55% in the ECMO treatment group (p = 0.0000). CONCLUSIONS: We conclude that patients with ARDS can be successfully treated with the clinical algorithm and high survival rates can be achieved.

Fractal analysis of surfactant deposition in rabbit lungs.

The effect of exogenous surfactant in the treatment of acute lung injury may depend on homogeneity of distribution of the material delivered. Analyses of distribution rely on sectioning the lung, determining surfactant concentration for each piece, and describing the variation in that value. Results of such analyses are influenced by how finely the lung is sectioned. We have reanalyzed data from prior experiments to determine whether the distribution of administered surfactant is fractal, that is, is independent of the scale of measurement. Lungs from animals receiving surfactant radiolabeled with [3H]dipalmitoylphosphatidylcholine were cut into 108 pieces, and the normalized radioactivity in each piece was determined. Sectioning of the lungs into different numbers of pieces (n = 2, 6, 12, 18, 36, 54, or 108) was simulated, and corresponding radioactivity contents were calculated. The coefficient of variation (CV) of these normalized values was then calculated for each scale of measurement (expressed as relative piece volume), and ln(CV) was plotted as a function of the logarithm of relative piece volume. These relationships were linear (average correlation coefficient = 0.96) for all animals, consistent with CV being a fractal property. We conclude that the intrapulmonary distribution of surfactant may be fractal and is therefore a property of the lung. This study demonstrates the utility of fractal analysis in describing the pulmonary distribution of substances introduced via the airway.

Influence of mixed venous PO2 and inspired O2 fraction on intrapulmonary shunt in patients with severe ARDS.

In 12 patients undergoing extracorporeal membrane oxygenation for treatment of severe acute respiratory distress syndrome (ARDS), we examined the effects of independent variations in mixed venous oxygen tension (PvO2) and inspired oxygen fraction (FIO2) on the distribution of ventilation and perfusion as assessed by the multiple inert gas elimination technique. Reducing the oxygen concentration of the constant gas stream through the membrane lungs allowed us to decrease the PvO2 by approximately 20 Torr independently of variations in cardiac output and FIO2 as well as to augment FIO2 without influencing PvO2. The interventions did not induce any change in heart rate or systemic or pulmonary hemodynamics. In general, neither during mechanical ventilation at FIO2 of 0.6 nor during mechanical ventilation at FIO2 of 1.0 did the reduced PvO2 cause variations in the distribution of pulmonary blood flow in our patients with severe ARDS. Nevertheless, in individual patients, decreasing PvO2 or ventilation at FIO2 of 1.0 was associated with changes in intrapulmonary shunt. Therefore, we conclude that it is not possible to predict the influence of such interventions in pulmonary gas exchange in the individual patient suffering from ARDS. Differences in the regulation of the local distribution of blood flow caused by the disease itself might explain this phenomenon.

Extracorporeal membrane oxygenation with heparin-coated systems in a 13-month-old infant with acute hypoxic respiratory failure after correction of tetralogy of Fallot.

Hemorrhagic disorders due to systemic heparinization are frequent during extracorporeal lung support (veno-venous extracorporeal membrane oxygenation: vv-ECMO). The development of heparin-coated systems has reduced the need for high-dose heparinization. Whereas the use of these heparin-coated membrane lungs and tubings has been described in former studies in adults, only few reports exist in children. This case report describes the application of a heparin-coated extracorporeal system for long-term vv-ECMO in a 13-month-old infant suffering from acute hypoxic respiratory failure after correction of tetralogy of Fallot. Only moderately elevated levels of activated clotting time (ACT, 120-160 s) and activated partial thromboplastin time (aPTT, 40-60 s) were necessary to avoid thrombotic events in the extracorporeal system. Thoracotomies were performed twice without bleeding complications by discontinuation of the systemic heparinization. We conclude that the use of heparin-coated membrane lungs in infants may improve the safety of extracorporeal lung support and permits surgical intervention without major risk of bleeding.

[Experiences with simultaneous exploration of the bile ducts in surgical therapy of gallstone ileus]. / Erfahrungen mit der gleichzeitigen Sanierung der Gallenwege bei der operativen Therapie des Gallensteinileus.

During the last 16 years, 14 patients with a gallstone ileus were treated at our institution. In 11 cases we performed in addition to the enterolithotomy, a cholecystectomy and a resection of the fistula as one-stage repair. Despite the high average age (74.3 years) and the presence of various other serious morbidity in our patient population, we only observed a hospital mortality of 7.1%. Serious postoperative complications, such as sepsis and/or shock were not observed. Utilizing today's advanced anesthesia and proper intensive-care therapy, as well as early operative intervention and safe surgical technique, we believe that enterolithotomy with cholecystectomy and fistula resection as one-stage operation, should primarily be considered before performing enterolithotomy alone.

Validation and clinical application of a continuous P0.1 measurement using standard respiratory equipment.

The airway occlusion pressure, P0.1, is the negative airway pressure generated during the first 100 msec of an occluded inspiration. P0.1 is a parameter for the neuro-muscular activation of the respiratory system, which is an important determinant for the work of breathing. It has been shown to be a good predictor for successful weaning from mechanical ventilation. Standard P0.1 measurement techniques are based on a total occlusion of the inspiration for more than 100 msec. These measurements are technically complex and therefore not useful for clinical purposes. Furthermore, a significant breath-by-breath variability has been shown for P0.1, which is neglected by any single point measurement technique. Therefore, we have developed a continuous on-line measurement for breath-by-breath determination of P0.1 using the Siemens Servo 900C respirator. In triggered mechanical ventilation the delay time between the onset of the patient's inspiration and flow delivery from the respiratory is more than 100 msec for this respirator. During that time the inspiration is occluded. Therefore, the trigger effort was proposed to be a good estimate of P0.1. Based on this, we calculated P0.1 as follows: airway pressure (Paw) was registered at the endotracheal tube site of the respiratory tubing, digitized and acquired by a personal computer at 100 Hz. The recorder output of the Servo 900C was connected to the same computer, delivering the electronical signal for the inspiratory valve to open when the inspiratory effort has exceeded the trigger threshold, which needs a minimal delay time of 80 msec. Around 20 msec after this signal flow is delivered from the respirator. The computer runs an algorithm, which recognizes this signal and calculates P0.1 (Servo P0.1) as the slope of the pressure drop during this 100 msec. Paw tracings and the calculated P0.1 values were displayed on the computer screen and stored on disk. This method was validated by comparing it to the standard technique, using a Hans-Rudolph valve for inspiratory occlusion and calculating P0.1 from Paw tracings during the occluded inspiration. For validation we used a mechanical lung model which generated P0.1 values ranging between 1.1-10.3 mbar. For a given adjustment of the lung model two standard measurements (standard P0.1) were made and compared to the Servo P0.1. In a total of 21 measurements the mean Servo P0.1 was 4.9 +/- 2.9 mbar; the mean standard P0.1 was 4.3 +/- 2.5 mbar. The mean difference between Servo P0.1 and standard P0.1 was 0.6 +/- 0.6 mbar (range: -0.3-1.8 mbar). The regression equation for linear regression analysis was: Servo P0.1 = 1.15* standard P0.1-0.05. This correlation was significant (r = 0.99, p < 0.01). From these data we conclude that the described method for continuous P0.1 measurement provides reliable values with the advantage of a maneuver-free, breath-by-breath measurement technique. It thereby opens the possibility for monitoring the neuro-muscular activation of the respiratory system at the bedside, which is shown as an example for a patient during weaning from mechanical ventilation.