A modified natural surfactant was administered to a patient with life-threatening adult respiratory distress sydrome caused by viral pneumonia. Subsequently, there was a marked improvement in gas exchange. In order to assess the mechanism for improved oxygenation, computed tomography of the lungs was done. Quantitative analysis of the scans taken before and after surfactant administration indicates that improvement in gas exchange was largely due to the expansion of underinflated and collapsed lung areas. Although this is a single case report, it provides insight into the possible beneficial effect of instilled surfactant in severe respiratory distress from viral pneumonia.

OBJECTIVE:Determine the influence of urapidil on mean lumbar cerebrospinal fluid pressure (CSFP), mean arterial pressure (MAP), mean central venous pressure (CVP) and heart rate (HR) in awake humans without any evidence of cerebral or cardiovascular disease.DESIGN:Open, single-dose volunteer study.INTERVENTIONS:CSFP was measured via a spinal needle after i.v. injection of a single dose of 0.2 mg kg-1 urapidil in six volunteers (2 female, 4 male).MEASUREMENTS AND RESULTS:After administration of urapidil, CSFP increased from 7 +/- 1 mmHg to 10 +/- 1 mmHg (p < 0.05), MAP decreased from 88 +/- 7 mmHg to 74 +/- 5 mmHg (p < 0.05), CPP decreased from 81 +/- 7 mmHg to 64 +/- 5 mmHg (p < 0.05) and CVP decreased from 0 +/- 1 mmHg to -3 +/- 1 mmHg (p < 0.05).CONCLUSION:Our data suggest that in humans with presumed normal intracranial compliance the administration of urapidil causes a small but statistically significant increase in CSFP due to a parallel decrease in MAP.

Die Einführung der “inverse ratio ventilation” (IRV) in die Erwachsenenbeatmung um 1980 [1, 2] erfolgte aufgrund klinischer und experimenteller Berichte über dramatische Verbesserungen der Oxygenation bei Lungenzuständen mit schwerem Parenchymschaden. Obwohl schon damals die Beeinflussung des endexspiratorischen Drucks durch eine Verkürzung der Exspirationszeit (“individual PEEP” [1]) als Mechanismus der IRV beschrieben wurde, blieb es der heutigen Zeit vorbehalten, den Vorteil des mittlerweile zum Gefahrenmoment stilisierten “intrinsic PEEP” gegenüber einem extern eingestellten PEEP in Frage zu stellen.

Der Gedanke, beatmete Patienten in Bauchlage zu lagern, um dadurch eine Verbesserung der Oxygenierung erzielen zu können, wurde erstmals von Bryan 1974 vorgeschlagen [1]. Aufgrund der Zwerchfellgeometrie vermutete er eine bessere Belüftung der abhängigen Lungenareale in Bauchlage. Obwohl in nachfolgenden Studien — sowohl klinisch als auch tierexperimentell — eine signifikante Verbesserung der Oxygenierung durch Bauchlagerung nachgewiesen werden konnte, blieb die klinische Bedeutung der Bauchlagerung in der Therapie des ARDS zunächst gering [2, 3, 4, 5].

As early as 1974, Brian advocated the prone position for ventilated patients [5]. He suggested that this position might enhance ventilation of the dorsal parts of the lungs, thereby improving oxygenation. These considerations have been confirmed by several experimental and clinical studies [1, 6, 13, 17]. Better secretion removal, decreased intrapulmonary shunting, and an increased FRC are thought to be responsible for the observed improvement of oxygenation. However, the prone position never became very popular in the clinical treatment of the adult respiratory distress syndrome (ARDS). Routine performance of thoracic CT scans in ARDS patients demonstrated preferential distribution of pathological densities in the dependent lung areas. The prone position therefore could possibly benefit these patients, as shown by two recent studies [8, 11]. The aim of our study was to evaluate the influence of repeatedly turning the patient to the prone position on gas exchange and thoracic CT findings in multiple-trauma patients. Methods. Seven ventilated intensive care patients with severe ARDS (Murray Score >2.5 [9], Quotient >0.7 [4], mean airway pressure >18 cm H2O, thoracic CT scan showing dorsal atelectases) were included in the study. Patients were turned from the supine to the prone position at 12-h intervals using an air-cushion bed (Mediscus, Austria). Redistribution of dystelectatic or atelectatic dependent lung areas was verified by means of repeated thoracic CT scans (Figs. 1, 8). Results. The patients were intermittently turned for 6.5 ± 1.1 days. The course of gas exchange is shown in Figs. 2 and 3. Initially, improvement of the respiratory quotient could only be achieved during prone positioning, from the 2nd day in the supine position as well. Intrapulmonary shunting showed a similar trend (Figs. 4 and 5). No significant changes in cardiovascular parameters could be observed. Control thoracic CT scans showed uniform reduction of atelectases in dependent lung areas (Figs. 1 and 8). The inspiratory fraction of oxygen could be reduced significantly as of the 2nd day (Fig. 7). Constant levels of positive end-expiratory pressure and tidal volume were associated with decreasing mean and plateau airway pressures (Fig. 6). Discussion. Repeatedly turning the patient to the prone position produced long-lasting improvement of arterial oxygenation, which persists up to the end of the weaning process. This is in good accordance with other studies [1, 2, 6, 8, 11, 13, 17], however, this is the first study to report an observation period of more than 6 days of repeatedly turning the patient. These positive effects on gas exchange can be attributed to sudden improvement of the ventilation-perfusion ratio within the lung areas that become dependent after turning to the prone position. Due to reduced hydrostatic pressure [11] and relative hyperventilation [7, 16], previously collapsed alveoli are recruited in the lung areas that become non-dependent after turning to the prone position.

As early as 1974, Brian advocated the prone position for ventilated patients [5]. He suggested that this position might enhance ventilation of the dorsal parts of the lungs, thereby improving oxygenation. These considerations have been confirmed by several experimental and clinical studies [1, 6, 13, 17]. Better secretion removal, decreased intrapulmonary shunting, and an increased FRC are thought to be responsible for the observed improvement of oxygenation. However, the prone position never became very popular in the clinical treatment of the adult respiratory distress syndrome (ARDS). Routine performance of thoracic CT scans in ARDS patients demonstrated preferential distribution of pathological densities in the dependent lung areas

The effect of a continuous positive airway pressure (CPAP) of 12 cm H2O on mean middle cerebral artery flow velocity (CBFV) was studied in nine human volunteers by means of transcranial Doppler sonography (TCD). During CPAP breathing, CBFV increased (45 +/- 9 vs 59 +/- 11 cm/s; P < 0.001; mean +/- SD), and pulsatility index (PI) decreased (0.87 +/- 0.1 vs 0.74 +/- 0.2; P < 0.05), indicating an increase in cerebral blood flow due to cerebral vasodilation. This phenomenon should be taken into account when CPAP is applied to patients with intracranial disease or when assessing CBFV patterns of patients during CPAP respiration.

In einer prospektiven, randomisierten Studie an 40 Patienten verabreichten wir 0,3 mg Buprenorphin sublinqual oder 20 mg Nalbuphin i.m. unmittelbar post-operativ. Die Schmerzlinderung, Vigilanz und Nebenwirkungen wurde nach international anerkannten Scoring Systemen gemessen. Weiters wurde auf die Beurteilung der Effizienz durch Arzt und Patienten besonderes Augenmerk gelegt.

Departments of Anesthesiology and Neurosurgery University Clinics of Innsbruck 6020 Innsbruck, Austria

Objective: To examine the glottic function in extubated patients recovering from acute lung injury by simultaneous measurement of airway opening and subglottic airway pressures while patients are breathing at ambient pressure and receiving continuous positive airway pressure by a face mask.Design: Descriptive, prospective study.Setting: Intensive care unit at a university hospital.Patients: Ten patients who required continuous positive airway pressure of at least 7 cm H2O in order to restore gas exchange after mechanical ventilation for acute lung injury.Interventions: Spontaneous breathing at ambient airway pressure and with continuous positive airway pressures of 5 and 10 cm H2O via face mask.Measurements and Main Results: Intratracheal pressure, airway opening pressure, and airflow at the airway opening were measured. Breathing at ambient pressure resulted in significantly higher end-expiratory intratracheal pressure than end-expiratory airway opening pressure (p < .01). No significant differences between end-expiratory intratracheal pressure and end-expiratory airway opening pressure were observed during breathing with continuous positive airway pressures of 5 and 10 cm H2O. A significant end-expiratory airflow at the airway opening (p < .01), observed during ambient pressure breathing, was not detectable while the patient received mask continuous positive airway pressure. The partial pressure of oxygen in the arterial blood (PaO2) increased significantly while patients breathed with 10 cm H2O, but not while patients breathed 5 cm H2O continuous positive airway pressure compared with breathing at ambient pressure (p < .05).Conclusions: Our data imply that patients recovering from acute lung injury create an intratracheal positive end-expiratory pressure by braking the expiratory airflow, probably by glottic narrowing. Despite compensatory glottic narrowing, extubated patients with reduced lung function may benefit from higher levels of continuous positive airway pressure.

Knowledge of the pressure/volume (P/V) relationship of the lung may allow selection of tidal volume and positive end-expiratory pressure (PEEP) to optimize gas exchange without adversely affecting lung function or hemodynamics. Ten patients with acute lung injury were stabilized on controlled mechanical ventilation, based on conventional practice, using criteria from arterial blood gas data. The P/V relationship was determined under quasi-static conditions (end-expiratory and end-inspiratory, no flow periods > 0.8 s) during mechanical ventilation with an automated procedure that changed PEEP in a stepwise fashion. Differences in expiratory tidal volumes before and after a change in PEEP equaled the change in functional residual capacity (delta FRC). PEEP was set above the lowest point of the steepest section of the P/V curve (inflection pressure) to prevent end-expiratory lung collapse. Inspiratory tidal volumes (VTI) were adjusted to avoid an end-inspiratory lung volume reaching the flat part of the P/V curve. Averaged delta FRC versus PEEP curves were shifted to the left and the slope increased 1, 6, and 12 h after changing ventilator settings compared to baseline (P < 0.01). Averaged baseline delta FRC versus PEEP curves showed a marked inflection pressure that decreased after adjusting ventilator settings (P < 0.01). PEEP was increased from 7.4 +/- 1.8 cm H2O (baseline) to 11.9 +/- 1.6 cm H2O (1 h) (P < 0.001) according to measured baseline inflection pressures. Simultaneously, VTI had to be reduced from 759 +/- 161 mL (baseline) to 664 +/- 101 mL (1 h) (P < 0.01) to avoid end-inspiratory overinflation. To maintain minute volume constant ventilator frequency was increased from 14 +/- 1.2 (baseline) to 16 +/- 1.2 breaths/min (1 h) (P < 0.01). Maximum quasi-static compliance of 38 +/- 7 mL/cm H2O (baseline) increased to 46 +/- 9 mL/cm H2O (1 h) (P < 0.01). Maintaining FIO2 constant, PaO2 increased from a baseline of 90 +/- 16 mm Hg to 122 +/- 24 mm Hg (1 h) (P < 0.001), to 130 +/- 20 mm Hg (6 h) (P < 0.01), and to 138 +/- 19 mm Hg (12 h) (P < 0.01). Intrapulmonary shunt decreased from 0.28 +/- 0.08 (baseline) to 0.14 +/- 0.05 (12 h) (P < 0.001). Hemodynamic variables did not change. Our data suggest that using variables derived from a quasi-static P/V loop during mechanical ventilation under muscle paralysis is clinically superior compared to blood gas criteria for titration of ventilator settings.

Objective. To examine the effects of continuous positive airway pressure applied via face masks and nose masks on the change in functional residual capacity and gas exchange.Design: Descriptive and prospective study.Setting. Intensive care unit of a university hospital.Patients. Ten patients with acute lung injury who had required mechanical ventilation.Interventions: Continuous positive airway pressure at a level of 10 cm H2O applied in random order via face and nose masks.Measurements and Main Results: Both continuous positive airway pressure methods resulted in an almost identical increase of functional residual capacity. During nasal continuous positive airway pressure, the increase in functional residual capacity was 294 +/- 82 mL. During mask continuous positive airway pressure, the increase in functional residual capacity was 290 +/- 85 mL. Pao2 increased and the alveolar-arterial oxygen tension/alveolar oxygen tension quotient decreased significantly during mask continuous positive airway pressure and nasal continuous positive airway pressure at a level of 10 cm H2O. Two patients showed a periodic change in their breathing patterns; they took a few breaths at an increased lung volume, followed by one deep expiration caused by mouth opening. Change in mask pressure was negligible in these two patients. Using a visual analog scale (10 = highly comfortable; 0 = severely uncomfortable), the patients rated nasal continuous positive airway pressure (8.6 +/- 0.9) significantly more comfortable than mask continuous positive airway pressure (2.6 +/- 0.8).Conclusion: The major advantages of continuous positive airway pressure (the improvement of functional residual capacity and oxygen transfer) can also be achieved with nasal continuous positive airway pressure in the postextubation period in patients who have been mechanically ventilated for acute lung injury.

The clinical interest for augmented modes of ventilatory support has increased in the last decade. A number of methods have been developed whose common goal is to improve the respiratory function without suppressing the patient’s own respiration.

We prospectively studied the variation in sequence of occurrence of lung microvascular permeability (LMVP) increase and clinical onset of posttraumatic acute lung failure (ALF) in the sequential failure of organ systems after direct and indirect lung injury. Acute lung failure developed in 52 of 255 trauma patients. Thirty-seven of these developed ALF after a direct injury to lung tissue and 11 after an indirect injury. Lung microvascular permeability was measured with a gamma camera simultaneously over both lungs using indium 113m-labeled transferrin and technetium 99m-labeled erythrocytes in 24 patients with ALF due to direct lung injury and in 4 with ALF due to indirect injury. A localized increased LMVP was observed initially only in the directly traumatized lung (traumatized/nontraumatized lung: 10.03 +/- 5.08/3.73 +/- 3.33 %/h), but involved the primarily nontraumatized lung within 4 days (traumatized/nontraumatized lung: 9.13 +/- 4.49/10.89 +/- 5.05 %/h). In contrast, in ALF due to indirect lung injury, an increased LMVP over both lungs was observed initially (right/left lung: 11.57 +/- 6.18/12.63 +/- 5.73 %/h) and 4 days later (right/left lung: 12.3 +/- 5.49/11.92 +/- 5.75 %/h). Acute lung failure due to direct lung injury occurred significantly earlier (less than 72 h) (P less than 0.01), whereas onset of indirectly induced ALF was later (greater than 72 h). Sepsis syndrome and multiple organ failure were the major complications once ALF occurred after a direct injury. In contrast, sepsis syndrome and multiple organ failure commonly preceded or paralleled the onset of ALF due to an indirect injury.(ABSTRACT TRUNCATED AT 250 WORDS)