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Biomedical subjects

U Kaisers

Publications and source records attributed to U Kaisers.

At least 37 records · Page 2Linked to original sources
PubMed2001

Incidence and indications for reintubation during postoperative care following orthotopic liver transplantation.

STUDY OBJECTIVE: To analyze the incidence and indications for reintubation during postoperative care following orthotopic liver transplantation (OLT). DESIGN: Retrospective chart review. SETTING: Large metropolitan teaching hospital. PATIENTS: 546 adult liver transplant recipients. MEASUREMENTS AND MAIN RESULTS: The medical charts of 546 patients who underwent OLT at our institution between January 1992 and September 1996 were reviewed for the incidence and indications of reintubation throughout primary hospitalization. Eighty-one of 546 patients (14.8%) required one or more episodes of reintubation after OLT. In the majority of cases, reintubation was performed for pulmonary complications (44.6%), followed by cerebral (19.1%) and surgical (14.5%) complications. Cardiac (9.1%) and peripheral neurologic (2.7%) complications were less frequent reasons for reintubation. Overall patient survival, according to the Kaplan-Meier estimates, was 89.9%, 87.5%, 86.5%, and 82.2% after 1, 2, 3, and 5 years, respectively. In patients with one or more episodes of reintubation, overall survival decreased to 62.5% after 1, 2, and 3 years, and to 56.4% after 5 years (p < 0.001). CONCLUSIONS: The main indications for reintubation after OLT were pulmonary, cerebral, and surgical complications. These reintubation events had a considerable influence on the patient's postoperative recovery, and were associated with a significantly higher rate of mortality, than for OLT patients who did not undo reintubation.

Anti-Infective Agents↗
PubMed2001

Postoperative tracheal extubation after orthotopic liver transplantation.

BACKGROUND: The duration of postoperative mechanical ventilation and its influence on pulmonary function in liver transplant recipients is still debated controversially. METHODS: We retrospectively analyzed the incidence of immediate tracheal extubation, prolonged mechanical ventilation (>24 h following surgery), and episodes of reintubation in 546 patients who underwent orthotopic liver transplantation (OLT) at our institution. RESULTS: Immediate tracheal extubation in the operating theater was achieved in 18.7% of patients, and prolonged mechanical ventilation was required by 11.2% of patients. In these, median time of extubation was 49.5 h, whereas the remaining 70.1% of patients required ventilation support for a median 5 h after OLT. As risk factors for prolonged mechanical ventilation we identified the indications of acute liver failure and retransplantation, as well as factors such as mechanical ventilation prior to OLT, massive intraoperative bleeding, and severe reperfusion injury of the liver graft. The incidence of reintubation was 8.8% in patients who were immediately extubated following surgery, and 13.1% in patients who underwent extubation within 24 h. The incidence was significantly increased in patients requiring prolonged mechanical ventilation (36.1%). CONCLUSIONS: Immediate tracheal extubation was safe and well tolerated. The incidence of reintubation was not increased when compared to patients in whom extubation succeeded later. However, special attention should be given to transplant recipients presenting in reduced clinical condition at the time of OLT, undergoing complicated surgery, or receiving liver allografts with severe reperfusion injury because of an increased risk for prolonged mechanical ventilation.

Adolescent↗
PubMed2001

Small dose of exogenous surfactant combined with partial liquid ventilation in experimental acute lung injury: effects on gas exchange, haemodynamics, lung mechanics, and lung pathology.

A combination of exogenous surfactant and partial liquid ventilation (PLV) with perfluorocarbons should enhance gas exchange, improve respiratory mechanics and reduce tissue damage of the lung in acute lung injury (ALI). We used a small dose of exogenous surfactant with and without PLV in an experimental model of ALI and studied the effects on gas exchange, haemodynamics, lung mechanics, and lung pathology. ALI was induced by repeated lavages (PaO2/FIO2 less than 13 kPa) in 24 anaesthesized, tracheotomized and mechanically ventilated (FIO2 1.0) juvenile pigs. They were treated randomly with either a single intratracheal dose of surfactant (50 mg kg(-1), Curosurf, Serono AG, München, Germany) (SURF-group, n=8), a single intratracheal dose of surfactant (50 mg kg(-1), Curosurf) followed by PLV with 30 ml kg(-1) of perfluorocarbon (PF 5080, 3M, Germany) (SURF-PLV-group, n=8) or no further intervention (controls, n=8). Pulmonary gas exchange, respiratory mechanics, and haemodynamics were measured hourly for a 6 h period. In the SURF-group, the intrapulmonary right-to-left shunt (QS/QT) decreased significantly from mean 51 (SEM 5)% after lavage to 12 (2)%, and PaO2 increased significantly from 8.1 (0.7) to 61.2 (4.7) kPa compared with controls and compared with the SURF-PLV-group (P<0.05). In the SURF-PLV-group, QS/QT decreased significantly from 54 (3)% after induction of ALI to 26 (3)% and PaO2 increased significantly from 7.2 (0.5) to 30.8 (5.0) kPa compared with controls (P<0.05). Static compliance of the respiratory system (C(RS)), significantly improved in the SURF-PLV-group compared with controls (P<0.05). Upon histological examination, the SURF-group revealed the lowest total injury score compared with controls and the SURF-PLV-group (P<0.05). We conclude that in this experimental model of ALI, treatment with a small dose of exogenous surfactant improves pulmonary gas exchange and reduces the lung injury more effectively than the combined treatment of a small dose of exogenous surfactant and PLV.

Animals↗
PubMed2001

Secondary insults in severe head injury--do multiply injured patients do worse?

OBJECTIVES: To study the occurrence of secondary insults and the influence of extracranial injuries on cerebral oxygenation and outcome in patients with closed severe head injury (Glasgow Coma Scale score < or =8). DESIGN: Two-year prospective, clinical study. SETTING: Two intensive care units in a level III trauma center. PATIENTS: We studied 119 patients. Eighty patients had severe head injury and were divided into two categories: "isolated" severe head injury patients (n = 36, Injury Severity Score <30), and severe head injury patients with associated extracranial injuries (n = 44, Injury Severity Score >29). Thirty-nine patients with extracranial injuries and no head injury served as the control group. INTERVENTIONS: After patients were admitted to the intensive care unit, we began continuous multimodal cerebral monitoring of intracranial pressure, mean arterial blood pressure, cerebral perfusion pressure, end-tidal Co2, brain tissue Po2 (Licox), jugular bulb oxyhemoglobin saturation in severe head injury patients, and mean arterial blood pressure in the control group. Targets of management included intracranial pressure <20 mm Hg, cerebral perfusion pressure >60 mm Hg, Paco2 > 30 mm Hg, control of cerebral oxygenation, and delayed surgery for non-life-threatening extracranial lesions. MEASUREMENTS AND MAIN RESULTS: Data were analyzed for critical thresholds. The occurrence of secondary insults (intracranial pressure >20 mm Hg, mean arterial blood pressure <70 mm Hg, cerebral perfusion pressure <60 mm Hg, end-tidal Co2 <30 torr, brain tissue Po2 <10 torr, jugular bulb oxyhemoglobin saturation <50%) was comparable in patients with isolated severe head injury and those with severe head injury with associated extracranial lesions (Abbreviated Injury Scale score < or =5). The duration of intracranial hypertension and arterial hypotension significantly correlated with an unfavorable outcome, independent of the Injury Severity Score. In patients with severe head injury, 1-yr outcome was 29% dead or vegetative, 17% severely disabled, and 54% moderate or good outcome. This was similar to patients with severe head injury and extracranial injuries (31% dead or vegetative, 14% severely disabled, and 56% moderate or good outcome) and was independent of the Injury Severity Score. Patients with no head injury had less secondary insults (mean arterial blood pressure <70 mm Hg, p <.01) and a better outcome compared with both severe head injury groups (p <.044). CONCLUSIONS: In patients with severe head injury who have targeted management including intracranial pressure- and cerebral perfusion pressure-guided therapy and delayed surgery for extracranial lesions, the occurrence of secondary insults in the intensive care unit and long-term neurological outcome were comparable and independent of the presence of extracranial lesions (Abbreviated Injury Severity level < or =5). A severe head injury is still a major contributor predicting an unfavorable outcome in multiply injured patients.

Adult↗
PubMed2001

[Intensive care management of ARDS].

The acute respiratory distress syndrome (ARDS) is characterized by (1) intrapulmonary right-to-left shunting, (2) permeability edema of the lung, and (3) alterations in pulmonary compliance. The clinical features of ARDS are due to an acute inflammatory reaction of the lung. Current clinical management of patients with ARDS aim at implementation of lung protective ventilatory strategies with adequate PEEP and low tidal volumes, diagnosis and treatment of underlying infections, and a negative fluid balance together with positional maneuvers like prone positioning.

Critical Care↗
PubMed2001

[Management of thoracic trauma in multiple injuries in the clinic].

Injuries to the chest and lung are common in the polytraumatized patient. Clinical series have shown that on average 20% of all deaths following a polytrauma are caused by a chest trauma. The most common chest injuries are rip- and serial rip fractures with an unstable chest as well as pneumo- and hematothorax. Further common injuries to the lung parenchyma are lung contusions, lacerations and lung hematoma. The clinical outcome of chest injuries is closely related on a clear treatment strategy, with a sufficient preclinical assessment and early intubation, early temporary or definitive fracture stabilisation and implementation of intensive care and lung protective treatment rules.

Critical Care↗
PubMed2000

Inhaled endothelin A antagonist improves arterial oxygenation in experimental acute lung injury.

OBJECTIVES: To study the effects of an inhaled endothelin A (ET(A)) receptor antagonist on hemodynamics and pulmonary gas exchange in experimental acute lung injury (ALI). DESIGN AND SETTING: Prospective, randomized, and controlled study in a university laboratory. PARTICIPANTS AND INTERVENTIONS: Sixteen pigs were ventilated in a volume controlled mode during general anesthesia. ALI was induced by surfactant depletion using repetitive lung lavages until the PaO2/FIO2 ratio was below 100 mmHg. The animals were then randomly assigned to receive either a nebulized ET(A) receptor antagonist (LU-135252, 3 mg/kg, inhaled over 1 h; LU group) or nebulization of saline (5-10 ml inhaled over 1 h) with no further intervention (controls). MEASUREMENTS AND RESULTS: Parameters of hemodynamics and gas exchange were measured for 6 h after induction of ALI. In the LU group intrapulmonary right-left shunting (QS/QT) decreased from 58 +/- 8% at the onset of ALI to 27 +/- 12% 3 h and 24 +/- 9% 6 h after ALI (p < 0.05); PaO2 increased from 55 +/- 12 to 257 +/- 148 mmHg 3 h and 270 +/- 136 mmHg 6 h after ALI. (p < 0.05), whereas in controls QS/QT and PaO2 did not improve over the 6 h after onset of ALI. In the LU group mean pulmonary artery pressure was stable for 6 h after ALI (26-29 mmHg), while in controls it increased from 28 +/- 2 to 41 +/- 2 mmHg (p < 0.05). Inhaled LU-135252 reduced cardiac output by 31 +/- 11% (p < 0.05) and increased systemic vascular resistance by 60 +/- 29 % (p < 0.05), while these parameters remained stable in controls. CONCLUSION: In this porcine model of ALI the inhalation of an ET(A) receptor antagonist improved arterial oxygenation and maintained a stable pulmonary artery pressure without inducing systemic vasodilatation.

Administration, Inhalation↗
PubMed2000

Dose-dependent effects of almitrine on hemodynamics and gas exchange in an animal model of acute lung injury.

OBJECTIVE: To determine the dose-response relationship of almitrine (Alm) on pulmonary gas exchange and hemodynamics in an animal model of acute lung injury (ALI). DESIGN: Prospective, randomized, controlled study. METHODS: Twenty anesthetized, tracheotomized and mechanically ventilated (FIO2 1.0) pigs underwent induction of ALI by repeated saline washout of surfactant. Animals were randomly assigned to either receive cumulating doses of Alm intravenously (0.5, 1.0, 2.0, 4.0, 8.0 and 16.0 micrograms.kg-1.min-1) for 30 min each (treatment; n = 10) or to receive the solvent malic acid (controls; n = 10). MEASUREMENTS AND RESULTS: Measurements of pulmonary gas exchange and hemodynamics were performed at the end of each infusion period. Alm < 4.0 micrograms.kg-1.min-1 improved arterial oxygen pressure (PaO2) (105 +/- 9 mmHg for Alm 1.0 vs 59 +/- 5 mmHg) and decreased intrapulmonary shunt (Qs/Qt) (32 +/- 4% for Alm 1.0 vs 46 +/- 4%) (P < 0.05). Alm > or = 8.0 micrograms.kg-1.min-1 did not improve pulmonary gas exchange compared to controls. When compared to low doses of Alm < 4.0 micrograms.kg-1.min-1, high doses > or = 8.0 micrograms.kg1.min-1 decreased PaO2 (58 +/- 11 mmHg for Alm 16.0) and increased Qs/Qt (67 +/- 10% for Alm 16.0) (P < 0.05). CONCLUSIONS: In experimental ALI, effects of almitrine on oxygenation are dose-dependent. Almitrine is most effective when used at low doses known to mimic hypoxic pulmonary vasoconstriction.

Almitrine↗
PubMed2000

A case of septicemia with Pediococcus acidilactici after long-term antibiotic treatment.

Presented here is a case of septicemia caused by an uncommon, multiresistant, gram-positive microorganism (Pediococcus acidilactici) after long-term antibiotic treatment. Pediococcus spp. are rarely cultivated from clinical specimens, and species differentiation is difficult due to the paucity of phenotypic traits. In this case, a polyphasic approach consisting of phenotypic and molecular genetic analyses was used, and the identification of Pediococcus acidilactici was conclusive. Precise identification and antimicrobial susceptibility testing of rarely isolated bacteria are required in order to provide adequate treatment to infected patients and to determine the pathogenic role of these organisms.

Adult↗
PubMed2000

Administration of prostacyclin after liver transplantation: a placebo controlled randomized trial.

The shortage of suitable organs for liver grafts is responsible for the use of marginal donors for liver transplantation (OLT). If these liver grafts function poorly initially after OLT, a supportive therapy is necessary. The purpose of this study was to evaluate the effects of prostacyclin (PGI2) on postoperative liver graft function after OLT. A total of 30 adult recipients of primary OLT were randomized to either receive PGI2 (4 ng/kg per min body weight, n = 15) or a placebo for 6 d. To evaluate regional splanchnic oxygenation a fiberoptic pulmonary-artery catheter was inserted into a hepatic vein and the difference between mixed venous oxygen content and hepatic venous oxygen content was determined (deltaO2). Measurements were performed directly after transplantation and at 6, 12, 24 and 48 h postoperatively. A significant correlation between deltaO2 and the level of transaminases (ALT/AST) was observed 24 and 48 h after transplantation (p < 0.05). PGI2 treatment induced a significant decrease in deltaO2 after 24 and 48 h after reperfusion (p < 0.05). Peak AST levels tended to be lower in the PGI2 treatment group (418 +/- 99 vs. 638 +/- 156 U/L, p < 0.1). These results suggest that administration of PGI2 after OLT improves hepatic-splanchnic oxygenation and may thereby reduce reperfusion injury after OLT.

Adult↗
PubMed2000

At surfactant deficiency, application of "the open lung concept" prevents protein leakage and attenuates changes in lung mechanics.

OBJECTIVE: To evaluate whether mechanical ventilation using "the open lung concept" during surfactant depletion can attenuate the deterioration in pulmonary function. DESIGN: Experimental, comparative study. SETTING: Research laboratory of a large university. SUBJECTS: Eighteen adult male Sprague-Dawley rats, weighing 280-340 g. INTERVENTIONS: Twelve rats were anesthetized, mechanically ventilated with 100% oxygen, and randomly divided into two groups (n = 6 each). The open lung group underwent six saline lavages at different ventilator settings that prevented alveolar collapse. The settings (expressed as frequency/peak inspiratory pressure/positive end-expiratory pressure/inspiratory:expiratory ratio) were 30/26/6/1:2 during the first lavage, 100/27/10/1:1 during the next two lavages, and 100/33/15/1:1 during the last three lavages and during the remaining ventilation period. The ventilated control group underwent six saline lavages with settings at 30/26/6/1:2. After the lavages, peak inspiratory pressure and positive end-expiratory pressure were increased in this group by 2 cm H2O each for the remaining study period. An additional group of six animals were killed immediately after induction of anesthesia and served as healthy controls. Blood gases were measured before lavage, immediately after the last lavage, and thereafter hourly. At the end of the 4-hr study period, we constructed pressure-volume curves from which we determined total lung capacity at a distending pressure of 35 cm H2O (TLC35). Subsequently, total lung volume at a distending pressure of 5 cm H2O (V5) was determined, followed by bronchoalveolar lavage. RESULTS: In the ventilated control group, PaO2, V5, and TLC35 were significantly decreased and protein concentration of bronchoalveolar lavage was significantly increased compared with the healthy control group. In the open lung group, PaO2 did not decrease after the lavage procedure, and V5, TLC35, and the protein concentration of bronchoalveolar lavage were comparable with the healthy controls. CONCLUSION: We conclude that application of the open lung concept during surfactant depletion attenuates deterioration in pulmonary function.

Animals↗
PubMed1999

Comparison of exogenous surfactant therapy, mechanical ventilation with high end-expiratory pressure and partial liquid ventilation in a model of acute lung injury.

We have compared three treatment strategies, that aim to prevent repetitive alveolar collapse, for their effect on gas exchange, lung mechanics, lung injury, protein transfer into the alveoli and surfactant system, in a model of acute lung injury. In adult rats, the lungs were ventilated mechanically with 100% oxygen and a PEEP of 6 cm H2O, and acute lung injury was induced by repeated lung lavage to obtain a PaO2 value < 13 kPa. Animals were then allocated randomly (n = 12 in each group) to receive exogenous surfactant therapy, ventilation with high PEEP (18 cm H2O), partial liquid ventilation or ventilation with low PEEP (8 cm H2O) (ventilated controls). Blood-gas values were measured hourly. At the end of the 4-h study, in six animals per group, pressure-volume curves were constructed and bronchoalveolar lavage (BAL) was performed, whereas in the remaining animals lung injury was assessed. In the ventilated control group, arterial oxygenation did not improve and protein concentration of BAL and conversion of active to non-active surfactant components increased significantly. In the three treatment groups, PaO2 increased rapidly to > 50 kPa and remained stable over the next 4 h. The protein concentration of BAL fluid increased significantly only in the partial liquid ventilation group. Conversion of active to non-active surfactant components increased significantly in the partial liquid ventilation group and in the group ventilated with high PEEP. In the surfactant group and partial liquid ventilation groups, less lung injury was found compared with the ventilated control group and the group ventilated with high PEEP. We conclude that although all three strategies improved PaO2 to > 50 kPa, the impact on protein transfer into the alveoli, surfactant system and lung injury differed markedly.

Animals↗
PubMed1998

Superimposing positive end-expiratory pressure during partial liquid ventilation in experimental lung injury.

This study was undertaken to determine the effects of superimposing incremental levels of positive end-expiratory pressure (PEEP) during partial liquid ventilation (PLV) on gas exchange, respiratory mechanics and morphological changes in experimental acute lung injury (ALI). In a prospective trial, six pigs weighing 30+/-5 kg (mean+/-SD) were tracheotomized, submitted to pressure-controlled mechanical ventilation (pc-CMV) and depleted of surfactant by lung lavage. Animals were then mechanically ventilated with three levels of PEEP: 0.5, 1.0 and 1.5 kPa. PLV was then initiated by intratracheal instillation of 30 mL x kg(-1) perfluorocarbon, followed by pc-CMV with PEEP 0.5, 1.0 and 1.5 kPa. Computed tomography (CT)-based analyses of lung volumes and density were obtained after lung lavage, in PLV and during the combined application of PLV and PEEP. Simultaneously, haemodynamics, gas exchange, dynamic compliance (Cdyn) and dynamic resistance (Rdyn) were determined. Statistical analysis was performed using multivariate analyses of variance for repeated measures (p<0.05). In ALI and before PLV, the application of PEEP significantly reduced cardiac output and intrapulmonary shunt. Arterial oxygen tension (Pa,O2) was increased from 6.9 kPa (52 (42, 54) mmHg) (median, (25th and 75th percentile)) to 8.6 kPa (65 (52, 133) mmHg) (PEEP 1.0 kPa) and 15.6 kPa (117 (90, 195) mmHg) (PEEP 15 kPa) (p<0.05). The lung volume obtained by CT increased, CT density was reduced (p<0.05), Cdyn tended to increase and Rdyn to decrease (nonsignificant). PLV increased arterial carbon dioxide tension and reduced pH (p<0.05). CT lung volume and lung density were increased (p<0.05). Superimposing PEEP on PLV increased Pa,O2 from 9.3 kPa (70 (52,124) mmHg) (PEEP 0.5 kPa) to 12.9 kPa (97 (55, 233) mmHg) (PEEP 1.0 kPa) and 403 kPa (303 (64, 426) mmHg) (PEEP 1.5 kPa) (p<0.05), but had no significant effect on CT lung volume and density. It was concluded that in experimental lung injury, positive end-expiratory pressure provided alveolar recruitment. The combined application of positive end-expiratory pressure and partial liquid ventilation significantly augmented oxygenation and might eventually allow either a reduction in the volumes of perfluorocarbons required, or a reduction in positive end-expiratory pressure necessary to maintain pulmonary gas exchange in acute lung injury.

Animals↗
PubMed1998

Surfactant therapy restores gas exchange in lung injury due to paraquat intoxication in rats.

Paraquat is a weed killer which causes often fatal lung damage in humans and other animals. There is evidence that the pulmonary surfactant system is involved in the pathophysiology of respiratory failure after paraquat intoxication and, therefore, the possible therapeutic effect of intratracheal surfactant administration on gas exchange in rats with progressive lung injury induced by paraquat poisoning was studied. In one group of rats, the time course of the development of lung injury due to paraquat intoxication was characterized. In a second group of rats, 72 h after paraquat intoxication, the animals underwent mechanical ventilation and only those animals in which the arterial oxygen tension/inspiratory oxygen fraction (Pa,O2/FI,O2) decreased to below 20 kPa (150 mmHg) received exogenous surfactant (200 mg x kg(-1) body weight). Within 3 days the rats in group 1 developed progressive respiratory failure, demonstrated not only by impaired gas exchange and lung mechanics but also by increased minimal surface tension and increased protein concentration in bronchoalveolar lavage fluid. In group 2, intratracheal surfactant administration increased Pa,O2/FI,O2 significantly within 5 min (14.4+/-2.4 kPa (108+/-18 mmHg)) to (55.2+/-53 kPa (414+/-40 mmHg)) and sustained this level for at least 2 h. It is concluded that intratracheal surfactant administration is a promising approach in the treatment of severe respiratory failure caused by paraquat poisoning.

Animals↗