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Biomedical subjects

M Zieger

Publications and source records attributed to M Zieger.

At least 37 records · Page 2Linked to original sources
PubMed1989

[A comparison between high-frequency jet ventilation (HFJV) and conventional positive end-expiratory pressure ventilation (CPPV)--an experimental study on dogs with acute lung damage].

In a controlled study on 24 dogs with severe damage to the lungs HFJV was compared to CPPV on the basis of selected cardiorespiratory parameters. The pulmonary damage was produced by injection of oleic acid (OA) into the right atrium under conventional mechanical ventilation (IPPV). After the damage, the dogs were randomly allotted into one of two groups. Twelve dogs (group I) were ventilated for 5 hours with a PEEP of 10 cm H2O (1 kPA), 12 animals (group II) for 5 hours with HFJV. The oleic-acid-induced damage results in the known hypoxaemia with an increase in the intrapulmonary shunt. After changing to CPPV, the PaO2, which fell from 27.2 +/- 3 kPa to 10.8 +/- 2.9 kPa, rises to 20.3 +/- 7.7 kPa, but shows no further significant alteration until the end of the experiment. In contrast to the clearly improved oxygenation, essential cardiocirculatory parameters (CI, SVI, RVSWI, LVSWI, TCO2) are partially reduced by more than 50% of the initial values. PAP, PCWP, HR, TPR and PVR increase significantly, MAP remaining nearly unchanged. After changeover to HFJV, there is first a further fall of PaO2 from 11.1. +/- 3.0 kPa to 9.1 +/- 1.4 kPa following OA, then, however, until the end of the experiment, a continuous elevation to 15.6 +/- 2.4 kPa with a mean airway pressure that is by 75% lower. The haemodynamic parameters show no significant changes as compared to the initial values, overall, however, they lie significantly below or above those of group I. The results from our investigations allow to draw the conclusion that, despite haemodynamic advantages, HFJV in consequence of deterioration of the arterial oxygenation currently is no alternative superior to CPPV in ventilating the severely damaged lung.

Animals↗
PubMed1989

[Perthes' disease. Accuracy potentials and the value of sonography].

During a 2-year period 59 patients underwent sonography, 33 of them with confirmed Legg-Perthes disease and 26 in whom clinical examination had given rise to suspicion of this disorder. An intraarticular effusion was found in 53% (n = 26) of the patients and characteristic sonographic findings could be detected in 84% (n = 41). The special examination technique and the diagnostic criteria and their validity and correlation to radiologic abnormalities are discussed.

Adolescent↗
PubMed1989

[Sonography of hypertrophic pyloric stenosis. Statistical analysis of the values and the diagnostic criteria].

On the basis of 149 patients with the clinical suspicion of hypertrophic pyloric stenosis, sonographic diagnostic criteria were defined retrospectively. The normal ranges for the various criteria were calculated on the basis of 90 patients in whom hypertrophic pyloric stenosis had been excluded. No correlation could be found between these normal ranges and chronological age. Cut-off values between normal (n = 90) and abnormal (n = 59) were calculated by means of ROC analysis. The cut-off value of 14 mm resulted in a sensitivity of 76.9% and a specificity of 97.8% for the diameter, while the cut-off value of 18 mm gave a sensitivity of 80.3% and a specificity of 100% for the canal length. The muscle wall thickness had a sensitivity of 84.4% and a specificity of 95.5% when 4 mm was taken as the cut-off value. Combination of several parameters did not improve the results. The influence of the prevalence on the positive and negative predictive values is calculated by applying the above-mentioned cut-off values and the corresponding sensitivities and specificities. A diagnostic procedure is recommended; this is shown in the form of a flow chart for various possible prevalences.

Humans↗
PubMed1988

Pediatric spinal sonography. Part II: Malformations and mass lesions.

The most important spinal disorders in childhood are malformations and mass lesions. The sonographic appearance of the various kinds of dysraphism and their differentiation, of malformations at the cranio-cervical junction, and of mass lesions is demonstrated and illustrated. Based on our preliminary experience, spinal sonography appears to be useful as the first imaging device for the differentiation of complex malformations and as a screening method for occult dysraphism. In mass lesions spinal sonography is useful to diagnose and follow-up disease, with additional imaging procedures currently needed for confirmation of diagnosis.

Arnold-Chiari Malformation↗
PubMed1988

Ultrasonography of the painful hip. Prospective studies in 204 patients.

A total number of 204 patients presenting with an acutely or subacutely painful hip joint were investigated in two prospective studies. Intraarticular fluid collections were detected in 104 patients. The joint effusions showed different echopatterns depending on etiology and duration of disease. Additional diagnostic criteria such as synovial hypertrophy and thickening of the articular capsule allowed the distinction between transient synovitis and septic arthritis. Bony changes were encountered in 40 patients with osteomyelitis, slipping femoral epiphysis or Perthes-Calvé disease. Ultrasonography is recommended as method of choice in detecting, excluding and differentiating of joint effusions.

Adolescent↗
PubMed1988

Pediatric spinal sonography. Part I: Anatomy and examination technique.

Ultrasonography with high resolution technique enables the differentiation of intra- and paraspinal structures in a significant way. Conditions, examination technique, and sonographic anatomy of the os sacrum, the lumbar and dorsal spinal canal as well as the cranio-cervical junction are presented.

Child↗
PubMed1988

[The painful hip--diagnostic possibilities of sonography].

205 patients with a painful hip joint have been investigated prospectively. The examination technique and the sonoanatomy of the hip joint are illustrated. An intraarticular effusion could be detected in 105 patients. Depending on the aetiology and the duration of disease, different echostructures of the fluid collections were noted. Additionally, the reaction of the synovia and of the articular capsule allowed the discrimination of transient synovitis and septic arthritis. Extraarticular alterations were found in 11, changes of the bone contour in 40 patients (osteomyelitis, slipping femoral epiphysis, or Perthes-Calvé disease). Sonography is recommended as method of choice in excluding, confirming and differentiating intraarticular effusions. Intra- and periarticular affections can be distinguished safely. Bone alterations may be detectable as well.

Arthritis↗
PubMed1987

Ultrasonography of the infant hip. Part III: Clinical application.

We report on our results of ultrasonography of the infant hip over 2 years. Twenty-three percent of patients with abnormal sonogram showed no clinical suggestion of hip disorder. Suspicion of dislocation based on mobility, asymmetrical trochanteric distance, click or snapping of the hip and inhibited abduction were the most useful clinical criteria predicting disease in 93%, 19% and 16%, respectively. Breech presentation and family history of hip dysplasia or dislocation were important anamnestic data (21% and 16% predictive value, respectively). The significantly shorter duration of therapy in early detected dislocation or dysplasia makes the need for early diagnosis of these disorders obvious. Special emphasis lies on the physiological maturation of the acetabulum and the femoral ossification center. Normal ranges of important diagnostic criteria and angles depending on chronological age are presented.

Hip↗
PubMed1987

Ultrasonography of the infant hip. Part IV: Normal development in the newborn and preterm neonate.

Based on preterm and term infants studied by ultrasonography, and on anatomical sections of various gestational ages the physiological maturation of the hip joint is analysed. Current concepts of a linear growth pattern with an arrest immediately after delivery are confirmed. A more rapid growth and ossification of the acetabular edge than of the femoral head postpartum is suggested. To avoid overtreatment, knowledge of the normal range of development as seen in ultrasonography is mandatory.

Acetabulum↗
PubMed1987

[Animal experiment studies of high frequency jet ventilation with a newly developed pneumatically controlled respirator].

The effects of high frequency jet ventilation (HFJV) were investigated in 12 mongrel dogs with normal lungs. A newly developed HFJV device with purely pneumatic regulation was used. In order to evaluate several ventilatory parameters, respiratory rate, breathing time quotient and jet emission pressure were varied. Thus, important ventilatory, hemodynamic and calculated values were recorded. Accordingly, HFJV is possible with the tested device under clinical conditions in the frequency range between 80 and 300/min, with a breathing time ratio of 1:21 to 1:1 and a driving pressure up to 0.4 MPa with an oxygen concentration of FiO2 = 0.21 to 1.0. Before clinical use, however, investigations on the damaged lung of the dog are necessary.

Animals↗
PubMed1987

[Preoperative diagnosis of abdominal space-occupying lesions in childhood].

Between 1977 to 1986 results of ultrasonography in 56 patients has been compared with computed tomography (CT), excretory urography, and in 19 cases with arteriography. In comparison to ultrasonography CT proved superior in diagnosing dignity (87% vs. 78%); in appointing to the original organ, and in diagnosing the type of tumour angiography turned out to be clearly superior to CT (89% vs. 65%, and 79% vs. 43%, resp.) Addition of CT to ultrasonography resulted in a gain of 10% concerning dignity, of 30% concerning appointing to the origin, and of 24% with respect to typing. With the question of renal or extrarenal origin of a mass lesion the EUG proved to be indispencable. The following procedure is recommended: in kidney-related tumours US plus EUG, in other cases additional imaging techniques only for special problems, or specific questions preoperatively. The routine implementation of computed tomography in abdominal masses seems not to be necessary.

Abdominal Neoplasms↗
PubMed1986

Ultrasound of the infant hip. Part 1. Basic principles.

Method and the basic principle of infant hip studies by means of ultrasound are described. It is the purpose of this imaging modality to detect dislocations and dysplasia at an early stage. The visible structures of the hip-joint are shown in histologic-sonographic correlation. Based on the pathomechanics of hip-dysplasia diagnostic criteria for ultrasound studies are developed. Our classification system, in close similarity to Graf, is presented.

Hip↗
PubMed1986

Ultrasound of the infant hip. Part 2. Validity of the method.

The reproducibility of classifications and measurements used in ultrasound of the infant hip has been evaluated in a prospective, double-blind study. Normal values and range distribution are defined for the main types as well as the potential for discriminating these types by means of ROC-analysis. The clinical validity of the method in defining normal and pathologic findings is discussed in comparison with X-ray diagnosis and follow-up sonographic investigations. Visual analysis focussing on a few diagnostic criteria, mainly the inclination of the acetabular roof and the position of the femoral head, provides sufficiently high accuracy (94% agreement rate) and the best diagnostic results. A correct examination which includes tests of the mobility of the hip joint and limitation of the section level to the maximal depth of the acetabular fossa, allows nearly perfect diagnosing of dysplasia and dislocation.

Hip↗
PubMed1986

[Image analysis in hip sonography. Classification criteria].

Based on 5000 ultrasound studies of infantile hips, Graf's classification and diagnostic criteria are reviewed with regard to their ability to discriminate between normal and pathological conditions. Additional criteria (delta angle and vector line) are presented, and the results compared. The proposed approach via visual analysis is explained as a flow chart. The consequences of the methodical limitations for use as a screening procedure are discussed.

Hip Dislocation, Congenital↗