Biomedical subjects

J M Strauss

Publications and source records attributed to J M Strauss.

At least 37 records · Page 2Linked to original sources

PubMed1994

[Malignant hyperthermia in swine during isoflurane anesthesia].

A case of porcine malignant hyperthermia (MH) is reported, which occurred during a cardiological animal experiment under general anaesthesia using isoflurane as inhalational anaesthetic. Initially, tachycardia (238 bpm) and a sudden increase of end-exspiratory pCO2 were noticed. Discontinuation of isoflurane followed by administration of dantrolene (7 mg/kg body weight) led to a rapid recovery. Two days later, no difference in clinical state was apparent in comparison with the remaining swine. After regular euthanasia, acute muscle necrosis was seen macroscopically in back and glutaeal muscles, which was confirmed by histological examination. The rise of end-tidal pCO2 was the striking symptom thus allowing the detection of the incipient malignant hyperthermia. Early onset of dantrolene therapy is shown to be sufficient in termination of this hyperacute complication, and may prevent its deleterious outcome. Therefore, the administration of dantrolene should be taken into account in case of porcine MH, especially in time-consuming and costly series of animal experiments.

Anesthesia, Inhalation↗

PubMed1994

[Postoperative monitoring of microvascular flap repair with pulse oximetry--initial experience].

The surgical success of microvascular free flaps or pedicled flaps depends on the function of the nutritive vessels. Complications such as thrombosis or vessel kinking, are dangerous and may result in flap loss. During the last decade, different methods were tested for their capability of monitoring flap perfusion. We report our preliminary experience with the continuous and non-invasive pulse oximetry by using a special reflection sensor positioned on the surface of the flap.

Adult↗

PubMed1994

[Arthroscopic subacromial decompression--indications in os acromiale?].

A total of 122 patients with subacromial pathology without tears in the rotator cuff underwent arthroscopic subacromial decompression (ASD) and were re-examined 1-3 years after the operation. All patients' data were recorded before and after operation with reference to a 100-point shoulder score. The group included 12 patients who proved to have an os acromiale on X-ray. Postoperatively scores wee significantly higher (p < 0.05). Patients with os acromiale had a slightly but not significantly worse outcome than the others. Results were excellent in 43% of all patients, good in 17%, and fair in 25%, while 15% were considered failures. Again patients with an os acromiale had a slightly, but not significantly, worse result. Patients with a preoperative pain history of more than 1 year had a significantly worse result than those with a preoperative course of less than 1 year (p < 0.05). This was true for both groups without any differences between them. Older patients also scored worse in both groups. Other factors, e.g. sex, preoperative range of motion, and muscle atrophy, did not significantly influence the result. Our results after ASD in patients with subacromial pathology without rupture of the rotator cuff and with os acromiale are encouraging. Therefore, this minimally invasive procedure seems to be a reasonable alternative to other complex procedures with ORIF in selected cases.

Acromion↗

PubMed1993

Accumulation of acetone in blood during long-term anaesthesia with closed systems.

During closed system anaesthesia with isoflurane, patients with a preoperative increase in blood concentration of acetone (> 10 mg litre-1) had a significantly greater concentration of acetone than patients with an initial normal blood concentration of acetone (P < 0.01). Flushing the closed system with a high flow of fresh gas had no effect on the blood concentration of acetone. Using a large fresh gas flow, there was no increase in blood acetone concentration. Acetone concentrations of about 50 mg litre-1 cause problems such as nausea and vomiting in the postoperative period. These symptoms occurred more frequently after closed system anaesthesia.

Acetone↗

PubMed1993

[Arthroscopy of the upper ankle joint. List of indications from the literature--realistic expectations--complications].

Based on the results of a retrospective study of 116 patients who underwent diagnostic and surgical arthroscopy of the ankle, we present the technique, the results, the complications, and the indications for ankle arthroscopy. The average age of the patients was 33 years (range 10-70 years). At follow-up the patients were examined clinically as well as radiologically. The results were scored for the criteria pain, function, athletic activity, walking aids, range of motion, and swelling. The overall score increased significantly from 50.1 preoperatively to 73.7 postoperatively (P < 0.05). The decrease in pain and the improvements in function and athletic activity after arthroscopy were significant. The other parameters (walking aids, range of motion, swelling) showed only slight changes. The patients' subjective assessment (visual analogue scale) also revealed a significant increase, from 35.6 to 69.5 (P < 0.05). After arthroscopy the preexisting radiologic lesions continued to progress. Some 71.2% of the patients suffered no limitations their work at follow-up but 13.6% reported slight limitations and 15.3% experienced moderate limitations. We documented severe restrictions in athletic activity; only 17% of the patients had maintained their previous level. In 16 cases we found iatrogenic temporary neurologic damage.

Adolescent↗

PubMed1992

[Ultrasound diagnosis of lumbar intervertebral disk displacement--a clinically relevant method?].

UNLABELLED: In a prospective clinical study, 102 patients suffering from low back pain were examined by ultrasound. In all patients the segments L3/4, L4/5, and L5/S1 were evaluated. We analysed a total of 306 lumbar disc segments. Ultrasound evaluation was transabdominally performed by using a 3,5 MHz scanner. The results of the ultrasound documentation were compared to MRI or if the patient was operated on with the intraoperative findings. In 25 disc the dorsal border of the disc could not be demonstrated by ultrasound. The statistical analysis resulted in the following values: [table: see text] Comparing these results with the results of other imaging modalities like myelography, CT, or MRI, ultrasound scores are significantly inferior. CLINICAL RELEVANCE: With the present technique ultrasound does not seem to be of diagnostic value for patients with herniated disk.

Adolescent↗

PubMed1992

[Suitability of capacitive sensors for measuring relative humidity in anesthetic gas systems].

A capacitive sensor was tested for its suitability for measuring relative humidity in an anaesthetic gas circuit. The valvo sensor PH1 was tested using various different anaesthetic gas mixtures. Measuring accuracy was influenced neither by such volatile anaesthetics as isoflurane and halothane, nor by oxygen or nitrous oxide. The response time of the sensor depends on its position within the gas, and in the most favourable case is about 3 minutes. The sensor is readily incorporated within an existing gas circuit. The linearity of the characteristic curve must be corrected by external electronic compensation to avoid measuring problems in the lower humidity range.

Anesthesia, Endotracheal↗

PubMed1992

[Humidification and heating of anesthetic gases during pediatric anesthesia using the Cicero Anesthesia Workstation].

A series of 52 infants underwent general or urological surgery; all were ventilated with the CICERO. Two different flows of fresh gas were used. In group I (n = 21) the fresh gas flow was set exactly at the level of the minute volume, representing a half-open, non-rebreathing system. In group II (n = 31) the fresh gas flow was adjusted to 10% of the required minute volume. Temperature and relative humidity of the inspired gas were measured continuously close to the tracheal tube. Anaesthesia was accomplished with 2 vol% isoflurane, 21-30 vol% oxygen in nitrous oxide. The results were compared with those achieved with our time-tested paediatric equipment, a SERVO 900D ventilator with a Fisher-Paykel humidifier (Group III, n = 35). Using a high fresh gas flow, no increase in relative humidity in the inspired gas could be detected. The values varied between 12% and 25% (group I). Reducing the flow of fresh gas as indicated above resulted in an increase in the relative humidity (group II). Over the evaluated period of 2 h, humidity increased slowly from an initial mean value of 20% to a maximum of something over 70%. Using the SERVO 900D ventilator combined with the Fisher-Paykel humidifier, humidity reached a value of greater 90% within 10 min after activation of the heated cascade. Humidity in the inspired gas should exceed 70% to avoid damage to infant airways. This will not be attained until after more than 2 h with unaided breathing systems, by when most operations performed on paediatric patients will already be over. Condensed water may aspirated by small infants. This potentially dangerous situation was only encountered in the CICERO circuit, and not in the system protected by the Fisher-Paykel cascade. Dry gases can result in thickened mucous and in obstruction of a small tracheal tube, which requires emergency reintubation. With artificial airways dry gases damage the ciliated epithelia of the trachea and cause loss of water and body heat. The temperature of the "cold" gases varied within a range of 21-33 degrees C and could not be adjusted by the anaesthetist. In the CICERO system, heating the gases at the valve only prevents mechanical failure caused by water condensation. In pediatric anaesthesia, variable heating and non-condensing humidity are essential. The dry and heated gases of the CICERO are not acceptable in the daily practice of paediatric anaesthesia.

Anesthesia, Inhalation↗

PubMed1991

[Resection of liver metastases of colorectal carcinoma: claims and reality].

Results of resection of potentially operable liver metastases from colorectal carcinomas were evaluated by analysis of 50 publications between 1985 and 1990, as well as own datas (88 patients). Average 1, 3 and 5-year survival rates without treatment were 71 +/- 14%, 18 +/- 10% and 3 +/- 4%, respectively. The extent of metastasization at the time of diagnosis was the decisive prognostic factor. After resection of metastases 80 +/- 21% of patients survived for 1 year, 43 +/- 12% for 3 years and 28 +/- 11% for 5 years. But only a small group of patients, those with single and small metastasis, limited to one liver lobe and without extrahepatic tumour deposits, clearly profited from resection, as long as this could be accomplished with a wide enough margin of safety. Studies on growth characteristics of metastases suggest that in a large proportion of the remaining patients the natural history of the disease is not significantly changed by the operation.

Colorectal Neoplasms↗

PubMed1991

[The evolution of carboxyhemoglobin during long-term closed-circuit anesthesia].

In 40 patients who underwent protracted orthodontic operations, the accumulation of carboxyhemoglobin (COHb) in the blood was studied. Mechanical ventilation during anesthesia was carried out in a closed system (group I, n = 20). Patients in a control group received mechanical ventilation with a constant fresh gas flow of 6 l/min (group II, n = 20). During closed-system ventilation, a constant rise of COHb was observed. Smokers had much higher COHb values than nonsmokers at the beginning of and during anesthesia. The relative increase of COHb in a defined time period was of the same magnitude for smokers and nonsmokers. Critical values for carbon monoxide (CO) intoxication were not measured. The mean rise was 0.05 g/100 ml COHb over 6 h. Two female patients had COHb rises of 0.29 g/100 ml and 0.18 g/100 ml over the same period. During ventilation with a high flow of fresh gas, the COHb level decreased in all patients. In nonsmokers, the value approached the physiological range of 0.4% to 0.8% COHb. A marked fall of COHb could also be observed in smokers; however, normal physiological values were not reached. Patients with low COHb tolerance (anemia, severe coronary heart disease, peripheral vascular disease) or with increased endogenous CO production (pregnancy, newborns, hemolytic disease, porphyria cutanea) should not undergo protracted ventilation in a closed circle system.

Adult↗

PubMed1988

[Functional importance of the m. extensor carpi ulnaris for distal radioulnar articulation].

Any analysis of the stability of the distal radio-ulnar joint should consider the extensor carpi ulnaris tendon. The static and kinematic function of this tendon depends on its relationship to the sigmoid notch of the radius. Morphological studies indicate the existence of a gliding surface in the sulcus of the tendon on the dorsal side of the ulnar head.

Biomechanical Phenomena↗

PubMed1978

Comparison of luteolytic potencies of aminoglutethimide enantiomers in the rabbit and rat.

The luteolytic potency of D- and L-aminoglutethimide (D- and L-AG) was compared in in vivo assays in the rat and rabbit. By assay of plasma progesterone depletion in the rabbit, the potency of L-AG relative to D-AG was 0.21. By the plasma procedure in the rat, the relative potencies of L-AG and of the racemic mixture to D-AG were 0.04 and 0.37, respectively. By the ovarian progesterone depletion method, the L-form had very little activity and the DL-mixture was half as active as the D-isomer. Thus, in both species, almost all of the activity of the racemic mixture results from the content of D-AG. Interpretation of paradoxical data implies that in the rat, L-AG may inhibit liver degradation of progesterone at levels which do not modify secretion from the corpus luteum.

Aminoglutethimide↗

PubMed1971