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ESWL treatment with ventral shock-wave application: therapy of iliac and distal ureteral calculi.

Because of the interposition of bony structures, extracorporeal shock-wave lithotripsy (ESWL) of middle or iliac ureteral calculi is not feasible in the conventional supine position. By a slight modification of the patient's couch allowing the prone positioning of the patient, 22 patients with calculi covered by bony structures were thus treated. The success rate of 95 percent without complications is promising and renders ESWL therapy as an alternative to ureteroscopic extraction of mid and iliac ureteral calculi.

Humans↗

Brachial plexus birth injuries: anaesthesia for surgical nerve reconstruction and preoperative myelography and computed tomographic myelography.

Surgical nerve reconstruction for brachial plexus birth injuries and preoperative myelography and computed tomographic (CT) myelography require special anaesthetic considerations. Anaesthesia and medical records were retrospectively reviewed for the infants who underwent myelography, CT myelography (n=37) and microsurgical nerve reconstruction (n=34) at our institution from January 1993 to August 1996. Anaesthetic considerations include long duration of operation, perioperative respiratory complications and plaster application which makes reintubation difficult. Myelography for diagnosis requires a specific positioning of the patient with the head fixed in a midline and prone position.

Anesthesia, Inhalation↗

The rate heterogeneity of nonsynonymous substitutions in mammalian mitochondrial genes.

Substitution rates at the three codon positions (r1, r2, and r3) of mammalian mitochondrial genes are in the order of r3 > r1 > r2, and the rate heterogeneity at the three positions, as measured by the shape parameter of the gamma distribution (alpha 1, alpha 2, and alpha 3), is in the order of alpha 3 > alpha 1 > alpha 2. The causes for the rate heterogeneity at the three codon positions remain unclear and, in particular, there has been no satisfactory explanation for the observation of alpha 1 > alpha 2. I attempted to dissect the causes of rate heterogeneity by studying the pattern of nonsynonymous substitutions with respect to codon positions in 10 mitochondrial genes from 19 mammalian species. Nonsynonymous substitutions involve more different amino acid replacements at the second than at the first codon position, which results in r1 > r2. The difference between r1 and r2 increases with the intensity of purifying selection, and so does the rate heterogeneity in nonsynonymous substitutions among sites at the same codon position. All mitochondrial genes appear to have functionally important and unimportant codons, with the latter having all three codon positions prone to nonsynonymous substitutions. Within the functionally important codons, the second codon position is much more conservative than the codon position. This explains why alpha 1 > alpha 2. The result suggests that overweighting of the second codon position in phylogenetic analysis may be a misguided practice.

Animals↗

Effect of PEEP and jugular venous compression on canine cerebral blood flow and oxygen consumption in the head elevated position.

Cerebral blood flow (CBF) (radiolabelled microspheres) and oxygen consumption (CMRO2) were studied in nine dogs during 30 min of either neck vein compression or application of positive end-expiratory pressure (PEEP) ventilation. With the animal in the prone position, elevation of the head from horizontal to 30 cm above the heart markedly decreased cisterna magna (PCSF) and dorsal sagittal sinus pressure (PCV). With the head elevated, compression of neck veins using neck tourniquet (pressure 40 mmHg) increased PCSF and PCV from 3.6 +/- 2.2 to 6.8 +/- 4.8 and -2.5 +/- 2.7 to 2.3 +/- 2.3 mmHg (mean +/- SE, P less than 0.05), respectively, while total or regional CBF and CMRO2 remained unchanged. Application of PEEP (15 cm H2O) increased right atrial pressure (-4.7 +/- 1.7 to -0.1 +/- 3.4 mmHg, P less than 0.05), but did not affect PCSF or PCV (3.4 +/- 3.3 to 3.3 +/- 3.7 and -3.5 +/- 2.6 to -4.1 +/- 2.4 mmHg, respectively, P greater than 0.05). Total or regional CBF and CMRO2 were also unaffected. These data demonstrate that, although neither maneuver affects CBF or CMRO2, neck vein compression elevates PCV above atmospheric pressure, but PEEP does not. In patients at risk for cerebral venous embolism, intermittent neck vein compression should be used as a prophylactic measure to prevent air embolism.

Animals↗

Mechanical ventilation in acute respiratory distress syndrome.

The acute respiratory distress syndrome occurs commonly in critical care. There is an increasing volume of clinical and experimental evidence that poor ventilatory technique that is injurious to the lungs can propagate the systemic inflammatory response and adversely affect mortality. Many ventilatory techniques have been hypothesized to 'protect' the lungs during mechanical ventilation, including tidal volume limitation, high positive end-expiratory pressure, pressure-controlled inverse ratio ventilation, and prone positioning. Experimental techniques include liquid ventilation, surfactant administration and extracorporeal gas exchange. Despite excellent rationale for their use, few techniques, apart from tidal volume limitation, have been shown to improve survival in randomized controlled trials.

Journal Article↗

Pediatric acute hypoxemic respiratory failure: management of oxygenation.

Acute hypoxemic respiratory failure (AHRF) is one of the hallmarks of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), which are caused by an inflammatory process initiated by any of a number of potential systemic and/or pulmonary insults that result in heterogeneous disruption of the capillary-pithelial interface. In these critically sick patients, optimizing the management of oxygenation is crucial. Physicians managing pediatric patients with ALI or ARDS are faced with a complex array of options influencing oxygenation. Certain treatment strategies can influence clinical outcomes, such as a lung protective ventilation strategy that specifies a low tidal volume (6 mL/kg) and a plateau pressure limit (30 cm H(2)O). Other strategies such as different levels of positive end expiratory pressure, altered inspiration to expiration time ratios, recruitment maneuvers, prone positioning, and extraneous gases or drugs may also affect clinical outcomes. This article reviews state-of-the-art strategies on the management of oxygenation in acute hypoxemic respiratory failure in children.

Adrenal Cortex Hormones↗

[Technique of measuring esophageal pressure in rabbits and its application to measurement of pulmonary compliance and resistance].

Esophageal pressure (Pes) was measured under non-invasive condition by an esophageal balloon made by ourselves, and the optimal position of rabbits for measuring Pes was explored. The correspondence between Pes and pleural pressure (Ppl) was examined in rabbits during different depths of breathing with varied lengths of balloon and varied depths of insertion of balloon into the esophagus. The results showed that the amplitude of Pes only on supine position was higher than that on the left and right lateral and prone positions, but no significant difference was noticed among the 3 positions. The optimal balloon length was 4-6 cm. The optimal depth of insertion of balloon into the esophagus was 20 cm. The pulmonary dynamic compliance and pulmonary resistance were measured in 11 white rabbits with 5 cm balloon, 20 cm depth of insertion, on the left lateral position. The results were correspondent with other authors. No significant difference was noticed in repeated measurements on 8 of the 11 rabbits 5 days later.

Airway Resistance↗

Prone versus supine sleep position: a review of the physiological studies in SIDS research.

A number of physiological studies, published over the last 10 years, have investigated the links between prone sleeping and sudden infant death syndrome (SIDS). This review evaluates those studies and derives an overview of the different affects of sleeping prone or supine in infancy. Generally, compared with the supine, the prone position raises arousal and wakening thresholds, promotes sleep and reduces autonomic activity through decreased parasympathetic activity, decreased sympathetic activity or an imbalance between the two systems. In addition, resting ventilation and ventilatory drive is improved in preterm infants, but in older infants (>1 month), there is no improvement in ventilation, and in 3-month-old infants, the position is adverse in terms of poorer ventilatory drive (in active sleep only). The majority of findings suggest a reduction in physiological control related to respiratory, cardiovascular and autonomic control mechanisms, including arousal during sleep in the prone position. Since the majority of these findings are from studies of healthy infants, continued reinforcement of the supine sleep recommendations for all infants is emphasized.

Arousal↗

Anatomic evaluation of postural bronchial drainage of the lung with special reference to patients with tracheal intubation: which combination of postures provides the best simplification?

BACKGROUND: Although several sequences of specific postures, each corresponding to a particular lung segment, have been recommended for therapeutic bronchial drainage, these are based on little or no anatomic evidence. Moreover, because these sequences are too complex, especially for intubated patients, they require simplification. MATERIALS AND METHODS: The courses of the segmental bronchi B(1), B(2), B(1 + 2), B(3), and B(6) and their subsegmental bronchi are extremely variable. This can result in a small branching angle at the subsegmental bronchial origin. Using 106 lungs, we measured the branching angles of the subsegmental bronchi and examined their running directions in each posture of the sequences recommended for bronchial drainage. RESULTS: A small branching angle (< 120 degrees ) at the subsegmental bronchial origin was sometimes evident, and this made postural drainage difficult. Drainage of B(3) and B(6) was often difficult because they formed angles of < 45 degrees from the horizontal in certain postures (supine for B(3) and prone for B(6)). Further, we found a 45 degrees rotative prone position effective for draining B(1)a and B(6). CONCLUSION: Our anatomic findings predicted increased effectiveness in a sequence of postures: supine, 45 degrees rotative prone with left side up, 45 degrees rotative prone with right side up, and return to supine for simple, safe, and effective bronchial drainage, especially for patients with tracheal intubation. The 10 degrees right-side-up supine and 45 degrees rotative prone with head raised 45 degrees positions seemed helpful if added to the basic sequence.

Bronchi↗

Hydrodynamics and electromyography: ergonomics aspects in aquatics.

In a quadruple approach we have suggested the ergonomics links between fundamental hydrodynamics, applied dynamics of swimming, electromyographical aspects and specific training. Fundamental and applied hydrodynamics were investigated in a Dutch Marine Ship model test station allowing for the measurement of passive drag in different positions and of active (swimming) drag. It was found that drag in a prone position under the water surface was greater than at the water surface, but active drag while swimming reached twice the drag values of any passive drag condition. This indicates that body form has no influence on drag and propulsion. Since it is merely the technical execution of the swimming movement that will influence performance, telemetric EMG of the involved musculature has allowed a complete kinesiological picture of the front crawl movements to be made. This knowledge is basic for the study of specific and alternative training systems, such as specific dry land training.

Journal Article↗

A computertomographic study on the congruence of the hip joint.

This study describes investigations into the appearance of intra-articular spaces of hip joints. In CT scans of cadaver hip joints in the supine position an increased intra-articular space was found dorsally, while in the prone position the same hip joint showed an increased intra-articular space ventrally. It is assumed generally that the gap between the bone ends seen on plane X-rays represents the cartilage, but this study indicates that there may in fact be a space between the cartilage surfaces in the unloaded joint.

Journal Article↗

EMG activities of the quadratus lumborum and erector spinae muscles during flexion-relaxation and other motor tasks.

OBJECTIVE: The aim of this study was to provide new information on the myoelectrical activation of the quadratus lumborum, the deep lateral and the superficial medial lumbar erector spinae, the psoas, and the iliacus muscles in various motor tasks. DESIGN: An intramuscular electromyographic study was performed. BACKGROUND: The contribution of individual deep trunk muscles to the stability of the lumbar spine is relatively unknown in different tasks, including the flexion-relaxation phenomenon. METHODS: Seven healthy subjects participated. Fine-wire electrodes were inserted with a needle guided by ultrasound. RESULTS: The highest activity observed for quadratus lumborum and deep lateral erector spinae occurred in ipsilateral trunk flexion in a side-lying position and for superficial medial erector spinae during bilateral leg lift in a prone position. Quadratus lumborum and deep lateral erector spinae were activated when the flexion-relaxation phenomenon was present for superficial medial erector spinae, i.e. when its activity ceased in the latter part of full forward flexion of the trunk, held relaxed and kyphotic. CONCLUSIONS: In general, the activation of the investigated muscles showed a high degree of task specificity, where activation of a certain muscle was not always predictable from its anatomical arrangement and mechanical advantage.

Journal Article↗

Frequency of gastroesophageal reflux disease in nonatopic children with asthma-like airway disease.

Gastroesophageal reflux disease (GERD) is commonly associated with asthma; however, frequency in nonatopic children with asthmatic symptoms is unknown. The aim of this study was to determine the frequency of gastroesophageal reflux (GER) in nonatopic children with asthma-like airway disease that recur despite conventional asthma treatment and to evaluate the clinical response to lansoprazole treatment. Twenty-five nonatopic children aged between 1 and 16 years who have asthma-like airway disease and 25 healthy children were included in the study. All cases underwent 24 h pH monitoring with dual sensor catheters. Additionally, acid suppressor treatment was administered to patients diagnosed as having GERD and clinical response was evaluated. Major symptoms encountered in the patient group included wheezing and cough (88%, and 32%, respectively). Reflux episodes were more common in distal esophagus during the prone position (reflux index (RI) of 11.5+/-10.3 vs. 16.2+/-9.4 during supine vs. prone). All distal esophageal parameters were significantly higher in the patient group except number of reflux episodes lasting longer than 5 min (RI of 13.3+/-13.1 vs. 3.9+/-2.9 in the patient vs. control groups, respectively). There was a significant improvement in symptoms and requirement for medication with treatment (number of systems decreased from 2.3+/-0.6 to 0.4+/-0.6, P=0.00). In conclusion, GERD is significantly more common in nonatopic children with asthma-like airway disease compared to the controls and clinical improvement is significant after acid suppressor treatment. Thus, we suggest that children followed-up with the diagnosis of nonatopic asthma with recurrent exacerbations despite adequate asthma treatment have a high frequency of GER and that lansoprazole treatment may be considered early in management.

2-Pyridinylmethylsulfinylbenzimidazoles↗

Mechanical ventilation of patients with acute lung injury.

Ventilatory management of patients with acute lung injury (ALI), particularly its most severe subset, acute respiratory distress syndrome (ARDS), is complex. Newer lung protective strategies emphasize measures to enhance alveolar recruitment and avoid alveolar overdistention, thus minimizing the risk of ventilator-induced lung injury (VILI). Key components of such strategies include the use of smaller-than-conventional tidal volumes which maintain peak transpulmonary pressure below the pressure associated with overdistention, and titration of positive end-expiratory pressure to promote maximal alveolar recruitment. Novel techniques, including prone positioning, inverse ratio ventilation, tracheal gas insufflation, and high frequency ventilation, are considerations in severe ARDS. No single approach is best for all patients; adjustment of ventilatory parameters to individual characteristics, such as lung mechanics and gas exchange, is required.

Algorithms↗

Smectite reduces gastroesophageal reflux in newborn infants.

We assessed the efficacy of a natural clay (smectite) on the frequency and the duration of acid (pH less than 4) and very acid (pH less than 3) gastroesophageal reflux (GER) measured by 24-hour continuous pH recording (CPR). Twenty newborn infants were enrolled in this double-blind controlled study owing to pathological CPR in supine position. After inclusion, all the patients were maintained in the 30-degree elevated prone position and received either smectite (3 g/day; n = 10) or placebo (n = 10) for 7 days. On the 8th day, a second 24-hour CPR was performed in supine position. The postural therapy alone (placebo group) was followed by a significant decrease in the numbers of acid GER (p less than 0.05) during the second CPR. The combination of postural therapy and smectite treatment was followed by a decrease in the number of acid (p less than 0.05) and very acid GER (p = 0.01), the percentages of time spent at pH below 4 (p less than 0.05) and 3 (p less than 0.01) and the maximal duration of acid GER (p less than 0.05).

Clinical Trials as Topic↗

[Computed tomography of pneumoconiosis].

This review describes the usefulness of computed tomography (CT) and high-resolution computed tomography (HRCT) in image evaluation in pneumoconiosis. For pneumoconiosis, in the same way as for other diffuse lung diseases, conventional CT includes 10 mm collimation scans at 1 cm intervals from the apex to the base of the lung, whereas HRCT uses five to six 1.2 to 3 mm collimation scans at predetermined representative locations including the aortic arch, the tracheal carina, and 2 cm above the dome of the right hemidiaphragm. The CT scans are performed in the supine position in silicosis and coal workers' pneumoconiosis, and both in the supine and prone position in asbestosis. In silicosis, CT is superior to chest radiography in detecting coalescence of nodules and early stage formation of large opacities. There are good correlations between HRCT findings and histological changes, especially in secondary pulmonary lobules. With HRCT, small nodules are found to be located in the center of the secondary pulmonary lobule in silicotic lungs. The mild emphysematous change associated with silicosis can also be found with HRCT. In coal workers' pneumoconiosis, the HRCT is useful in detecting nodules located in the subpleural and fissural subpleural areas. In asbestosis, the conventional CT can detect pleural plaques more sensitively than chest radiography. HRCT is also especially useful in detecting earlier fibrotic change in asbestosis in lung parenchyma, apparent as subpleural lines, parenchymal bands, subpleural curvilinear line shadows and so on.(ABSTRACT TRUNCATED AT 250 WORDS)

Asbestosis↗

Thin-section CT evaluation and pathologic correlation of therapeutic effect of neoadjuvant chemotherapy for axillary lymph nodes of clinically node-positive breast cancer patients.

In breast cancer patients, the number of surgically resected metastatic axillary lymph nodes has been considered to correlate closely with patient prognosis. Therefore, if metastatic lymph nodes could be controlled by neoadjuvant chemotherapy pre-operatively, we would be able to select a more appropriate regimen of post-operative chemotherapy for the individual patient and expect prognostic advantages of each patient with node-positive breast cancer. In this study, we aimed to evaluate the therapeutic effect of neoadjuvant chemotherapy for metastatic lymph nodes of node-positive breast cancer patients, using thin-section (5 mm) helical CT (prone-position) with bolus injection of contrast agent. Between April 1994 and March 2002, 49 patients with node-positive breast cancer who had undergone thin-section CT study both before and following neoadjuvant chemotherapy enrolled in the study. The mean age of the patients was 48.9 years and all were female. Concerning metastatic lymph nodes status, 45 patients were classified as N1, 2 patients as N2, and another 2 as N3. In the evaluation, if at least one lymph node of >5 mm in the short diameter was detected on the CT study, the case was classified as node-positive. For lymph nodes of >1 cm in short diameter, fine-needle aspiration biopsy guided by ultrasonography was performed in order to obtain pathological confirmation of the existence of cancer metastasis. The diagnostic results of the CT study were compared with the pathologic findings of the resected specimen operatively. The neoadjuvant chemotherapy consisted of 3 to 4 times of CAF chemotherapy and an anti-estrogen agent, and intra-arterial infusion chemotherapy was also performed in patients with lymph node status of N2 or N3. The axillary status of 15 (30.6%) out of the 49 patients was evaluated as N0 after neoadjuvant chemotherapy, and 14 out of the 15 patients were confirmed as node-negative based on the pathological results. Therefore, the diagnostic accuracy of the second CT study performed following the neoadjuvant chemotherapy was 85.7%, with a sensitivity of 96.6%, a specificity of 70.0%, a positive predictive value of 82.4%, and a negative predictive value of 93.3%. The results described above demonstrate that such a sophisticated and precise CT study performed following neoadjuvant chemotherapy and evaluating the therapeutic effect on metastatic lymph nodes following the neoadjuvant chemotherapy can help to determine an appropriate regimen of post-operative chemotherapy and be of prognostic advantage in patients with node-positive breast cancer.

Antineoplastic Combined Chemotherapy Protocols↗