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PubMed2002

CT colonography: colonic distention improved by dual positioning but not intravenous glucagon.

The aim of this study was to determine whether intravenous (IV) glucagon and dual positioning administered prior to CT colonography enhances colonic distention. We assessed the effect of dual positioning and IV glucagon on colonic distention in 96 patients who underwent CT colonography examinations. The CT colonography was performed in both supine and prone positions. Seventy-four patients received glucagon (1 mg i.v.) immediately prior to CT scanning and 22 patients did not. The bowel was divided into ten segments and colonic distention was scored by two radiologists in the supine, prone, and combined supine/prone positions using a five-point scale: 1=collapsed; 2=poorly visualized; > or = 3=adequate distention; 4=entire segment visualized and well distended; 5=excellent distention). A combined segmental and overall supine/prone distention score was calculated based on the sum of the mean score for each position. There was no significant difference in the degree of colonic distention between patients who received glucagon and those who did not [supine/prone distention score (mean +/- SE): 3.63 +/- 0.2 vs 3.85 +/- 0.2; p=n.s.]. The degree of colonic distention was greater in the prone position in both the glucagon (3.87 +/- 0.2 vs 3.38 +/- 0.2; p<0.05) and non-glucagon groups (4.01 +/- 0.2 vs 3.69 +/- 0.2; p=N.S.) particularly in the proximal colon. There was almost perfect agreement between both radiologists in their scoring of colonic distention on a per-patient basis ( k=0.9; p<0.001). Of 1480 bowel segments, 1261 (85.2%) were adequately distended in the glucagon group compared with 370 of 440 bowel segments (84%) in the non-glucagon group ( p=n.s.) Colonic distention at CT colonography is improved by dual positioning but not by the administration of intravenous glucagon. While our results suggest that other smooth muscle relaxants, including butyl scopolamine, may only have a limited role in improving colonic distention in CT colonography, further studies are required.

Adult↗
PubMed1999

Local invasion of gastric cancer: CT findings and pathologic correlation using 5-mm incremental scanning, hypotonia, and water filling.

OBJECTIVE: Our purpose was to assess the accuracy of CT with drug-induced hypotonia and water filling in revealing the depth of tumor invasion of the gastric wall, according to the T factor of TNM classification, and to verify the capability of this technique in differentiating diffuse from intestinal gastric cancer. SUBJECTS AND METHODS: Forty patients (age range, 35-78 years) with histologically proven gastric tumors underwent CT, in the prone position, with drug-induced hypotonia and water filling. The images were prospectively reviewed by two radiologists who were asked to assess the depth of tumor invasion in the gastric wall. The thickening of the hypodense layer and the contrast enhancement of lesion were measured. RESULTS: CT correctly assessed gastric wall invasion in 77% and 82% of cases for observers A and B, respectively; overstaging was 20% and 15%, respectively; and understaging occurred in 3% of cases for both observers. Diagnostic sensitivity for serosal invasion was 100% for both observers; specificity was 80% and 87%, respectively. Substantial agreement between the observers was obtained (kappa = .6). Diffuse and intestinal cancers could be differentiated by CT in 92% of cases, considering the thickening of the hypoattenuating layer of the gastric wall (diffuse cancer: 7 +/- 1.2 mm; intestinal cancer: 1.4 +/- 0.4 mm) and contrast enhancement (diffuse cancer: 85 +/- 8.2 H; intestinal cancer: 51 +/- 3 H). CONCLUSION: CT with patients in a drug-induced hypotonia and in a prone position, and using water filling, is a promising technique for evaluating the depth of tumor invasion and for differentiating intestinal from diffuse gastric cancer.

Adult↗
PubMed2006

Mast cell tryptase in postmortem serum-reference values and confounders.

We have investigated the effects of some factors suspected of inducing spuriously increased tryptase concentrations, specifically sampling site, conjunctival petechial bleeding and prone position at the time of death as indicators of premortem asphyxia, and resuscitation efforts by external cardiac massage. Tryptase was measured in blood from the femoral vein in 60 deaths: 39 control cases who died rapidly (within minutes) from natural causes (sudden cardiac death and acute aortic dissection), 16 with death caused by prolonged asphyxia (traumatic compression of the chest and suffocation due to body position or smothering), and five anaphylactic deaths. In 44 of these cases, tryptase was measured in both heart and femoral blood. Mast cell tryptase was analyzed with a commercial FEIA method (Pharmacia Diagnostics AB, Uppsala, Sweden) measuring both alpha- and beta-tryptase. Assuming that tryptase values in the control group were gamma distributed, we calculated the upper normal limits for tryptase concentrations in femoral blood. It was found that 95% of the controls had values below 44.3 mug/l (femoral blood), SD 5.27 mug/l. All but one of the anaphylactic deaths had tryptase concentrations exceeding that limit. Tryptase was significantly elevated in femoral blood from anaphylactic deaths (p<0.007), compared with the controls. Also, in the cases where death had occurred due to asphyxia tryptase was elevated in femoral blood (p<0.04). A significant difference in tryptase concentrations was seen between blood from the heart and the femoral vessels (p<0.02) in the whole material (n=44). Tryptase concentrations in femoral blood were not influenced by prone position at death, or resuscitation efforts. It is concluded that asphyxia premortem seems to affect tryptase concentrations, that postmortem tryptase measurements should be done in serum from femoral blood, and that the normal upper limit, covering 95%, is 44.3 microg/l.

Adolescent↗
PubMed2006

Combination propofol/ketamine is a safe and efficient anesthetic approach to anorectal surgery.

PURPOSE: Concerns persist regarding respiratory complications from combination deep intravenous sedation and local anesthesia for prone position anorectal surgery. We examined the safety and efficacy of this approach by using a propofol-based and ketamine-based technique. METHODS: A retrospective review was conducted on all patients undergoing anorectal surgery. Outcomes (perioperative times, specific complications) were compared with respect to operative position and anesthetic approach. Significance was determined using Student's t-test and chi-squared analysis. RESULTS: Surgery was performed on 448 patients during a three-year period. There was no significant difference in the two anesthetic groups with regard to age and gender. There were 19 anesthesia-related adverse events occurring in the study group (Monitored Anesthesia Care Group): nausea and vomiting (n = 8), airway obstruction necessitating conversion to general anesthesia (n = 2), excessive pain (n = 2), urinary retention (n = 5), and hospital readmission (n = 2). These occurred in <5 percent of those receiving the combination technique (19/407). Although there was no difference in total procedural time, there was a significant difference in total time spent in the operating room (P = 0.001) and in the hospital overall (P = 0.002). Of the patients receiving combination technique anesthesia, only 31 (7 percent) required the use of the postanesthesia care unit. All patients receiving general anesthesia (n = 23) required the postanesthesia care unit. CONCLUSIONS: Combination deep intravenous sedation with local anesthesia based on propofol and ketamine is a safe and effective technique for prone-position anorectal surgery. It results in decreased use of the postanesthesia care unit and earlier hospital discharge, reflecting a more efficient use of hospital resources.

Adult↗
PubMed1991

[Importance of cardiocirculatory and pulmonary monitoring in endoscopic retrograde cholangiopancreatography (ERCP)].

Among the side effects of endoscopy, cardiopulmonary complications are particularly important. This risk appears to be greatest in endoscopic retrograde cholangio- and pancreaticography (ERCP) because of the patient's prone position, iv sedatives and analgetics and the relatively long duration of the examination. We studied 75 patients (50 patients without and 25 patients with premedication) who were to undergo ERCP and looked at these data: age, weight, premedication, accompanying diseases, reason for this examination, blood count, oxygen saturation SaO2 (pulse oximeter), pulse, blood pressure and length of the examination. Overall, the oxygen saturation decreased considerably and two patients only had 69%. Pulse rate increased and one patient had 205 beats per minute, one 172. We looked for a correlation between SaO2, pulse rate and blood pressure and studied the patients' usual medication, the length of the ERCP, the indication for ERCP, age and hemoglobin. There was no correlation. But all patients suffering from a compromised cardiopulmonary status had received a rather heavy premedication and the ERCP was longer than in other patients. Since it is not clear which patients may develop cardiopulmonary complications, it is advisable to monitor all patients by pulse oximeter in order to avoid these complications. This seems also advisable because the rooms where the examination takes place are darkened and the patient is in a prone position so he cannot be seen clearly.

Adult↗
PubMed2002

Sidestream end-tidal capnometry as related to infant's position and maturation.

UNLABELLED: The objective of this study was to investigate the effect of body position on sidestream, end-tidal carbon dioxide (EtCO2) wave measurements in maturing infants. Sidestream EtCO2 wave patterns were analysed longitudinally in 20 preterm infants (born at > or = 32 wk) at 32-37 wk gestation, and in 39 full-term controls. Capnography measurements included maximal EtCO2, inspired CO2 and frequency of apnoea events (>3 s) in the supine, supine with inclination, side and prone positions. Apnoea frequency decreased during maturation, and was less prevalent in the prone than in the supine and side positions in preterm as well as in term infants (p < 0.05). No clinically significant apnoea episodes were found in our cohort. EtCO2 in term infants was lower than that in preterm infants (p < 0.05) and was not affected by sleep position in the most premature (<33 wk) and in term infants (>36 wk). EtCO2 was higher in the prone position than in supine or side positions in infants between 33 and 35 wk gestation (p < 0.01). CONCLUSION: Short apnoeic episodes decrease during maturation, and are less prevalent in the prone position in maturing infants (32-37 wk). Only modest changes in EtCO2 were recorded in the different positions during maturation.

Birth Weight↗
PubMed2003

Sleep apnea in mice: a useful animal model for study of SIDS?

Although the incidence of sudden infant death syndrome (SIDS) has been decreased by education programs to avoid sleeping in prone position, the pathological mechanisms of SIDS have not fully been understood. Basic research on sleep apnea using experimental animals may help further understanding and prevention of SIDS because the syndrome is thought as inability to wake up from respiratory arrest (apnea) during sleep. Although several animal models of sleep apnea have been described previously, mice would be useful experimental animals in that these animals are frequently used in genetic engineering. Those considerations prompted us to establish a method for measuring ventilation of mice concomitantly with electroencephalography and electromyography for assessing sleep-wake states. Normal wild-type mice developed two types of central sleep apneas (CSA), that is, post-sigh and spontaneous apneas, as normal humans do. Moreover, post-sigh apneas in mice were observed exclusively during slow-wave sleep (SWS) while spontaneous apneas were seen in both SWS and rapid eye movement (REM) sleep. These characteristics are very similar to those of sleep apneas in healthy human infants and children. Therefore, mice seem to be a promising experimental animal model for studying the genetic and molecular basis of respiratory regulation and dysregulation during sleep in humans, especially infants and children. However, we should keep in mind limitations in studying mice as an animal model of SIDS, since they are nocturnal rodents and they sleep in the prone position.

Animals↗
PubMed2004

Correcting the saddlebag deformity in the massive weight loss patient.

Skin redundancy of the trunk and thigh is treated by a circumferential abdominoplasty and a lower body lift. Despite preservation and tight approximation of the subcutaneous facial system, the authors have failed to adequately correct severe saddlebag deformity and midthigh laxity in the massive weight loss patient. The technique used in the last nine of the senior author's 43 lower body lifts was modified by fully abducting each operated thigh on a side utility table, before closure in the prone position. This maneuver permits an increase in width of skin excision and causes the lateral thigh skin to be taut upon leg adduction. This is a retrospective review of the senior surgeon's experience over a 3-year period. Postoperative follow-up of the nine-patient cohort ranged from 8 to 12 months. A standardized set of six-view preoperative and postoperative photographs was available for each patient. A regional grading system was developed to assign points for deformity seen in preoperative and postoperative photographs. To compare the effect of the new technique on the correction of hip/lateral thigh deformities, the authors used this same grading system to analyze 10 other lower body lift patients treated by the same surgeon without full thigh abduction who had six sets of standardized photographs. A deformity severity score was determined for each anatomic region by four trained observers blinded to the surgical technique. The nonparametric Mann-Whitney U test using exact p values was used to compare preoperative and percentage change in deformity severity score from preoperative to postoperative scores relative to preoperative scores for each anatomical region among subjects in each treatment group. The nonparametric Wilcoxon signed rank test using exact p values was used to evaluate the change in deformity severity score from preoperative to postoperative values. The change in technique resulted in an observable symmetrical correction of the severe saddlebag deformity and better contour to the distal lateral thighs. All evaluated patients were satisfied with the lateral thigh skin contour. The grading system revealed that patients treated with or without intraoperative thigh abduction had similar preoperative deformity severity scores for each anatomic region (p > 0.05). Postoperatively, all subjects showed improvement in scores for all treated regions. However, patients closed during full thigh abduction had significantly lower deformity severity scores for the hip/thigh complex when compared with patients treated without full thigh abduction (p < 0.05). Complications in these 19 patients consisted of one 6-cm superficial skin layer dehiscence due to a broken polyester suture that healed spontaneously. There were three seromas that responded to a short series of aspirations or catheter drainage. There were no infections. Distal abdominal flap tip skin necrosis in four patients responded to outpatient débridement and healed secondarily. A new grading system for body contour deformities was successfully utilized to judge differences in the quality of trunk and thigh deformity and outcome in 19 patients with adequate photographic records. Tight suture closure in full thigh abduction in the prone position results in improved treatment of significant saddlebag deformity and midthigh skin laxity in the massive weight loss patient. The essential principles are meticulous planning, careful isolation, tight closure of the lateral trunk and thigh subcutaneous fascial system, and artistic contouring of remaining tissues. Dehiscence, undesirable scarring, and seromas were minor issues in the entire group of 43 patients.

Abdomen↗
PubMed2002

MR-guided interventional breast procedures considering vacuum biopsy in particular.

Histologic work-up of just MR-detected breast lesions has become essential with increasing use of contrast-enhanced MR imaging. In the present article an overview is given about the different MR-guided breast interventions, performed since 1990. Presently, for reasons of costs and image quality closed magnets are most widely used. The following approaches have been described: MR-guided freehand localization in supine position, stereotaxic localization in supine position and most frequently used localization in the prone position by means of a compression device that immobilises the breast to prevent tissue shift during intervention. Only limited experience exists with interventions on open magnets. MR-guided wire localization is a well-established procedure. Recently, percutaneous vacuum biopsy of enhancing breast lesions has become possible under MR guidance. The new system allows accurate and safe access to lesions in any location of the breast and direct check-up of representative excision by visualisation of the cavity. Thus reliable histologic evaluation of lesions smaller than 10 mm is possible with this approach.

Biopsy, Needle↗
PubMed1991

Effect of infant position on breath amplitude measured by transthoracic impedance and strain gauges.

Continuous monitoring of respiration by transthoracic electrical impedance gives a signal that has certain not well understood irregularities. Among them is a change in the amplitude of the signal when there is no apparent change in the infant's tidal respiration. One factor that could hypothetically account for alterations of the impedance signal is a change in current path through the thorax secondary to a change in body position. To test this hypothesis we have studied the relationships between breath amplitude measured by transthoracic impedance, one strain gauge on the chest and one on the abdomen, and tidal volume by integrated flow in four body positions. Median breath amplitude was found to vary significantly with body position according to the measuring device. The median impedance breath amplitude increased by 27% in the supine position compared with the prone position, with no associated change in tidal volume. Differences in the strain gauge signal amplitude for these positions were not statistically significant. Correlation between breath amplitude measured by impedance changes and tidal volume was minimal (r = 0.114). These results indicate that infant position affects impedance breath amplitude independently of changes in tidal volume.

Cardiography, Impedance↗
PubMed1996

[Venovenous extracorporeal membrane oxygenation (ECMO) with a heparin-lock bypass system. An effective addition in the treatment of acute respiratory failure (ARDS)].

Mortality of severe acute respiratory distress syndrome (ARDS) in Germany is about 60%. Respiratory therapy can make the lung injury worse by high positive airway pressures, high tidal volumes and high inspiratory oxygen concentrations. Extracorporeal membrane oxygenation (ECMO) was employed to reduce aggressive mechanical ventilation, but it has not been proved to be superior to conventional ventilation. However, encouraged by recently developed improvements in the technique and concept of ECMO, we introduced this therapy into our program for the treatment of ARDS. PATIENTS AND METHODS. All patients with severe ARDS (lung injury score > 2.5) admitted to our multidisciplinary intensive care unit from March 1992 to March 1995 were evaluated prospectively. After admission, the patients first underwent a conventional therapeutic approach, including pressure-controlled inverse-ratio ventilation, permissive hypercapnia, changes in body position (in particular, the prone position), negative fluid balance, anti-biotics, and low-dose hydrocortisone infusion. ECMO via a covalently heparin-coated, venovenous bypass-system with a vortex pump and two membrane lungs was performed if ARDS did not improve after 24-96 h of conventional therapy and if two of three of the slow-entry criteria for ECMO were fulfilled: (1) PaO2/FiO2 < 150 mmHg at PEEP > 5 mbar; (2) semistatic compliance < 30 ml/mbar; (3) right-left shunt > 30%. Only in cases of life-threatening hypoxemia (PaO2 < 50 mmHg at FiO2 1.0 and PEEP > 5 mbar for > 2 h (fast-entry criteria) was ECMO instituted immediately. RESULTS. Sixty patients fulfilled the entry criteria for our study. Thirty-nine patients were treated with a conventional protocol, 37 after improvement of ARDS and 2 who had not improved but in whom there were contraindications to the use of ECMO. ECMO was performed in 10 patients who had not improved, but who fulfilled the slow-entry criteria and in 11 primarily hypoxemic patients who fulfilled the fast-entry criteria. The survival rate was 30/39 (77%) for the conventional therapy group, 6/10 (60%) for the slow-entry group, and 11/11 (100%) for the fast-entry group. The onset of ECMO allowed a significant decrease in peak and mean airway pressures, tidal volume, ventilatory rate, minute volume and inspiratory oxygen concentration. Sufficient gas exchange was provided, and pulmonary artery pressures significantly decreased on bypass. The most frequent complications on bypass were pneumothorax (15/21 patients) and bleeding (7/21 patients). CONCLUSION. In comparison with the historical results at our own institution, the present study demonstrates an improvement in the survival rate from 56% to 78% since ECMO has become available. We conclude that venovenous ECMO with a heparin-bonded bypass circuit is an effective additional option for the treatment of patients with severe ARDS.

Adolescent↗
PubMed2006

Rectourethral fistula associated with two short segment urethral strictures in the anterior and posterior urethra: single-stage reconstruction using buccal mucosa and a radial forearm fasciocutaneous free flap.

INTRODUCTION: We report a novel surgical technique used to repair a rectourethral fistula associated with two short-segment urethral strictures located in the anterior and posterior segments of the urethra in a patient with prior unsuccessful repairs. TECHNICAL CONSIDERATIONS: The anterior urethral stricture was reconstructed with a ventral onlay of buccal mucosa in the exaggerated lithotomy position. In a modified prone position, the rectourethral fistula was repaired using the transrectal transsphincteric (York-Mason) technique and the posterior urethral stricture with a radial forearm fasciocutaneous free flap which was anastomosed to the inferior gluteal artery and vein. The coexistence of a rectourethral fistula and distal urethral stricture requires simultaneous repair, because the urethral pressure from the distal obstruction may compromise fistula closure. Reconstructive efforts should be tailored to minimize disruption of the urethral blood supply in patients with previous pelvic trauma. Rectal and urethral repairs should be separated by well-vascularized tissue to prevent fistula recurrence. CONCLUSIONS: The radial fasciocutaneous flap may offer the reconstructive surgeon another surgical option for complex urethral stricture and rectourethral fistula reconstruction when the local blood supply is in question. Longer follow-up and more cases are needed to further evaluate the continued use of this technique.

Adult↗
PubMed1992

Intraosseous vertebral body pressures.

In an effort to determine the relationship between low-back pain and intraosseous hypertension, in vivo vertebral pressure measurements were performed on 19 patients. A cannulated screw was placed percutaneously into the middle of the vertebral body by a transpedicular route. Pressure measurements were recorded with the patient in various positions. Pressures were greatest in the sitting position, lowest in the prone position, and intermediate in the standing position. A correlation was found between intravertebral body pressure and patient position. Pressures were highest in the positions most commonly associated with low-back pain.

Back Pain↗
PubMed2005

A new approach to estimation of the number of central synapse(s) included in the H-reflex.

BACKGROUND: Among the main clinical applications of the H-reflex are the evaluation of the S1 nerve root conductivity such as radiculopathy and measurement of the excitability of the spinal motoneurons in neurological conditions. An attempt has been made to reduce the pathway over which H-reflex can be obtained in a hope to localize a lesion to the S1 nerve root, so the S1 central loop has been suggested. The main goal of this study is the estimation of the H-reflex number of synapse(s) for better understanding of the physiology of this practical reflex. METHODS: Forty healthy adult volunteers (22 males, 18 females) with the mean age of (37.7 +/- 10.2) years participated in this study. They were positioned comfortably in the prone position, with their feet off the edge of the plinth. Recording electrodes were positioned at the mid point of a line connecting the mid popliteal crease to the proximal flare of the medial malleolus. Stimulation was applied at the tibial nerve in the popliteal fossa and H, F and M waves were recorded. Without any change in the location of the recording electrodes, a monopolar needle was inserted as cathode at a point 1 cm medial to the posterior superior iliac spine, perpendicular to the frontal plane. The anode electrode was placed over the anterior superior iliac spine, and then M and H waves of the central loop were recorded. After processing the data, sacral cord conduction delay was determined by this formula: sacral cord conduction delay = central loop of H-reflex - (delays of the proximal motor and sensory fibers in the central loop). RESULTS: The central loop of H-reflex was (6.77 +/- 0.28) msec and the sacral cord conduction delay was (1.09 +/- 0.06) msec. CONCLUSION: The sacral cord conduction time was estimated to be about 1.09 msec in this study and because at least 1 msec is required to transmit the signal across the synapse between the sensory ending and the motor cell, so this estimated time was sufficient for only one central synapse in this reflex.

Adult↗
PubMed2002

Effects of positive end-expiratory pressure and body position on pulmonary blood flow redistribution in mechanically ventilated normal pigs.

STUDY OBJECTIVES: To assess the respective effects of position and positive end-expiratory pressure (PEEP) on the distribution of regional pulmonary blood flow (PBF). DESIGN: Prospective randomized animal study. SETTING: Animal research facility in a university hospital. PARTICIPANTS: Normal pigs that were tracheostomized, anesthetized, and mechanically ventilated. INTERVENTIONS: PBF was measured in seven pigs in the supine position (SP) and the prone position (PP) at both zero end-expiratory pressure (ZEEP) and 10 cm H(2)O of PEEP. The regional PBF was assessed by the radioactive microsphere method. The lungs from each pig were sliced into 90 samples. The heterogeneity of PBF was estimated from its coefficient of variation. MEASUREMENTS AND RESULTS: The lung samples had a mean (+/- SD) weight of 1.60 +/- 0.39 g. Changing position from SP to PP at ZEEP redistributed PBF toward the anterior, superior, and peripheral regions and did not significantly reduce the coefficient of variation for regional PBF (reduction, 44.7 +/- 7% to 42.2 +/- 8%). Changing from the SP to PP position at PEEP induced a similar, but more marked, redistribution of PBF and a significant reduction in the coefficient of variation from 53 +/- 13% to 30.4 +/- 7% (p < 0.001). In the SP, PEEP redistributed PBF toward the posterior, inferior, and central regions without changing the heterogeneity of PBF. In the PP, PEEP had little effect on the PBF redistribution but significantly reduced the coefficient of variation of PBF from 42.2 +/- 8% to 30.4 +/- 7% (p < 0.05). CONCLUSIONS: Pigs in the PP had altered gravitational dependence of PBF compared to that observed when pigs were in the SP. This effect was enhanced by using a PEEP of 10 cm H(2)O.

Animals↗