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At least 793 records · Page 44Linked to original sources
PubMed2002

Ventilatory adjuncts.

A number of adjuncts to mechanical ventilation have been the focus of recent research. Automatic tube compensation (the regulation of airway pressure by estimation of tracheal pressure) appears to be an ideal approach to unloading the resistive effort imposed by the endotracheal tube. Randomized controlled trials have recently been performed with high frequency oscillation (HFO), partial liquid ventilation (PLV), and prone positioning. Unfortunately, all of those trials were negative; however, it appears the only technique that will be abandoned for the near future is PLV. The HFO trial trended toward benefit with HFO, and one must question the protocol used in the prone positioning trial. With both HFO and prone positioning we will have to wait for additional randomized clinical trials before the status of those techniques can be determined. No randomized trials of tracheal gas insufflation have been performed. Of major concern with tracheal gas insufflation is the lack of a commercial product.

High-Frequency Ventilation↗
PubMed2002

Effects of prone and supine posture on cardiopulmonary function after experimental chlorine gas lung injury.

BACKGROUND: Chlorine gas may induce severe acute lung injury. Improvement of pulmonary gas exchange in patients and animals with acute lung injury nursed in the prone position was observed in recent years. The purpose of this study was to evaluate the effects of prone and supine positions on pulmonary and cardiovascular functions following experimental chlorine gas lung injury. METHODS: Twenty anesthetized and mechanically ventilated pigs were exposed to chlorine gas (400 p.p.m. in air) for 20 min in the supine position, then assigned randomly to ventilation in the supine or prone positions (n=10 in each group). Hemodynamics, gas exchange, lung mechanics and oxygen transport were evaluated for 5 h. RESULTS: All animals showed severe pulmonary dysfunction immediately after chlorine gassing with a threefold increase in pulmonary vascular resistance index, a drop in arterial oxygenation (12.3+/-1.3 kPa to 5.4+/-0.7 kPa) and a fall in lung-thorax compliance (22+/-1 ml cmH2O-1 to 8+/-2 ml cmH2O-1). Venous admixture (Qs/Qt) improved in animals in the prone position while there was no change in the supine position (prone 32+/-11% vs. supine 42+/-9% at 5 h,P<0.05). Lung-thorax compliance improved significantly with time in the prone group only (P<0.01). Oxygen delivery increased significantly in prone animals compared with animals nursed in the supine posture (P<0.001). CONCLUSION: Immediate prone positioning after chlorine gas injury not only inhibited deterioration of gas exchange but was also associated with improved pulmonary function and oxygen transport.

Administration, Inhalation↗
PubMed2003

Neurobehavioral and autonomic effects of hammock positioning in infants with very low birth weight.

PURPOSE: This study was designed to determine whether supine positioning of infants born preterm in a hammock instead of the prone position affects their neuromuscular maturity, growth, and autonomic stability. METHODS: Twenty healthy infants who were born premature with very low birth weight (VLBW) (<1500 g) were randomized into two groups. Subjects were pair-matched for weight (difference less than 100 g), gestational age (difference less than eight days), and postnatal age (difference less than eight days). Ten infants were placed supine in a hammock for three hours daily for ten consecutive days, and ten infants were maintained nested in the prone position. Neuromuscular maturity (based on three neurological parameters adopted from the Ballard examination), heart rate, respiratory rate, and weight gain (g/cal) were compared between the groups. RESULTS: Compared with nested prone positioning, supine positioning in a hammock was associated with a higher neuromuscular maturity score (p < 0.003) and a more relaxed condition, as expressed by lower heart rate and respiratory rate (p < 0.05 and p < 0.01, respectively). CONCLUSIONS: Maintaining infants who were born preterm with VLBW in the supine position in a hammock may positively affect their autonomic stability and neuromuscular maturity.

Journal Article↗
PubMed1992

[Crib death, sleeping position and temperature].

Sudden infant death syndrome (SIDS) is the commonest cause of death in children over one week of age. Norway has the highest incidence in Scandinavia and the figure has increased during the last 20 years. There has been much discussion as to whether sleeping in the prone position rather than in the supine or lateral position may be a predisposing factor to cot death. In all 14 studies in seven countries where the question has been investigated, there was a higher proportion of prone infants in the SIDS group than in the control group. Intervention studies have shown that reducing the proportion of infants sleeping prone was followed by a reduction in cot deaths. There is also evidence that overheating is a risk factor for SIDS. In one British study it was found that infants who died of SIDS had more clothes on, and blankets covering them, and that both prone position and overheating were independently associated with SIDS. A possible mechanism is that overheating interferes with respiratory control. Although we do not completely understand the mechanisms underlying the links between SIDS and the prone position, the epidemiological evidence and the evidence from intervention are now so strong that it is fully justified to advice against the general use of the prone sleeping position for babies.

Australia↗
PubMed1992

Effect of position on the mechanical interaction between the rib cage and abdomen in preterm infants.

To determine the influence of body position on chest wall and pulmonary function, we studied the ventilatory, pulmonary mechanics, and thoracoabdominal motion profiles in 20 preterm infants recovering from respiratory disease who were positioned in both the supine and prone position. Thoracoabdominal motion was assessed from measurements of relative rib cage and abdominal movement and the calculated phase angle (an index of thoracoabdominal synchrony) of the rib and abdomen Lissajous figures. The ventilatory and pulmonary function profiles were assessed from simultaneous measurements of transpulmonary pressure, airflow, and tidal volume. The infants were studied in quiet sleep, and the order of positioning was randomized across patients. The results demonstrated no significant difference in ventilatory and pulmonary function measurements as a function of position. In contrast, there was a significant reduction (-49%) in the phase angle of the Lissajous figures and an increase (+66%) in rib cage motion in prone compared with the supine position. In addition, the degree of improvement in phase angle in the prone position was correlated to the severity of asynchrony in the supine position. We speculate that the improvement in thoracoabdominal synchrony in the prone position is related to alterations of chest wall mechanics and respiratory muscle tone mediated by a posturally related shift in the area of apposition of the diaphragm to the anterior inner rib cage wall and increase in passive tension of the muscles of the rib cage. This study suggests that the mechanical advantage associated with prone positioning may confer a useful alternative breathing pattern to the preterm infant in whom elevated respiratory work loads and respiratory musculoskeletal immaturity may predispose to respiratory failure.

Abdominal Muscles↗
PubMed2000

Efficiency of chest computed tomography in critically ill patients with multiple traumas.

OBJECTIVE: The efficiency of secondary thoracic computed tomography (TCT) in critically ill patients with multiple traumas was assessed by comparison of TCT with chest radiograph findings. The subsequent therapeutic consequences based on the additional information of TCT were evaluated. SETTING: A six-bed trauma intensive care unit in a university hospital. DESIGN: Prospective, descriptive study. PATIENTS AND INTERVENTIONS: One hundred one computed tomographic (CT) examinations (mean, 2.6 per patient; range, 1-10) were performed in 39 patients, fulfilling the following indications for TCT: a) sepsis with suspected pulmonary focus (n = 41); b) deterioration of pulmonary gas exchange (n = 35); c) guiding the duration of intermittent prone positioning (n = 25). The information provided by TCT was compared with corresponding chest radiographs (CXR). Therapeutic consequences drawn after TCT were compared with the additional diagnostic information of TCT. The change of therapy was documented that would not have been undertaken or may have been delayed had TCT evaluation not been used. RESULTS: TCT was significantly superior to CXR in detecting pneumothoraces, pleural effusions, and pulmonary abscesses. Furthermore, a significantly higher accuracy regarding pulmonary densities was found. Subsequent therapeutic interventions ensued from 85 (84.2%) CT scans. After TCT, intermittent prone positioning was initiated in 31 patients, chest tubes were inserted in 16 patients, and intermittent prone positioning was terminated in 13 patients and was continued in 12 patients. Eleven thoracotomies were performed because of the TCT findings. The described therapeutic interventions were based on abnormalities seen on CT scans but were not evident in CXR in 58 patients (57.4%). Significant information that influenced therapeutic concepts was obtained in 66% (n = 23) of patients with pulmonary deterioration of gas exchange, in 61% (n = 25) of patients with sepsis, and in 40% (n = 10) of patients to guide the duration of intermittent prone positioning. Thoracotomy and specific drainage by tube thoracostomy was always dependent on the findings of TCT. CONCLUSION: Performed under the above displayed defined indications, TCT had an overall efficiency of 57%. It provided an increased sensitivity for intrathoracic lesions and a more comprehensive diagnosis of chest abnormalities.

Adolescent↗
PubMed2002

Posterior ankle arthroscopy: an anatomic study.

BACKGROUND: Ankle arthroscopy has generally been performed with use of anterior portals with the patient in the supine position. Little has been published on ankle arthroscopy performed with use of posterior portals, particularly with the patient in the prone position. The purpose of the present study was to evaluate the relative safety and efficacy of ankle arthroscopy with use of posterior portals with the limb in the prone position. METHODS: Thirteen fresh-frozen cadaver specimens were used. Posterolateral and posteromedial portals were established. Arthroscopy was performed, and the extent of the talar dome that could be visualized was marked. Four-millimeter plastic cannulae were filled with oil and were placed in the portals for use as reference landmarks on magnetic resonance imaging studies. The proximity of the portal cannulae to the adjacent structures was measured on standard magnetic resonance images and then during careful dissection. The distances measured by dissection were compared with the measurements made on magnetic resonance images. RESULTS: An average of 54% (range, 42% to 73%) of the talar dome could be visualized. The average distance between a cannula and adjacent anatomic structures after dissection was 3.2 mm (range, 0 to 8.9 mm) to the sural nerve, 4.8 mm (range, 0 to 11.0 mm) to the small saphenous vein, 6.4 mm (range, 0 to 16.2 mm) to the tibial nerve, 9.6 mm (range, 2.4 to 20.1 mm) to the posterior tibial artery, 17 mm (range, 19 to 31 mm) to the medial calcaneal nerve, and 2.7 mm (range, 0 to 11.2 mm) to the flexor hallucis longus tendon. The magnetic resonance images demonstrated very similar distances except in the case of the distance between the posteromedial cannula and the tibial nerve, which often was difficult to specifically identify on magnetic resonance imaging studies. CONCLUSIONS: The findings of the present cadaveric study suggest that, with the patient in the prone position, arthroscopic equipment may be introduced into the posterior aspect of the ankle without gross injury to the posterior neurovascular structures. Limited clinical trials should be carried out to confirm this finding.

Ankle Injuries↗
PubMed1983

Postural effects on behavioral states of newborn infants--a sleep polygraphic study.

Physiological and behavioral correlates of neonates in the supine and prone positions were examined. Polygrams were recorded in 10 newborn infants in the prone and supine positions. Newborn infants slept more in the prone position than in the supine, and quiet sleep was significantly more in the prone position. Gross movement, jerky movement and twitch movement were less in the prone than the supine position. There was no difference in localized movement or tremor-like movement in the two positions. Respiration was more regular in the prone than the supine position. Sleep apnea (greater than or equal to 6 seconds) was less in the prone position. The pulse rate during quiet sleep was higher in the prone position.

Arousal↗
PubMed1989

[A study on the relationship between pre- and post-hysterectomy sexual behavior differences and the sexual satisfaction of women who have had a hysterectomy].

The objective of this study was to provide a basis for sexual counselling and education for women who have had a hysterectomy. This was a cross sectional descriptive correlation study. There were 230 subjects in the study. The time period from the hysterectomy varied from one month to eighteen months. The subjects were selected by a convenient sampling method. The tool for this study was developed by the researcher through a literature review, consultation from 36 women who have had a hysterectomy and nursing faculty. A pilot study was done to determine the necessary modifications. Data collection was done between Sept. 1987 and Dec. 1987 using a mailed questionnaire. The results of this study are summarized as follows; 1. The differences between pre-post hysterectomy sexual behavior in frequency was that all the sexual behaviors were decreased; the decreased rate of coitus was 20.7%, of kissing or embracing 10.9%, of fondling of sexual organs 8.7%, of female prone-position 3.3%, of petting 7.7%, of sexual day dream 1.0%. 2. For the low income group, the sexual behavior with the most significant decrease in frequency was fondling the sex organs (t = 2.21, p less than .05). For the housewife group, it was a decrease in the one of the female prone position (t = -2.02, p less than .05). For the group under the age of 39, it was petting (t = -2.13, p less than .05). The housewife group showed an increase in sexual day dreams as compared to the group having a job (t = -3.12, p less than .01). The group that did not received the post-op information, showed a significant decrease in kissing or embracing behavior (t = 2.73, p less than .01), and male prone position (t = -2.46, p less than .01), and also the group that did not receive the pre-op information showed a significant decrease of male prone position (t = -2.19, p less than .05), and also of petting (t = -2.95, p less than .01). 3. The relationship between sexual behavior pre-post hysterectomy differences and sexual satisfaction only showed a significant correlation for the sexual behavior of coitus (r = -2.012, p less than .001), and fondling of sex organs (r = -.1121, p less than .05). In conclusion, although there were a decrease in all sexual behavior after the hysterectomy, the difference between the pre hysterectomy sexual behavior and the post hysterectomy sexual behavior correlated with sexual satisfaction for only of the two behaviors.

Coitus↗
PubMed1999

Prone ventilation--it's time.

Prone positioning to improve oxygenation in acute lung injury was first reported over 20 years ago. Although this and several subsequent studies have shown that prone positioning improved oxygenation in the majority of patients, it has failed to become common practice in intensive care units. This paper reviews the mechanism by which prone positioning improves oxygenation and the clinical studies of its use to date.

Humans↗
PubMed2001

Strategies to optimize alveolar recruitment.

Low tidal volume (4-8 mL/kg) during mechanical ventilation in adult respiratory distress syndrome is the standard of care. However, there are questions regarding the approach to setting positive end-expiratory pressure and the use of recruitment maneuvers in patients with adult respiratory distress syndrome. Animal data and preliminary patient data suggest that lung recruitment maneuvers can markedly improve arterial oxygen tension (PaO2). Prone positioning has also become established a method of recruiting lung and improving PaO2 in those with adult respiratory distress syndrome. The data suggest that recruitment maneuvers in the prone position are most effective in improving PaO2 and that the positive end-expiratory pressure level required to sustain the improved PaO2 is less in the prone position than in the supine position.

Adult↗
PubMed1994

Extracorporeal shock-wave lithotripsy for stones in middle third of ureter (overlying pelvic bone).

OBJECTIVE: To compare the results of using Dornier HM3 and Medstone STS lithotriptors to treat a ureteral stone overlying the pelvic bone (mid third of ureter) requiring the patient to be in the prone position. METHOD: The ease of use with each lithotriptor was evaluated and a retrospective review of the results using a Dornier HM3 in 53 patients and a Medstone STS in 143 patients was performed. The chi-square test was used to determine statistical difference. RESULTS: With single stones, the re-treatment rate, the post-ESWL secondary procedure rate, and the stone-free rate were 6 percent, 13 percent, and 75 percent, respectively, with the Dornier, and 6 percent, 8 percent, and 80 percent, respectively, with the Medstone. There was no statistically significant difference between these outcome results (p > 0.05). CONCLUSION: The prone position was difficult to achieve with the Dornier HM3, while the Medstone STS, a tubeless lithotriptor, allowed easy positioning of the patient in the prone position on its flat table. Satisfactory results were achieved using either machine.

Equipment Design↗
PubMed2005

Optimization of conformal avoidance: a comparative study of prone vs. supine interstitial high-dose-rate breast brachytherapy.

PURPOSE: Several recent studies indicate high-dose-rate (HDR) breast brachytherapy as an alternative to standard external beam radiation therapy for partial breast irradiation with high dose conformality to the target. However, this article presents an exploration of the possibility of achieving higher conformal avoidance of sensitive structures through detailed and comparative 3D CT-based anatomical dose distribution of a patient in supine and prone positions. METHODS AND MATERIALS: A patient treated with accelerated partial breast HDR breast brachytherapy in the supine position was selected for two CT-based analyses, one in the supine and one in the prone position. The optimized plan (Nucletron HDR planning station) for each position was achieved using graphical optimization with local adjustment of isodose lines to cover the planned target volume (PTV, lumpectomy with 2 cm margin) with 100% of the prescribed dose (34 Gy in 10 fractions) while minimizing the hot spots. Cumulative dose-volume histograms (DVH) were analyzed for the PTV, lung, skin, pectoral muscle, and chest wall. RESULTS: The PTV received 100% of prescribed dose in both the prone and supine positions. A significant (>40%) dose reduction was achieved in the lung in the prone treatment position. Similar dose reductions were also achieved for prone pectoral muscle, chest wall, and breast skin, irradiating less volume with high doses. Pectoral muscle, lumpectomy, and the breast skin showed prominent differences in shape and displacement in the prone compared with the supine position. CONCLUSION: CT-based treatment planning allowed calculations of volumetric dose distribution to the target and all sensitive structures with proper visualization and volumetric delineation of organs of interest. The treatment plan shows significant dose reduction may be possible in various sensitive structures if the patient is treated with HDR brachytherapy in the prone position.

Breast Neoplasms↗
PubMed1995

Quantitative comparison of prone and supine myocardial SPECT MIBI images.

The myocardial count distribution and the stress/rest ratio distribution were compared between prone and supine Tc-99m MIBI myocardial SPECT acquisitions. Ninety-nine male patients with a low stress supine inferior wall count underwent stress and rest acquisitions in the supine and prone positions successively. For each study, values depicting the inferior, anterior, septal, and lateral wall counts were extracted from a medioventricular normalized circumferential profile and underwent a statistical analysis (Student's paired t-test). On prone imaging, when compared to supine imaging, counts showed a highly significant mean relative increase of 11% +/- 1% in the inferior wall and of 7% +/- 1% in the septum. Conversely, these counts showed a significant mean relative decrease of 4% +/- 1% in the anterior wall and of 3% +/- 1% in the lateral wall. Moreover, the inferior wall stress/rest ratio showed a highly significant mean relative increase (6% +/- 2%). The prone position is probably preferable for interpreting the inferior wall and septum, where relative counts are enhanced, as with TI-201, and because the inferior stress-rest discrepancies are reduced in that position. But the anterior and lateral wall information is impaired in the prone position. The authors suggest, in case of a low stress supine inferior count, the combination of both positions, which is feasible with Tc-99m MIBI, in order to prevent a misleading interpretation.

Adult↗
PubMed2002

Prospective evaluation of anesthetic technique for anorectal surgery.

PURPOSE: Deep intravenous sedation plus local anesthesia for anorectal surgery in the prone position is used frequently at our institution, but is not widely accepted because of concerns regarding airway management. The purpose of this study was to prospectively evaluate the safety and efficacy of this anesthetic technique for anorectal surgery. METHODS: Data were collected prospectively on 413 consecutive patients (mean age, 47 years; mean weight, 80 kg) undergoing anorectal surgical procedures. RESULTS: Of the 389 patients who underwent anorectal procedures in the prone position, 260 (67 percent) received intravenous sedation plus local anesthesia, 125 (32 percent) received regional anesthesia (spinal or epidural), and 4 (1 percent) received general endotracheal anesthesia. Of the 24 patients who underwent anorectal procedures in the lithotomy position, 13 (54 percent) received intravenous sedation plus local anesthesia, 2 (8 percent) received regional anesthesia, 2 (8 percent) received general endotracheal anesthesia, and 7 (29 percent) received mask inhalational anesthesia. Forty-two adverse events attributable to the anesthetic occurred in 18 patients: nausea and vomiting (n = 17), transient hypotension, bradycardia, or arrhythmia (n = 8), transient hypoxia or hypoventilation (n = 7), urinary retention (n = 6), and severe patient discomfort (n = 2). These complications occurred in 4 percent (10/273) of patients receiving intravenous sedation plus local anesthesia and in 6 percent (8/127) of patients receiving regional anesthesia. Two of 260 patients (0.8 percent) receiving intravenous sedation plus local anesthesia in the prone position were rolled supine before completing the surgical procedure. Recovery time before discharge for patients treated on an ambulatory basis was significantly shorter for those patients undergoing intravenous sedation plus local anesthesia (79 +/- 34 minutes, n = 174) than for patients undergoing regional anesthesia (161 +/- 63 minutes, n = 45; P < 0.001, t-test). CONCLUSION: Intravenous sedation plus local anesthesia in the prone position is safe and effective for anorectal surgery and offers potential cost savings by decreasing recovery room time for outpatient procedures.

Adult↗