PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Prone Position”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 883 records · Page 49Linked to original sources
PubMed2002

Fetal and ovarian radiation dose in patients undergoing gamma knife radiosurgery.

BACKGROUND: It is difficult to estimate the fetal or ovarian radiation dosage for female patients undergoing Gamma Knife radiosurgery. Our goals are to determine the fetal and ovarian radiation dose at various distances from a cranial isocenter, to provide a reference for practitioners to estimate the fetal dose with respect to gestational age, and to identify the components of pelvic extracranial radiation. METHODS: An anthropomorphic phantom and ion chamber were used to measure the dose at 50, 60, and 70 cm from a cranial isocenter and at three points within the transverse plane for the supine position. Each measurement consisted of a 5-minute exposure. Additional measurements were taken for four collimator sizes, the prone position, off-axis, and with one-half of all collimator holes plugged. RESULTS: The values of the fetal and ovarian dose rates ranged from 0.27 cGy/min to 0.05 cGy/min based on distance from the isocenter. The fetal and ovarian dose can be up to 8.1 cGy for a 30-minute Gamma Knife treatment. The dose fell off more rapidly than predicted by the inverse square law. There was no dependence of fetal dose rate on collimator size. No advantage to the prone position could be shown. Leakage and collimator scatter are the main components of extracranial dose 50 to 70 cm from the isocenter. CONCLUSIONS: The fetal and ovarian dose is a function of treatment time and distance from the isocenter. We recommend pregnancy status assessment in women of reproductive age and treatment plan design using large volume shots in order to minimize treatment time.

Brain Neoplasms↗
PubMed1994

The effect of therapeutic massage on H-reflex amplitude in persons with a spinal cord injury.

BACKGROUND AND PURPOSE: The effect of therapeutic massage on the H-reflex amplitude in persons without neurological impairment has been established. To investigate its effects in a sample of persons with a spinal cord injury (SCI), two independent but interrelated studies were undertaken. Study 1 investigated whether the recorded response (H-reflex amplitude) to massage with the subjects in the supine testing position was similar to that recorded in previous studies in which the subjects were tested in the prone position. This study was undertaken because the prone testing position was considered inappropriate for persons with SCI. In study 2, the therapeutic effect of massage (petrissage) on H-reflex amplitude in persons with SCI was examined. SUBJECTS: Seven persons without neurological impairment volunteered to participate in study 1, and 10 individuals with a traumatic SCI volunteered to participate in study 2. METHODS: The two studies shared many methodological features and involved the recording of 10 H-reflex and M-response peak-to-peak amplitudes from the triceps surae muscle during each of five sequential, 3-minute time periods. Massage treatment (MASS) was given during the third time period, and the premassage time periods (C1, C2) and postmassage time periods (C3, C4) served as control conditions. Study 2, in addition to recording the peak-to-peak amplitudes of the recorded responses, also included the recording of the H-reflex latencies. RESULTS: The results of study 1 showed that massage applied with the subjects in the supine position decreased the H-reflex amplitude during the massage. A 56% decrease in the H-reflex amplitude was recorded. Study 2 demonstrated a 27% mean group decrease in the H-reflex peak-to-peak amplitude during the massage for all subjects, with variations in individual responses ranging from an increase in the H-reflex amplitude of 20% to a decrease of 84%. An analysis of variance revealed that the H-reflex means of the five conditions were significantly different. Newman-Keuls post hoc analyses revealed that the mean of the MASS condition (2.01 mV) was significantly different from the means of C1, C2, and C4 (2.79, 2.81, 2.58 mV). The mean of C3 (2.42 mV) was not found to be statistically different from the means of the other conditions. These changes were noted against a stable M-response. CONCLUSION AND DISCUSSION: The results recorded in study 1 are comparable to those obtained with the subjects in the prone position. Based on these results, the supine position was adopted as the testing position for study 2. Study 2 further showed a decrease in H-reflex amplitude concomitant with massage in persons with SCI, but no long-term effects were noted.

Adult↗
PubMed2005

"Back to sleep": parents compliance with the recommendation on the most appropriate sleeping position of infants, Haifa District, Israel, 2001.

BACKGROUND: In 1993, the Israel Ministry of Health issued a formal recommendation to avoid placing healthy infants to sleep in the prone position in order to prevent sudden infant death. The objective of the study was to study parents' compliance with this recommendation and to identify characteristics of noncompliant parents of infants aged less than 6 months old. METHODS: The study population consisted of 1912 parents of infants aged 0-12 months who visited the Haifa District primary preventive health centers during the study week and answered the self-administered questionnaire. RESULTS: 15.6% of infants younger than 1 year were placed to sleep in the prone position: 12.4% among infants younger than 3 months, and 17.6% among infants 3-6 months old. Surprisingly, multiple logistic regression analysis demonstrated that Israeli-born Jewish mothers were more likely to place their babies prone than Israeli-born Arab mothers or mothers born in the former Soviet Union who had immigrated to Israel after 1990. CONCLUSIONS: At-risk behaviors are usually associated with minority and immigrant populations. Culture specific and other possible reasons for our unusual findings are discussed.

Adult↗
PubMed1996

[Sleeping position, prevention of sudden death syndrome and gastroesophageal reflux].

Based on results of epidemiological studies, dorsal or lateral sleeping positions are now recommanded in the prevention of sudden infant death syndrome (SIDS). This raises an ethical question about the attitude towards the ventral positioning therapy for gastroesophageal reflux (GOR). The consensus conference considers that the ventral position should only be recommanded in GOR when the benefit appears to outweigh the risk of SIDS that it induces. The conference proposes that for infants with simple uncomplicated reflux, sleeping in the prone position should not be introduced in the first line treatment. Prone positioning should be restricted to complicated cases resistant to dietary and medical measures.

Gastroesophageal Reflux↗
PubMed1998

Massive bleeding during spine surgery in a patient with ankylosing spondylitis.

PURPOSE: Ankylosing spondylitis is associated with pathophysiology that has important anaesthetic implications. We report a case where the sequelae of ankylosing spondylitis may have been responsible for massive bleeding during emergency spine surgery. CLINICAL FEATURES: A 69 yr old man with long standing ankylosing spondylitis sustained a complex fracture of the lumbar spine in a fall, and was scheduled for stabilization of the spine. Under general anaesthesia, prone positioning was difficult because of the extreme spinal deformity. During exploration, dilatation of epidural veins was encountered and sustained haemorrhage was encountered throughout the surgical procedure. Estimated blood loss was 17,000 ml which was replaced with 31 units of packed red blood cells, 3200 ml of salvaged blood, 18 units of fresh frozen plasma, 26 units of platelets, 1,000 ml of albumin and 9,000 ml of crystalloid. CONCLUSIONS: Extreme deformity of the spine led to positioning difficulties that may have contributed to massive blood loss during complex spine surgery. Difficulties with placement in the prone position in-patients with advanced ankylosing spondylitis should be anticipated.

Aged↗
PubMed1997

Two cases of fatal air embolism in children undergoing scoliosis surgery.

Venous air embolism during surgery is a rare but important complication and can be rapidly fatal. We present two cases of fatal air embolism in the prone position occurring in small children undergoing surgery for progressive scoliosis. Venous air embolism is a rare complication in the prone position. This is thought to be because in this position there is virtually no gravitational gradient between the site of surgery and the right atrium. The possible sites of entry of air and ways that this may be minimized are discussed.

Child↗
PubMed2000

Extracorporeal support in an adult with severe carbon monoxide poisoning and shock following smoke inhalation: a case report.

The objective of this study was to discuss the case of a patient with severe smoke inhalation-related respiratory failure treated with extracorporeal support. The study was set in a 12-bed multi-trauma intensive care unit at a level one trauma center and hyperbaric medicine center. The patient under investigation had carbon monoxide poisoning, and developed acute respiratory distress syndrome and cardiovascular collapse following smoke inhalation. Rapid initiation of extracorporeal support, extreme inverse-ratio ventilation and intermittent prone positioning therapy were carried out. Admission and serial carboxyhemoglobin levels, blood gases, and computerized tomography of the chest were obtained. The patient developed severe hypoxia and progressed to cardiovascular collapse resistant to resuscitation and vasoactive infusions. Veno-venous extracorporeal support was initiated. Cardiovascular parameters of blood pressure, cardiac output, and oxygen delivery were maximized; oxygenation and ventilation were supported via the extracorporeal circuit. Airway pressure release ventilation and intermittent prone positioning therapy were instituted. Following 7 days of extracorporeal support, the patient was decannulated and subsequently discharged to a transitional care facility,neurologically intact. Smoke inhalation and carbon monoxide poisoning may lead to life-threatening hypoxemia associated with resultant cardiovascular instability. When oxygenation and ventilation cannot be achieved via maximal ventilatory management, extracorporeal support may prevent death if initiated rapidly.

Adult↗
PubMed1997

Oxygen venous embolism after the use of hydrogen peroxide during lumbar discectomy.

PURPOSE: The knee-prone position is commonly used for patients undergoing spinal surgery. Venous air embolism in such a position may be produced by the negative venous pressure gradient between the ambient air and the venous plexuses of the spinous process. When hydrogen peroxide is used to cleanse the wound, oxygen is produced. We report a case of suspected oxygen venous embolism during lumbar discectomy in the knee-prone position after use of H2O2. CLINICAL FEATURES: Immediately after irrigation of a discectomy wound with H2O2, a dramatic decrease of the PETCO2, blood pressure and oxygen saturation coincident with ST segment elevation occurred suggesting a coronary gas embolism. Symptomatic treatment was initiated immediately and the patient recovered without any sequelae. CONCLUSION: Although hydrogen peroxide has an innocuous reputation, cases of accidental ingestion or massive gas embolism after wound irrigation leading to death have been reported. A review of the literature suggests that many of the clinical and physiopathological features of air and oxygen emboli are similar. For both, measures of prevention and treatment of complications are similar. We argue that the use of hydrogen peroxide should be avoided during procedures where the position of the patient (sitting, knee-prone) increases the risk of gas embolism and that hydrogen peroxide is a potentially dangerous solution.

Adult↗
PubMed1999

[Errors in pointing under various body orientation relative to the gravity vector].

Errors in pointing to remembered target locations were measured in healthy subjects in upright, supine and prone positions, i.e. in three positions differing in body and arm movement orientation relative to the gravity vector. The X-error was unaffected by the body position, whereas the Y-error was dependent on subject's orientation relative to the gravity vector. In two lying positions, the subjects pointed below and in the vertical posture above the remembered target locations. On the contrary, the variable error was differentially affected by orientation of the movement trajectory relative to the gravity vector. In the supine position, the variable error was larger and in the prone position, smaller than in the upright posture. The gravity bias in pointing errors suggests that the motor program generated in the lying position is not modified to adapt to altered orientation relative to the gravity vector.

Adult↗
PubMed1994

The Pierre Robin sequence: review of 125 cases and evolution of treatment modalities.

All children admitted to our hospital between 1964 and 1991 with a diagnosis of Pierre Robin sequence were divided into three groups according to the severity of their symptoms: group I: adequate respiration in prone position and bottle feeding; group II: adequate respiration in prone position but feeding difficulties requiring gavage; and group III: children with respiratory distress and endotracheal intubation and gavage. The presence of associated anomalies, prematurity, and psychomotor impairment was noted as well as the surgical interventions performed. We found 56 children (44.8 percent) in group I, 40 children (32 percent) in group II, and 29 children (23.2 percent) in group III. Seventeen children (13.6 percent) died: 1 of 56 in group I, 4 of 40 in group II, and 12 of 29 in group III. Among the 125 patients, 57 presented at least one associated anomaly other than a cleft palate and the Pierre Robin triad. Thirteen deaths were found in this group (13 of 57 = 22.8 percent). Ten children were premature (10 of 125), and 6 of the premature infants died (60 percent). Twenty-two children required at least one surgical procedure to relieve the upper airway obstruction. Among the 108 survivors in this study, 25 presented a psychomotor impairment (23.1 percent). The children admitted after 1986 were submitted to routine serial blood gases, oxygen saturation monitoring, and polysomnographic recordings. The therapeutic interventions were done earlier. Thirty-four children were followed after 1986: 14 in group I, 11 in group II, and 9 in group III.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormalities, Multiple↗
PubMed1995

Correlates of prone infant sleeping position by period of birth.

Intervention to avoid the prone sleeping position during infancy has occurred in various countries after evidence that it increases the risk of sudden infant death syndrome (SIDS). This study examined cohort data to determine if correlates of the prone position differed by period of birth, before intervention (1 May 1988 to 30 April 1991) compared with after intervention (1 May 1991 to 30 April 1992). The usual prone sleeping position was more closely associated with the following factors after intervention: teenage motherhood, low maternal education, paternal unemployment, unmarried motherhood, non-specialist antenatal care, not reading books to prepare for a baby, poor smoking hygiene, and bottle feeding. For example, the association of usual prone position with being unmarried shown by the odds ratio (95% confidence interval) was 0.54 (0.47 to 0.63) in the period before intervention and 1.92 (1.18 to 3.15) in the period after intervention. The alteration in correlates of the prone position reported here provide an example to support the theoretical concept that well known 'modifiable' risk factors for disease tend to be associated with each other in both populations and individuals. This phenomenon was not evident in the population before intervention, that is, before the prone sleeping position became a well known SIDS risk factor.

Adult↗
PubMed2006

Comparison of different extubation techniques in lumbar surgery: prone extubation versus supine extubation with or without prior injection of intravenous lidocaine.

The aim of this study was to evaluate the incidence of coughing and breath holding in patients undergoing lumbar surgery extubated in prone position, supine position, or supine position with intravenous lidocaine before extubation. About 105 ASA I to II patients undergoing lumbar surgery were extubated in prone position in group P (n = 35), in supine position in group S (n = 35) and in supine position with intravenous 1.5 mg/kg lidocaine 10 minutes before extubation in group SL (n = 35). The number of patients who coughed and demonstrated breath holding was noted at emergence period. The time of loss of monitoring while repositioning the patient was recorded. The frequency of cough in group S was higher compared with group P at 1 minute after extubation (P = 0.008). Two and three minutes after extubation, the patients in group S demonstrated higher cough incidence compared with groups P and SL (P < 0.05). The incidence of breath holding in the first 6 minutes was lower in group P (n = 11) compared with groups S (n = 29) and SL (n = 25)(P = 0.001). The loss of monitoring time was longer in groups S (62 +/- 40 s) and SL (53 +/- 39 s) when compared with group P (0 s) (P < 0.01). Prone emergence and supine emergence with intravenous lidocaine provides an alternative approach to conventional supine emergence and prone extubation offers less cough and breath holding and continuation of monitoring.

Adult↗
PubMed1990

Mechanical efficiency of the elbow flexors in rowing.

Biomechanical and especially kinesiological investigations of the mechanical efficiency of rowers are rarely found in today's literature. The coach frequently relates to skills or technical movements in terms of their aesthetic appearance rather than their mechanical effectiveness. The force output of the elbow flexors appears to be a function of the forearm position. The literature referring to the mechanical efficiency of the elbow flexors seems to favor both semiprone and supine positions, whereas the prone position appears to be discredited. It is the latter grip position that is actually employed and traditionally accepted in the sport of rowing. In fact, this technique was never challenged or scientifically researched to see whether a modified one might lead to better efficiency. Consequently, the purpose of this investigation was to analyze whether athletes' force output differed if the gripping technique was changed from pronation to a semiprone grip (one arm prone, the other semiprone). Under the specific conditions of this investigation, it was demonstrated that the semiprone position was generating greater force output and higher electrical activity, thus being superior to the classical prone grip.

Adult↗
PubMed2006

Prone versus supine positioning in the well preterm infant: effects on work of breathing and breathing patterns.

Premature infants with respiratory distress oxygenate better and have improved breathing synchrony when they are nursed in the prone position. We investigated whether work of breathing (WOB) is decreased in the prone position in healthy premature infants nearing discharge from the neonatal intensive care unit. Nineteen convalescing premature infants in room air were studied in both supine and prone position. Positioning order was randomized. Mean birth weight was 1358 +/- 332 (SD) g, gestational age 29.7 +/- 2.1 weeks, weight at study 1757 +/- 248 g, and age at study 33.6 +/- 1.4 days. Calibrated respiratory inductance plethysmography (RIP) was used to measure tidal volume; an esophageal catheter estimated pleural pressure. Inspiratory, elastic, and resistive WOB were calculated and were unaffected by prone versus supine positioning (P = 0.46, 0.36, and 0.87, respectively). Similarly, respiratory rate, tidal volume, minute ventilation, and lung compliance did not differ between positions. These data suggest that sleep position recommendations for healthy premature infants discharged home without oxygen should be no different than for term infants.

Female↗
PubMed1996

Thermal stress, sleeping position, and the sudden infant death syndrome.

We review the evidence than overheating or disordered thermoregulation may be responsible for some cases of the Sudden Infant Death Syndrome (SIDS). Possible mechanisms for an interaction of thermal stress and the prone position are discussed with an emphasis on heat production and loss via the infant head. After the reduction in the prevalence of the prone position following "Back to Sleep" campaigns, and the emergence of cigarette smoking as a key risk factor, the role of disordered thermoregulation continues to be important in many cases of SIDS.

Bedding and Linens↗
PubMed2006

Barriers to following the supine sleep recommendation among mothers at four centers for the Women, Infants, and Children Program.

OBJECTIVES: The risk for sudden infant death syndrome in black infants is twice that of white infants, and their parents are less likely to place them in the supine position for sleep. We previously identified barriers for parents to follow recommendations for sleep position. Our objective with this study was to quantify these barriers, particularly among low-income, primarily black mothers. DESIGN/METHODS: We conducted face-to-face interviews with 671 mothers, 64% of whom were black, who attended Women, Infants, and Children Program centers in Boston, Massachusetts, Dallas, Texas, Los Angeles, California, and New Haven, Connecticut. We used univariate analyses to quantify factors that were associated with choice of sleeping position and multivariate logistic regression to calculate adjusted odds ratios for the 2 outcome variables: "ever" (meaning usually, sometimes, or last night) put infant in the prone position for sleep and "usually" put infant in the supine position to sleep. RESULTS: Fifty-nine percent of mothers reported supine, 25% side, 15% prone, and 1% other as the usual position. Thirty-four percent reported that they ever placed infants in the prone position. Seventy-two percent said that a nurse, 53% a doctor, and 38% a female friend or relative provided source of advice. Only 42% reported that a nurse, only 36% a doctor, and only 15% a female friend or relative recommended the supine position for sleep. When a female friend or relative recommended the prone position, mothers were more likely ever to place their infants in the prone position and less likely usually to choose supine compared with those who received no advice from friends or relatives. When a doctor or a nurse recommended a nonsupine position, the mothers were less likely to choose supine compared with those who received no advice from a doctor or a nurse. Mothers who trusted the opinion of a doctor or a nurse about infant sleeping position were more likely to place their infants in the supine position. Half of the mothers believed that infants were more likely to choke when supine, and they were less likely to place their infants supine. Mothers who believed that infants are more comfortable in the prone position (36%) were more likely to place their infants prone. Twenty-nine percent believed that having their infants sleep with an adult helps prevent sudden infant death syndrome, and only 43% believed that sudden infant death syndrome is related to sleeping position. CONCLUSIONS: We identified specific barriers to placing infants in the supine position for sleep (lack of or wrong advice, lack of trust in providers, knowledge and concerns about safety and comfort) in low-income, primarily black mothers that should be considered when designing interventions to get more infants onto their back for sleep.

Adult↗
PubMed1994

MR assessment of the normal position of the spinal cord in the spinal canal.

PURPOSE: To investigate intradural geometry, which strongly influences the effects of epidural spinal cord stimulation. METHODS: Axial MR images with turbo spin-echo were made of 26 healthy subjects at C-4 through C-6, T-5 and T-6, and T-11 and T-12, at T-11 and T-12 both in the supine and the prone position. Measurements were made of the dorsomedial and the ventromedial cerebrospinal fluid layer and the anteroposterior and transverse sizes of both the spinal cord and the dural sac. The samples of all variables were analyzed statistically. The distance between spinal and vertebral midline was also determined. RESULTS: The dorsal cerebrospinal fluid layer was 1.5 to 4.0 mm at C-4 through C-6 and 4.0 to 8.5 mm at T-5 and T-6. At T-11 it was 2.0 to 6.0 mm in the supine position and was increased by approximately 2.2 mm in the prone position. At T-12 these values were 1.5 to 4.5 mm and approximately 3.4 mm, respectively. Differences between the spinal and vertebral midline up to 1.5 to 2.0 mm occurred in approximately 40% of the images. CONCLUSIONS: Because there are variations of the dorsal cerebrospinal fluid layer among subjects by more than a factor of 2, and significant variations of the mediolateral position of the spinal cord, information on these parameters in patients will be essential for the optimal application of epidural spinal cord stimulation.

Adult↗