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Results for “Prone Position”

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At least 937 records · Page 52Linked to original sources

PubMed2000

The effect of patient positioning on intraabdominal pressure and blood loss in spinal surgery.

UNLABELLED: Intraabdominal pressure (IAP) can influence blood loss during spinal surgery. We examined the relationship of IAP changes to blood loss with a rectal balloon pressure catheter. Forty patients were randomly assigned to narrow (Group 1) or wide (Group 2) pad support widths of the Wilson frame. IAP was measured when the patient was supine after the induction of anesthesia, prone on a gurney, prone on the Wilson frame before and after incision, and then, again supine after tracheal extubation. IAP in the prone position on the Wilson frame before incision (3.6 cm H(2)O) in Group 2 was significantly less than in Group 1 (8.8 cm H(2)O) (P: < 0.05). Intraoperative blood loss per vertebra in Group 2 (190 +/- 65 mL) was significantly less than in Group 1 (381 +/- 236 mL) (P: < 0.05). The correlation between blood loss and IAP in the prone position on the Wilson frame in Group 1 was significant (P: = 0.0022). In conclusion, IAP and intraoperative blood loss were significantly less in the wide, than in the narrow, pad support width of the Wilson frame. Blood loss tended to increase with an increase in IAP in the narrow pad support width of the Wilson frame. IMPLICATIONS: The relationship of intraabdominal pressure changes to blood loss were examined with a rectal balloon pressure catheter during spinal surgery. Blood loss tended to increase with an increase in intraabdominal pressure in the narrow pad support width of the Wilson frame.

Abdomen↗

PubMed2006

Pars plana vitrectomy with peripheral retinotomy after injection of preoperative intravitreal tissue plasminogen activator: a modified procedure to drain massive subretinal haemorrhage.

AIMS: To report outcome of a modified procedure for draining massive subretinal haemorrhages (SRHs). METHODS: The charts of eight consecutive eyes from eight patients with massive SRHs extending to the periphery and involving two or more quadrants with haemorrhagic and bullous retinal detachment were reviewed. Tissue plasminogen activator (tPA) was injected intravitreally 12-24 h preoperatively; vitrectomy was carried out with peripheral retinotomy, drainage of the SRH from the retinotomy using perfluorocarbon liquid and gas tamponade with prone positioning postoperatively. RESULTS: The preoperative visual acuities ranged from light perception to 20/200. Most of the subretinal haematomas moved postoperatively to the vitreous cavity through the peripheral retinotomy using perfluorocarbon liquid. Residual SRHs were drained from the anterior chamber at the bedside after prone positioning overnight. SRH recurred in one eye 14 months postoperatively and was successfully retreated. No other serious complications developed. The final visual acuity improved in seven eyes (range 20/1000-20/60). Polypoidal lesions in choroidal vasculatures were present in three of seven patients. CONCLUSIONS: The technique seems safe and effective for treating massive SRH. However, visual recovery is limited by the underlying macular pathology. Polypoidal choroidal vasculopathy, other than age-related macular degeneration, may be another cause of massive SRHs.

Aged↗

PubMed2002

Bilateral anterior superior iliac spine pressure ulcers: a case report.

The most frequent sites for pressure ulcers are the occiput, sacrum, ischial tuberosities, trochanters, lateral malleoli, and posterior heels. A 27-year-old woman with Wegener's granulomatosis was admitted to our rehabilitation unit after spending 65 days in an intensive care unit and 40 days in an internal medicine ward. She required mechanical ventilation because of respiratory failure. Adequate oxygenation was only achieved in the prone position. As a result, she developed bilateral anterior superior iliac spine pressure ulcers. Pressure ulcers in this location have not been reported in the literature. Complicating factors included variable levels of oxygenation, malnutrition, anemia, and steroid therapy. Complete healing, documented with serial photographs, occurred over 9 months. Although prone positioning can improve pulmonary gas exchange, it exposes the patient to unique complications. When it is required, specific care should be directed to the unusual weight-bearing surfaces to avoid pressure ulcers.

Adult↗

PubMed2005

Cervical osteotomy in ankylosing spondylitis: evaluation of new developments.

OBJECTIVES: Cervical osteotomy can be performed on patients with cervical kyphosis due to ankylosing spondylitis. This study reviews the role of two new developments in cervical osteotomy surgery: internal fixation and transcranial electrical stimulated motor evoked potential monitoring (TES-MEP). METHODS: From 1999 to 2004, 16 patients underwent a C7-osteotomy with internal fixation. In 11 patients, cervical osteotomy was performed in a sitting position with halo-cast immobilization (group S), five patients underwent surgery in prone position with Mayfield clamp fixation (group P). In group P, longer fusion towards T4-T6 could be obtained that created a more stable fixation. Therefore, post-operative immobilization protocol of group P was simplified from halo-cast to cervical orthosis. RESULTS: Consolidation was obtained in all patients without loss of correction. Post-operative chin-brow to vertical angle measured 5 degrees (range 0-15). TES-MEP was successfully performed during all surgical procedures. In total, nine neurological events were registered. Additional surgical intervention resulted in recovery of amplitudes in six of nine events. In two patients spontaneous recovery took place. One patient showed no recovery of amplitudes despite surgical intervention and a partial C6 spinal cord lesion occurred. CONCLUSION: We conclude that C7 osteotomy with internal fixation has been shown to be a reliable and stable technique. When surgery is performed the in prone position, distal fixation can be optimally obtained allowing post-operative treatment by cervical orthosis instead of a halo-cast. TES-MEP monitoring has been shown to be a reliable neuromonitoring technique with high clinical relevancy during cervical osteotomy because it allows timely intervention before occurrence of permanent cord damage in a large proportion of the patients.

Adult↗

PubMed2003

[Craniospinal irradiation -- patient positioning and verification with portal films].

BACKGROUND: Implementation of an important step for quality assurance in irradiation of the craniospinal axis was made through changes in the irradiation technique. Crucial improvements in patient positioning and the possibility of taking portal films of the field junctions are described. MATERIAL AND METHODS: A box for the positioning of the head of the patient in has been developed. In combination with vacuum cushions, it is a cheap method for the individual and secure positioning of the patient in prone position. Furthermore, a method for taking portal films of the field junctions between the lateral cranial and the upper dorsal spinal field as well as between the two dorsal spinal fields is described. DISCUSSION: The use of the "Bonner Box" improves the patient positioning with respect to reproducibility, setup time and comfort. The documentation of the field junctions in craniospinal irradiation, which is described for the first time, is an important tool for quality assurance.

Brain Neoplasms↗

PubMed1993

Comparison of sacrospinalis myoelectric activity and pain levels in patients undergoing static and intermittent lumbar traction.

The purposes of this study of low back pain patients were to determine: 1) if presence of sacrospinalis myoelectric activity is a consistent phenomenon in supine and prone positions; 2) if there is a difference between magnitudes of myoelectric activity for two types of lumbar traction (static and intermittent); and 3) if there is a difference in patient perceived pain level after traction between the two types of traction. Results show that surface electrode myoelectric activity is absent in resting supine and prone positions, there is no significant difference in magnitude of myoelectric activity between the two different types of traction, and more than 50% of patients in both traction groups experienced decreased pain after traction.

Adult↗

PubMed1997

[The sitting position in neurosurgical operations. Results of a survey].

METHODS: In February 1995 a questionnaire was sent out on perioperative management during neurosurgical operations performed in the sitting position to 136 centres and hospitals within the Federal Republic of Germany that perform neuroanaesthesia. The response rate was 61.02%. Besides the question of perioperative monitoring during neurosurgical operations in the sitting position, we asked about currently used positions for patients during the following neurosurgical operations:posterior fossa, craniospinal and posterior cervical surgery. RESULTS: Of all centres, 32.9% use the sitting position only for posterior fossa and craniospinal surgery. For posterior cervical surgery the sitting and prone positions are favoured by 25.6% of all clinics. Nonspecific basic monitoring (electrocardiogram, pulse oximetry, central venous pressure, invasive or noninvasive arterial pressure) is an accepted standard in all clinics. Capnometry, as a specific monitor for venous air embolism, is used in all centres (100%). Precordial Doppler ultrasound (US) monitoring is used in 69.2% of all clinics; 3.8% use transoesophageal Doppler US as a diagnostic method for venous air embolism. DISCUSSION: The sitting position is the preferred position for posterior fossa and craniospinal surgery in neurosurgical patients in Germany. For posterior cervical surgery the German centres use both the sitting and prone positions. Alternative positions like the lateral or the "park-bench" positions are hardly ever used. The essential monitoring devices for neurosurgical operations in the sitting position, as recommended after the survey by the German Society for Anaesthesiology and Intensive Care Medicine (DGAI) in 1995, are predominantly used. However, the use of Doppler US (precordial or transoesophageal) for the detection of venous air embolism and the preoperative diagnosis of a persistent foramen ovale is not yet widespread. CONCLUSIONS: To determine the effect of the recommendations by the DGAI on clinical practice, the survey will be repeated in 1997.

Anesthesia↗

PubMed1989

An approach to abutting adjacent fields.

Problems arise in designing treatment techniques involving two pair of adjacent opposing fields where machine limitations require the patient to flip from supine to prone positions. Mantle and para-aortic treatments, in particular, can create challenging problems because of changes in patient position, different SSD's between adjacent fields, internal anatomical changes from supine to prone position, as well as field size and other treatment machine limitations. A simulator technique has been developed which takes cognizance of these limitations in specifying the gap between adjacent fields. It employs collinearity of the 50% decrement lines of adjacent-opposed field edges and the intersection of all four edges at an internal mid-plane match point. The technique maintains dose homogeneity and eliminates hot and cold triangles in the area of abutment. Simulation radiographs facilitate identification of collinearity with respect to a specific vertebra in the plane of abutment. In summary, this approach: Verifies abutment of coplanar fields by use of match film, improves isodose uniformity at mid-plane, evaluates dose distributions when abutment occurs at a point anterior or posterior to midline, prevents the possibility of spinal cord complications that might occur due to three field overlap.

Humans↗

PubMed2006

The posture-related interaction between Ia-afferent and descending input on the spinal reflex excitability in humans.

The separate and combined depressive effects induced by vibration and standing on the soleus H-reflex have been studied by administering Achilles' tendon vibration in prone position and during stance. Without vibration, H-reflex amplitude was larger under prone than standing condition. Vibration reduced the reflex both in prone position and even more during stance. When vibration was superimposed to inclined stance (greater EMG background), the reflex was reduced of the same absolute amount as when it was superimposed to normal stance. When vibration was superimposed on stance with minimal or no background EMG, the reflex disappeared. These results confirm that both upright posture and vibration have a strong depressive effect on the H-reflex. They also show that muscle activity during stance is enough for overcoming the reflex depression. These findings provide information about the origin of the disfacilitatory effects on the monosynaptic reflex pathway, contribute to the understanding of the posture-related mechanisms responsible for the modulation of the spinal reflex excitability, and allow arguing in favour of a minor but adaptable role for the short latency stretch reflex in the control of quiet unperturbed stance.

Adult↗

PubMed1994

Reduction in mortality from sudden infant death syndrome in New Zealand: 1986-92.

Mortality from sudden infant death syndrome (SIDS, or cot death) in New Zealand has been high by international standards (4/1000 live births). Within New Zealand the rate is higher in Maori than in non-Maori (predominantly European infants) and higher in South Island than in North Island. The National Cot Death Prevention Programme aims to reduce the prevalence of four modifiable risk factors for SIDS, namely infants sleeping prone, maternal smoking, lack of breast feeding, and infants sharing a bed with another person. The aim of this study is to describe the total postneonatal and total SIDS mortality in New Zealand from 1986 to 1992. Official publications from 1986 to 1990 and preliminary death notifications for 1991 and 1992 were examined. Deaths from all causes in the postneonatal age group (28 days to 1 year) and the total number of deaths from SIDS irrespective of age decreased markedly in 1990 and has continued to decrease. This decrease occurred particularly in non-Maori groups, in South Island, and in the winter months. The proportion of infants sleeping in a prone position has decreased from 43% to less than 5%. This suggests that the prone position is causally related to SIDS. The mechanism appears to be related directly or indirectly to environmental temperature.

Age Factors↗

PubMed1989

[The threshold of pupil-blocking force].

The purpose of this study was to quantitate the dynamic changes which take place in the anterior eye segment during the prone position test. The pupil-blocking force was measured before and after the prone position test (PTT) by a method of image analysis using a computer. The changes in the magnitude of pupillary block were evaluated. The mechanics of this provocation seems to be both pupillary block and direct lens block angle-closure. Pupil-blocking force standardizes the assessment of the eyes with relative pupil-block. The present results provide valuable information in the analysis of the mechanism of primary angle-closure glaucoma and also contribute to the determination of a real value for the threshold of the pupil-blocking force (approximately 0.1 or greater), followed by a clinically significant elevation of intraocular pressure.

Biomechanical Phenomena↗

PubMed1999

Relation of body position at the time of discovery with suspected aspiration pneumonia in poisoned comatose patients.

OBJECTIVE: The left lateral decubitus position is generally accepted as the position of choice to protect against aspiration pneumonia in comatose poisoned patients. We studied the relationship between initial body position during coma and subsequent development of suspected aspiration pneumonia (SAP). DESIGN: Observational, descriptive study. SETTING: Toxicology intensive care unit in a university hospital. PATIENTS: Acutely poisoned comatose patients admitted to our intensive care unit. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Glasgow Coma Scale score (GCS) and body position were recorded in poisoned patients on discovery. Chest radiographs were examined for infiltrates suggesting SAP within 24 hrs of hospitalization. The prone positioned patients had a lower incidence of SAP than patients in the lateral decubitus and supine positions, despite similar GCS scores. Patients in the semi-recumbent position had an incidence of SAP similar to prone patients, but with higher GCS values. CONCLUSIONS: The prone position appears to be associated with a lower incidence of SAP than the lateral decubitus position in comatose poisoned patients.

Acute Disease↗

PubMed2005

Intraocular pressure during lumbar disc surgery in the knee-elbow position.

Increased intraocular pressure is often implicated in the aetiology of postoperative visual impairment. Such an increase in intraocular pressure has been demonstrated in the prone position. We investigated intraocular pressure in seven patients undergoing lumbar disc surgery in the knee-elbow position with the head resting on a cushion and turned to the side. Measurements were performed in the supine position before induction of anaesthesia and in the knee-elbow position after surgery with the patient still anaesthetised. After a mean (SD) duration of prone positioning of 121 (18) min, mean (SD) intraocular pressure in the nondependent eye was unchanged when compared to the awake state (17.7 (2.4) mmHg vs 18.9 (5.5) mmHg), whereas the intraocular pressure in the dependent eye had significantly decreased (17.0 (3.6) mmHg vs 8.1 (1.8) mmHg; p < 0.01). These results may be important for choosing the optimal position for spinal surgery when an increase in intraocular pressure should be avoided.

Adult↗

PubMed1998

Effects of sleeping position and time after feeding on the organization of sleep/wake states in prematurely born infants.

Epidemiologic studies provide strong evidence for the conclusion that sleeping in the prone position places infants at greater risk for sudden infant death syndrome (SIDS). Prior studies in newborn infants found that in the prone sleeping position there is less time awake and more quiet sleep, but little change in the amount of active sleep. To determine whether the effects of sleeping position on state distribution vary with time after feeding, we studied prematurely born infants in both the prone and supine sleeping positions. Sleep states were recorded each minute during interfeed intervals. Results demonstrate expected effects of sleep position on state distribution: prone sleeping is associated with a 79% increase in quiet sleep and a 71% decrease in time awake. While the decreases in time awake are seen throughout the interfeed interval, increases in quiet sleep in the prone position are found only within the first hour and again near the end of the interfeed interval. These results are consistent with the hypothesis that prone sleeping could increase risk for SIDS by altering the organization of sleep, and that time after feeding may play an important role in the expression of these effects.

Analysis of Variance↗

PubMed2001

Position dependent changes of cerebral blood flow velocities in premature infants.

UNLABELLED: The supine or prone positioning of infants has been a cause of much controversy. Recently it has been postulated that the position dependent hypoperfusion of the brainstem represents a possible cause of sudden infant death. To demonstrate position dependency and maturational changes of cerebral perfusion in premature newborn infants we investigated cerebral blood flow velocities (CBFV) in the main supratentorial and brainstem cerebral arteries. Measurements of CBFV were done with transfontanellar colour-coded Doppler sonography in the internal carotid artery (ICA), basilar artery (BA), and vertebral artery (VA) in the prone (head centered-baseline) and supine positions (maximal rotation to both sides) in 23 premature infants aged between 3-5 days of life. We performed follow-up measurements in 17 infants 7-10 days later and in 16 infants at the corrected age of 1 month. There was no difference in mean CBFVs between the prone and supine position at the first investigation. At the third investigation, CBFVs were significantly higher in the supine compared to the prone position. The CBFVs of the ICA were higher than in the BA and VA. This difference was not influenced by the body position but increased with post-natal age more in the VA (159%) than in the BA (129%) and ICA (128%). Position dependency was not seen in the ICA perfusion. In the prone position, five infants showed an incomplete steal effect in the contralateral VA. There was no significant side difference in the CBFVs of the ICA and VA, but in the resistance indices in the VA (left > right). CONCLUSION: in premature newborns, position dependent changes of cerebral blood flow velocity develop with maturation and are most pronounced in the vertebrobasilar system. These changes are possibly due to compression of the vertebral artery by neck movement and suggest an individual risk of brainstem perfusion deficits that may be aggravated with age and head rotation in a prone position.

Analysis of Variance↗

PubMed2005

Percutaneous access to upper pole renal stones: role of prone 3-dimensional computerized tomography in inspiratory and expiratory phases.

PURPOSE: We evaluated the role of noncontrast, prone position, inspiratory and expiratory 3-dimensional spiral computerized tomography (PIE-CT) for preoperative planning of percutaneous treatment in patients with complex upper pole renal calculi. MATERIALS AND METHODS: In this pilot study a total of 6 renal units in 4 women and 1 man with complex upper pole calculi who were candidates for percutaneous nephrolithotomy were evaluated with thin section PIE-CT. With the patient imaged in the prone position percutaneous access was simulated under 4 potential access conditions, including subcostal and intercostal, in inspiration and expiration. Each potential access was then deemed transpleural or extrapleural and minimally angulated or severely angulated cephalad. RESULTS: PIE-CT was performed uneventfully in all patients. Ideal nonangulated extrapleural percutaneous access was deemed possible in 5 of 6 renal units. However, inspiratory plus expiratory phases were necessary to identify the most suitable access site. In 2 renal units only 1 safe access site was identified. No pulmonary complications were noted in any of these patients. In 1 renal unit no suitable access could be identified and this patient was treated with laparoscopic caliceal diverticulectomy. CONCLUSIONS: Thin section PIE-CT offers 3-dimensionally rendered images that clearly demonstrate anatomical relationships among the kidney, calculi, pleura, diaphragm, ribs and surrounding organs. In this pilot study PIE-CT provided useful data for planning urological intervention for complex upper pole renal stones. This study also suggests that generalizations regarding the safety of upper pole access in the inspiratory or expiratory phase are not warranted.

Exhalation↗

PubMed1995

The effect of operative position on lumbar lordosis. A radiographic study of patients under anesthesia in the prone and 90-90 positions.

STUDY DESIGN: The effect of intraoperative positioning on lumbar lordosis was retrospectively studied by radiographic analysis of 40 patients under general anesthesia. OBJECTIVES: The aim of this study was to document changes in segmental and total lumbar lordosis between preoperative standing and intraoperative radiographs taken in the "90-90" and prone positions. SUMMARY OF BACKGROUND: Preservation of physiologic lordosis was an important consideration in reconstructive lumbar spine surgery. To avoid iatrogenic loss of lordosis when using spinal instrumentation and to facilitate decompressive procedures, it was necessary to understand how segmental alignments were affected by intraoperative positioning. Although many positioning techniques were used, the effect on lumbar lordosis was not well established. METHODS: Preoperative (standing 36" lateral spine) and intraoperative radiographs (lateral lumbar spine L1 to the sacrum) in either the "90-90" position on a Hastings frame (n = 20) or the prone position on a Jackson table (n = 20) were measured twice by two independent observers using Cobb methodology for total and segmental lordosis between L1 and S1. Data were analyzed for intra- and interobserver reliability and changes in segmental and total lordosis between standing and intraoperative radiographs. RESULTS: Analysis of intra- and interobserver reliability revealed measurements were accurate and reproducible. The "90-90" position produced significant loss (P < or = 0.01) of total and segmental lordosis at all levels except L1-L2, which showed no change. Segmental lordosis was reduced nearly 60% at L2-L3, L3-L4, and L4-L5, and total lordosis was reduced by more than 35%. The prone position on the Jackson table increased segmental lordosis at L5-S1 by 22% (P < or = 0.01) and preserved total and segmental standing lordosis at all other levels. CONCLUSIONS: The "90-90" position on the Hastings frame was associated with significant reduction of total and segmental lordosis in the middle and lower lumbar spine. Positioning prone on a Jackson table maintained standing lumbar lordosis and increased lumbosacral lordosis.

Adult↗

PubMed2006

Sleeping position, oxygen saturation and lung volume in convalescent, prematurely born infants.

OBJECTIVE: To determine whether the effects of sleeping position on lung volume and oxygenation are influenced by postmenstrual age (PMA) and oxygen dependency in convalescent prematurely born infants. DESIGN: Prospective study. SETTING: Tertiary neonatal unit. PATIENTS: 41 infants (21 oxygen dependent), median gestational age 28 weeks (range 24-31 weeks) and birth weight 1120 g (range 556-1780 g). INTERVENTION: Infants were studied both supine and prone at two-weekly intervals from 32 weeks' PMA until discharge. Each posture was maintained for 1 h. MAIN OUTCOME MEASURES: Pulse oximeter oxygen saturation (Spo(2)) was monitored continuously, and at the end of each hourly period functional residual capacity (FRC) was measured. RESULTS: Overall, lung volumes were higher in the prone position throughout the study period; there was no significant effect of PMA on lung volumes. Overall, Spo(2) was higher in the prone position (p = 0.02), and the effect was significant in the oxygen-dependent infants (p = 0.03) (mean difference in Spo(2) between prone and supine was 1.02%, 95% CI 0.11% to 1.92%), but not in the non-oxygen-dependent infants. There was no significant influence of PMA on Spo(2). CONCLUSION: In the present study, prone sleeping did not improve oxygenation in prematurely born infants, 32 weeks' PMA or older and with no ongoing respiratory problems. However, the infants were monitored in each position for an hour, thus it is recommended that oxygen saturation should continue to be monitored after 32 weeks' PMA to be certain that longer periods of supine sleeping are not associated with loss of lung volume and hypoxaemia.

Functional Residual Capacity↗