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The Cochrane Database of Systematic... Jan 2015Pressure, from lying or sitting on a particular part of the body results in reduced oxygen and nutrient supply, impaired drainage of waste products and damage to cells.... (Review)
Review
BACKGROUND
Pressure, from lying or sitting on a particular part of the body results in reduced oxygen and nutrient supply, impaired drainage of waste products and damage to cells. If a patient with an existing pressure ulcer continues to lie or bear weight on the affected area, the tissues become depleted of blood flow and there is no oxygen or nutrient supply to the wound, and no removal of waste products from the wound, all of which are necessary for healing. Patients who cannot reposition themselves require assistance. International best practice advocates the use of repositioning as an integral component of a pressure ulcer management strategy. This review has been conducted to clarify the role of repositioning in the management of patients with pressure ulcers.
OBJECTIVES
To assess the effects of repositioning patients on the healing rates of pressure ulcers.
SEARCH METHODS
For this third update we searched the Cochrane Wounds Group Specialised Register (searched 28 August 2014); The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 7); Ovid MEDLINE (2013 to August Week 3 2014); Ovid MEDLINE (In-Process & Other Non-Indexed Citations 29 August, 2014); Ovid EMBASE (2012 to 29 August, 2014); and EBSCO CINAHL (2012 to 27 August 2014).
SELECTION CRITERIA
We considered randomised controlled trials (RCTs) comparing repositioning with no repositioning, or RCTs comparing different repositioning techniques, or RCTs comparing different repositioning frequencies for the review. Controlled clinical trials (CCTs) were only to be considered in the absence of RCTs.
DATA COLLECTION AND ANALYSIS
Two authors independently assessed titles and, where available, abstracts of the studies identified by the search strategy for their eligibility. We obtained full versions of potentially relevant studies and two authors independently screened these against the inclusion criteria.
MAIN RESULTS
We identified no studies that met the inclusion criteria.
AUTHORS' CONCLUSIONS
Despite the widespread use of repositioning as a component of the management plan for individuals with existing pressure ulcers, no randomised trials exist that assess the effects of repositioning patients on the healing rates of pressure ulcers. Therefore, we cannot conclude whether repositioning patients improves the healing rates of pressure ulcers. The effect of repositioning on pressure ulcer healing needs to be evaluated.
Topics: Humans; Moving and Lifting Patients; Patient Positioning; Pressure Ulcer; Wound Healing
PubMed: 25561248
DOI: 10.1002/14651858.CD006898.pub4 -
Medicina 2016Acute respiratory distress syndrome (ARDS) is an acute respiratory failure produced by an inflammatory edema secondary to increased lung capillary permeability. This... (Review)
Review
Acute respiratory distress syndrome (ARDS) is an acute respiratory failure produced by an inflammatory edema secondary to increased lung capillary permeability. This causes alveolar flooding and subsequently deep hypoxemia, with intrapulmonary shunt as its most important underlying mechanism. Characteristically, this alteration is unresponsive to high FIO2 and only reverses with end-expiratory positive pressure (PEEP). Pulmonary infiltrates on CXR and CT are the hallmark, together with decreased lung compliance. ARDS always occurs within a week of exposition to a precipitating factor; most frequently pneumonia, shock, aspiration of gastric contents, sepsis, and trauma. In CT scan, the disease is frequently inhomogeneous, with gravitational infiltrates coexisting with normal-density areas and also with hyperaerated parenchyma. Mortality is high (30-60%) especially in ARDS associated with septic shock and neurocritical diseases. The cornerstone of therapy lies in the treatment of the underlying cause and in the use mechanical ventilation which, if inappropriately administered, can lead to ventilator-induced lung injury. Tidal volume = 6 ml/kg of ideal body weight to maintain an end-inspiratory (plateau) pressure = 30 cm H2O ("protective ventilation") is the only variable consistently associated with decreased mortality. Moderate-to-high PEEP levels are frequently required to treat hypoxemia, yet no specific level or titration strategy has improved outcomes. Recently, the use of early prone positioning in patients with PaO2/FIO2 = 150 was associated with increased survival. In severely hypoxemic patients, it may be necessary to use adjuvants of mechanical ventilation as recruitment maneuvers, pressure-controlled modes, neuromuscular blocking agents, and extracorporeal-membrane oxygenation. Fluid restriction appears beneficial.
Topics: Adrenal Cortex Hormones; Extracorporeal Membrane Oxygenation; Humans; Neuromuscular Blocking Agents; Patient Positioning; Positive-Pressure Respiration; Prognosis; Prone Position; Respiration, Artificial; Respiratory Distress Syndrome; Risk Factors; Tomography, X-Ray Computed
PubMed: 27576283
DOI: No ID Found -
British Journal of Psychology (London,... Aug 2022The way human bodies are represented is central in everyday activities. The cognitive system must combine internal, visceral, and somatosensory, signals to external,...
The way human bodies are represented is central in everyday activities. The cognitive system must combine internal, visceral, and somatosensory, signals to external, visually driven information generated from the spatial placement of others' bodies and the own body in the space. However, how different body representations covertly interact among them when observing human body parts is still unclear. Therefore, we investigated the implicit processing of body parts by manipulating either the body part stimuli' posture (conditions a and b) or the participants' response body posture (conditions c, d, and e) in healthy participants (N = 70) using a spatial compatibility task called Sidedness task. The task requires participants to judge the colour of a circle superimposed on a task-irrelevant body part picture. Responses are facilitated when the spatial side of the responding hand corresponds to the spatial code generated by the hand stimulus's position with respect to a body of reference. Results showed that the observation of the task-irrelevant body parts oriented participants' attention and facilitated responses that were spatial compatible with the spatial position such body parts have within a configural representation of the body structure (i.e., Body Structural Representation) in all the five experimental conditions. Notably, the body part stimuli were mentally attached to the body according to the most comfortable and less awkward postures, following the anatomo-physiological constraints. Moreover, the pattern of the results was not influenced by manipulating the participants' response postures, suggesting that the automatic and implicit coding of the body part stimuli does not rely on proprioceptive information about one's body (i.e., Body Schema). We propose that the human body's morphometry knowledge is enriched by biomechanical and anatomo-physiological information about the real body movement possibilities. Moreover, we discuss the importance of the automatic orienting of attention based on the sidedness within the context of imitational learning.
Topics: Body Image; Human Body; Humans; Movement; Posture; Proprioception
PubMed: 35181883
DOI: 10.1111/bjop.12558 -
Ultrasound in Medicine & Biology Apr 2021Ultrasound bladder vibrometry (UBV) parameters have been shown in previous studies to strongly correlate with measurements from urodynamic studies. Just like urodynamic... (Comparative Study)
Comparative Study
Ultrasound bladder vibrometry (UBV) parameters have been shown in previous studies to strongly correlate with measurements from urodynamic studies. Just like urodynamic studies, UBV can be performed in supine and sitting positions. The objective of this study is to compare UBV parameters obtained in the two different positions using statistical methods. We recruited eight volunteers with healthy bladders for this purpose. The elasticity, group velocity squared and thickness of the bladder were the UBV parameters of interest, and their values were recorded at different bladder volumes for each volunteer. The results presented indicate that the measurements made in the two positions are in agreement using the Bland-Altman method and a parameter q which compares the values at each bladder volume for each volunteer. UBV parameters were also repeatable for measurements recorded in the supine and sitting positions.
Topics: Adult; Aged; Elasticity; Elasticity Imaging Techniques; Female; Humans; Male; Middle Aged; Patient Positioning; Pilot Projects; Prospective Studies; Sitting Position; Supine Position; Urinary Bladder; Young Adult
PubMed: 33446373
DOI: 10.1016/j.ultrasmedbio.2020.12.016 -
Magnetic Resonance in Medicine May 2022The use of high-performance gradient systems (i.e., high gradient strength and/or high slew rate) for human MRI is limited by physiological effects (including the...
PURPOSE
The use of high-performance gradient systems (i.e., high gradient strength and/or high slew rate) for human MRI is limited by physiological effects (including the elicitation of magnetophosphenes and peripheral nerve stimulation (PNS)). These effects, in turn, depend on the interaction between time-varying magnetic fields and the body, and thus on the participant's position with respect to the scanner's isocenter. This study investigated the occurrence of magnetophosphenes and PNS when scanning participants on a high-gradient (300 mT/m) system, for different gradient amplitudes, ramp times, and participant positions.
METHODS
Using a whole-body 300 mT/m gradient MRI system, a cohort of participants was scanned with the head, heart, and prostate at magnet isocenter and a train of trapezoidal bipolar gradient pulses, with ramp times from 0.88 to 4.20 ms and gradient amplitudes from 60 to 300 mT/m. Reports of magnetophosphenes and incidental reports of PNS were obtained. A questionnaire was used to record any additional subjective effects.
RESULTS
Magnetophosphenes were strongly dependent on participant position in the scanner. 87% of participants reported the effect with the heart at isocenter, 33% with the head at isocenter, and only 7% with the prostate at isocenter. PNS was most widely reported by participants for the vertical gradient axis (67% of participants), and was the dominant physiological effect for ramp times below 2 ms.
CONCLUSION
This study evaluates the probability of eliciting magnetophosphenes during whole-body imaging using an ultra-strong gradient MRI system. It provides empirical guidance on the use of high-performance gradient systems for whole-body human MRI.
Topics: Human Body; Humans; Magnetic Fields; Magnetic Resonance Imaging; Male; Probability
PubMed: 34932236
DOI: 10.1002/mrm.29118 -
Clinical Neurophysiology : Official... Aug 2020There are questions and challenges regarding neurologic complications in COVID-19 patients. EEG is a safe and efficient tool for the evaluation of brain function, even... (Review)
Review
There are questions and challenges regarding neurologic complications in COVID-19 patients. EEG is a safe and efficient tool for the evaluation of brain function, even in the context of COVID-19. However, EEG technologists should not be put in danger if obtaining an EEG does not significantly advance diagnosis or change management in the patient. Not every neurologic problem stems from a primary brain injury: confusion, impaired consciousness that evolves to stupor and coma, and headaches are frequent in hypercapnic/hypoxic encephalopathies. In patients with chronic pulmonary disorders, acute symptomatic seizures have been reported in acute respiratory failure in 6%. The clinician should be aware of the various EEG patterns in hypercapnic/hypoxic and anoxic (post-cardiac arrest syndrome) encephalopathies as well as encephalitides. In this emerging pandemic of infectious disease, reduced EEG montages using single-use subdermal EEG needle electrodes may be used in comatose patients. A full 10-20 EEG complement of electrodes with an ECG derivation remains the standard. Under COVID-19 conditions, an expedited study that adequately screens for generalized status epilepticus, most types of regional status epilepticus, encephalopathy or sleep may serve for most clinical questions, using simplified montages may limit the risk of infection to EEG technologists. We recommend noting whether the patient is undergoing or has been placed prone, as well as noting the body and head position during the EEG recording (supine versus prone) to avoid overinterpretation of respiratory, head movement, electrode, muscle or other artifacts. There is slight elevation of intracranial pressure in the prone position. In non-comatose patients, the hyperventilation procedure should be avoided. At present, non-specific EEG findings and abnormalities should not be considered as being specific for COVID-19 related encephalopathy.
Topics: Brain Diseases; COVID-19; Coronavirus Infections; Critical Care; Electroencephalography; Humans; Pandemics; Patient Positioning; Pneumonia, Viral; Practice Guidelines as Topic
PubMed: 32405259
DOI: 10.1016/j.clinph.2020.05.006 -
Journal of Vascular Research 2020The dynamics ofpulsatile waveforms travelling the central aorta are governed by pressures and arterial compliance. Arterial stiffness, the inverse of compliance, is an... (Comparative Study)
Comparative Study
BACKGROUND
The dynamics ofpulsatile waveforms travelling the central aorta are governed by pressures and arterial compliance. Arterial stiffness, the inverse of compliance, is an independent risk factor for cardiovascular disease and has been suggested as a superior risk index compared to brachial blood pressure (BP). Arterial stiffness is typically measured via carotid-femoral pulse wave velocity (cfPWV) in the supine position; however, different body positions alter orthostatic column height, impacting heart rate and BP. The purpose of this investigation was to examine different body positions and associated measures of cfPWV.
METHODS
Measures of resting cfPWV were acquired simultaneously with BP during supine, head-up tilt (HUT), head-down tilt (HDT), and Fowler's position, all at 45 degrees from vertical.
RESULTS
Relative to supine, cfPWV was increased 1.1 ± 1.0 and 1.5 ± 1.1 m/s (both p ≤ 0.001) in HUT and Fowler's positions, respectively. Supine to HDT cfPWV was unaltered (p = 0.1), despite an increase in mean arterial pressure (MAP) (10 ± 9 mm Hg). When cfPWV was normalized to MAP, the same effects persisted (p ≤ 0.001).
CONCLUSION
Increasing orthostatic column height by changing posture independently increases resting cfPWV, concurrent with increases in BP. This data demonstrates the impact of body position on measures of central artery stiffness, which may have clinical relevance.
Topics: Adult; Arterial Pressure; Carotid-Femoral Pulse Wave Velocity; Female; Head-Down Tilt; Humans; Male; Patient Positioning; Posture; Predictive Value of Tests; Reproducibility of Results; Sex Factors; Supine Position; Tilt-Table Test; Vascular Stiffness; Young Adult
PubMed: 32235116
DOI: 10.1159/000506351 -
The Cochrane Database of Systematic... Nov 2016In patients of various ages undergoing mechanical ventilation (MV), it has been observed that positions other than the standard supine position, such as the prone... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
In patients of various ages undergoing mechanical ventilation (MV), it has been observed that positions other than the standard supine position, such as the prone position, may improve respiratory parameters. The benefits of these positions have not been clearly defined for critically ill newborns receiving MV.This is an update of a review first published in 2005 and last updated in 2013.
OBJECTIVES
Primary objectiveTo assess the effects of different positioning of newborn infants receiving MV (supine vs prone, lateral decubitus or quarter turn from prone) in improving short-term respiratory outcomes. Secondary objectiveTo assess the effects of different positioning of newborn infants receiving MV on mortality and neuromotor and developmental outcomes over the long term, and on other complications of prematurity.
SEARCH METHODS
We used the standard search strategy of the Cochrane Neonatal Review Group to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 8), MEDLINE via PubMed (1966 to 22 August 2016), Embase (1980 to 22 August 2016) and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to 22 August 2016). We also searched clinical trials databases, conference proceedings and reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.
SELECTION CRITERIA
Randomised and quasi-randomised clinical trials comparing different positions in newborns receiving mechanical ventilation.
DATA COLLECTION AND ANALYSIS
Three unblinded review authors independently assessed trials for inclusion in the review and extracted study data. We used standard methodological procedures as expected by The Cochrane Collaboration and assessed the quality of the evidence using the GRADE approach. If the meta-analysis was not appropriate owing to substantial clinical heterogeneity between trials, we presented review findings in narrative format.
MAIN RESULTS
We included in this review 19 trials involving 516 participants. Seven of the included studies (N = 222) had not been evaluated in the previous review. Investigators compared several positions: prone versus supine, prone alternant versus supine, prone versus lateral right, lateral right versus supine, lateral left versus supine, lateral alternant versus supine, lateral right versus lateral left, quarter turn from prone versus supine, quarter turn from prone versus prone and good lung dependent versus good lung uppermost.Apart from two studies that compared lateral alternant versus supine, one comparing lateral right versus supine and two comparing prone or prone alternant versus the supine position, all included studies had a cross-over design. In five studies, infants were ventilated with continuous positive airway pressure (CPAP); in the other studies, infants were treated with conventional ventilation (CV).Risks of bias did not differ substantially for different comparisons and outcomes. This update detects a moderate to high grade of inconsistency, similar to previous versions. However, for the analysed outcomes, the direction of effect was the same in all studies. Therefore, we consider that this inconsistency had little effect on the conclusions of the meta-analysis. When comparing prone versus supine position, we observed an increase in arterial oxygen tension (PO) in the prone position (mean difference (MD) 5.49 mmHg, 95% confidence interval (CI) 2.92 to 8.05 mmHg; three trials; 116 participants; I= 0). When percent haemoglobin oxygen saturation was measured with pulse oximetry (SpO), improvement in the prone position was between 1.13% and 3.24% (typical effect based on nine trials with 154 participants; I= 89%). The subgroup ventilated with CPAP (three trials; 59 participants) showed a trend towards improving SpO2 in the prone position compared with the supine position, although the mean difference (1.91%) was not significant (95% CI -1.14 to 4.97) and heterogeneity was extreme (I= 95%).Sensitivity analyses restricted to studies with low risk of selection bias showed homogeneous results and verified a small but significant effect (MD 0.64, 95% CI 0.26 to 1.02; four trials; 92 participants; I= 0).We also noted a slight improvement in the number of episodes of desaturation; it was not possible to establish whether this effect continued once the intervention was stopped. Investigators studied few adverse effects from the interventions in sufficient detail. Two studies analysed tracheal cultures of neonates after five days on MV, reporting lower bacterial colonisation in the alternating lateral position than in the supine posture. Other effects - positive or negative - cannot be excluded in light of the relatively small numbers of neonates studied.
AUTHORS' CONCLUSIONS
This update of our last review in 2013 supports previous conclusions. Evidence of low to moderate quality favours the prone position for slightly improved oxygenation in neonates undergoing mechanical ventilation. However, we found no evidence to suggest that particular body positions during mechanical ventilation of the neonate are effective in producing sustained and clinically relevant improvement.
Topics: Humans; Infant, Newborn; Oxygen; Patient Positioning; Prone Position; Randomized Controlled Trials as Topic; Respiration, Artificial; Supine Position
PubMed: 27819747
DOI: 10.1002/14651858.CD003668.pub4 -
Revista Brasileira de Terapia Intensiva 2019Evaluate the physiological and autonomic nervous system responses of premature newborns to body position and noise in the neonatal intensive care unit.
OBJECTIVE
Evaluate the physiological and autonomic nervous system responses of premature newborns to body position and noise in the neonatal intensive care unit.
METHODS
A quasi-experimental study. The autonomic nervous system of newborns was evaluated based on heart rate variability when the newborns were exposed to environmental noise and placed in different positions: supine without support, supine with manual restraint and prone.
RESULTS
Fifty premature newborns were evaluated (gestational age: 32.6 ± 2.3 weeks; weight: 1816 ± 493g; and Brazelton sleep/awake level: 3 to 4). A positive correlation was found between environmental noise and sympathetic activity (R = 0.27, p = 0.04). The mean environmental noise was 53 ± 14dB. The heart rate was higher in the supine position than in the manual restraint and prone positions (148.7 ± 21.6, 141.9 ± 16 and 144 ± 13, respectively) (p = 0.001). Sympathetic activity, represented by a low frequency index, was higher in the supine position (p < 0.05) than in the other positions, and parasympathetic activity (high frequency, root mean square of the sum of differences between normal adjacent mean R-R interval and percentage of adjacent iRR that differed by more than 50ms) was higher in the prone position (p < 0.05) than in the other positions. The complexity of the autonomic adjustments (approximate entropy and sample entropy) was lower in the supine position than in the other positions.
CONCLUSION
The prone position and manual restraint position increased both parasympathetic activity and the complexity of autonomic adjustments in comparison to the supine position, even in the presence of higher environmental noise than the recommended level, which tends to increase sympathetic activity.
Topics: Autonomic Nervous System; Female; Heart Rate; Humans; Infant, Newborn; Infant, Premature; Intensive Care Units, Neonatal; Male; Noise; Patient Positioning; Prone Position; Prospective Studies
PubMed: 31618347
DOI: 10.5935/0103-507X.20190054