Facilitators & barriers and practices of early mobilization in critically ill burn patients: A survey.

BACKGROUND: Early mobilization (EM) of intensive care (IC) patients is important but complex with facilitators and barriers. Compared to general IC patients, burn IC patients are more hyper-metabolic. They have extensive wounds, lengthy wound dressing changes, and repeated surgeries that may affect possibilities of EM. This study aimed to identify facilitators and barriers of EM in burn IC patients among all disciplines involved. Additionally, we assessed EM practices, i.e. when are which patients considered suitable for EM. METHODS: A survey was sent to 139 professionals involved in EM of burn IC patients (discipline groups: Intensivists, medical doctors, registered nurses, therapists). RESULTS: Response rate was 57 %. The majority found EM very important, yet different definitions were chosen. Perceived barriers mainly concerned patient-level factors, most frequently hemodynamic instability and excessive sedation followed by skin graft surgery, fatigue, and pain management. Most frequent barriers at the provider-level were limited staffing, safety concerns, and conflicting perceptions about the suitability of EM. At the institutional-level, we found no high barriers. Interdisciplinary variation on perceived barriers, when to initiate it, and permitted maximal activity were ascertained. CONCLUSION: Skin grafts and pain management were barriers of EM specific for burn care. Opinions on frequency, dosage and duration of EM varied widely. Improving interdisciplinary communication is key.

Joint flexibility problems and the impact of its operationalisation.

BACKGROUND: Dissatisfaction is being voiced with the generally used way joint flexibility problems are defined (operationalised), i.e. as a range of motion (ROM) one or more degrees lower than normative ROM of healthy subjects. Other, specifically more function-related operationalisations have been proposed. The current study evaluated the effect of applying different operationalisations of joint flexibility problems on its prevalence. METHOD: ROM data of 95 joints affected by burns of 23 children were used, and data on 18 functional activities (Burn Outcome Questionnaire (BOQ)). Five methods were used to operationalise joint flexibility problems: (1) ROM below normative ROM, (2) ROM below normative ROM minus 1SD, (3) ROM below normative ROM minus 2SD, (4) ROM below functional ROM, and (5) a score of 2 or more on the Likert Scale (BOQ). RESULTS: Prevalence of joint flexibility problems on a group level ranged from 13 to 100% depending on the operationalisation used. Per joint and movement direction, prevalence ranged from 40% to 100% (Method 1) and 0% to 80% (Methods 2-4). 18% of the children received '2' on the Likert Scale (Method 5). CONCLUSION: The operationalisation of joint flexibility problems substantially influences prevalence, both on group and joint level. Changing to a function-related operationalisation seems valuable; however, international consensus is required regarding its adoption. TRIAL REGISTRATION: The study is registered in the National Academic Research and Collaborations Information System of the Netherlands (OND1348800).

Shoulder and elbow range of motion for the performance of activities of daily living: A systematic review.

The loss of range of motion (ROM) in the upper extremities can interfere with activities of daily living (ADL) and, therefore, many interventions focus on improving impaired ROM. The question, however, is what joint angles are needed to naturally perform ADL. The present review aimed to compile and synthesize data from literature on shoulder and elbow angles that unimpaired participants used when performing ADL tasks. A search was conducted in PubMed, Cochrane, Scopus, CINAHL, and PEDro. Studies were eligible when shoulder (flexion, extension, abduction, adduction) and/or elbow (flexion, extension) angles were measured in unimpaired participants who were naturally performing ADL tasks, and angles were provided per task. Thirty-six studies involving a total of 66 ADL tasks were included. Results demonstrated that unimpaired participants used up to full elbow flexion (150°) in personal care, eating, and drinking tasks. For shoulder flexion and abduction approximately 130° was necessary. Specific ADL tasks were measured often, however, almost never for tasks such as dressing. The synthesized information can be used to interpret impairments on the individual level and to establish rehabilitation goals in terms of function and prevention of secondary conditions due to excessive use of compensatory movements.

The effect of the height to which the hand is lifted on horizontal curvature in horizontal point-to-point movements.

In point-to-point reaching movements, the trajectory of the fingertip along the horizontal plane is not completely straight but slightly curved sideward. The current paper examines whether this horizontal curvature is related to the height to which the finger is lifted. Previous research suggested that the height to which the hand is lifted might be a determinant of horizontal curvature. We asked participants to make point-to-point movements in three conditions: constrained movements (i.e., fingertip keeps contact with table top) over vertically curved surfaces that differed in height, constrained movements over a flat surface, and unconstrained movements (i.e., fingertip lifted from table top). In constrained movements, we found a strong relation between horizontal curvature and lifted height of the finger. Interestingly, for unconstrained movements, the relation between horizontal curvature and height to which the finger was lifted was weak. This demonstrates that the height to which the finger was lifted relates to horizontal curvature in some, but not in all conditions. This suggests that the height to which the hand is lifted should be included, in particular for constrained movements, when giving a full account of horizontal curvature in point-to-point movements.

Direct projections from the sacral spinal cord to the medial preoptic area in cat and guinea pig.

The medial preoptic area (MPO) plays an important role in many behavioral, autonomic and endocrine functions, including micturition and genital responses. Although afferents of the MPO have been studied extensively, it is unknown whether direct lumbosacral-MPO projections exist that could convey afferent information from the pelvic organs. We hypothesized that, if such direct projections exist, MPO projecting cells would be located in the lateral part of the sacral cord, where primary afferents from pelvic and pudendal nerves terminate. We used retro- and anterograde tracing techniques in cat and guinea pig to study this. In cats, injections in the MPO resulted in labeled cells throughout the spinal cord, but with the highest density in the S1-S2 segments. In guinea pigs, labeled cells were found exclusively in the S1-S3 segments after MPO injections. Labeled cells in the sacral segments were not located in the lateral parts of the gray matter, but were found in the medial laminae VI-VII and dorsal lamina VIII in cats, and mainly in lamina X in guinea pigs. Anterograde tracing results after injections in the sacral cord in cats or guinea pigs showed labeled fibers in the MPO, just ventral to the anterior commissure. The central location of the cells of origin within the sacral cord, together with the termination pattern of the spino-MPO projections, strongly suggest a role for the spino-MPO pathway in the sensory relay of pelvic viscera, important for micturition and genital responses.

Estrous cycle-dependent neural plasticity in the caudal brainstem in the female golden hamster: ultrastructural and immunocytochemical studies of axo-dendritic relationships and dynamic remodeling.

UNLABELLED: During the short four-day estrous cycle of the female hamster various behavioral (lordosis, vocalization and aggression) and autonomic adaptations occur. Presumably, these changes are under ovarian control. Recently, we described a distinct estrogen receptor-alpha immunoreactive (ER-alpha-IR) cell group, now called nucleus para-retroambiguus (NPRA), in the caudal ventrolateral medulla (Gerrits et al., 2008). Neurons of this group project to the ipsilateral intermediolateral cell column in the thoracic and upper lumbar cord. Clearly, the NPRA is part of an estrogen-sensitive neuronal network and the same applies to the region containing the commissural part of the solitary tract nucleus (NTScom) and the A2 group, here called NTScom/A2. Estrogen is known to modulate neuronal ultrastructure in various brain areas and spinal cord, but not in the caudal brainstem. Because we assumed that the NPRA plays a role in estrous cycle related adaptations, we hypothesized the occurrence of plasticity in this nucleus. In the present study we examined morphological changes of axo-dendritic relationships in NPRA and NTScom/A2 in estrous, diestrous and ovariectomized (OVX) hamsters, using immuno-electron microscopy and the 1D5 anti-ER-alpha antibody. Ultrastructural analysis revealed that the ratio "axon terminals surface/dendrite surface" was significantly increased in both the NPRA and NTScom/A2 during the estrous phase compared to the OVX and diestrous conditions. Remodeling of axon terminals due to axonal sprouting into large terminal fields filled up with pleomorphic vesicles resulted in contacts with more dendrites, and was the main cause for the "axonal terminal-dendritic-ratio" shift. IN CONCLUSION: Estrous cycle-induced axonal and dendritic plasticity is present in the NPRA, and in the NTScom/A2 group. Our findings support our hypothesis that estrogen-sensitive neuronal networks in the caudal brainstem display structural plasticity, probably to modulate steroid hormone dependent behaviors or autonomic adaptations.

The nucleus para-retroambiguus: a new group of estrogen receptive cells in the caudal ventrolateral medulla of the female golden hamster.

Receptive female hamsters display very rigid lordotic postures. Estradiol facilitates this behavior via activation of estrogen receptors. In the hamster brainstem estrogen receptor-alpha-immunoreactive neurons (ER-alpha-IR) are present in various brainstem regions including nucleus retroambiguus (NRA) in the caudal ventrolateral medulla (CVLM) and nucleus of the solitary tract. ER-alpha-IR neurons in the CVLM project to the thoracic and upper lumbar cord. However, A1 neurons in this region do not project to the spinal cord, in contrast to overlapping C1 neurons. The question now arises: are ER-alpha-IR cells in the CVLM part of the A1/C1 group, or do they belong to the NRA or do they compose a separate cluster. A study in ovariectomized female hamsters using a combination of double immunostaining and retrograde tracing techniques and measurement of soma diameters was carried out. The results showed that A1/C1 neurons in the CVLM are almost never ER-alpha-positive; neurons inside or bordering the NRA can be divided in two different types: large multipolar and small; the large NRA-neurons, projecting caudally, are neither tyrosine hydroxylase- (TH) nor ER-alpha-IR; the small neurons, bordering the NRA and projecting caudally, are ER-alpha-IR but not TH-IR. From the available evidence and the present findings it can be concluded that the group of small ER-alpha-IR neurons in the CVLM has to be considered as a distinct entity, probably involved in the autonomic physiological changes concurring with successive phases of the estrous cycle. Because the location is closely related to the NRA itself the nucleus is called nucleus para-retroambiguus, abbreviated (NPRA).

In cat four times as many lamina I neurons project to the parabrachial nuclei and twice as many to the periaqueductal gray as to the thalamus.

The spinothalamic tract, and especially its fibers originating in lamina I, is the best known pathway for transmission of nociceptive information. On the other hand, different studies have suggested that more lamina I cells project to the parabrachial nuclei (PBN) and periaqueductal gray (PAG) than to the thalamus. The exact ratio of the number of lamina I projections to PBN, PAG and thalamus is not known, because comprehensive studies examining these three projections from all spinal segments, using the same tracers and counting methods, do not exist. In the present study, the differences in number and distribution of retrogradely labeled lamina I cells in each segment of the cat spinal cord (C1-Coc2) were determined after large wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP) injections in either PBN, PAG or thalamus. We estimate that approximately 6000 lamina I cells project to PBN, 3000 to PAG and less than 1500 to the thalamus. Of the lamina I cells projecting to thalamus or PAG more than 80%, and of the lamina I-PBN cells approximately 60%, were located on the contralateral side. In all cases, most labeled lamina I cells were found in the upper two cervical segments and in the cervical and lumbar enlargements.

How many spinothalamic tract cells are there? A retrograde tracing study in cat.

The spinothalamic tract, well known for its role in nociception, is the most frequently studied ascending pathway originating from the spinal cord. It is known that spinothalamic neurons are located in all segments of the spinal cord, but in most mammals the total number of spinothalamic neurons is not known. In three cats, after large wheat germ agglutinin-conjugated horseradish peroxidase injections involving all parts (one case) or almost all parts of the thalamus (two cases), the number of retrogradely labeled profiles was counted in a 1:4 series of sections of all spinal segments from C1 to Coc2. After applying the correction factor of Abercrombie (Anat. Rec. 94 (1946) 239), it appears that a total of 12,000 cells in the spinal cord project to the thalamus.

Less than 15% of the spinothalamic fibers originate from neurons in lamina I in cat.

Lamina I neurons sending their axons into the spinothalamic tract are thought to play a crucial role in nociception, but many spinothalamic fibers do not originate from lamina I neurons. In cat, no consensus exists about what percentage of the spinothalamic tract cells are located in lamina I. After wheat germ agglutinin-conjugated horseradish peroxidase injections that covered large parts of the thalamus, retrogradely labeled cells were plotted and counted in all segments of the spinal cord. Results show that, averaged over all spinal segments, the percentage of labeled lamina I neurons was 4.9-14.2%. These results demonstrate that, in contrast to what is concluded in several previous studies, lamina I in the cat provides only a limited part of the total spinal input to the thalamus.

Lamina I-periaqueductal gray (PAG) projections represent only a limited part of the total spinal and caudal medullary input to the PAG in the cat.

The periaqueductal gray is well known for its involvement in nociception control, but it also plays an important role in the emotional motor system. To accomplish these functions the periaqueductal gray receives input from the limbic system and from the caudal brainstem and spinal cord. Earlier studies gave the impression that the majority of the periaqueductal gray projecting cells in caudal brainstem and spinal cord are located in the contralateral lamina I, which is involved in nociception. The present study in the cat, however, demonstrates that of all periaqueductal gray projecting neurons in the contralateral caudal medulla less than 7% was located in lamina I. Of the spinal periaqueductal gray projecting neurons less than 29% was located in lamina I. However, within the spinal cord large segmental differences exist: in few segments of the enlargements the lamina I-periaqueductal gray projecting neurons represent a majority. In conclusion, although the lamina I-periaqueductal gray projection is a very important nociceptive pathway, it constitutes only a limited part of the total projection from the caudal medulla and spinal cord to the periaqueductal gray. These results suggest that a large portion of the medullo- and spino-periaqueductal gray pathways conveys information other than nociception.

Segmental and laminar organization of the spinal neurons projecting to the periaqueductal gray (PAG) in the cat suggests the existence of at least five separate clusters of spino-PAG neurons.

The present retrograde tracing study in the cat describes the spinal cord projections to the periaqueductal gray (PAG), taking into account different regions of the PAG and all spinal segments. Results show that injecting different parts of the PAG leads to different laminar and segmental distributions of labeled spinal neurons. The impression was gained that at least five separate clusters of spinal neurons exist. Cluster I neurons are found in laminae I and V throughout the length of the cord and are probably involved in relaying nociceptive information to the PAG. Cluster II neurons lie in the ventrolateral part of laminae VI-VII of the C1-C4 spinal cord and were labeled by injecting the ventrolateral or lateral part of the rostrocaudal PAG or the deep tectum. Cluster III neurons are located in lamina X of the thoracic and upper lumbar cord and seem to target the PAG and the deep tectum. Cluster IV neurons are located in the medial part of laminae VI-VII of the lumbosacral cord and seem to project predominantly to the lateral and ventrolateral caudal PAG. These neurons may play a role in conveying tactile stimuli to the PAG during mating behavior. Neurons of cluster V are located in the lateral part of lamina I of L6-S2 and in laminae V-VII and X of S1-S3. They are labeled only after injections into the central portion of the lateral and ventrolateral caudal PAG and probably relay information concerning micturition and mating behavior.

Three times as many lamina I neurons project to the periaqueductal gray than to the thalamus: a retrograde tracing study in the cat.

The number and distribution of lamina I neurons projecting to the periaqueductal gray (PAG) were examined by a retrograde tracing study in the cat. WGA-HRP injections in the intermediate and caudal PAG resulted in as much as 1600 labeled lamina I neurons throughout the length of the spinal cord, counted in a 1:4 series of sections. The lamina I-PAG projection was predominantly contralateral and most labeled lamina I neurons were found in the enlargements. Comparing these results with the number of lamina I-thalamic neurons leads to the conclusion that in the cat about three times as many lamina I neurons project to the PAG than to the thalamus. Considering this, one can conclude that the spino-PAG system is a virtually neglected area in pain research.

Large segmental differences in the spinal projections to the periaqueductal gray in the cat.

The periaqueductal gray (PAG) is involved in motor activities, such as movements of the neck, back and hind limbs, cardiovascular regulation, micturition, vocalization, and mating behavior, as well as in nociception control. To accomplish these functions the PAG uses information from other parts of the limbic system, from the lower brainstem, and from the spinal cord. To study the ascending projections from the spinal cord to the PAG, tracer was injected in different parts of the PAG, and the number of retrogradely labeled neurons were counted for each spinal segment. Results show that large segmental differences exist in the number of PAG projecting neurons throughout the length of the spinal cord and that different parts of the spinal cord project to specific areas in the PAG.

Distinct cell groups in the lumbosacral cord of the cat project to different areas in the periaqueductal gray.

The periaqueductal gray (PAG) is involved in aggressive and defensive behavior, micturition, and lordosis. Especially for the latter two functions, PAG afferents from the lumbosacral cord are of vital importance because, in addition to information regarding homeostasis and thermoregulation, they convey information from the pelvic viscera and sex organs. In the present retro- and antero-grade tracing study, the projection patterns of different lumbosacral cell groups in the PAG were determined. In the retrograde study, wheatgerm agglutinin-horseradish peroxidase (WGA-HRP) injections were made in the PAG and/or adjacent tegmentum, and in the anterograde study, WGA-HRP was injected in different lumbosacral segments. The results revealed that lumbosacral-PAG neurons could be divided into three groups. The first and largest group was present in lumbar 7-sacral 3 segments (L7-S3) and consisted of small, oval, and fusiform neurons. It extended from the dorsolateral part of lamina I in L7, along the lateral part of the dorsal horn in S1, and into lamina V of S2. In the lateral part of S2, some of its neurons formed clusters with intervals of +/- 230 microns. The location of the first group overlapped extensively with the termination area of pelvic and pudendal afferents. The main midbrain target of the first group was the medial part of the lateral PAG. The second group consisted of small to large multipolar neurons in laminae VIII and medial VII of caudal L6, L7, and rostral S1. This group projected strongly to a distinct region in the lateral part of the lateral PAG and the laterally adjacent tegmentum. About 10% of the labeled neurons did not fit in the two groups. They were evenly distributed throughout lumbar 4-coccygeal 3 segments (L4-Co3) and consisted of large multipolar lamina V neurons and small lamina I neurons that projected diffusely to the lateral and dorsal PAG. The large lamina V neurons also targeted the laterally adjacent tegmentum. The possible involvement of the lumbosacral-PAG projections in micturition, lordosis, and defensive and aggressive behavior is discussed.

Dorsal border periaqueductal gray neurons project to the area directly adjacent to the central canal ependyma of the C4-T8 spinal cord in the cat.

In a previous study horseradish peroxidase (HRP) injections in the upper thoracic and cervical spinal cord revealed some faintly labeled small neurons at the dorsal border of the periaqueductal gray (PAG). The present light microscopic and electronmicroscopic tracing study describes the precise location of these dorsal border PAG-spinal neurons and their terminal organization. Wheat germ agglutinin-conjugated HRP (WGA-HRP) injections into cervical and upper thoracic spinal segments resulted in several hundreds of small retrogradely labeled neurons at the dorsal border of the ipsilateral caudal PAG. These neurons were not found after injections in more caudal segments. WGA-HRP injections in the dorsal border PAG region surprisingly resulted in anterogradely labeled fibers terminating in the area dorsally and laterally adjoining the central canal ependyma of the C4-T8 spinal cord. No anterogradely labeled fibers were found more caudal in the spinal cord. The labeled fibers found in the upper cervical cord were not located in the area immediately adjoining the ependymal layer of the central canal, but in the lateral part of laminae VI, VII and VIII and in area X bilaterally. Electronmicroscopic results of one case show that the dorsal border PAG-spinal neurons terminate in the neuropil of the subependymal area and in the vicinity of the basal membranes of capillaries located laterally to the central canal. The terminal profiles contain electron-lucent and densecored vesicles, suggesting a heterogeneity of possible transmitters. A striking observation was the lack of synaptic contacts, suggesting nonsynaptic release from the profiles. The function of the dorsal border PAG-spinal projection is unknown, but considering the termination pattern of the dorsal border PAG neurons on the capillaries the intriguing similarity between this projection system and the hypothalamohypophysial system is discussed.

The periaqueductal gray in the cat projects to lamina VIII and the medial part of lamina VII throughout the length of the spinal cord.

The periaqueductal gray (PAG) plays an important role in analgesia as well as in motor activities, such as vocalization, cardiovascular changes, and movements of the neck, back, and hind limbs. Although the anatomical pathways for vocalization and cardiovascular control are rather well understood, this is not the case for the pathways controlling the neck, back, and hind limb movements. This led us to study the direct projections from the PAG to the spinal cord in the cat. In a retrograde tracing study horseradish peroxidase (HRP) was injected into different spinal levels, which resulted in large HRP-labeled neurons in the lateral and ventrolateral PAG and the adjacent mesencephalic tegmentum. Even after an injection in the S2 spinal segment a few of these large neurons were found in the PAG. Wheat germ agglutinin-conjugated HRP injections in the ventrolateral and lateral PAG resulted in anterogradely labeled fibers descending through the ventromedial, ventral, and lateral funiculi. These fibers terminated in lamina VIII and the medial part of lamina VII of the caudal cervical, thoracic, lumbar, and sacral spinal cord. Interneurons in these laminae have been demonstrated to project to axial and proximal muscle motoneurons. The strongest PAG-spinal projections were to the upper cervical cord, where the fibers terminated in the lateral parts of the intermediate zone (laminae V, VII, and the dorsal part of lamina VIII). These laminae contain the premotor interneurons of the neck muscles. This distribution pattern suggests that the PAG-spinal pathway is involved in the control of neck and back movements. Comparing the location of the PAG-spinal neurons with the results of stimulation experiments leads to the supposition that the PAG-spinal neurons play a role in the control of the axial musculature during threat display.

Influence of posture on the relation between surface electromyogram amplitude and back muscle moment: consequences for the use of surface electromyogram to measure back load.

The aim of the study was to analyse the effect of posture on the relation between EMG amplitude and moment of the back muscles in different subjects, in order to gain a better insight into the possibilities of EMG as a means of measuring individual back load. Eight healthy subjects participated in the experiments. Isometric back extensions were performed in three postures: upright standing, standing with the spine flexed, and upright sitting. In each posture the lumbar moments of three maximal voluntary contractions were measured and then exertions of 10 to 90% of maximal voluntary contraction (increments of 10) were performed. EMG signals from the back muscles were recorded with four pairs of surface electrodes located 3 cm and 6 cm lateral to the midline of the spine at the L3 level. EMG signals were full-wave rectified and averaged over 2 s intervals of constant moment. The results show that posture has a considerable influence on the relationship between EMG and the lumbar moment. Besides this, large individual differences and an influence of electrode position on the relationship were found. Therefore it is concluded that whenever EMG is to be used as a means to measure individual back load, a calibration of the EMG amplitude to lumbar moment ratio is necessary for each subject, each electrode position, and each posture. Interpretation of EMG amplitudes has to be done on an individual basis and taking influences of posture and electrode location on the EMG-lumbar moment relationship into account.