Hammock Positioning's Influence on the Electromyographic Activity in the Flexor Muscles in Newborn Preterm

Overview

The individual who is born premature, in addition to a CNS still in accelerated training suffers early loss of intrauterine restraint, conditions that promote hypotonia characteristic of premature birth. Given this hypotonia associated with musculoskeletal immaturity when improperly positioned in the incubator for an extended period, the PN can develop joint contractures and postural imbalances that, in most cases, are transitory, however can become persistent, causing delay in their Motor development. The aim of this study is to analyze the influence of the positioning of preterm infants in the incubator hammock on the tone and the myoelectric activity of the rectus abdominis flexor muscles, biceps and hamstrings. Study type controlled, randomized, double-blind, to be carried out from November 2015 to April 2016 will be obtained two groups, control (in containment nest "U") and experimental (with hammock) to from randomized samples with premature births in Barao de Lucena Hospital or the Hospital das Clinicas, UFPE, the Intermediate Care Units (ICU) Neonatal. The sample will consist of 30 premature. To collect, pulse oximeter will be used, electromyography, neurological testing Dubowitz and recording behavioral responses. Each baby will be accompanied for about 8 hours daytime placement for two days and three evaluations performed.

The study population will consist of moderately preterm newborns, attended by SUS, admitted to the NICU of HBL or HC UFPE. From randomized samples with preterm infants born in the HBL or HC, and are admitted to the NICU, will be obtained two groups, one for positioning in hammock (experimental group) and the other in incubator containment nest "U" ( group control). The sample will consist of 30 premature babies, 15 in each group. The allocation of the PN is made in two blocks, using the site randomization.com, so that the block 1 corresponds to the group with hammock and positioning block 2, the group subjected to the usual positioning in the incubator, which at the study site it is "containment nest in U". The recruitment of premature will be conducted by researcher 1, which will identify premature the NICU potentially eligible for the study, invite the parents or guardians to sign the consent form and clear, and then make the screening (inclusion) of the truly eligible babies after filling in a checklist of eligibility criteria, always registering why exclude the other. Then, the PN will be wrapped in a sheet and carried by the investigator 1 to the support area of neonatal sector, located within the NICU, and where they will be placed on the counter, a mattress (incubator) and electromyography to carry out the assessments. Since each premature will be submitted to reviews of protocol only when alert according to the state 4 or 5 (warning with little activity and alert to activity) of the Brazelton scale, evaluations will be carried out between meals, avoiding the baby stay angry or sleepy. This procedure will be followed regardless of the position that the baby will be submitted later. In the event, the evaluation will be interrupted, and the baby will be taken back to the incubator, receiving the assistance that is required, and will be excluded from the study. The electromyographic and clinical evaluations will be conducted by researcher 1, preventing the masking at this stage. The results obtained in the evaluations (global posture, gathering maneuvers arm and popliteal angle, via video recording, and the electromyographic signal) will be analyzed by researchers 2 and 3, blind research. The EMG will be made via a portable electromyography surface mark with four channels, which will be connected to a laptop, and double electrode surface, specially developed for use in EMG, disposable, adhesive gel Ag conductor / AgCl, intended for clinical and research use. According to SENIAM recommendations (EMG Surface European consortium for the Non-Invasive Assessment of Muscles), the pads will be fixed between the motor point and the tendon of the flexor muscles: rectus abdominis, biceps and hamstrings, and the electrode reference on the left lateral malleolus. Three channels will be used to record the electrical activity unilateral (right of all PN) and simultaneously in the three above-mentioned places, so that the spontaneous muscle activity baby is captured under the same conditions. The PTN will be submitted for evaluation by surface EMG while simultaneously performed the clinical evaluation of tone with the neurological test Dubowitz. It will only be applied to size of that test by referring to the tone match the focus of this research, and only the chosen sub-items that do not require much manipulation premature. These sub-items refer to the observation of global postural baby standard (which observe the legs and the upper to the trunk in the supine position), the arms collection operation (in which it analyzes the by rapid extension muscle strength elbow, and elbow flexion speed and angle he takes after three seconds long maintained the elbow), and popliteal angle (baby knee is positioned over the abdomen and exercises to gentle pressure with the index finger behind the ankle in order to increase the popliteal angle, the maximum angle observing obtained. Test up one leg at a time). Thus, after placement of the electrodes, it will initially be observed and recorded the signal picked up by EMG of the rectus abdominis muscles, biceps and hamstrings for 30 seconds, representing the muscle tone baby home. Simultaneously to this first record in the EMG, the researcher will make the clinical evaluation of the tone by observing the posture of premature standard. Then, still using the EMG in association with the Dubowitz Test, evaluation of the maneuvers of the popliteal angle and gathering arms are made that lead to be performed 30 seconds each. Similarly, in parallel to this clinical evaluation of tone, will be made in the records EMG muscle activity of the biceps and hamstrings related to muscle resistance to stretching caused the Dubowitz test. All evaluations of muscle activity (EMG and clinical) will be recorded on video using a digital camera Sony® brand (model 1000 Cyber Shot 7.2 Mega Pixels), attached to a tripod positioned in order to capture the image of the entire PN body, so researchers can analyze 2 and 3 evaluation results, but also so that we can resolve any doubt about the future evaluations. After the evaluations, the researcher first position the PN in hammock or incubator containment nest "U", according to the randomization envelope content to it corresonding. The hammock was made of knitted fabric (100% cotton) for improved tactile comfort and prevent allergic reactions in the baby, and its dimensions follow the determinations that are in the process of patenting requested by Roberta Tenorio and Roberta Bione the National Institute of Industrial Property (INPI) in 2014, with number 19140000184 protocol and order number BR 20 2014 017 809 6. In the control group, the position will follow the routine procedure of HBL and HC, which is the use of containment nests "U" , made with rolled sheet placed on the mattress of the incubator and covered by another sheet. To identify if there was adaptation of premature positioning, physiological parameters (RR, HR and SaO2) and motor behavior (approach reactions and Withdrawal) shall be observed and recorded 5 minutes before the positioning in the hammock or incubators containment nest "U" immediately following (1 minute), after 5minutes and 10 minutes. The behavioral state of the newborn will be given by the presence or absence of specific movements welfare indicators (Approach reactions - hands to her mouth / face, holding hands, gripping motion, curling up on itself); and specific movements of stress indicators (Withdrawal reactions - aircraft wing, greeting, removal of the fingers, sitting in the air, arching). If the baby does not display any of these reactions at predefined times, the comfort will be checked only by physiological indicators. HR and SaO2 will be obtained by the pulse oximeter, and the FR will be obtained by the number of breaths per minute count made by the researcher 1. In order to detect any complications during the positioning, continuous monitoring of physiological parameters will be baby both by the researcher as one by the nursing staff of the NICU as routine neonatal sector. If there apnea situations, desaturation or no adjustment to the positioning in the hammock, the baby will be removed from this position and use the hammock will be discontinued, but should be placed in an incubator with containment nest "U" (routine neonatal HBL sector and HC), excluding the study of preterm infants and considering it as sample loss. The first stage assessment will be before the positioning, being named T0. At the end of about 8 positioning daylight hours, babies are taken from the hammock, being positioned according to routine neonatal sector (in containment nest "U" in the incubator) for the nighttime. All of the protocol tone evaluations will also be repeated the next day, 24 hours after the beginning of the positioning, both for the group that was placed in the hammock in the group that was placed in the incubator containment nest "U". This second assessment will be called T1. Again, after about 8 hours of daytime position, the baby will be removed from the hammock or position "U" for the nighttime. The final evaluation will take place the next morning, approximately 48 hours after the start of positioning hammock or containment nest, a time called T2. Also, all revaluations will be filmed for any questions that may arise.