Selective Paralysis Research Articles

Adaptation after vastus lateralis denervation in rats demonstrates neural regulation of joint stresses and strains.

In order to produce movements, muscles must act through joints. The translation from muscle force to limb movement is mediated by internal joint structures that permit movement in some directions but constrain it in others. Although muscle forces acting against constrained directions will not affect limb movements, such forces can cause excess stresses and strains in joint structures, leading to pain or injury. In this study, we hypothesized that the central nervous system (CNS) chooses muscle activations to avoid excessive joint stresses and strains. We evaluated this hypothesis by examining adaptation strategies after selective paralysis of a muscle acting at the rat's knee. We show that the CNS compromises between restoration of task performance and regulation of joint stresses and strains. These results have significant implications to our understanding of the neural control of movements, suggesting that common theories emphasizing task performance are insufficient to explain muscle activations during behaviors.

Astrocyte Depletion Impairs Redox Homeostasis and Triggers Neuronal Loss in the Adult CNS.

Although the importance of reactive astrocytes during CNS pathology is well established, the function of astroglia in adult CNS homeostasis is less well understood. With the use of conditional, astrocyte-restricted protein synthesis termination, we found that selective paralysis of GFAP(+) astrocytes in vivo led to rapid neuronal cell loss and severe motor deficits. This occurred while structural astroglial support still persisted and in the absence of any major microvascular damage. Whereas loss of astrocyte function did lead to microglial activation, this had no impact on the neuronal loss and clinical decline. Neuronal injury was caused by oxidative stress resulting from the reduced redox scavenging capability of dysfunctional astrocytes and could be prevented by the in vivo treatment with scavengers of reactive oxygen and nitrogen species (ROS/RNS). Our results suggest that the subpopulation of GFAP(+) astrocytes maintain neuronal health by controlling redox homeostasis in the adult CNS.

P72: Selective paralysis of long thoracic nerve with concomitant involvement of the lateral cutaneous nerve of the forearm. An unusual form of Parsonage-Turner syndrome

P72: Selective paralysis of long thoracic nerve with concomitant involvement of the lateral cutaneous nerve of the forearm. An unusual form of Parsonage-Turner syndrome

Botulinum toxin for masseter hypertrophy

Benign masseter muscle hypertrophy is an uncommon clinical phenomenon of uncertain aetiology which is characterised by a soft swelling near the angle of the mandible. The swelling may on occasion be associated with facial pain and can be prominent enough to be considered cosmetically disfiguring. Varying degrees of success have been reported for some of the treatment options for masseter hypertrophy, which range from simple pharmacotherapy to more invasive surgical reduction. Injection of botulinum toxin type A into the masseter muscle is generally considered a less invasive modality and has been advocated for cosmetic sculpting of the lower face. Botulinum toxin type A is a powerful neurotoxin which is produced by the anaerobic organism Clostridium botulinum and when injected into a muscle causes interference with the neurotransmitter mechanism producing selective paralysis and subsequent atrophy of the muscle.This review is an update of a previously published Cochrane review. To assess the efficacy and safety of botulinum toxin type A compared to placebo or no treatment, for the management of benign bilateral masseter hypertrophy. We searched the following databases from inception to April 2013: the Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE (via PubMed); EMBASE (via embase.com); Web of Science; CINAHL; Academic Search Premier (via EBSCOhost); ScienceDirect; LILACS (via BIREME); PubMed Central and Google Scholar (from 1700 to 19 April 2013). We searched two bibliographic databases of regional journals (IndMED and Iranmedex) which were expected to contain relevant trials. We also searched reference lists of relevant articles and contacted investigators to identify additional published and unpublished studies. Randomised controlled trials (RCTs) and controlled clinical trials (CCTs) comparing intra-masseteric injections of botulinum toxin versus placebo administered for cosmetic facial sculpting in individuals of any age with bilateral benign masseter hypertrophy, which had been self-evaluated and confirmed by clinical and radiological examination were considered for inclusion. We excluded participants with unilateral or compensatory contralateral masseter hypertrophy resulting from head and neck radiotherapy. Two review authors independently screened the search results. For future updates, two authors will independently extract data and assess trial quality using the Cochrane risk of bias tool. Risk ratios (RR) and corresponding 95% confidence intervals (CI) will be calculated for all dichotomous outcomes and the mean difference (MD) and 95% CI will be calculated for continuous outcomes. We retrieved 683 unique references to studies. After screening these references 660 were excluded for being non-applicable. We assessed 23 full text articles for eligibility and all of these studies were excluded from the review. We were unable to identify any RCTs or CCTs assessing the efficacy and safety of intra-masseteric injections of botulinum toxin for people with bilateral benign masseter hypertrophy. The absence of high level evidence for the effectiveness of this intervention emphasises the need for well-designed, adequately powered RCTs.

Effects of selective paralysis of the supraspinatus muscle using botulinum neurotoxin a in rotator cuff healing in rats

We hypothesized that a temporary rotator cuff paralysis using botulinum-neurotoxin A (BoNtA) would lead to an improved tendon-to-bone healing after repair of supraspinatus lesions. One hundred sixty Sprague-Dawley rats were randomly assigned to either the BoNtA or the control (saline) group. BoNtA/saline-solution was injected into the supraspinatus muscle 1 week prior to surgery. A supraspinatus defect was made; we distinguished between a lesion with normal and increased repair load. Furthermore, one subgroup had the operated shoulder immobilized in a cast. Histologic analysis and biomechanical testing followed. Specimens from the BoNtA-group, which were treated with an increased repair load, showed less cellularity and more organization in the interface tissue compared to the saline control group. In addition, we found that the collagen 1-3 quotient in the BoNtA specimen was significantly (p = 0.0051) higher than in the control group. Ultimate load at failure between the groups was not significantly different (p > 0.05). We did not observe any significant differences between the mobilized and immobilized specimen (p = 0.2079). The study shows that tendon-to-bone healing after rotator cuff repair can be altered positively using BoNtA pre-operatively. Tears with increased repair load seem to benefit the most-at least histologically.

Treatment of masseteric hypertrophy with botulinum toxin: A report of two cases

Masseter muscle hypertrophy is a rare condition of unknown cause which is important in the differential diagnosis of head and neck masses, located in the cheek. Several treatment options reported for masseter hypertrophy, which range from simple pharmacotherapy to more invasive surgical reduction. Botulinum toxin type A is a powerful neurotoxin which is produced by the anaerobic organism Clostridium botulinum and when injected into a muscle causes interference with the neurotransmitter mechanism producing selective paralysis and subsequent atrophy of the muscle. Injection of botulinum toxin type A into the masseter muscle is generally considered a less invasive modality and has been advocated for cosmetic sculpting of the lower face. Botulinum toxin type A injection is considered to be a beneficial treatment modality in masseter muscle hypertrophy patients. The aim of this article is to report two cases of masseteric muscle hypertrophy which were treated with botulinum toxin type A injection. Marked changes in facial feature were achieved 3 months after the procedure.

Immunolocalization of GQ1b and Related Gangliosides in Human Extraocular Neuromuscular Junctions and Muscle Spindles

To examine the distribution of anti-GQ1b, -GT1a, and -GD1b antibody binding in human extraocular muscles (EOMs), axial and limb muscles, and muscle spindles and thereby test the hypothesis that their distinctive ganglioside composition provides the molecular basis for selective involvement of EOMs and muscle spindles in Miller Fisher syndrome. Muscle samples from adult human EOMs, vastus lateralis, biceps brachii, lumbrical, psoas, and deep muscles of the neck were processed for immunohistochemistry, with monoclonal antibodies against ganglioside GQ1b, GT1a, and GD1b. Neuromuscular junctions (NMJs) were detected by alpha-bungarotoxin binding and by acetyl cholinesterase reaction. Most motor endplates of human EOMs richly bound anti-GQ1b, -GT1a, and -GD1b ganglioside antibodies. Anti-GQ1b, -GT1a, and -GD1b ganglioside antibody bindings to NMJs in human limb and axial muscle were scarce, but the nerve terminals inside muscle spindles and in direct contact with intrafusal fibers were labeled with anti- GQ1b, -GT1a, and -GD1b ganglioside antibodies. The abundant and synaptic-specific binding of anti-GQ1b, -GT1a, and -GD1b ganglioside antibodies and the rich capillary supply in the human EOMs may partly explain the selective paralysis of these muscles in Miller Fisher syndrome.

Drug Insight: biological effects of botulinum toxin A in the lower urinary tract

Botulinum toxins can effectively and selectively disrupt and modulate neurotransmission in striated muscle. Recently, urologists have become interested in the use of these toxins in patients with detrusor overactivity and other urological disorders. In both striated and smooth muscle, botulinum toxin A (BTX-A) is internalized by presynaptic neurons after binding to an extracellular receptor (ganglioside and presumably synaptic vesicle protein 2C). In the neuronal cytosol, BTX-A disrupts fusion of the acetylcholine-containing vesicle with the neuronal wall by cleaving the SNAP-25 protein in the synaptic fusion complex. The net effect is selective paralysis of the low-grade contractions of the unstable detrusor, while still allowing high-grade contraction that initiates micturition. Additionally, BTX-A seems to have effects on afferent nerve activity by modulating the release of ATP in the urothelium, blocking the release of substance P, calcitonin gene-related peptide and glutamate from afferent nerves, and reducing levels of nerve growth factor. These effects on sensory feedback loops might not only help to explain the mechanism of BTX-A in relieving symptoms of overactive bladder, but also suggest a potential role for BTX-A in the relief of hyperalgesia associated with lower urinary tract disorders.

A case report of myasthenia gravis localized to the larynx

This report describes a very rare case of myasthenia gravis (MG) localized to the larynx, with the onset of dyspnea requiring tracheotomy. The vocal cords of this patient were fixed in the paramedian position. Under fiberscopic observation, improvement of laryngeal function was demonstrated after intravenous injection of edrophonium. However, no voice change occurred. The posterior crico-arytenoid muscle has the sole responsibility of abducting the vocal cord; thus, it is concluded that the dyspnea was caused by the selective paralysis of this muscle. We suggest that MG should be considered in cases of vocal cord paralysis of unknown etiology.

Neuromuscular paralysis for newborn infants receiving mechanical ventilation

AbstractBackgroundVentilated newborn infants breathing in asynchrony with the ventilator are at risk for complications during mechanical ventilation, such as pneumothorax or intraventricular hemorrhage, and are exposed to more severe barotrauma, which consequently could impair their clinical outcome. Neuromuscular paralysis, which eliminates spontaneous breathing efforts of the infant, has potential advantages in this respect. However, a number of complications have been reported with muscle relaxation in infants, so that concerns exist regarding the safety of prolonged neuromuscular paralysis in newborn infants.ObjectivesTo determine whether routine neuromuscular paralysis of newborn infants receiving mechanical ventilation compared with no routine paralysis results in clinically important benefits or harms.Search strategyThe Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2004), MEDLINE (from 1966 to April 2004) and EMBASE (from 1988 to April 2004) were searched. References of review articles were hand searched. Language restriction was not imposed.Selection criteriaAll trials using random or quasi‐random patient allocation, in which the routine use of neuromuscular blocking agents during mechanical ventilation was compared to no paralysis or selective paralysis in newborn infants. Methodological quality was assessed blindly and independently by the two authors.Data collection and analysisData were abstracted using standard methods of the Cochrane Collaboration and its Neonatal Review Group, with independent evaluation of trial quality, and abstraction and synthesis of data by both authors. Treatment effect was analysed using relative risk, risk difference and weighted mean difference.Main resultsTen possibly eligible trials were identified, of which six were included in the review. All the included trials studied preterm infants ventilated for respiratory distress syndrome, and used pancuronium as the neuromuscular blocking agent. In the analysis of the results of all trials, no significant difference was found in mortality, air leak or chronic lung disease, but there was a significant reduction in intraventricular hemorrhage and a trend towards less severe intraventricular hemorrhages. In the subgroup analysis of trials studying a selected population of ventilated infants with evidence of asynchronous respiratory efforts, a significant reduction in intraventricular hemorrhage (any grade and severe IVH) was found, and a trend towards less air leak. In the subgroup analysis of trials studying an unselected population of ventilated infants, no significant differences were found for any of the outcomes.Authors' conclusionsFor ventilated preterm infants with evidence of asynchronous respiratory efforts, neuromuscular paralysis with pancuronium seems to have a favourable effect on intraventricular hemorrhage and possibly on air leak. Uncertainty remains, however, regarding the long term pulmonary and neurologic effects, and regarding the safety of prolonged use of pancuronium in ventilated newborn infants. There is no evidence from randomized trials on the effects of neuromuscular blocking agents other than pancuronium. The routine use of pancuronium or any other neuromuscular blocking agent in ventilated newborn infants cannot be recommended based on current evidence.Plain language summaryLong term effects of muscle paralysing drugs on newborns needing mechanical ventilation are as yet unclear.When newborn infants develop breathing difficulties, they need mechanical ventilation to help them breathe. Sometimes they do not breathe in rhythm with the ventilator but 'fight' it, causing bleeding in the brain or serious lung injuries. Treating distress or pain caused by the ventilator and tuning the ventilator to the infant's own breathing pattern can help. Paralysing newborn infants with muscle relaxing drugs such as pancuronium also stops them fighting the ventilator. However, the review of trials found that, although there seems to be some advantage regarding bleeding in the brain, long term effects of this method are not clear. More research is needed. Copyright © 2006 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.

Automatic respiration in amyotrophic lateral sclerosis

Sirs: Several patients with pathologically proven amyotrophic lateral sclerosis (ALS) have been reported to run a benign course without need for a mechanical ventilator [5, 6, 9]. We observed autonomous breathing in a case of long-surviving ALS, and the effects of the metabolic control system on respiration were revealed. The patient in this report is a housewife with no family history of neuromuscular disease or consanguineous pedigree. She noticed difficulty in speech at age 53 years, followed by gradual muscular weakness in her upper and lower extremities. She was diagnosed as ALS based on the clinical and EMG findings. At age 56, her developing dyspnea led to a tracheostomy and mechanical ventilation control. Three months later, she was transferred to our hospital. At that time, she was alert and had no sensory deficits. Though her ocular movements were normal, there was both moderate weakness of her facial muscles together with marked tongue atrophy with fasciculation. Muscular atrophy and motor weakness were remarkable in the upper limbs and moderate in the lower limbs. Muscle stretch reflex was hyperactive in facial muscles, jaw jerk and lower extremities, but there was areflexia in the upper extremities. There was foot clonus but no Babinski’s reflex. In spite of being under mechanical ventilation when admitted to our hospital, spontaneous breathing with SpO2 of 97–98 % has been observed during these past three years since admission. Now, she is 60 years old and in a state of tetraplegia with marked facial muscle weakness. PTR and ATR are still hyperactive. She is alert, very intelligent, and communication is maintained via a computer-assisted communication system. Neuroimaging studies show normal finding. Her respiration states are minute volume of 3–4 l and PO2 92.7 Torr/PCO2 43.5 Torr without mechanical ventilator, but she cannot voluntarily control her breathing (Fig. 1A). Her attempt to hold her breath causes decreasing amplitude of her breathing while maintainig respiration rhythm, and her intention to hold her breathing merely increases the amplitude. Laughing causes irregular respiration rhythm and increases amplitude (Fig. 1B), and her cough reflex from tracheal stimulation is positive (Fig. 1C). She cannot speak via a tracheostomy tube equipped with a speech bulb. The hypercapnic response was measured by a modification of Read’s method [10], which was performed after obtaining the informed consent of the patient and her family. She rebreathed 5 % CO2 in oxygen from a 7 l anesthesia bag. The results revealed an augmentation of ventilation in response to the progressive increase of PtCO2 up to 55 Torr (Fig. 2). Breathing is controlled separately by the autonomic and voluntary pathways [1]. A discrete lesion in the central nervous system may cause a selective paralysis of one type of respiration, but spare the other. The respiratory findings in the present case are a loss of voluntary respiration but preservation of autonomous rhythm, metabolic control and evidence of activation in response to emotional stimuli. These findings have been reported in patients with lesions in the ventral pons [2, 3, 4, 8] and bilateral pyramidal tracts [7]. The reverse condition of an impaired autonomic but preserved volitional system is called central alveolar hypoventilation syndrome or Ondine’s curse [11, 12], which requires mechanical ventilation during sleep. Preservation of autonomous respiration suggests intact medullary respiratory neurons such as the ambiguous and retroambiguous nuclei of the vagus, and respiratory rhythm-generating neurons in the caudal ventral pons [1]. Also, this patient showed normal activity of CO2/H+ sensitive neurons which are located in the solitary nuclei and ventrolateral field of the caudal medulla oblongata [1]. The influence of emotional laughing on the autonomic respiration rhythm suggests the retained pathway of limbic cortex to these respiratory neurons [3, 8]. Descending bulbospinal respiratory pathways, which run in the anterior funiculus [1], and the anterior horn cell originating the phrenic nerve must be preserved to some degree to maintain spontaneous breathing. At the same time, a loss of volitional respiration indicates quite severe degeneration in the corticospinal tract, which is indicated by hyperactive tendon reflex in extremely weakened muscle. This case shows a peculiar symptom of impaired volitional but preserved autonomous respiration. To our knowledge, this is the first report of physiological study in ALS with a benign respiration course. Metabolic stimulation seems to be useful to reinforce the respiratory movement in such patients. LETTER TO THE EDITORS

Neuromuscular paralysis for newborn infants receiving mechanical ventilation.

Ventilated newborn infants breathing in asynchrony with the ventilator are at risk for complications during mechanical ventilation, such as pneumothorax or intraventricular hemorrhage, and are exposed to more severe barotrauma, which consequently could impair their clinical outcome. Neuromuscular paralysis, which eliminates spontaneous breathing efforts of the infant, has potential advantages in this respect. However, a number of complications have been reported with muscle relaxation in infants, so that concerns exist regarding the safety of prolonged neuromuscular paralysis in newborn infants. To determine whether routine neuromuscular paralysis of newborn infants receiving mechanical ventilation compared with no routine paralysis results in clinically important benefits or harms. The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2004), MEDLINE (from 1966 to April 2004) and EMBASE (from 1988 to April 2004) were searched. References of review articles were hand searched. Language restriction was not imposed. All trials using random or quasi-random patient allocation, in which the routine use of neuromuscular blocking agents during mechanical ventilation was compared to no paralysis or selective paralysis in newborn infants. Methodological quality was assessed blindly and independently by the two authors. Data were abstracted using standard methods of the Cochrane Collaboration and its Neonatal Review Group, with independent evaluation of trial quality, and abstraction and synthesis of data by both authors. Treatment effect was analysed using relative risk, risk difference and weighted mean difference. Ten possibly eligible trials were identified, of which six were included in the review. All the included trials studied preterm infants ventilated for respiratory distress syndrome, and used pancuronium as the neuromuscular blocking agent. In the analysis of the results of all trials, no significant difference was found in mortality, air leak or chronic lung disease, but there was a significant reduction in intraventricular hemorrhage and a trend towards less severe intraventricular hemorrhages. In the subgroup analysis of trials studying a selected population of ventilated infants with evidence of asynchronous respiratory efforts, a significant reduction in intraventricular hemorrhage (any grade and severe IVH) was found, and a trend towards less air leak. In the subgroup analysis of trials studying an unselected population of ventilated infants, no significant differences were found for any of the outcomes. For ventilated preterm infants with evidence of asynchronous respiratory efforts, neuromuscular paralysis with pancuronium seems to have a favourable effect on intraventricular hemorrhage and possibly on air leak. Uncertainty remains, however, regarding the long term pulmonary and neurologic effects, and regarding the safety of prolonged use of pancuronium in ventilated newborn infants. There is no evidence from randomized trials on the effects of neuromuscular blocking agents other than pancuronium. The routine use of pancuronium or any other neuromuscular blocking agent in ventilated newborn infants cannot be recommended based on current evidence.

Quantifying deficits in the 3D force capabilities of a digit caused by selective paralysis: application to the thumb with simulated low ulnar nerve palsy

We present the development of a vision-feedback method to characterize how selective paralysis distorts the three-dimensional (3D) volume representing digit-tip force production capability and its application to healthy individuals producing thumb-tip force with and without simulated low ulnar nerve palsy (LUNP). Subjects produced maximal static voluntary force spanning the transverse, sagittal and frontal planes of the thumb (16, 15 and 10 subjects, respectively). Subjects produced thumb-tip force tasks in guided and self-selected directions. The envelope (convex hull) of extreme forces in each plane approximated that cross-section of the 3D volume of force capability. Some subjects repeated the tasks with a temporary ulnar nerve block applied at the wrist to simulate complete acute LUNP. Three geometric properties of the force convex hull characterized each cross-section's shape: the ratios of its principal moments of inertia (RPMIs), the orientation of its principal axis (OPA), and its centroid location. Our results show that force production in the thumb's sagittal plane may be a reproducible and objective test to grade motor impairment in LUNP: paired t-tests of the larger RPMI in this plane best distinguished the nerve-blocked cases from the control cases in the guided task ( p=0.012), and Discriminant Analysis of the centroid location for the self-selected task in this plane correctly classified 94.7% of subjects into the control and ulnar nerve-blocked groups. We show that our method measures and detects changes in a digit's force production capabilities. Towards a clinical test of motor impairment in LUNP, this biomechanical study dictates which 3D thumb-tip forces to measure (those in the sagittal plane) and how to measure them (using the self-selected task).

The Cosmetic Use of Botulinum Toxin

The approach to facial rejuvenation continues to evolve. For decades, the primary focus on rejuvenation has centered on modalities such as skin care, skin resurfacing, soft-tissue augmentation, and surgical intewention. A better understanding of the physiologic changes that occur with facial aging lends itself to new approaches and techniques that are mindful of the causes. As animation has shown to be a significant contributor to both the appearance of facial lines and soft-tissue malposition, there has been recent interest in chemodenervating agents and their applications in the field of facial rejuvenation. These agents, by and large, efface rhytides by selective and precise focal paralysis of the underlying facial musculature and, therefore, reduce or eliminate the prominence of the overlying rhytides. In addition, chemodenemation call serve as an adjunct for facial rejuvenation because of its influence on facial soft-tissue position and shape. Botulinum toxin, derived from Clostridium botulinum, is the most widely used agent; therefore, this new nodality, its applications in cosmetic plastic surgery, and its applications to other areas will be discussed.

Paralisia do músculo cricoaritenóideo lateral: relato de caso como contribuição ao estudo da anatomia funcional da laringe

A eletromiografia da laringe (EMG) vem sendo útil nas avaliações das alterações de mobilidade das pregas vocais, sobretudo diferenciando as paralisias das fixações, e também fornecendo dados para o prognóstico e localização de lesões neuromusculares. Com base na EMG e na telelaringoscopia buscamos entender o papel dos músculos intrínsecos da laringe a partir de um caso de paralisia de músculo cricoaritenóideo lateral, confirmado por estudo eletromiográfico, em uma paciente com história de afonia e perda de mobilidade da prega vocal esquerda, fixa na posição lateral.

Selective paralysis of the upper extremities after odontoid fracture: acute central cord syndrome or cruciate paralysis?

A patient presented with selective paralysis of the arms after having sustained a fall. X-ray of the cervical spine showed a type II odontoid fracture with posterior atlantoaxial dislocation. The diagnosis in the emergency room was cruciate paralysis, which is frequently associated with fractures of axis and/or atlas. However, magnetic resonance imaging (MRI) of the cervical spine revealed a lesion consistent with the acute central cord syndrome (CCS) at the C2–C6 level. The patient underwent posterior atlantoaxial arthrodesis to correct instability and was discharged, without much neurological improvement. Cruciate paralysis has been reported to be associated with fractures of axis and/or atlas, and acute CCS has rarely been associated with the fractures. However, this case illustrates that the lesion responsible for selective paralysis of the upper extremities is not as specific as it had been thought to be, and that it is difficult to accurately identify the level of the cervical cord injury by neurological diagnosis and X-rays alone. Supplementary diagnostic modalities, particularly MRI, are required to make a correct diagnosis and develop a therapeutic strategy.

Botulinum toxin puts a new twist on pain therapy

Botulinum toxin is a potent neurotoxin that blocks neuromuscular transmission. When injected in minute quantities it causes selective paralysis and weakening of muscle and is able to alleviate spasms. Because of this it is already an accepted treatment for blepharospasm and strabismus. However, it also appears to offer a useful therapeutic alternative for patients with various refractory pain syndromes, according to researchers at the 17th Annual Scientific Meeting of the American Pain Society [San Diego, US; November 1998].

Randomised Trial of Routine versus Selective Paralysis during Ventilation for Neonatal Respiratory Distress Syndrome

The strategy of non-selective neuromuscular paralysis was compared with that of synchronised (fast rate) ventilation and selective paralysis in infants receiving mechanical ventilation for respiratory distress syndrome with chronic lung disease as the primary outcome measure. One hundred and ninety three infants weighing under 2000 g were randomly allocated to receive either pancuronium during mechanical ventilation in the acute phase of respiratory distress syndrome (non-selective group) or synchronised ventilation (initial ventilatory rate at or above that of the infant's) (selective group). Infants in the selective group received pancuronium if they were consistently expiring during the inspiratory phase of the ventilator cycle. There was no significant difference between the groups with respect to birth weight, gestation, and sex distribution. There was no significant difference between the group with respect to death (selective 19%, non-selective 16%), pneumothorax (selective 14%, non-selective 14%), chronic lung disease (selective 49%), non-selective 47%), and oxygen dependency at 36 weeks' postmenstrual age (selective 32%, non-selective 39%). Routine paralysis of ventilated infants has potential complications that may be avoided by using synchronised ventilation. As the latter is not associated with an increased incidence of long term respiratory complications, it is concluded that it is the optimum strategy of the two for ventilating infants with respiratory distress syndrome.

RANDOMISED TRIAL OF ROUTINE VERSUS SELECTIVE PARALYSIS DURING VENTILATION FOR NEONATAL RESPIRATORY DISTRESS SYNDROME (RDS)

We aimed to compare the strategy of non-selective neuromuscular paralysis with that of synchronised (fast rate) ventilation and selective paralysis in infants receiving mechanical ventilation for RDS with chronic lung disease as the primary outcome measure. One hundred and ninety-three infants under 24 hours of age were enrolled in the study and were allocated to receive either pancuronium during mechanical ventilation in the acute phase of RDS (non-selective group) or synchronised ventilation (initial ventilatory rate at or above that of the infant's) (selective group). Infants in the selective group received pancuronium if they were consistently expiring during the inspiratory phase of the ventilator. There was no significant difference between the groups with respect to birth weight, gestation and sex distribution. There was no significant difference between the groups with respect to death (selective 19%; non-selective 16%). pneumothorax (selective 13 %: nonselective 16%, CLD (selective 47%, non-selective 47%) and oxygen, dependency at 36 weeks post conceptual age (selective 27%: non-selective 34% Routine paralysis of ventilated infants has potential complications which may be avoided by using synchronised ventilation. As the latter is not associated with an increased incidence of long term respiratory complications we conclude that it is the optimal strategy of the two for ventilating infants with RDS.

Selective Paralysis of Downward Saccades

Selective Paralysis of Downward Saccades