Fist Clenching Research Articles

Reducing the Incidence of Pseudohyperkalemia by Avoiding Making a Fist During Phlebotomy: A Quality Improvement Report

Pseudohyperkalemia is uncommon, but important. Local release of potassium caused by contraction of the forearm muscles from a tightly clenched fist or repeated fist clenching during phlebotomy is a recognized cause of pseudohyperkalemia. We investigated the use of a standard protocol to avoid fist clenching during phlebotomy. Quality improvement report. In 7 healthy volunteers, 10 blood samples were collected over 10-second intervals after 20 repeated fist clenching and unclenching movements. In 86 healthy volunteers, 3 blood samples were collected with and without prior fist clenching. Between September 1, 2006, and June 30, 2007, peripheral venous blood samples were collected from 73,846 outpatients at Chiba University Hospital without a protocol to avoid fist clenching. Between July 1, 2007, and March 31, 2009, blood samples were collected from 171,053 outpatients using the protocol. After July 1, 2007, blood samples were collected from the basilic or cephalic vein without making a fist or by making a fist using minimal gripping strength. Also, when multiple specimens were obtained from 1 patient, the specimen for measuring serum electrolytes was obtained after the other specimens. Pseudohyperkalemia, defined as unexplained serum potassium level ≥6.5 mmol/L. In the 7 volunteers, the decrease in serum potassium levels after cessation of fist clenching ranged from 8.4%-25.9%. In the 86 volunteers, the percentage with a decrease in serum potassium level ≥0.2 mmol/L between the first and third samples was 25.6% versus 6.7% with or without prior fist clenching, respectively. In clinical practice, we observed 8 cases of pseudohyperkalemia before implementing the protocol (0.0081%) and 1 case (0.00058%) after implementing the protocol (P = 0.001). Causes of hyperkalemia before using precautions were assessed using retrospective analyses. Avoiding fist clenching during phlebotomy and not using the first specimen for electrolyte measurements when obtaining multiple specimens from a single patient can reduce the occurrence of pseudohyperkalemia.

Is suboptimal phlebotomy technique impacting on potassium results for primary care?

Pre-analytical problems causing pseudohyperkalaemia have been highlighted previously. These include transit time and temperature effects when sample collection points are geographically widely spread. Similarly, inappropriate phlebotomy technique (in particular, requesting patients to fist clench to facilitate venesection) is a documented cause of pseudohyperkalaemia, but its incidence may be impossible to establish. This study illustrates how primary care population serum potassium data altered when local phlebotomy clinics optimized their technique. The effect of improving phlebotomy was studied by plotting average monthly primary care population serum potassium data and average percentage of samples with hyperkalaemia (5.2 mmol/L or higher) against mean monthly temperature before and after changes in phlebotomy practice. Only samples from primary care were included between 2002 and 2005 inclusive. Primary care population serum potassium was inversely related to ambient temperature. Following the change in phlebotomy practice, the annual percentage of results above reference range (5.2 mmol/L or higher) was reduced from 9% to 6% and the number of results breaching the upper telephoning threshold (5.8 mmol/L or higher) fell from 0.9% to 0.5%. Ensuring that phlebotomists were trained to avoid facilitating venesection by requesting patients to hand grip (fist clench), was associated with lower mean serum potassium results for the primary care patient population and a reduced incidence of hyperkalaemia. It is likely that the contribution of patient fist clenching during phlebotomy to pseudohyperkalaemia has been underestimated.

Disparities in Fistula Maturation Persist Despite Preoperative Vascular Mapping

Failure to mature (primary failure) of new fistulas remains a major obstacle to increasing the proportion of dialysis patients with fistulas. This failure rate is higher in women than in men, higher in older than in younger patients, and higher in forearm than in upper arm fistulas. These disparities in the frequency of failure to mature may be due in part to marginal vessels in the high-risk groups and should be reduced by routine preoperative vascular mapping. A prospective, computerized database was queried retrospectively to evaluate the frequency of primary fistula failure in 205 hemodialysis patients for whom preoperative mapping was obtained. The association between clinical characteristics and risk for primary fistula failure was analyzed by univariate and multiple variable regression analysis. The overall primary fistula failure rate was 40% (82 of 205 patients). On multiple variable logistic regression, three clinical factors were associated with an increased risk for failure to mature among patients who underwent preoperative vascular mapping: Female gender, age > or =65 yr, and forearm location. The primary fistula failure rate varied from 22% in younger men with an upper arm fistula to 78% in older women with a forearm fistula. Dynamic preoperative vascular measurements (change in peak systolic velocity and resistive index after tight fist clenching) did not differ between patients with mature and immature forearm fistulas. Disparities in fistula maturation persist despite the use of routine preoperative vascular mapping.

Memantine und komplexes regionales Schmerzsyndrom (CRPS): Behandlungseffekte und kortikale Reorganisation

In recent studies a central nervous system involvement in the pathogenesis of Complex Regional Pain Syndrome (CRPS) was suggested, stimulating the introduction of central acting drugs. Animal studies have demonstrated an increased expression of the N-methyl-D-aspartate (NMDA) receptors in experimental neuropathic pain. The aim of this study was to investigate the relationship between NMDA receptor blockers and CRPS. Three patients suffering from CRPS of one upper extremity where treated with oral NMDA antagonist Memantine for eight weeks. Patients expressed their pain levels with a visual analog scale ranging from zero to ten at rest and after fist clenching. Furthermore, the range of movement of the fingers and the wrist were documented. To assess force, a pinchmeter and a dynamometer were used. Cortical reorganisation was studied with functional Magnetic Resonance Imaging (fMRI) and Magnetoencephalography (MEG). Six months after treatment with Memantine no rest pain was present in any of the patients. Furthermore, an increase in finger movement was observed after six-month follow-up with no deficits and free movement ranges. Additionally, wrist movement was improved and an increase of force was measured after six months with the dynamometer and the pinchmeter. Moreover the functional impairment, cortical reorganisation was observed in all patients before treatment. These changes returned to a normal pattern after eight weeks of treatment with Memantine. These first results demonstrate central nervous system involvement in the development and maintenance of CRPS. The results (functional, pain, fMRI, MEG) after treatment with Memantine indicate the importance of the NMDA receptor system in neuropathic pain syndromes and provide a promising approach for the treatment of CRPS.

Clinical Neurophysiology: EEG–Video Monitoring

Clinical Neurophysiology: EEG–Video Monitoring

Preoperative sonographic radial artery evaluation and correlation with subsequent radiocephalic fistula outcome.

Primary failure of forearm radiocephalic dialysis fistulas is common even when preoperative vascular mapping is used. Previous studies have suggested that low peak systolic velocity of the radial artery predicts subsequent fistula failure. The study goal was to evaluate whether preoperative spectral Doppler assessment of radial artery inflow can improve forearm fistula outcome prediction. Forearm fistulas were placed in 112 patients after preoperative sonographic mapping. Preoperative spectral Doppler sonography measured radial artery peak systolic velocity during tight fist clenching for 3 minutes and after fist relaxation. Vessel diameters and peak systolic velocity were assessed for predictive value based on subsequent fistula adequacy. Fistula flow rates were determined 6 to 12 weeks postoperatively in a subset of patients. Failed and successful fistulas were similar in their preoperative arterial and vein diameters, resistive index, and peak systolic velocity during fist clenching and after fist relaxation. Specifically, there was no difference in fistula success with radial artery peak systolic velocity lower than 50 cm/s versus peak systolic velocity of 50 cm/s or higher. The change in peak systolic velocity after fist relaxation was highly predictive of subsequent fistula outcome among female patients in ad hoc analysis. Fistula adequacy for dialysis in women was 11% when the change in peak systolic velocity was lower than 0 cm/s and 50% when the change was 0 cm/sec or higher (P = .02). The postoperative fistula flow rates were lower when the preoperative change in peak systolic velocity was lower than 0 cm/s than when it was 0 cm/s or higher (316 +/- 46 versus 781 +/- 150 mL/min; P = .003). There was no difference in the preoperative peak systolic velocity or the resistive index of successful and failed fistulas. Measurement of the radial artery peak systolic velocity change after release of fist clenching was not useful in predicting outcomes in male patients but identified a subset of female patients with a very low likelihood of success. This criterion may merit further investigation in future trials.

Pain behaviors observed during six common procedures: results from Thunder Project II.

Patients frequently display behaviors during procedures that may be pain related. Clinicians often rely on the patient's demonstration of behaviors as a cue to presence of pain. The purpose of this study was to identify specific pain-related behaviors and factors that predict the degree of behavioral responses during the following procedures: turning, central venous catheter insertion, wound drain removal, wound care, tracheal suctioning, and femoral sheath removal. Prospective, descriptive study. Multiple units in 169 hospitals in United States, Canada, England, and Australia. A total of 5,957 adult patients who underwent one of the six procedures. None. A 30-item behavior observation tool was used to note patients' behaviors before and during a procedure. By comparing behaviors exhibited before and during the procedure as well as behaviors in those with and without procedural pain (as noted on a 0-10 numeric rating scale), we identified specific procedural pain behaviors: grimacing, rigidity, wincing, shutting of eyes, verbalization, moaning, and clenching of fists. On average, there were significantly more behaviors exhibited by patients with vs. without procedural pain (3.5 vs. 1.8 behaviors; t = 38.3, df = 5072.5; 95% confidence interval, 1.6-1.8). Patients with procedural pain were at least three times more likely to have increased behavioral responses than patients without procedural pain. A simultaneous regression model determined that 33% of the variance in amount of pain behaviors exhibited during a procedure was explained by three factors: degree of procedural pain intensity, degree of procedural distress, and undergoing the turning procedure. Because of the strong relationship between procedural pain and behavioral responses, clinicians can use behavioral responses of verbal and nonverbal patients to plan for, implement, and evaluate analgesic interventions.

The arteriovenous fistula.

The ground-breaking article by Brescia and Cimino in 1966 ([1][1]) revolutionized the creation of the vascular access, and the Cimino fistula was soon used in almost all dialysis patients. Unfortunately, subsequent wide-spread use of PTFE grafts instead of AV fistulae occurred because of the ease of

Perception of muscle strength with and without biofeedback during swallowing and fist-clenching tasks

This study investigated the accuracy of the proprioceptive system in swallowing as compared with fist clenching. The role of surface electromyography (SEMG) biofeedback in replicating motor strength was also evaluated. The study was completed in two phase. Phase 1 participants (n = 50) were aged 20–30 years; phase 2 involved participants(n= 50) aged over 50 years. SEMG activity was measured during performance of maximal and graded (half) strength swallowing and fist-clenching tasks. Subjects performed each task eight consecutive times, under three conditions: (1) with biofeedback; (2) without biofeedback; and (3) without feedback following a delay. A portable SEMG biofeedback device recorded the strength and timing of muscular activity and represented the information in analogue waveform on a computer screen. Under biofeedback conditions, subjects were instructed to observe the SEMG waveform to determine their maximal peak SEMG amplitudes. Data were collected from the final five of eight consecutive attempts of each task and a measure of variance calculated. Results demonstrated greater variation in strength of muscle contraction for swallowing attempts than for fist-clenching tasks, in younger participants only. This effect was only statistically significant for full-strength conditions regardless of feedback. In the older age group, variation was higher in the ‘with feedback’ condition; this was not evident in the younger group. For both age groups, graded strength responses were more varied than maximal strength responses. It is postulated that these results indicate that the proprioceptive system of unimpaired subjects may respond differently to SEMG biofeedback than that of participants with an impaired system who require SEMG biofeedback to compensate for a proprioceptive loss. Inferences and applications to the dysphagic population are discussed.

Atypical Down Syndrome phenotype with translocation Trisomy 21

Down Syndrome (DS) is the most common chromosomal aneuploidy. Ninety-five percent of DS cases are due to free Trisomy while 3-4% are due to an unbalanced translocation. Generally, there are no phenotypic differences between these two causes of DS. We report an infant with Trisomy 21 due to 21q 21q translocation, who presented with an atypical DS phenotype.The proband was an AGA 36-week gestation infant born by SVD to a 35y.o. G2P2AB1 woman following two normal prenatal ultrasounds and a normal MSAFP. Pregnancy, labor and delivery were uncomplicated. At 2.5 months, exam revealed ht at 10-25th %, wt and HC at <5th%, mild facial asymmetry, high mildly deviated nasal bridge, downslanting palpebral fissures, absent Brushfield spots, moderate micrognathia, left ptosis, low set ears with overfolded superior helices, right Bell's palsy, left torticollis. Other findings were dermatoglyphics: right WRWAU, left ARUUU, tapered fingers with positional clenching of fist, sacral dimple and neurological abnormalities of hypertonia and arching of the back. Vision, hearing and echocardiogram were normal. By diagnostic criteria published in the J. of Peds. (1982), she did not meet the diagnosis of DS. Chromosome analysis by two laboratories at band level KI 550 revealed: 46,XX, +21, der (21; 21)(q10; q10). Both parents had normal karyotypes. FISH analysis utilizing the TUPLE; LSI 13,21 probe confirmed the Trisomy 21 translocation. At 8 months, she has continued hypertonia and developmental delay with functioning at 5-6 months.Our patient with Trisomy 21 due to translocation does not have the characteristic phenotype of DS. In 1977, Avramopoulos et al (1997) reported a patient with full standard Trisomy 21, who also had atypical phenotypes for DS. Possible etiologies for these findings may include: 1) small molecular deletion of the critical region of chromosome 21, 2) disruption of a gene by gene- gene interaction or 3) mosaicism in other cell lines. Further molecular research studies are planned.

Dystonia in Huntington's disease: prevalence and clinical characteristics.

The prevalence and clinical characteristics of dystonia in Huntington's disease (HD) have not been formally assessed. To study (1) the prevalence of dystonia in HD in a clinic population, (2) the clinical features of dystonia, and (3) clinical correlates of dystonia (for example, age, disease duration). Patients with HD attending the HD Center at the New York State Psychiatric Center were administered the Unified HD Rating Scale and underwent a standardized 5.5-minute videotaped examination. Two neurologists reviewed the videotaped examination and rated the severity and constancy of dystonia, calculating a total dystonia score for each patient. Prevalence of dystonia of any severity was 95.2%. Twenty-four of 42 (57.1%) had dystonia in at least one body region that was moderate and present more than half of the time, and seven of 42 (16.7%) had dystonia that was severe and constant. The most prevalent types of dystonia were internal shoulder rotation (64.3%), sustained fist clenching (47.1%), excessive knee flexion (42.9%), and foot inversion (42.9%). In 37 of 42 (88.1%) patients, there were more than two types of dystonia, and in the average patient, three to four types of dystonia. The mean severity was between 1 (mild) and 2 (moderate), and the mean constancy was between 2 (present less than half of the time) and 3 (present more than half of the time). Multivariate linear regression revealed that disease duration (p = 0.0005) and taking an antidopaminergic agent (p = 0.03) were positively associated with the total dystonia score. The majority of patients in this HD clinic exhibited some dystonia. The dystonia was present in several body regions and manifested by a variety of movements and postures not typical of idiopathic torsion dystonia. The dystonia was not bothersome to most patients, and its severity was a function of disease duration and use of an antidopaminergic agent.

The interpretation of infant pain: Physiological and behavioral indicators used by NICU nurses

The purpose of this descriptive study was to identify the indicators used by neonatal nurses to interpret the experience of pain in infants in a Neonatal Intensive Care Unit (NICU). A sample of 72 NICU nurses completed a structured questionnaire to identify the physiological and behavioral indicators they used to interpret the experience of pain in the infants entrusted to their care. The 10 pain indicators used by more than 50% of the nurses, listed in decreasing order of frequency, were: fussiness, restlessness, grimacing, crying, increasing heart rate, increasing respirations, wiggling, rapid state changes, wrinkling of forehead, and clenching of fist. These findings are consistent with existing literature, are compatible with the stress cues identified in Als' Synactive Theory of Development, and lend support to the use of such measures for the assessment of infant pain.

Pseudohyperkalemia Caused by Fist Clenching during Phlebotomy

CLINICIANS are occasionally confronted with the finding of an elevated serum or plasma potassium level in an otherwise healthy person. Such an abnormality may herald the presence of occult mineralocorticoid deficiency or a defect in renal tubular transport.1 Alternatively, it may represent so-called pseudohyperkalemia, caused by the release of potassium from formed elements in the blood in patients with leukocytosis or thrombocytosis.2 , 3 We report here on a patient in whom pseudohyperkalemia resulted from the common practice of repeatedly clenching and unclenching a fist during venipuncture. This maneuver, which has been passed on from generation to generation of house staff, medical . . .

Human fetal dopamine neurons grafted into the striatum in two patients with severe Parkinson's disease. A detailed account of methodology and a 6-month follow-up.

By using stereotaxic surgical techniques, ventral mesencephalic tissues from aborted human fetuses of 8 to 10 weeks' gestational age were implanted unilaterally into the striata in two patients with advanced Parkinson's disease. The patients were treated with a cyclosporine, azathioprine, and steroid regimen to minimize the risk for graft rejection. They were examined for 6 months preoperatively and 6 months postoperatively and continued to receive the same doses of antiparkinsonian medication. There were no significant postoperative complications. No major therapeutic effect from the operation was observed. However, in the clinical tests, both patients showed small but significant increases of movement speed for repeated pronation-supination, fist clenching, and foot lifting. The rate of walking also increased in the one patient tested. For both patients, there was an initial worsening postoperatively, followed by improvement vs preoperative performance at 1 to 3 months. Both patients also showed significant improvement in the magnitude of response to a single dose of levodopa (L-dopa), but there was no increase in the duration of drug action. The motor readiness potential increased in both patients postoperatively, primarily over the operated hemisphere. Neurophysiological measurements also showed a more rapid performance of simple and complex arm and hand movements on the side contralateral to transplantation in one patient at 5 months postoperatively. Positron emission tomography demonstrated no increased uptake of 6-L-(18F)-fluorodopa in the transplanted striatum at 5 and 6 months. Taken together, these results suggest that the fetal nigral implants may have provided a modest improvement in motor function, consistent with the presence of small surviving grafts. Although our results support further scientific experimentation with transplantation in Parkinson's disease, widespread clinical trials with this procedure are probably not warranted at this time.

“Weapons effect” revisited: Motor effects of the reception of aversive stimulation and exposure to pictures of firearms

AbstractThe effect of presenting images of firearms on the speed of clenching of the fist of human subjects simultaneously receiving an aversive stimulation was studied. It was thought that, whereas the classic interpersonal experimental situation confounds the effects of the stimulus presented and several interpersonal processes, speed of fist clenching in a noninterpersonal setting could constitute a valid measure of the subject's readiness to fight. Twenty‐four male and 24 female students (ages &gt; 20 and &lt;36 years) were instructed to press with their right hand a device commanding the projection of slides upon reception of an acoustic signal. Speed of clenching of the hand was recorded in the four conditions generated by the combination of two levels of acoustic signal (aversive and nonaversive) and two modalities of slides (firearms or tools). The results show that the reception of aversive sound accelerates fist clenching. Simultaneous presentation of slides of firearms and reception of aversive noise increases the speed of clenching of the fist. The slides' main effect was not significant. More irritable subjects tend to execute this movement faster than their less irritable counterparts, and more emotionally susceptible subjects tend to be slower than less susceptible ones. Male subjects were faster than females. This pattern of results is discussed in relation to the hypothesis formulated by the authors.

Human patellar reflex and conditioned reflex compared electromyographically

Inspite of continued work on the stretch reflex and “voluntary” movement study of the conditioned stretch reflex declined early in this century. The present experiments surveyed seven classical conditioning regimens for the human rectus femoris EMG seen after a blow to the patellar tendon. It was possible to (1) rule out conditioning to a knee touch that occured together with the tap, (2) establish weak conditioned stimulus, Sc, control for a tape recorder click and subsequent fist clench that preceded the tap by variable elapsed times, and (3) establish strong Sc control for a tone that sounded an invariant 0.27 sec before the tap. There were large differences, however, in Sc power across subjects, as measured by amplitude, latency, and frequency of conditioned EMG activity that occured prior to tap or when the tap was omitted. Purely reflexive responses, especially later EMG segments, also varied in amplitude and frequency, to support a conclusion that numerous controlling stimuli added or competed from trial to trial. Further disclosure of Sc contributions, including those from movement-generated stimulation, is warranted, especially for behaviors whose rhythmic timings, as in locomotion, might favor Pavlovian conditioning.

Analysis of inphase interaction pattern in EEG.

Inphase interactions among EEG signals recorded using eight electrodes were investigated. The inphase interaction parameters are presented in two ways: (1) matrix form in which the number of inphase interactions are tabulated; and (2) histogram in which the number of inphase interactions are plotted pair-wise between two sites as a function of phase delays in milliseconds. The highest number of interactions occurs between 0 and 8 ms in normal brains. The values of interactions parameters are enhanced by various activities. For example, inphase interaction parameters increase in the motor area in the right hemisphere if the EEG is recorded during repeated left fist clenching. Inphase interactions are drastically altered by the presence of a tumor. We studied the inphase interactions of the EEG of a patient having an occipital tumor. The interaction parameters are greatly diminished in this area, indicating a severe impairment of neuronal communications between both hemispheres in the occipital region. The confidence limits of the changes in inphase interaction parameters during fist clenching are tested statistically using the Student's test. The test shows that the interaction parameters increase, in general, with 1-5% confidence limits in respective cortex areas as a result of fist clenching.

Measurements of the concentration and size distribution of particles in the Arctic air of Greenland

A series of aerosol measurements at a remote site on the Greenland ice cap (Fist Clench, 210 miles east of Thule Air Force Base, and Camp Century, 150 miles east of Thule) was conducted during August 1959 and March 1960 to determine the concentration and size distribution of the natural aerosol in air which is free of direct contamination from the soil or any human activity. Analyses made with a Goetz aerosol spectrometer and a particle cascade impactor show concentrations between 1 and 3 particles/cm3 and a very narrow size spectrum of 1μ±0.1μ diameter for the summer measurements. During winter the measured concentrations were below 0.02 particles/cm3. Some aspects of a possible explanation of the formation of this very characteristic aerosol are discussed.