Admission Functional Status is Associated With Intensivists Perception of Extracorporeal Membrane Oxygenation Candidacy for Pediatric Acute Respiratory Failure

OBJECTIVES

To determine the association between admission Functional Status Scale (FSS) category and perceived extracorporeal membrane oxygenation (ECMO) candidacy for pediatric acute respiratory failure.

DESIGN

Prospective, cross-sectional study.

SETTING

Single-center, quaternary, and ECMO referral academic children's hospital between March 2021 and January 2022.

SUBJECTS

Pediatric intensivists directly caring for patients admitted with acute respiratory failure secondary to shock or respiratory disease.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Pediatric intensivists were surveyed about current patients within 72 hours of initiation or escalation of invasive mechanical ventilation on whether they would offer ECMO should their patient deteriorate. Baseline functional status was assessed using trichotomized admission FSS: 1) normal/mild dysfunction (6-9), 2) moderate dysfunction (10-15), and 3) severe dysfunction (> 16). Multivariable logistic regression clustered by physician was used to assess the association between admission FSS category with perceived ECMO candidacy. Thirty-seven intensivists participated with 76% (137/180) of survey responses by those with less than 10 years of experience. 81% of patients (146/180) were perceived as ECMO candidates and 19% of patients (34/180) were noncandidates. Noncandidates had worse admission FSS scores than candidates (15.5 vs. 9, p < 0.001). After adjustment for age, admission FSS category of severe dysfunction had lower odds of perceived ECMO candidacy compared with normal to mild dysfunction (odds ratio [OR] 0.18 [95% CI, 0.06-0.56], p < 0.003). Patients with an abnormal communication subscore domain had the lowest odds of being considered a candidate (unadjusted OR 0.44 [95% CI, 0.29-0.68], p < 0.0001).

CONCLUSIONS

In this prospective, single-center, cross-sectional study, admission FSS category indicating worse baseline functional status impacted pediatric intensivists' perceptions of ECMO candidacy for patients with acute respiratory failure. Abnormal FSS subscores in the neurocognitive domains were the most important considerations. Future studies should better seek to define the decision-making priorities of both parents and medical specialists for the utilization of ECMO in children with acute respiratory failure.

Ventilator Weaning and Terminal Extubation: Withdrawal of Life-Sustaining Therapy in Children. Secondary Analysis of the Death One Hour After Terminal Extubation Study

OBJECTIVE

Terminal extubation (TE) and terminal weaning (TW) during withdrawal of life-sustaining therapies (WLSTs) have been described and defined in adults. The recent Death One Hour After Terminal Extubation study aimed to validate a model developed to predict whether a child would die within 1 hour after discontinuation of mechanical ventilation for WLST. Although TW has not been described in children, pre-extubation weaning has been known to occur before WLST, though to what extent is unknown. In this preplanned secondary analysis, we aim to describe/define TE and pre-extubation weaning (PW) in children and compare characteristics of patients who had ventilatory support decreased before WLST with those who did not.

DESIGN

Secondary analysis of multicenter retrospective cohort study.

SETTING

Ten PICUs in the United States between 2009 and 2021.

PATIENTS

Nine hundred thirteen patients 0-21 years old who died after WLST.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

71.4% ( n = 652) had TE without decrease in ventilatory support in the 6 hours prior. TE without decrease in ventilatory support in the 6 hours prior = 71.4% ( n = 652) of our sample. Clinically relevant decrease in ventilatory support before WLST = 11% ( n = 100), and 17.6% ( n = 161) had likely incidental decrease in ventilatory support before WLST. Relevant ventilator parameters decreased were F io2 and/or ventilator set rates. There were no significant differences in any of the other evaluated patient characteristics between groups (weight, body mass index, unit type, primary diagnostic category, presence of coma, time to death after WLST, analgosedative requirements, postextubation respiratory support modality).

CONCLUSIONS

Decreasing ventilatory support before WLST with extubation in children does occur. This practice was not associated with significant differences in palliative analgosedation doses or time to death after extubation.

A Taxonomy of Objections to Brain Death Determination

Family objections to evaluating a patient for death by neurologic criteria, or "brain death," are challenging for the family and the medical team. In this article, we categorize brain death evaluation refusals into a taxonomy: informational objections, emotional objections, and principled objections. We offer suggested approaches for clinicians to respond to refusals on the basis of the category. The category of objection may also be important in considering when accommodation of refusals should be considered. The goal in all such situations is to promote compassionate, ethical, and equitable care for the patient and family.

The Association of Perceived Social Support with Anxiety over Time in Parents of Children with Serious Illnesses

Background: Parenting a child with a serious life-threatening illness (SLTI) may impact parents' mental health. The protective association of social support with anxiety over time following an acute medical event has not been empirically tested in a sample of parents of children with oncologic and nononcologic serious illnesses. Objective: To test the potential association of perceived social support with anxiety in parents of children with SLTIs over time. Design: Prospective cohort study. Setting/Subjects: Two hundred parents of 158 children in the Decision Making in Serious Pediatric Illness study, conducted at the Children's Hospital of Philadelphia. Measurements: Parental anxiety and perceived social support were assessed using the Hospital Anxiety and Depression Scale (HADS) and the Social Provisions Scale (SPS). We performed bivariate linear regressions to test cross-sectional and longitudinal associations between the SPS and anxiety scores at baseline, 12 months, and 24 months. Results: The average SPS total and subscale scores decreased significantly from baseline to 12 months, and increased from 12 to 24 months. The average HADS-Anxiety scores decreased significantly from baseline to 12 months, and remained stable at 24 months. Cross-sectionally, total SPS scores were negatively associated with anxiety scores at each time point. Longitudinally, SPS scores were associated with anxiety scores, although this association weakened in adjusted modeling. Conclusions: Over a two-year period, higher levels of perceived social support were associated with lower levels of anxiety in parents of seriously ill children. Clinicians and researchers should work to optimize social support for families to improve parental mental health outcomes.

Integration of Pediatric Palliative Care Into Cardiac Intensive Care: A Champion-Based Model

Integration of pediatric palliative care (PPC) into management of children with serious illness and their families is endorsed as the standard of care. Despite this, timely referral to and integration of PPC into the traditionally cure-oriented cardiac ICU (CICU) remains variable. Despite dramatic declines in mortality in pediatric cardiac disease, key challenges confront the CICU community. Given increasing comorbidities, technological dependence, lengthy recurrent hospitalizations, and interventions risking significant morbidity, many patients in the CICU would benefit from PPC involvement across the illness trajectory. Current PPC delivery models have inherent disadvantages, insufficiently address the unique aspects of the CICU setting, place significant burden on subspecialty PPC teams, and fail to use CICU clinician skill sets. We therefore propose a novel conceptual framework for PPC-CICU integration based on literature review and expert interdisciplinary, multi-institutional consensus-building. This model uses interdisciplinary CICU-based champions who receive additional PPC training through courses and subspecialty rotations. PPC champions strengthen CICU PPC provision by (1) leading PPC-specific educational training of CICU staff; (2) liaising between CICU and PPC, improving use of support staff and encouraging earlier subspecialty PPC involvement in complex patients' management; and (3) developing and implementing quality improvement initiatives and CICU-specific PPC protocols. Our PPC-CICU integration model is designed for adaptability within institutional, cultural, financial, and logistic constraints, with potential applications in other pediatric settings, including ICUs. Although the PPC champion framework offers several unique advantages, barriers to implementation are anticipated and additional research is needed to investigate the model's feasibility, acceptability, and efficacy.

The Development of Tracheal Intubation Proficiency Outside the Operating Suite During Pediatric Critical Care Medicine Fellowship Training: A Retrospective Cohort Study Using Cumulative Sum Analysis

OBJECTIVE

Tracheal intubation is a core technical skill for pediatric critical care medicine fellows. Limited data exist to describe current pediatric critical care medicine fellow tracheal intubation skill acquisition through the training. We hypothesized that both overall and first-attempt tracheal intubation success rates by pediatric critical care medicine fellows improve over the course of training.

DESIGN

Retrospective cohort study at a single large academic children's hospital.

MATERIALS AND METHODS

The National Emergency Airway Registry for Children database and local QI database were merged for all tracheal intubations outside the Operating Suite by pediatric critical care medicine fellows from July 2011 to January 2015. Primary outcomes were tracheal intubation overall success (regardless of number of attempts) and first attempt success. Patient-level covariates were adjusted in multivariate analysis. Learning curves for each fellow were constructed by cumulative sum analysis.

RESULTS

A total of 730 tracheal intubation courses performed by 33 fellows were included in the analysis. The unadjusted overall and first attempt success rates were 87% and 80% during the first 3 months of fellowship, respectively, and 95% and 73%, respectively, during the past 3 months of fellowship. Overall success, but not first attempt success, improved during fellowship training (odds ratio for each 3 months, 1.08; 95% CI, 1.01-1.17; p = 0.037) after adjusting for patient-level covariates. Large variance in fellow's tracheal intubation proficiency outside the operating suite was demonstrated with a median number of tracheal intubation equal to 26 (range, 19-54) to achieve a 90% overall success rate. All fellows who completed 3 years of training during the study period achieved an acceptable 90% overall tracheal intubation success rate.

CONCLUSIONS

Tracheal intubation overall success improved significantly during the course of fellowship; however, the tracheal intubation first attempt success rates did not. Large variance existed in individual tracheal intubation performance over time. Further investigations on a larger scale across different training programs are necessary to clarify intensity and duration of the training to achieve tracheal intubation procedural competency.

Parental Sources of Support and Guidance When Making Difficult Decisions in the Pediatric Intensive Care Unit

OBJECTIVE

To assess sources of support and guidance on which parents rely when making difficult decisions in the pediatric intensive care unit and to evaluate associations of sources of support and guidance to anxiety, depression, and positive and negative affect.

STUDY DESIGN

This was a prospective cohort study of 86 English-speaking parents of 75 children in the pediatric intensive care unit at The Children's Hospital of Philadelphia who were hospitalized greater than 72 hours. Parents completed standardized instruments and a novel sources of support and guidance assessment.

RESULTS

Most parents chose physicians, nurses, friends, and extended family as their main sources of support and guidance when making a difficult decision. Descriptive analysis revealed a broad distribution for the sources of support and guidance items related to spirituality. Parents tended to fall into 1 of 2 groups when we used latent class analysis: the more-spiritual group (n = 47; 55%) highly ranked "what my child wants" (P = .023), spouses (P = .002), support groups (P = .003), church community (P < .001), spiritual leader (P < .001), higher power (P < .001), and prayer (P < .001) compared with the less-spiritual group (n = 39; 45%). The more-spiritual parents had greater positive affect scores (P = .005). Less-spiritual parents had greater depression scores (P = .043).

CONCLUSIONS

Parents rely most on physicians, nurses, and friends and extended family when making difficult decisions for their critically ill child. Respondents tended to fall into 1 of 2 groups where the more-spiritual respondents were associated with greater positive affect and may be more resistant to depression.

Good-parent beliefs of parents of seriously ill children

IMPORTANCE

Parents' beliefs about what they need to do to be a good parent when their children are seriously ill influence their medical decisions, and better understanding of these beliefs may improve decision support.

OBJECTIVE

To assess parents' perceptions regarding the relative importance of 12 good-parent attributes.

DESIGN, SETTING, AND PARTICIPANTS

A cross-sectional, discrete-choice experiment was conducted at a children's hospital. Participants included 200 parents of children with serious illness.

MAIN OUTCOMES AND MEASURES

Ratings of 12 good-parent attributes, with subsequent use of latent class analysis to identify groups of parents with similar ratings of attributes, and ascertainment of whether membership in a particular group was associated with demographic or clinical characteristics.

RESULTS

The highest-ranked good-parent attribute was making sure that my child feels loved, followed by focusing on my child's health, making informed medical care decisions, and advocating for my child with medical staff. We identified 4 groups of parents with similar patterns of good-parent-attribute ratings, which we labeled as: child feels loved (n=68), child's health (n=56), advocacy and informed (n=55), and spiritual well-being (n=21). Compared with the other groups, the child's health group reported more financial difficulties, was less educated, and had a higher proportion of children with new complex, chronic conditions.

CONCLUSIONS AND RELEVANCE

Parents endorse a broad range of beliefs that represent what they perceive they should do to be a good parent for their seriously ill child. Common patterns of how parents prioritize these attributes exist, suggesting future research to better understand the origins and development of good-parent beliefs among these parents. More important, engaging parents individually regarding what they perceive to be the core duties they must fulfill to be a good parent may enable more customized and effective decision support.

Regoaling: a conceptual model of how parents of children with serious illness change medical care goals

BACKGROUND

Parents of seriously ill children participate in making difficult medical decisions for their child. In some cases, parents face situations where their initial goals, such as curing the condition, may have become exceedingly unlikely. While some parents continue to pursue these goals, others relinquish their initial goals and generate new goals such as maintaining the child's quality of life. We call this process of transitioning from one set of goals to another regoaling.

DISCUSSION

Regoaling involves factors that either promote or inhibit the regoaling process, including disengagement from goals, reengagement in new goals, positive and negative affect, and hopeful thinking. We examine these factors in the context of parental decision making for a seriously ill child, presenting a dynamic conceptual model of regoaling. This model highlights four research questions that will be empirically tested in an ongoing longitudinal study of medical decision making among parents of children with serious illness. Additionally, we consider potential clinical implications of regoaling for the practice of pediatric palliative care.

SUMMARY

The psychosocial model of regoaling by parents of children with a serious illness predicts that parents who experience both positive and negative affect and hopeful patterns of thought will be more likely to relinquish one set of goals and pursue a new set of goals. A greater understanding of how parents undergo this transition may enable clinicians to better support them through this difficult process.

"To be a phenomenal doctor you have to be the whole package": physicians' interpersonal behaviors during difficult conversations in pediatrics

BACKGROUND

Delivery of bad news is a challenging task for physicians and other health care professionals. Several studies have assessed parental perceptions of the delivery of bad news, but none have focused on the role of physicians' interpersonal behaviors in the communication process.

OBJECTIVE

The study's objective was to assess parental perceptions of physicians' interpersonal behaviors and their role in communication of bad news.

DESIGN

The design was a cross-sectional qualitative interview study of 13 parents of patients hospitalized or previously hospitalized in the pediatric intensive care unit or oncology/bone marrow transplant unit at an academic children's hospital.

RESULTS

Eleven interpersonal behaviors were identified as important by parents. The majority of parents identified empathy in physicians as critical. Availability, treating the child as an individual, and respecting the parent's knowledge of the child were mentioned by almost half of parents. Themes also considered important but by a smaller number of parents were allowing room for hope, the importance of body language, thoroughness, going beyond the call of duty, accountability, willingness to accept being questioned, and attention to the suffering of the child.

CONCLUSIONS

To increase parental satisfaction and enhance the parent-physician therapeutic partnership, we recommend that physicians consider attending to the 11 interpersonal behaviors described in this manuscript, and that educational programs pay particular attention to these behaviors when training health care providers in the communication of bad news.

Family factors affect clinician attitudes in pediatric end-of-life decision making: a randomized vignette study

CONTEXT

Conflicts between families and clinicians in pediatric end-of-life (EOL) care cause distress for providers, dissatisfaction for patients' families, and potential suffering for terminally ill children.

OBJECTIVES

We hypothesized that family factors might influence clinician decision making in these circumstances.

METHODS

We presented vignettes concerning difficult EOL decision making, randomized for religious objection to therapy withdrawal and perceived level of family involvement, to clinicians working in three Children's Hospital intensive care units. Additionally, attitudes about EOL care were assessed.

RESULTS

Three hundred sixty-four respondents completed the questionnaire, for an overall response rate of 54%. Respondents receiving the "involved family" vignette were more likely to agree to continue medical care indefinitely (P<0.0005). Respondents were marginally more likely to pursue a court-appointed guardian for those patients whose families had nonreligious objections to withdrawal (P=0.05). Respondents who thought that a fear of being sued affected decisions were less likely to pursue unilateral withdrawal (odds ratio 0.8, 95% CI=0.6-0.9). Those who felt personal distress as a result of difficult EOL decision making, thought they often provided "futile" care, or those who felt EOL care was effectively addressed at the institution were less likely to want to defer to the parents' wishes (range of odds ratios 0.7-1).

CONCLUSION

In this randomized vignette study, we have shown that family factors, particularly how involved a family seems to be in a child's life, affect what clinicians think is ethically appropriate in challenging EOL cases. Knowledge of how a family's degree of involvement may affect clinicians should be helpful to the clinical ethics consultants and offer some degree of insight to the clinicians themselves.

Medical ethics in pediatric critical care

Ethically charged situations are common in pediatric critical care. Most situations can be managed with minimal controversy within the medical team or between the team and patients/families. Familiarity with institutional resources, such as hospital ethics committees, and national guidelines, such as publications from the American Academy of Pediatrics, American Medical Association, or Society of Critical Care Medicine, are an essential part of the toolkit of any intensivist. Open discussion with colleagues and within the multidisciplinary team can also ensure that when difficult situations arise, they are addressed in a proactive, evidence-based, and collegial manner.

Salinity-linked growth in anguillid eels and the paradox of temperate-zone catadromy

Temperate-zone anguillid eels use both saline (marine or brackish) and fresh waters during their continental phase, but use of fresh waters is paradoxical because on average these fishes grow more rapidly in saline than in fresh waters. Based on data from anguillid eels whose habitat-residency histories had been determined by Sr:Ca otolithometry, superiority of growth rates in saline water is much greater in American eels Anguilla rostrata in north-eastern North America (mean saline:fresh growth rate ratio 2.07) than in European Anguilla anguilla, Japanese Anguilla japonica and shortfinned Anguilla australis eels (range of mean ratios 1.12-1.14). Data from A. rostrata in the Hudson Estuary, U.S.A., and Prince Edward Island, Canada, were used to test adaptive explanations of catadromous migrations. The hypothesis that lower mortality in fresh water offsets faster growth in saline water was not supported because loss (mortality + emigration ) rates did not vary between saline and fresh zones of the Hudson Estuary. Hypotheses that anguillid eels move to fresh water to escape from larger anguillid eels in saline water or to evaluate habitat quality were not supported by size and age distributions. Catadromy in temperate-zone anguillid eels increases the diversity of occupied habitats and therefore lowers fitness variance caused by environmental fluctuations. Catadromy in temperate-zone anguillid eels could be due to natural selection for maximum geometric mean fitness which is sensitive to fitness variance. Temperate-zone catadromy might also be maladaptive, at least in local areas, due to shifts over time in selective pressures or to inability of panmictic genetic systems to adapt to local conditions.

Gender and age effects on outcome after pediatric traumatic brain injury

OBJECTIVE

To evaluate whether girls have better outcomes after traumatic brain injury than boys.

DESIGN

Retrospective cohort study.

SETTING

University hospital.

PATIENTS

A 16,586 patient subset of the National Pediatric Trauma Registry with nonpenetrating traumatic brain injury.

INTERVENTIONS

Retrospective review.

MEASUREMENTS AND MAIN RESULTS

The patients were subdivided by age into prepubertal (0-7 yrs), indeterminate pubertal (8-12 yrs), and probable pubertal (13-19 yrs). All analyses were adjusted for injury severity using the Injury Severity Score. Outcome variables were in-hospital death rate, intensive care unit length of stay, total length of stay, discharge to home vs. rehabilitation, and functional status at discharge. Overall, 6.1% of girls and 5.3% of boys died. A higher proportion of girls were injured in motor vehicle crashes. Gender did not have a significant effect on in-hospital mortality rate after adjustment for age, Injury Severity Score, and motor vehicle crashes. Boys had a shorter intensive care unit length of stay (p =.027). There were no statistically significant differences between boys and girls in total hospital length of stay, functional outcome, and discharge location, although for every outcome there was a trend toward girls doing worse.

CONCLUSIONS

There is evidence from this large study that girls do not have a better outcome after pediatric traumatic brain injury than boys, with a suggestion that girls may do worse.

Noise, stress, and annoyance in a pediatric intensive care unit

OBJECTIVE

To measure and describe hospital noise and determine whether noise can be correlated with nursing stress measured by questionnaire, salivary amylase, and heart rate.

DESIGN

Cohort observational study.

SETTING

Tertiary care center pediatric intensive care unit.

SUBJECTS

Registered nurses working in the unit.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Eleven nurse volunteers were recruited. An audiogram, questionnaire data, salivary amylase, and heart rate were collected in a quiet room. Each nurse was observed for a 3-hr period during patient care. Heart rate and sound level were recorded continuously; saliva samples and stress/annoyance ratings were collected every 30 mins. Variables assessed as potential confounders were years of nursing experience, caffeine intake, patients' Pediatric Risk of Mortality Score, shift assignment, and room assignment. Data were analyzed by random effects multiple linear regression using Stata 6.0. The average daytime sound level was 61 dB(A), nighttime 59 dB(A). Higher average sound levels significantly predicted higher heart rates (p =.014). Other significant predictors of tachycardia were higher caffeine intake, less nursing experience, and daytime shift. Ninety percent of the variability in heart rate was explained by the regression equation. Amylase measurements showed a large variability and were not significantly affected by noise levels. Higher average sound levels were also predictive of greater subjective stress (p =.021) and annoyance (p =.016).

CONCLUSIONS

In this small study, noise was shown to correlate with several measures of stress including tachycardia and annoyance ratings. Further studies of interventions to reduce noise are essential.

Effects of muscle fatigue and temperature on electromechanical delay

The effect of repeated maximal isometric knee extensions on electromechanical delay (EMD) and associated muscle temperature changes were investigated on seven college aged subjects. The exercise produced a significant reduction in muscle contraction force, rate of force development and muscle conduction velocity, whilst the muscle temperature increased by 2.1 degrees C. The EMD increased from a pre-exercise value of 38.4 (SEM 3.4) ms to 55.7 (SEM 3.4) ms post-exercise. In an attempt to evaluate the effect of muscle temperature on EMD, hot and ice-water bags were placed on the quadriceps muscle to alter muscle temperature. The EMD in isometric maximal knee extension was measured at 38, 36, 34, 32 and 30 degrees C. The results showed that the EMD elongated at muscle temperatures either lower or higher than 36 degrees C. It was speculated that the increased muscle temperature might contribute to 20-25% of the EMD elongation found during the fatiguing intermittent exercise. The information of the effects of muscle temperature on EMD could be useful when evaluating the effects of strenuous exercise, in which a substantial muscle temperature change might occur, on the time delay between myoelectrical activity and force generation.

Sports injury surveillance and protective equipment

Protective equipment is adopted in the hope of reducing the incidence and severity of injuries. To objectively assess the effectiveness of such equipment, injury data is required prior to and after the introduction of this countermeasure. In many cases, there has been no appropriate evaluation of the countermeasure. Pre- and postintervention data is vital to the protective equipment developer. Such information may be obtained from injury surveillance systems. Other information which is just as vital but not obtainable from such a system is injury tolerance levels. Additional information from injury surveillance such as the type of protective equipment worn, its condition prior to and after impact, and a description of the event leading to injury would be most valuable.

Effects of fatigue and sprint training on electromechanical delay of knee extensor muscles

Electromechanical delay (EMD) of knee extensors in isometric contraction was investigated in six healthy men before and after four periods of 30-s allout sprint cycling exercise, conducted pre and post a 7-week sprint cycling training programme. The EMD was lengthened from 40.4 (SEM 3.46) ms at rest to 63.4 (SEM 7.80) ms after the fatiguing exercise (P < or = 0.05) in the pre-training test. During maximal voluntary contractions (MVC) conducted after the fatiguing exercise, the peak contraction force (Fpeak) and peak rate of force development (RFDpeak) were reduced by 51%-56% and 38%-50%, respectively (both P < or = 0.05). The mechanisms of EMD lengthening during fatigue could have been due to the deterioration in muscle conductive, contractile or elastic properties and require further study. The training programme increased the total work performed during the four periods of sprint exercise (P < or = 0.05). However, no significant training effects were found in the resting or postexercise EMD, Fpeak and RFDpeak during isometric MVC. These unchanged isometric contraction variables but enhanced dynamic performance suggest that isometric tests of muscle are insensitive to the neuromuscular adaptations to sprint training.

Electromechanical delay in isometric muscle contractions evoked by voluntary, reflex and electrical stimulation

Electromechanical delay (EMD) in isometric contractions of knee extensors evoked by voluntary, tendon reflex (TR) and electrical stimulation (ES) was investigated in 21 healthy young subjects. The subject performed voluntary knee extensions with maximum effort (maximal voluntary contraction, MVC), and at 30%, 60% and 80% MVC. Patellar tendon reflexes were evoked with the reflex hammer being dropped from 60 degrees, 75 degrees and 90 degrees positions. In the percutaneous ES evoked contractions, single switches were triggered with pulses of duration 1.0 ms and of intensities 90, 120 and 150 V. Electromyograms of the vastus lateralis and rectus femoris muscles were recorded using surface electrodes. The isometric knee extension force was recorded using a load cell force transducer connected to the subject's lower leg. The major finding of this study was that EMD of the involuntary contractions [e.g. mean 22.1 (SEM 1.32) ms in TR 90 degrees; mean 17.2 (SEM 0.62) ms in ES 150 V] was significantly shorter than that of the voluntary contractions [e.g. mean 38.7 (SEM 1.18) ms in MVC, P < 0.05]. The relationships between EMD, muscle contractile properties and muscle fibre conduction velocity were also investigated. Further study is needed to explain fully the EMD differences found between the voluntary and involuntary contractions.

Soft Contact Lenses for Sports

Good vision is essential in sports, but many athletes go without correction because the solution is worse than the problem. This study shows that soft contact lenses correct more than vision.