Is there cardiac autonomic dysfunction in children and adolescents with exercise-induced bronchospasm?

BACKGROUND: The pulmonary impairment in patients with bronchoconstriction induced by eucapnic voluntary hyperpnea(EVH) goes beyond the respiratory system, also impairing autonomic nervous modulation. This study aimed to evaluate the behavior of cardiac autonomic modulation in young asthmatics with and without EIB after the EVH test. RESEARCH DESIGN AND METHODS: A cross-sectional study design using 54 asthmatics(51.9% female), aged between 10 and 19 years, investigated with the EVH test. Forced expiratory volume in one second(FEV1) was measured at 5, 10, 15, and 30 min after EVH. Heart rate variability(HRV) measures of time were assessed pre and 30 min-post EVH. The diagnosis of Exercise-Induced bronchoconstriction with underlying clinical asthma(EIBA) was confirmed by a fall in FEV1 ≥10% compared to baseline. RESULTS: Thirty(55.5%) asthmatics had EIBA. Subjects with EIBA have reduced mean of the R-R intervals in relation to baseline until 15 minutes after EVH. Individuals without EIBA had increased parasympathetic activity compared to baseline(rMSSD) from 5 min after EVH(p < 0.05). This parasympathetic activity increase in relation to baseline was seen in individuals with EIBA after 25 minutes (rMSSD = 49.9 ± 5.3 vs 63.5 ± 7.2, p < 0.05). CONCLUSION: Young asthmatics with EIBA present a delay in the increase of the parasympathetic component after EVH when compared to asthmatics without EIBA.

Comparing the Effects of the EU- Versus the US-JUUL Pod in a Sample of UK Smokers: Nicotine Absorption, Satisfaction, and Other Nicotine-Related Subjective Effects.

INTRODUCTION: Pod Vaping Devices (PVD) such as JUUL have become extremely popular in the United States although their uptake and use in the United Kingdom remain lower. A key difference between the United States and the United Kingdom is the nicotine strength legally permitted, typically 59 mg/mL in the United States but capped at 20 mg/mL in the United Kingdom and European Union. This may limit the ability of EU vaping devices to deliver satisfactory nicotine levels. The primary aim was to compare the EU- (18 mg/mL nicotine strength) with the U.S.-JUUL (59 mg/mL) on daily smokers' subjective experiences, craving relief, and blood nicotine levels. AIMS AND METHODS: Double-blind, counterbalanced within-participants design with two conditions: 18 mg/mL versus 59 mg/mL. On two separate occasions, UK smokers (N =19, 10 males, 9 females) vaped ad libitum for 60 mins and provided blood samples at baseline 5, 15, 30, and 60 min. Subjective effects (incl. satisfaction) were measured at 10 and 60 min and, craving and withdrawal symptoms (WS) at baseline, 10 and 60 min. RESULTS: Satisfaction did not differ between conditions. There was a significant interaction between Time and Nicotine concentration for Nicotine Hit (p = .045). Mean self-report of Nicotine Hit increased under the use of the 59 mg/mL from 10 to 60 min and decreased under the 18 mg/mL. Participants reported higher Throat Hits following use of the 59 mg/mL (p = .017). There were no differences in other subjective effects including craving, WS relief (ps > .05). Liquid consumption was doubled under the 18 versus the 59 mg/mL (p = .001) and nicotine boost was significantly higher in the 59 mg/mL at all time-points (p ≤ .001). CONCLUSIONS: The results did not support our hypotheses that satisfaction, craving, and withdrawal reduction would be higher with the 59 mg/mL JUUL. This could be because of the doubling of liquid consumption in the 18 mg/mL. Whether satisfaction and craving relief persist over the longer-term outside of the lab remains to be determined. IMPLICATIONS: In a 60-min ad-lib vaping session, the EU-JUUL was found to produce comparable satisfaction, craving- and withdrawal relief as the U.S.-JUUL in this sample of UK smokers. These findings could suggest that the higher nicotine concentrations available in PVDs in the United States are not necessary for providing satisfaction and improving craving and WS. However, this was at the expense of a considerable increase in liquid consumption indicative of compensatory puffing.

The Type of Per-Cooling Strategies Currently Employed by Competitive and Professional Cyclists-Triathletes During Training and Competition Are Condition (Dry vs. Humid) Dependant.

Purpose: To investigate cooling strategies employed by athletes (cyclists-triathletes) during training and competition in hot and dry (HD) and hot and humid (HH) conditions. Methods: Thirty-five athletes completed an online questionnaire on the type, timing, and justification of cooling strategies employed during past training and/or competitions in HD and HH conditions. In addition, 3 athletes also completed a one-to-one follow-up interview. Results: Comparisons between strategies employed in all conditions were based on N = 14 (40%). Cold-water pouring was the most employed (N = 4; 21%) strategy during training and/or competing in hot conditions. The timing of the strategies employed was based on pitstops only (N = 7; 50%). The justification for strategies employed was based on trial and error (N = 9, 42.85%: N = 10, 47.61%). All athletes rated strategies employed as 1 ("not effective for minimising performance impairments and heat-related illnesses"). Comparisons between HD and HH were based on N = 21 (60%), who employed different strategies based on condition. Cold-water ingestion was the most employed (N = 9, 43%) strategy in HD, whereas a combination of cold-water ingestion and pouring was the most employed (N = 9, 43%) strategy in HH. The timing of strategies employed in the HD split was pre-planned by distance but was modified based on how athletes felt during (N = 8, 38%), and pre-planned by distance and pit stops (N = 8, 38%). The timing of strategies employed in HH was pre-planned based on distance and how athletes felt during (N = 9, 42%). About 57% (N = 12) of the 60% (N = 21) perceived effectiveness in HD and HH as 3 ("Sometimes effective and sometimes not effective"), whereas 43% (N = 9) of the 60% (N = 21) perceived effectiveness in HD and HH as 4 ("Effective for minimising performance impairments"). Conclusion: Cold-water ingestion is the preferred strategy by athletes in HD compared to a combination of cold-water ingestion and pouring in HH conditions. All strategies were pre-planned and trialled based on distance and how athletes felt during training and/or competition. These strategies were perceived as effective for minimising performance impairments, but not heat-related illnesses. Future studies should evaluate the effectiveness of these cooling strategies on performance and thermoregulatory responses in HD and HH conditions.

Accuracy of peak nasal flow to determine nasal obstruction in patients with allergic rhinitis.

Objective: The aim of this study was to investigate the ability of Peak Nasal Inspiratory Flow (PNIF) and Peak Nasal Expiratory Flow (PNEF) measures to predict symptoms of nasal obstruction. Methods: This is a cross-sectional study, carried out in 131 individuals (64 with symptomatic allergic rhinitis and 67 asymptomatic) aged between 16 and 50 years. Results: PNIF and PNEF were higher among non-rhinitis. In the curve analysis (receiver operating characteristic), a value of 115 was found for PNIF with a sensitivity of 98.4% and specificity of 87.5% (AUC = 0.99, p < 0.001) and 165 in PNEF with a sensitivity of 65.7% and specificity of 85.1% (AUC = 0.92, p < 0.001). Conclusions: PNIF and PNEF values were lower in patients with AR compared to asymptomatic cases. Our findings present reference values of PNIF and PNEF in the evaluation of nasal obstruction symptoms and reinforce the importance to complement more refined assessment of patients' symptoms. PNEF can be a valuable tool in screening patients and to complement PNIF measurement.

Reliability and Accuracy of a Time-Efficient Method for the Assessment of Achilles Tendon Mechanical Properties by Ultrasonography.

The assessment of the force-length relationship under mechanical loading is widely used to evaluate the mechanical properties of tendons and to gain information about their adaptation, function, and injury. This study aimed to provide a time-efficient ultrasound method for assessing Achilles tendon mechanical properties. On two days, eleven healthy young non-active adults performed eight maximal voluntary isometric ankle plantarflexion contractions on a dynamometer with simultaneous ultrasonographic recording. Maximal tendon elongation was assessed by digitizing ultrasound images at rest and at maximal tendon force. Achilles tendon stiffness index was calculated from the ratio of tendon force-to-strain. No within- and between-day differences were detected between the proposed method and manual frame by frame tracking in Achilles tendon maximal force, maximal elongation, maximal strain, and stiffness index. The overall coefficient of variation between trials ranged from 3.4% to 10.3% and average difference in tendon tracking between methods was less than 0.6% strain. Furthermore, an additional assessment demonstrated significant differences between elite athletes, healthy young, and older adults in Achilles tendon force and stiffness index. Hence, the analysis has the potential to reliably and accurately monitor changes in Achilles tendon mechanical properties due to aging and altered mechanical loading in a time-efficient manner.

Ventilation Rates Achieved in Eucapnic Voluntary Hyperpnea Challenge and Exercise-Induced Bronchoconstriction Diagnosis in Young Patients with Asthma.

PURPOSE: Exercise-induced bronchoconstriction (EIB) affects approximately 50% of young asthma patients, impairing their participation in sports and physical activities. Eucapnic voluntary hyperpnea (EVH) is an approved surrogate challenge to exercise for objective EIB diagnosis, but the required minimum target hyperventilation rates remain unexplored in this population. This study aimed to evaluate the association between the achieved ventilation rates (VRs) during a challenge and EIB-compatible response (EIB-cr) in young asthma patients. METHODS: This cross-sectional study included 72 asthma patients aged 10-20 years. Forced expiratory volume in the first second (FEV1) was measured before and 5, 15, and 30 min after the EVH. The target VR was set at 21 times the individual's baseline FEV1. A decrease of > 10% in FEV1 after the challenge was considered an EIB-cr. The challenge was repeated after 48-72 h in those without an EIB-cr. RESULTS: Thirty-six individuals had an EIB-cr at initial evaluation. The median VRs achieved was not different between individuals with and without an EIB-cr (19.8 versus 17.9; p = 0.619). The proportion of individuals with an EIB-cr was nor different comparing those who achieved (12/25) or not (24/47) the calculated target VRs (p = 0.804). At the repeated EVH challenge an EIB-cr was observed in 14/36 individuals with a negative response in the first evaluation, with no differences in achieved VRs between the two tests (p = 0.463). CONCLUSION: Irrespective of the achieved VR, an EIB-compatible response after an EVH challenge must be considered relevant for clinical and therapeutic judgment and negative tests should be repeated.

The impact of virtual simulation on the recognition and response to the rapidly deteriorating patient among undergraduate nursing students.

A major patient safety challenge is recognition and response to deteriorating patients since early warning signs are often not detected in a timely manner. Nursing students typically learn the skills for early identification through clinical placement, but clinical placements are not guaranteed to provide exposure to deteriorating patients. Nursing students require practice with emergency scenarios to develop their competency and confidence to act in this area. This study aimed to explore the impact of a virtual simulation intervention on the recognition and response to the rapidly deteriorating patient among undergraduate nursing students. A mixed methods study involving a quasi-experimental pre/post design and focus groups. The participants were third or final year undergraduate nursing students from five university sites across four countries (Canada, England, Scotland and Australia, n = 88). Students were randomly assigned to a treatment or control group. The treatment group received a virtual simulation intervention and participated in a focus group. The virtual simulation intervention had a significant effect on improving nursing student knowledge and clinical self-efficacy in the recognition and response to the rapidly deteriorating patient. Students reported that the virtual simulations decreased anxiety, helped them prioritize, filled gaps in their learning, and encouraged autonomous learning within a safe 'low risk' environment. Virtual simulation is an effective strategy for improving knowledge and confidence in recognizing and responding to the rapidly deteriorating patient among undergraduate nursing students.

A survey of minimally invasive cardiac surgery during the COVID-19 pandemic.

BACKGROUND: Lack of scientific data on the feasibility and safety of minimally invasive cardiac surgery (MICS) during the COVID-19 pandemic has made clinical decision making challenging. This survey aimed to appraise MICS activity in UK cardiac units and establish a consensus amongst front-line MICS surgeons regarding standard best MICS practise during the pandemic. METHODS: An online questionnaire was designed through the 'googleforms' platform. Responses were received from 24 out of 28 surgeons approached (85.7%), across 17 cardiac units. RESULTS: There was a strong consensus against a higher risk of conversion from minimally invasive to full sternotomy (92%; n = 22) nor there is increased infection (79%; n = 19) or bleeding (96%; n = 23) with MICS compared to full sternotomy during the pandemic. The majority of respondents (67%; n = 16) felt that it was safe to perform MICS during COVID-19, and that it should not be halted (71%; n = 17). London cardiac units experienced a decrease in MICS (60%; n = 6), whereas non-London units saw no reduction. All London MICS surgeons wore an FP3 mask compared to 62% (n = 8) of non-London MICS surgeons, 23% (n = 3) of which only wore a surgical mask. London MICS surgeons felt that routine double gloving should be done (60%; n = 6) whereas non-London MICS surgeons held a strong consensus that it should not (92%; n = 12). CONCLUSION: Whilst more robust evidence on the effect of COVID-19 on MICS is awaited, this survey provides interesting insights for clinical decision-making regarding MICS and aids to facilitate the development of standardised MICS guidelines for an effective response during future pandemics.

Short-Term Perceptually Regulated Interval-Walk Training in Hypoxia and Normoxia in Overweight-to-Obese Adults.

We compared the effects of short-term, perceptually regulated training using interval-walking in hypoxia vs. normoxia on health outcomes in overweight-to-obese individuals. Sixteen adults (body mass index = 33 ± 3 kg·m-2) completed eight interval-walk training sessions (15 × 2 min walking at a rating of perceived exertion of 14 on the 6-20 Borg scale; rest = 2 min) either in hypoxia (FiO2 = 13.0%) or normoxia during two weeks. Treadmill velocity did not differ between conditions or over time (p > 0.05). Heart rate was higher in hypoxia (+10 ± 3%; p = 0.04) during the first session and this was consistent within condition across the training sessions (p > 0.05). Similarly, arterial oxygen saturation was lower in hypoxia than normoxia (83 ± 1% vs. 96 ± 1%, p < 0.05), and did not vary over time (p > 0.05). After training, perceived mood state (+11.8 ± 2.7%, p = 0.06) and exercise self-efficacy (+10.6 ± 4.1%, p = 0.03) improved in both groups. Body mass (p = 0.55), systolic and diastolic blood pressure (p = 0.19 and 0.07, respectively) and distance covered during a 6-min walk test (p = 0.11) did not change from pre- to post-tests. Short term (2-week) perceptually regulated interval-walk training sessions with or without hypoxia had no effect on exercise-related sensations, health markers and functional performance. This mode and duration of hypoxic conditioning does not appear to modify the measured cardiometabolic risk factors or improve exercise tolerance in overweight-to-obese individuals.

Acute psycho-physiological responses to perceptually regulated hypoxic and normoxic interval walks in overweight-to-obese adults.

OBJECTIVES: We investigated psycho-physiological responses to perceptually regulated interval walks in hypoxia versus normoxia in obese individuals. DESIGN: Within-participants repeated measures. METHODS: Ten obese adults (BMI=32±3kg/m-2) completed a 60-min interval session (15×2min walking at a rating of perceived exertion of 14 on the 6-20 Borg scale with 2min of rest) either in hypoxia (FiO2=13.0%, HYP) or normoxia (NOR). A third trial replicating the HYP speed pattern was carried out in normoxia as a control (CON). Exercise responses were analysed comparing the average of 1st to 3rd exercise bouts to those of the 4th-6th, 7th-9th, 10th-12th and 13th-15th exercise bouts (block 1 versus 2, 3, 4 and 5). RESULTS: Treadmill speed was slower during block 4 (6.14±0.67 versus 6.24±0.73km/h-1) and block 5 (6.12±0.64 versus 6.25±0.75km/h-1) in HYP compared to NOR or CON (p=0.009). Compared to NOR and CON, heart rate was +6-10% higher (p=0.001), whilst arterial oxygen saturation (-12-13%) was lower (p<0.001) in HYP. Perceived limb discomfort was lower in HYP and CON versus NOR (-21±4% and -34±6%; p=0.004). CONCLUSIONS: In overweight-to-obese adults, perceptually regulated interval walks in hypoxia versus normoxia leads to progressively slower speeds along with lower limb discomfort and larger physiological stress than normoxia. Walking at the speed adopted in hypoxia produces similar psycho-physiological responses at the same absolute intensity in normoxia.

Running mechanics adjustments to perceptually-regulated interval runs in hypoxia and normoxia.

OBJECTIVES: We determined whether perceptually-regulated, high-intensity intermittent runs in hypoxia and normoxia induce similar running mechanics adjustments within and between intervals. DESIGN: Within-participants repeated measures. METHODS: Nineteen trained runners completed a high-intensity intermittent running protocol (4×4-min intervals at a perceived rating exertion of 16 on the 6-20 Borg scale, 3-min passive recoveries) in either hypoxic (FiO2=0.15) or normoxic (FiO2=0.21) conditions. Running mechanics were collected over 10 consecutive steps, at constant velocity (∼15.0±2.0km.h-1), at the beginning and the end of each 4-min interval. Repeated measure ANOVA were used to assess within intervals (onset vs. end of each interval), between intervals (interval 1, 2, 3 vs. 4) and FiO2 (0.15 vs. 0.21) main effects and any potential interaction. RESULTS: Participants progressively reduced running velocity from interval 1-4, and more so in hypoxia compared to normoxia for intervals 2, 3 and 4 (P<0.01). There were no between intervals (across all intervals P>0.298) and FiO2 (across all intervals P>0.082) main effects or any significant between intervals×within intervals×FiO2 interactions (all P>0.098) for any running mechanics variables. Irrespective of interval number or FiO2, peak loading rate (+10.6±7.7%; P<0.001) and duration of push-off phase (+2.0±3.1%; P=0.001) increased from the onset to the end of 4-min intervals, whereas peak push-off force decreased (-4.0±4.0%; P<0.001). CONCLUSIONS: When carrying out perceptually-regulated interval treadmill runs, runners adjust to progressively slower velocities in hypoxia compared to normoxia. However, only subtle constant-velocity modifications of their mechanical behaviour occurred within each set, independently of FiO2 or interval number.

Less Is More-Cyclists-Triathlete's 30 min Cycling Time-Trial Performance Is Impaired With Multiple Feedback Compared to a Single Feedback.

Purpose: The purpose of this article was to (i) compare different modes of feedback (multiple vs. single) on 30 min cycling time-trial performance in non-cyclist's and cyclists-triathletes, and (ii) investigate cyclists-triathlete's information acquisition. Methods: 20 participants (10 non-cyclists, 10 cyclists-triathletes) performed two 30 min self-paced cycling time-trials (TT, ∼5-7 days apart) with either a single feedback (elapsed time) or multiple feedback (power output, elapsed distance, elapsed time, cadence, speed, and heart rate). Cyclists-triathlete's information acquisition was also monitored during the multiple feedback trial via an eye tracker. Perceptual measurements of task motivation, ratings of perceived exertion (RPE) and affect were collected every 5 min. Performance variables (power output, cadence, distance, speed) and heart rate were recorded continuously. Results: Cyclists-triathletes average power output was greater compared to non-cyclists with both multiple feedback (227.99 ± 42.02 W; 137.27 ± 27.63 W; P < 0.05) and single feedback (287.9 ± 60.07 W; 131.13 ± 25.53 W). Non-cyclist's performance did not differ between multiple and single feedback (p > 0.05). Whereas, cyclists-triathletes 30 min cycling time-trial performance was impaired with multiple feedback (227.99 ± 42.02 W) compared to single feedback (287.9 ± 60.07 W; p < 0.05), despite adopting and reporting a similar pacing strategy and perceptual responses (p > 0.05). Cyclists-triathlete's primary and secondary objects of regard were power (64.95 s) and elapsed time (64.46 s). However, total glance time during multiple feedback decreased from the first 5 min (75.67 s) to the last 5 min (22.34 s). Conclusion: Cyclists-triathletes indoor 30 min cycling TT performance was impaired with multiple feedback compared to single feedback. Whereas non-cyclist's performance did not differ between multiple and single feedback. Cyclists-triathletes glanced at power and time which corresponds with the wireless sensor networks they use during training. However, total glance time during multiple feedback decreased over time, and therefore, overloading athletes with feedback may decrease performance in cyclists-triathletes.

Acute Psychophysiological Responses to Cyclic Variation of Intermittent Hypoxic Exposure in Adults with Obesity.

Background: We compared acute psychophysiological responses with a single intermittent hypoxic exposure (IHE)/normoxic exposure trial with varying cycle lengths in adults with obesity. Materials and Methods: Eight obese adults (body mass index = 33.0 ± 2.2 kg/m2) completed three 60-minute IHE trials (passive seating), separated by 7 days. Trials comprised 30-minute hypoxia/30-minute normoxia (inspired oxygen fraction = 12.0%/20.9%) over Short (15 × 2/2 minutes), Medium (10 × 3/3 minutes), and Long (5 × 6/6 minutes) hypoxic/normoxic cycles and a control trial (60-minute normoxia). Results: Arterial oxygen saturation was lower during hypoxic periods of Long versus Medium and Short trials (90.1% vs. 93.0% and 94.2%; p = 0.02 and p = 0.05), with no differences between Short and Medium. Prefrontal cortex oxygenation was lower (-5.1%) during all IHE interventions versus control (p < 0.02), independent of cycle length. Perceived breathlessness was unaffected during IHE but increased 15 minutes after exposure versus baseline (+34%; p = 0.04). Breathlessness was lowest after Short versus control from 15 to 60 minutes (-7%; p = 0.01). Conclusions: When implementing IHE, greater desaturation is observed during longer compared with shorter hypoxic/normoxic cycles in adults with obesity. However, IHE tends to be better tolerated perceptually with shorter rather than longer cycles.

Evidence of a Uniform Muscle-Tendon Unit Adaptation in Healthy Elite Track and Field Jumpers: A Cross Sectional Investigation.

Different adaptive responses to mechanical loading between muscle and tendon can lead to non-uniform biomechanical properties within the muscle-tendon unit. The current study aimed to analyze the mechanical properties of the triceps surae muscle-tendon unit in healthy male and female elite track and field jumpers in order to detect possible inter-limb differences and intra-limb non-uniformities in muscle and tendon adaptation. The triceps surae muscle strength and tendon stiffness were analyzed in both limbs during maximal voluntary isometric plantar flexion contractions using synchronous dynamometry and ultrasonography in sixty-seven healthy young male (n = 35) and female (n = 32) elite international level track and field jumpers (high jump, long jump, triple jump, pole vault). Triceps surae muscle-tendon unit intra-limb uniformity was assessed using between limb symmetry indexes in the muscle strength and tendon stiffness. Independent from sex and jumping discipline the take-off leg showed a significantly higher (p < 0.05) triceps surae muscle strength and tendon stiffness, suggesting different habitual mechanical loading between legs. However, despite these inter-limb discrepancies no differences were detected in the symmetry indexes of muscle strength (5.9 ± 9.4%) and tendon stiffness (8.1 ± 11.5%). This was accompanied by a significant correlation between the symmetry indexes of muscle strength and tendon stiffness (r = 0.44; p < 0.01; n = 67). Thus, the current findings give evidence for a uniform muscle-tendon unit adaptation in healthy elite track and field jumpers, which can be reflected as a protective mechanism to maintain its integrity to meet the functional demand.

Perception, Action, and Cognition of Football Referees in Extreme Temperatures: Impact on Decision Performance.

Different professional domains require high levels of physical performance alongside fast and accurate decision-making. Construction workers, police officers, firefighters, elite sports men and women, the military and emergency medical professionals are often exposed to hostile environments with limited options for behavioral coping strategies. In this (mini) review we use football refereeing as an example to discuss the combined effect of intense physical activity and extreme temperatures on decision-making and suggest an explicative model. In professional football competitions can be played in temperatures ranging from -5°C in Norway to 30°C in Spain for example. Despite these conditions, the referee's responsibility is to consistently apply the laws fairly and uniformly, and to ensure the rules are followed without waning or adversely influencing the competitiveness of the play. However, strenuous exercise in extreme environments imposes increased physiological and psychological stress that can affect decision-making. Therefore, the physical exertion required to follow the game and the thermal strain from the extreme temperatures may hinder the ability of referees to make fast and accurate decisions. Here, we review literature on the physical and cognitive requirements of football refereeing and how extreme temperatures may affect referees' decisions. Research suggests that both hot and cold environments have a negative impact on decision-making but data specific to decision-making is still lacking. A theoretical model of decision-making under the constraint of intense physical activity and thermal stress is suggested. Future naturalistic studies are needed to validate this model and provide clear recommendations for mitigating strategies.

Distinguishing between acute and chronic elements of ill health when assessing patients.

Recognising ill health in patients is a multifaceted skill. Nurses can use aneclectic mix of assessment tools to differentiate between the severity of acute illness and to grade chronic illness. The end point of such assessment is an appropriate and individualised patient management plan.

Holistic assessment of patients with COPD before the use of non-invasive ventilation.

The use of non-invasive ventilation (NIV) to manage patients with exacerbations of COPD has increased in the past 10 years. However, this intervention can be counterproductive. This article highlights why holistic patient assessment as well as arterial blood gas analysis are important before NIV is used.

Aortic valve replacement with the Sorin Pericarbon Freedom stentless valve: five-year follow up.

BACKGROUND AND AIM OF THE STUDY: Presumed benefits from stentless bioprostheses include larger orifice areas with lower transvalvular gradients, and improved hemodynamic flow characteristics and annular mechanics. Herein are reported the results of a large series of the Sorin Pericarbon Freedom stentless valve implanted in the aortic position. METHODS: Between July 1998 and June 2003, a total of 102 consecutive patients (58 males, 44 females; mean age 71.7+/-7.8 years; range: 28-87 years) requiring aortic valve replacement (AVR), including those undergoing concomitant procedures of coronary artery bypass, mitral valve repair and mini-maze, was recruited. The predominant lesion was aortic stenosis (n = 92; 90.2%); aortic regurgitation (AR) occurred in five patients (4.9%) (including three with endocarditis), and mixed aortic valve disease in five (4.9%). Six patients (5.9%) had undergone previous cardiac surgery. The median preoperative NYHA class was III. Thirsty-six patients (35.3%) underwent AVR alone. The mean valve size was 25 mm (range: 21-29 mm). Sixty-three patients (61.8%) had concomitant coronary artery disease that required a mean of 2.4+/-1.1 bypass grafts; three patients (3.0%) had combined AVR and mitral valve repair. The study end points observed were mortality, valve failure due to degeneration or endocarditis, reoperation, thromboembolism, transvalvular gradients and left ventricular (LV) mass regression. RESULTS: The median follow up for all patients was 31 months (range: 12 months to 5 years). The mean total cross-clamp time was 71.7+/-17.6 min without associated procedures, and 93.9+/-19.7 min with concomitant procedures. Early mortality was 4/102 (3.8%); actuarial survival over five years was 89.2%. Freedom from thromboembolism over five years was 95.9%, from reoperation 100%, and from endocarditis 99.98%. Fifty-seven patients (56.4%) had no AR detected postoperatively, and 34 (33.3%) had trivial or mild AR. A significant decline was observed in indexed LV mass regression within six months of surgery, from 190+/-72 g/m(2) at baseline to 152+/-47 g/m(2) (p = 0.01). CONCLUSION: In an elderly population with a high incidence of coronary artery disease, the Sorin Pericarbon Freedom stentless valve offers excellent hemodynamics, resulting in significant regression of left ventricular hypertrophy, together with acceptable operation times, morbidity and mortality in the medium term.