Caffeine does not influence persistent inward current contribution to motoneuron firing.

The purpose of this study was to investigate whether caffeine consumption would change persistent inward current (PIC) contribution to motoneuron firing at increased contraction intensities and after repetitive sustained maximal contractions. Before and after the consumption of 6 mg·kg-1 of caffeine or placebo, 16 individuals performed isometric triangular-shaped ramp dorsiflexion contractions (to 20% and 40% of peak torque), followed by four maximal contractions sustained until torque production dropped to 60% of maximum, and consecutive 20% triangular-shaped contractions. Tibialis anterior motor unit firing frequencies were analyzed from high-density surface electromyograms. PIC contribution to motor unit firing was estimated by calculating the delta frequency (ΔF) using the paired motor unit technique. Motoneuron peak firing frequencies at 20% and 40% contractions and total torque-time integral during the repetitive sustained maximal contractions were also assessed. ΔF increased 0.69 peaks per second (pps) (95% CI = -0.98, -0.405; d = -0.87) from 20% to 40% contraction intensities and reduced 0.85 pps (95% CI = 0.66, 1.05; d = 0.99) after the repetitive sustained maximal contractions, regardless of caffeine consumption. Participants produced 337 Nm·s (95% CI = 49.9, 624; d = 0.63) more torque integral during the repetitive sustained maximal contractions after caffeine consumption. A strong repeated-measures correlation (r = 0.61; 95% CI = 0.49, 0.69) was observed between reductions of ΔF and peak firing frequencies after the repetitive sustained maximal contractions. PIC contribution to motoneuron firing increases from 20% to 40% contraction intensities, with no effect of caffeine (on rested tibialis anterior). Repetitive sustained maximal contractions reduced PIC contribution to motoneuron firing, regardless of caffeine or placebo consumption, evidencing that changes in intrinsic motoneuron properties contributed to performance loss. Caffeine-attenuated reduction of torque production capacity was unlikely mediated by PICs.NEW & NOTEWORTHY Persistent inward current (PIC) contribution to motoneuron firing increases with contraction intensities and is reduced after repetitive sustained maximal contractions, regardless of caffeine consumption. Reductions of PIC contribution to motoneuron firing and peak firing frequencies were largely associated, evidencing a novel mechanism underpinning decrements in maximal torque production capacity following repetitive sustained maximal contractions. Caffeine consumption attenuated neuromuscular performance reductions-allowing higher time-torque integral production during repetitive sustained maximal contractions. This was unlikely mediated by PIC.

Intrinsic motor neuron excitability is increased after resistance training in older adults.

This study investigated the effects of high-intensity resistance training on estimates of the motor neuron persistent inward current (PIC) in older adults. Seventeen participants (68.5 ± 2.8 yr) completed a 2-wk nonexercise control period followed by 6 wk of resistance training. Surface electromyographic signals were collected with two 32-channel electrodes placed over soleus to investigate motor unit discharge rates. Paired motor unit analysis was used to calculate delta frequency (ΔF) as an estimate of PIC amplitudes during 1) triangular-shaped contractions to 20% of maximum torque capacity and 2) trapezoidal- and triangular-shaped contractions to 20% and 40% of maximum torque capacity, respectively, to understand their ability to modulate PICs as contraction intensity increases. Maximal strength and functional capacity tests were also assessed. For the 20% triangular-shaped contractions, ΔF [0.58-0.87 peaks per second (pps); P ≤ 0.015] and peak discharge rates (0.78-0.99 pps; P ≤ 0.005) increased after training, indicating increased PIC amplitude. PIC modulation also improved after training. During the control period, mean ΔF differences between 20% trapezoidal-shaped and 40% triangular-shaped contractions were 0.09-0.18 pps (P = 0.448 and 0.109, respectively), which increased to 0.44 pps (P < 0.001) after training. Also, changes in ΔF showed moderate to very large correlations (r = 0.39-0.82) with changes in peak discharge rates and broad measures of motor function. Our findings indicate that increased motor neuron excitability is a potential mechanism underpinning training-induced improvements in motor neuron discharge rate, strength, and motor function in older adults. This increased excitability is likely mediated by enhanced PIC amplitudes, which are larger at higher contraction intensities.NEW & NOTEWORTHY Resistance training elicited important alterations in soleus intrinsic motor neuronal excitability, likely mediated by enhanced persistent inward current (PIC) amplitude, in older adults. Estimates of PICs increased after the training period, accompanied by an enhanced ability to increase PIC amplitudes at higher contraction intensities. Our data also suggest that changes in PIC contribution to self-sustained discharging may contribute to increases in motor neuron discharge rates, maximal strength, and functional capacity in older adults after resistance training.

Neither Beetroot Juice Supplementation nor Increased Carbohydrate Oxidation Enhance Economy of Prolonged Exercise in Elite Race Walkers.

Given the importance of exercise economy to endurance performance, we implemented two strategies purported to reduce the oxygen cost of exercise within a 4 week training camp in 21 elite male race walkers. Fourteen athletes undertook a crossover investigation with beetroot juice (BRJ) or placebo (PLA) [2 d preload, 2 h pre-exercise + 35 min during exercise] during a 26 km race walking at speeds simulating competitive events. Separately, 19 athletes undertook a parallel group investigation of a multi-pronged strategy (MAX; n = 9) involving chronic (2 w high carbohydrate [CHO] diet + gut training) and acute (CHO loading + 90 g/h CHO during exercise) strategies to promote endogenous and exogenous CHO availability, compared with strategies reflecting lower ranges of current guidelines (CON; n = 10). There were no differences between BRJ and PLA trials for rates of CHO (p = 0.203) or fat (p = 0.818) oxidation or oxygen consumption (p = 0.090). Compared with CON, MAX was associated with higher rates of CHO oxidation during exercise, with increased exogenous CHO use (CON; peak = ~0.45 g/min; MAX: peak = ~1.45 g/min, p < 0.001). High rates of exogenous CHO use were achieved prior to gut training, without further improvement, suggesting that elite athletes already optimise intestinal CHO absorption via habitual practices. No differences in exercise economy were detected despite small differences in substrate use. Future studies should investigate the impact of these strategies on sub-elite athletes' economy as well as the performance effects in elite groups.

Estimates of persistent inward currents increase with the level of voluntary drive in low-threshold motor units of plantar flexor muscles.

This study tested whether estimates of persistent inward currents (PICs) in the human plantar flexors would increase with the level of voluntary drive. High-density surface electromyograms were collected from soleus and gastrocnemius medialis of 21 participants (29.2 ± 2.6 yr) during ramp-shaped isometric contractions to 10%, 20%, and 30% (torque rise and decline of 2%/s and 30-s duration) of each participant's maximal torque. Motor units identified in all the contraction intensities were included in the paired-motor unit analysis to calculate delta frequency (ΔF) and estimate the PICs. ΔF is the difference in discharge rate of the control unit at the time of recruitment and derecruitment of the test unit. Increases in PICs were observed from 10% to 20% [Δ = 0.6 pulse per second (pps); P < 0.001] and from 20% to 30% (Δ = 0.5 pps; P < 0.001) in soleus and from 10% to 20% (Δ = 1.2 pps; P < 0.001) but not from 20% to 30% (Δ = 0.09 pps; P = 0.724) in gastrocnemius medialis. Maximal discharge rate increased for soleus and gastrocnemius medialis from 10% to 20% [Δ = 1.75 pps (P < 0.001) and Δ = 2.43 pps (P < 0.001), respectively] and from 20% to 30% [Δ = 0.80 pps (P < 0.017) and Δ = 0.92 pps (P = 0.002), respectively]. The repeated-measures correlation identified associations between ΔF and increases in maximal discharge rate for soleus (r = 0.64; P < 0.001) and gastrocnemius medialis (r = 0.77; P < 0.001). An increase in voluntary drive tends to increase PIC strength, which has key implications for the control of force but also for comparisons between muscles or studies when relative force levels might be different. Increases in voluntary descending drive amplify PICs in humans and provide an important spinal mechanism for motor unit discharging, and thus force output modulation.NEW & NOTEWORTHY Animal experiments and computational models have shown that motor neurons can amplify the synaptic input they receive via persistent inward currents. Here we show in humans that this amplification varies proportionally to the magnitude of the voluntary drive to the muscle.

Risk to human health related to the presence of perfluoroalkyl substances in food.

The European Commission asked EFSA for a scientific evaluation on the risks to human health related to the presence of perfluoroalkyl substances (PFASs) in food. Based on several similar effects in animals, toxicokinetics and observed concentrations in human blood, the CONTAM Panel decided to perform the assessment for the sum of four PFASs: PFOA, PFNA, PFHxS and PFOS. These made up half of the lower bound (LB) exposure to those PFASs with available occurrence data, the remaining contribution being primarily from PFASs with short half-lives. Equal potencies were assumed for the four PFASs included in the assessment. The mean LB exposure in adolescents and adult age groups ranged from 3 to 22, the 95th percentile from 9 to 70 ng/kg body weight (bw) per week. Toddlers and 'other children' showed a twofold higher exposure. Upper bound exposure was 4- to 49-fold higher than LB levels, but the latter were considered more reliable. 'Fish meat', 'Fruit and fruit products' and 'Eggs and egg products' contributed most to the exposure. Based on available studies in animals and humans, effects on the immune system were considered the most critical for the risk assessment. From a human study, a lowest BMDL 10 of 17.5 ng/mL for the sum of the four PFASs in serum was identified for 1-year-old children. Using PBPK modelling, this serum level of 17.5 ng/mL in children was estimated to correspond to long-term maternal exposure of 0.63 ng/kg bw per day. Since accumulation over time is important, a tolerable weekly intake (TWI) of 4.4 ng/kg bw per week was established. This TWI also protects against other potential adverse effects observed in humans. Based on the estimated LB exposure, but also reported serum levels, the CONTAM Panel concluded that parts of the European population exceed this TWI, which is of concern.

Acute human exposure assessment to tetrahydrocannabinol (Δ9-THC).

Delta-9-tetrahydrocannabinol (Δ9-THC) is a naturally occurring psychoactive compound derived from the hemp plant Cannabis sativa. In 2015, EFSA established an acute reference dose (ARfD) of 1 µg/kg body weight (bw) for Δ9-THC and assessed acute dietary exposure from milk and dairy products. This resulted at the most 3% and 13% of the ARfD for adults and toddlers, respectively. Following the European Commission Recommendation 2016/2115 on the monitoring of the presence of Δ9-THC in food and the issuing of a new mandate, EFSA assessed the acute human exposure to Δ9-THC. 'Standard' food categories were used as proxies for consumption of hemp and hemp-based products. Twelve independent scenarios based on single food categories were considered and acute exposure was assessed for consumption days only for all age groups excluding infants. Occurrence data for Total-Δ9-THC (588 samples in total) were used for this assessment up to the highest reliable percentile for each food category. The EFSA ARfD of 1 µg/kg bw was exceeded in the adult high consumers of most considered hemp and hemp-containing products, under the lower-bound (LB) and upper-bound (UB) scenario. At the UB, acute exposure in adult high consumers was estimated based on the highest reliable percentile of occurrence, for Hemp seeds (P95, up to 9 µg/kg bw), Hemp oil (P95, up to 21 µg/kg bw), Tea (Infusion) (P95, up to 208 µg/kg bw), Breakfast cereals (P50, up to 1.3 µg/kg bw), Pasta (Raw) (P75, up to 6.4 µg/kg bw), Bread and rolls (P75, up to 1.3 µg/kg bw), Bread and rolls from hemp flour (P90, up to 4.1 µg/kg bw), Cereal bars (P50, up to 0.3 µg/kg bw), Fine bakery wares (P75, up to 5.1 µg/kg bw), Chocolate (Cocoa) products (P75, up to 1.1 µg/kg bw), Energy drinks (P75, up to 0.2 µg/kg bw), Dietary supplements (P75, up to 9.9 µg/kg bw), Beer and beer-like beverages (P90, up to 41 µg/kg bw). The use of proxies for the consumption of hemp and hemp-containing products, the limited number of occurrence data and the analytical limitations in the quantification of Δ9-THC represent the most important sources of uncertainty. Overall, exposure estimates presented in this report are expected to represent an overestimation of acute exposure to Δ9-THC in the EU.

Physiological response to eccentric and concentric cycling in patients with chronic obstructive pulmonary disease.

We aimed to compare the cardiorespiratory, metabolic, and perceptual responses to high- and moderate-intensity eccentric cycling versus moderate-intensity concentric cycling in chronic obstructive pulmonary disease (COPD) patients. Ten patients with moderate COPD (forced expiratory volume in 1 s (FEV1) = 68.6% ± 20.4% of predicted; 68.3 ± 9.1 years) performed 30 min of moderate-intensity concentric (CONC-M: 50% maximum workload; Wmax), moderate-intensity eccentric (ECC-M: 50% Wmax), and high-intensity eccentric (ECC-H: 100% Wmax) cycling. Average power output, oxygen consumption (V̇O2), minute ventilation (VE), respiratory frequency (fR), oxygen saturation (SpO2), heart rate (HR), systolic and diastolic blood pressure (SBP and DBP), rate of perceived exertion (RPE), and dyspnea were measured during cycling. Compared with CONC-M, lower V̇O2 (-52% ± 14%), VE (-47% ± 16%), fR (-21% ± 14%), HR (-14% ± 16%), SBP (-73% ± 54%), RPE (-36% ± 26%), and dyspnea (-41% ± 37%) were found during ECC-M. During ECC-H, a similar metabolic demand to CONC-M was found. However, average power output was 117% ± 79% higher during ECC-H. Eccentric cycling can be safely performed by COPD patients and induced lower cardiorespiratory, metabolic, and perceptual responses than concentric exercise when performed at the same workload. Novelty Moderate- and high-intensity eccentric cycling can be performed by COPD patients. Moderate-intensity eccentric cycling showed lower cardiorespiratory, metabolic, and perceptual demand than concentric cycling at the same workload in COPD patients. Even at double workload, eccentric cycling induces lower cardiorespiratory, metabolic, and perceptual demand than moderate-intensity concentric cycling.

Effects of skim milk and isotonic drink consumption before exercise on fluid homeostasis and time-trial performance in cyclists: a randomized cross-over study.

BACKGROUND: Hydration status affects endurance performance. Pre-exercise hydration recommendations target the consumption of high carbohydrate and sodium beverages. Milk, due to its carbohydrate and sodium content, may be considered an effective pre-exercise hydration beverage. PURPOSE: In a randomized cross-over trial, we compared the effects of an isotonic sport drink (SPD) with skim milk (SM) consumption before a race, on fluid homeostasis and time-trial performance in road cyclists. METHODS: Male road cyclists (n = 9; age, 26.8 ± 4.78 years) with 10.8 ± 8.56 years of experience in national competitions, consumed either SPD or SM in doses of 350 mL at 3 h and 350 mL at 1.5 h before a 18.6 km time-trial race. Measurements of body mass, urine specific gravity (USG), urine color and time-trial were compared between drinks (group; g) before and after the race (time; t). RESULTS: The two-way ANOVA showed no differences between SPD and SM in body mass (t, p < 0.0001; g, p = 0.89; t × g, p = 0.54), USG (t, p = 0.01; g, p = 0.63; t × g, p = 0.29) and urine color (t, p = 0.01; g, p = 0.54; t × g, p = 0.28) before or after race. Furthermore, no differences on water consumption during the race (p = 0.55) or time-trial performance (p = 0.84) were observed between trials. CONCLUSION: Current results may help athletes with different beverages preferences to increase their options of hydration strategies.

Effects of oral contraceptive use on female sexual salivary hormones and indirect markers of muscle damage following eccentric cycling in women.

PURPOSE: To determine the effects of oral contraceptive (OC) use on salivary concentrations of testosterone, estrogen, progesterone, and its effects on the changes in indirect markers of muscle damage following eccentric cycling in women. METHODS: 10 oral contraceptive users at follicular phase (OC-FOL), 10 non-oral contraceptives users at follicular phase (NOC-FOL), and 10 non-oral contraceptives users at ovulation phase (NOC-OV) participated. Subjects performed 30 min of eccentric cycling at 90% of their maximal concentric power output (PO). Maximal voluntary isometric contraction (MVC), creatine kinase activity (CK), muscle soreness (SOR), and pain pressure threshold of vastus lateralis (PPT-VL) was assessed before, immediately after, and 24-96 h after cycling. Salivary estrogen, progesterone and testosterone concentrations were measured before, 72 and 96 h after exercise. RESULTS: No difference in estrogen levels between users and non-users was observed. Testosterone was 45% lower in OC-FOL than NOC-FOL at 96 h post-exercise (P = 0.01). Progesterone was 30.8-fold higher in NOC-OV than OC-FOL and 9.7-fold higher than NOC-FOL at 96 h post-exercise. The NOC-FOL recovered all indirect markers of muscle damage by 72 h post-exercise (P > 0.05). NOC-OV recovered MVC strength and muscle soreness (SOR and PPT-VL) by 96 h post-exercise (P > 0.05). OC-FOL did not recover baseline values of MVC, SOR, CK, and PPT-VL by 96 h. CONCLUSION: These results suggest that recovery after exercise-induced muscle damage took longer in OC-FOL, followed by NOC-OV and by NOC-FOL, respectively. Furthermore, testosterone and progesterone levels may affect recovery of indirect markers of muscle damage in women.

Changes in oxidative stress, inflammation and muscle damage markers following eccentric versus concentric cycling in older adults.

PURPOSE: To compare concentric and eccentric cycling performed by older adults for metabolic demand and post-exercise oxidative stress, inflammation and muscle damage. METHODS: Eight male and two female healthy older adults (60.4 ± 6.8 years) performed 30 min of moderate-intensity concentric (CONC-M: 50% maximum power output; POmax) and eccentric cycling (ECC-M: 50% POmax) and high-intensity eccentric cycling (ECC-H: 100% POmax) in a randomized order. Average power output (PO), oxygen consumption (VO2), heart rate (HR) and rate of perceived exertion were recorded during cycling. Some indirect markers of muscle damage were assessed before, and immediately, 24 and 48 h after cycling. Markers of oxidative stress (malondialdehyde: MDA, protein carbonyl), antioxidant (total antioxidant capacity, glutathione peroxidase activity: GPx) and inflammation (IL-6, TNF-α) were measured before and 5 min after cycling. RESULTS: PO in ECC-H (202.6 ± 78.5 W) was > 50% greater (P < 0.05) than that of CONC-M (98.6 ± 33.1 W) and ECC-M (112.0 ± 42.1 W). VO2 and HR were also greater (P < 0.05) for ECC-H than CONC-M (50% and 17%, respectively) and ECC-M (40% and 23%, respectively). Muscle strength loss at 1 day post-exercise (8-22%), peak soreness (10-62 mm) and creatine kinase activity (30-250 IU/L) after ECC-H were greater (P < 0.05) than those after ECC-M and CONC-M. MDA decreased (P < 0.05) after CONC-M (- 28%) and ECC-M (- 22%), but not after ECC-H. GPx activity increased after all exercises similarly (20-27%). IL-6 increased (P < 0.05) only after ECC-H (18%). CONCLUSION: Oxidative stress was minimal after eccentric cycling, but high-intensity eccentric cycling induced moderate muscle damage and inflammation, which is not desirable for older individuals.

Rating of Perceived Exertion During Concentric and Eccentric Cycling: Are We Measuring Effort or Exertion?

Despite the terms' often being used interchangeably, it has been suggested that perceptions of effort and perceptions of exertion may differ. Eccentric (ECC) cycling may provide a model of exercise by which differences between these perceptions can be examined. PURPOSE: To examine and compare perceptions of effort and exertion during ECC and concentric (CONC) cycling at 4 intensities. METHODS: Ten healthy male participants (mean [SD]: age = 29.8 [2.3] y) performed an incremental cycling test for the determination of maximal aerobic power output, followed in a randomized and crossover design, by four 5-min bouts (30%, 60%, 80%, and maximal) of either ECC or CONC cycling. Through each bout, participants were asked to report their perceived effort, exertion, and muscle pain. Heart rate and oxygen consumption were continuously recorded throughout each bout. RESULTS: Perceived exertion was greater for CONC at 30% (8.5 [1.5] vs 7.1 [1.8]; P = .01), 60% (12.4 [1.4] vs 10.3 [2.0]; P = .01), 80% (15.8 [1.7] vs 12.4 [2.5]; P < .01), and maximal (17.2 [1.3] vs 15.6 [1.8]; P = .03) in comparison with ECC. Perceptions of effort and pain were similar between CONC and ECC. Heart rate and oxygen consumption were greater during CONC than ECC. CONCLUSIONS: Perceived exertion was greater during CONC compared with ECC cycling, yet effort was similar between conditions despite different physiological stress. Such findings have implications for understanding the development of such perceptions during exercise.

Risk to human health related to the presence of perfluorooctane sulfonic acid and perfluorooctanoic acid in food.

The European Commission asked EFSA for a scientific evaluation on the risks to human health related to the presence of perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) in food. Regarding PFOS and PFOA occurrence, the final data set available for dietary exposure assessment contained a total of 20,019 analytical results (PFOS n = 10,191 and PFOA n = 9,828). There were large differences between upper and lower bound exposure due to analytical methods with insufficient sensitivity. The CONTAM Panel considered the lower bound estimates to be closer to true exposure levels. Important contributors to the lower bound mean chronic exposure were 'Fish and other seafood', 'Meat and meat products' and 'Eggs and egg products', for PFOS, and 'Milk and dairy products', 'Drinking water' and 'Fish and other seafood' for PFOA. PFOS and PFOA are readily absorbed in the gastrointestinal tract, excreted in urine and faeces, and do not undergo metabolism. Estimated human half-lives for PFOS and PFOA are about 5 years and 2-4 years, respectively. The derivation of a health-based guidance value was based on human epidemiological studies. For PFOS, the increase in serum total cholesterol in adults, and the decrease in antibody response at vaccination in children were identified as the critical effects. For PFOA, the increase in serum total cholesterol was the critical effect. Also reduced birth weight (for both compounds) and increased prevalence of high serum levels of the liver enzyme alanine aminotransferase (ALT) (for PFOA) were considered. After benchmark modelling of serum levels of PFOS and PFOA, and estimating the corresponding daily intakes, the CONTAM Panel established a tolerable weekly intake (TWI) of 13 ng/kg body weight (bw) per week for PFOS and 6 ng/kg bw per week for PFOA. For both compounds, exposure of a considerable proportion of the population exceeds the proposed TWIs.

Presence of free gossypol in whole cottonseed.

The European Commission asked EFSA to assess information provided by the Spanish Ministry of Agriculture, Food and Environment, on the toxicity of free gossypol in relation to the use of whole cotton seed in feed for ruminants, in particular dairy cows, and, if necessary, to update the previous opinion of the EFSA Panel on Contaminants in the Food Chain (CONTAM) on gossypol as an undesirable substance in animal feed. Gossypol is a polyphenolic compound that exists in a racemic mixture of (+)-gossypol and (-)-gossypol isomers. It occurs in free or (protein-) bound forms in cottonseeds. The most commonly used cottonseeds in feed are from Upland and Pima varieties. The Pima variety is considered more toxic due to a higher content of the (-)-gossypol isomer. Upland whole cottonseeds (WCS) are fed with no further processing (after delinting); Pima varieties normally undergo further processing (grinding or cracking). It is claimed that WCS have a greater retention time in the rumen, which results in an increased detoxifying activity, compared to a shorter ruminal retention time, in the case of cracked cottonseed or cottonseed meal products. Increased erythrocyte fragility has been observed in cows given WCS Upland varieties at similar exposure levels as those resulting from an inclusion rate of 10% of WCS containing gossypol at 7,000 mg/kg in feed - the maximum permitted level of gossypol in WCS suggested by the Spanish Delegation. The information from the Spanish delegation does not differentiate between varieties in their suggestion for an increase in the maximum permitted content of free gossypol for WCS. As both Upland and Pima varieties are grown in the EU and are used for animal feed, both varieties of WCS should be considered. The CONTAM Panel considered it not necessary to update the previous opinion.

Utility of the "surprise" question to identify dialysis patients with high mortality.

BACKGROUND AND OBJECTIVES: Dialysis patients are increasingly characterized by older age, multiple comorbidities, and shortened life expectancy. This study investigated whether the "surprise" question, "Would I be surprised if this patient died in the next year?" identifies patients who are at high risk for early mortality. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This prospective cohort study of 147 patients in three hemodialysis dialysis units classified patients into "yes" and "no" groups on the basis of the "surprise" question response and tracked patient status (alive or dead) at 12 mo. Demographics, Charlson Comorbidity Index score, and Karnofsky Performance Status score were measured. RESULTS: Initially, 34 (23%) patients were classified in the "no" group. Compared with the 113 patients in the "yes" group, the patients in the "no" group were older (72.5 +/- 12.8 versus 64.5 +/- 14.9), had a higher comorbidity score (7.1 +/- 2.3 versus 5.8 +/- 2.1), and had a lower performance status score (69.7 +/- 17.1 versus 81.6 +/- 15.8). At 12 mo, 22 (15%) patients had died; the mortality rate for the "no" group was 29.4% and for the "yes" group was 10.6%. The odds of dying within 1 yr for the patients in the "no" group were 3.5 times higher than for patients in the "yes" group, (odds ratio 3.507, 95% CI 1.356 to 9.067, P = 0.01). CONCLUSIONS: The "surprise" question is effective in identifying sicker dialysis patients who have a high risk for early mortality and should receive priority for palliative care interventions.

Ethylene glycol intoxication: Disparate findings of immediate versus delayed presentation.

Ethylene glycol is a common household substance responsible for a large number of ingestions in the U.S. each year. In 2001, nearly 5,000 ethylene glycol exposures were reported with more than 1,600 patients requiring medical treatment. There were 16 deaths attributed to ethylene glycol in 2001, second only to ethanol overdose for lethal ingestions. Diagnosis of ethylene glycol ingestion is relatively straight-forward when an individual with a history of exposure is found to have a high anion-gap metabolic acidosis and an elevated osmolar gap. Appropriate treatment can be immediately employed and the diagnosis confirmed by the finding of elevated ethylene glycol levels in the serum. In the absence of exposure history, the differential diagnosis of a high anion-gap metabolic acidosis and an elevated osmolar gap will also lead to consideration of ethylene glycol ingestion. This well-recognized presentation of ethylene glycol toxicity includes findings expected in individuals who present for care soon after their ingestion. A less well-known pattern may be seen in those for whom care is delayed. We present a patient with delayed presentation of ethylene glycol ingestion and review the physiology and biochemistry that underlies this different presentation. Unfortunately, without history or strong laboratory evidence, ethylene glycol ingestion may be easily overlooked in individuals with delayed presentation.