[Refeeding syndrome in geriatric patients : A frequently overlooked complication]. / Refeeding-Syndrom bei geriatrischen Patienten : Eine oft übersehene Komplikation.

The refeeding syndrome is a life-threatening complication that can occur after initiation of a nutrition therapy in malnourished patients. If the risk factors and pathophysiology are known, the refeeding syndrome can effectively be prevented and treated, if recognized early. A slow increase of food intake and the close monitoring of serum electrolyte levels play an important role. Because the refeeding syndrome is not well known and the symptoms may vary extremely, this complication is poorly recognized, especially against the background of geriatric multimorbidity. This overview is intended to increase the awareness of the refeeding syndrome in the risk group of geriatric patients.

Risk factors of refeeding syndrome in malnourished older hospitalized patients.

BACKGROUND & AIMS: Despite the high prevalence of malnutrition among older hospitalized persons, it is unknown how many of these malnourished patients are at risk of developing the refeeding syndrome (RFS). In this study, we sought to compare the prevalence and severity of malnutrition among older hospitalized patients with prevalence of known risk factors of RFS. METHODS: This cross-sectional multicenter-study investigated older participants who were consecutively admitted to the geriatric acute care ward. Malnutrition screening was conducted using Nutritional Risk Screening (NRS-2002), Malnutrition Universal Screening Tool (MUST) and Mini Nutritional Assessment-Short Form (MNA-SF). The National Institute for Health and Clinical Excellence (NICE) criteria were applied for assessing patients at risk of RFS. Weight and height were measured. Degree of weight loss (WL) was obtained by interview. Serum phosphate, magnesium, potassium, sodium, calcium, creatinine and urea were analyzed according to standard procedures. RESULTS: The study group comprised 342 participants (222 females) with a mean age of 83.1 ± 6.8 and BMI range of 14.7-43.6 kg/m2. More participants were assessed at risk of malnutrition using NRS-2002 (n = 253, 74.0%) compared to MUST (n = 170, 49.7%) and MNA-SF (n = 191, 55.8%). Of total participants, 239 (69.9%; 157 females) were considered to be at risk of RFS. Based on NRS-2002, 75.9% (n = 192) of patients at risk of malnutrition are at risk of RFS whereas according to MUST and MNA-SF, 85.9% (n = 146) and 69.1% (n = 132) of patients at risk of malnutrition are exposed to high risk of RFS, respectively. In addition, the prevalence of risk of RFS is significantly increased with higher score of NRS-2002 and MUST and lower score of MNA-SF. In a stepwise multiple regression analysis, disease severity (38.2%), WL in 3 months (20.3%) and BMI (33.3%) mainly explained variance in NRS-2002, MUST and MNA-SF scores, respectively, in patients with risk of RFS. CONCLUSION: Nearly three-quarters of geriatric hospitalized patients with risk of malnutrition demonstrated significant risk of RFS. Therefore, additional screening for risk of RFS in patients screened for malnutrition appears to be abdicable among this population.

Exercise responses of elderly patients with diastolic versus systolic heart failure.

PURPOSE: Little information is available regarding peak and submaximal exercise performance in elderly heart failure (HF) patients, particularly in those with diastolic dysfunction (DD). Therefore, the purpose of this investigation was to compare exercise responses of elderly patients with HF due to either systolic dysfunction (SD) or DD, to age-matched healthy volunteers (HV). METHODS: Patients with chronic HF > or = 60 yr (N = 119) due to SD (N = 60) or primary DD (N = 59) underwent a maximal cycle ergometry test with expired gas analysis and venous lactate measurement. Twenty-eight HV > or = 60 yr served as a control group. Anaerobic threshold was determined by gas analysis (ATVEN) and by plasma lactate rise (ATLAC). RESULTS: Peak oxygen consumption (VO(2peak)) was significantly (P < 0.001) reduced in both SD and DD patients (13 +/- 0.4 vs 14 +/- 0.4 ml x kg(-1) x min(-1), respectively) versus HV (20 +/- 0.6 ml x kg(-1) x min(-1)). Peak heart rate was reduced in patients versus HV (131 +/- 3 bpm vs 145 +/- 4, respectively; P < or = 0.01), but heart rate at a given submaximal work rate was significantly lower (P < or = 0.01) in HV than in SD and DD patients. ATVEN of 11.8 +/- 0.3 ml x kg(-1) x min(-1) for HV was significantly higher than SD (8.9 +/- 0.2) and DD (9.2 +/- 0.3). Peak lactate concentration was 6.6 +/- 0.6 mmol x kg(-1) x l(-1) in HV and was significantly reduced in both SD and DD HF patients. ATVEN correlated well with ATLAC in HV and in DD patients, but not in SD patients. CONCLUSIONS: Submaximal and peak exercise performance are markedly altered in elderly HF patients compared with age-matched HV but do not appear to be different between SD and DD patients.

Pathophysiological characterization of isolated diastolic heart failure in comparison to systolic heart failure.

CONTEXT: Many older patients with symptoms of congestive heart failure have a preserved left ventricular ejection fraction (LVEF). However, the pathophysiology of this disorder, presumptively termed diastolic heart failure (DHF), is not well characterized and it is unknown whether it represents true heart failure. OBJECTIVE: To assess the 4 key pathophysiological domains that characterize classic heart failure by systematically performing measurements in older patients with presumed DHF and comparing these results with those from age-matched healthy volunteers and patients with classic systolic heart failure (SHF). DESIGN AND SETTING: Observational clinical investigation conducted in 1998 in a general community and teaching hospital in Winston-Salem, NC. PARTICIPANTS: A total of 147 subjects aged at least 60 years. Fifty-nine had isolated DHF defined as clinically presumed heart failure, LVEF of at least 50%, and no evidence of significant coronary, valvular, or pulmonary disease. Sixty had typical SHF (LVEF < or =35%). Twenty-eight were age-matched healthy volunteer controls. MAIN OUTCOME MEASURES: Left ventricular structure and function, exercise capacity, neuroendocrine function, and quality of life. RESULTS: By echocardiography, mean (SE) LVEF was 60% (2%) in patients with DHF vs 31% (2%) in those with SHF and 54% (2%) in controls. Mean (SE) LV mass-volume ratio was markedly increased in patients with DHF (2.12 [0.14] g/mL) vs those with SHF (1.22 [0.14] g/mL) (P<.001) and vs controls (1.49 [0.17] g/mL) (P =.002). Peak oxygen consumption by expired gas analysis during cycle ergometry was similar in the DHF and SHF groups (14.2 [0.5] and 13.1 [0.5] mL/kg per minute, respectively; P =.40) and in both was markedly reduced compared with healthy controls (19.9 [0.7] mL/kg per minute) (P =.001 for both). Ventilatory anaerobic threshold was similar in the DHF and SHF groups (9.1 [0.3] and 8.7 [0.3] mL/kg per minute, respectively; P<.001) and in both was reduced compared with healthy controls (11.5 [0.4] mL/kg per minute) (P<.001). Norepinephrine levels were similar in the DHF (306 [64] pg/mL) and SHF (287 [62] pg/mL) groups (P =.56) and in both were markedly increased vs healthy controls (169 [80] pg/mL) (P =.007 and.03, respectively). Brain natriuretic peptide was substantially increased in both the DHF (56 [30] pg/mL) and the SHF (154 [28] pg/mL) groups compared with healthy controls (3 [38] pg/mL) (P =.02 and.001, respectively). Quality-of-life decrement score as assessed by the Minnesota Living with Heart Failure Questionnaire was substantially increased from the benchmark score of 10 in both groups (SHF: 43.8 [3.9]; DHF: 24.8 [4.4]). CONCLUSION: Patients with isolated DHF have similar though not as severe pathophysiologic characteristics compared with patients with typical SHF, including severely reduced exercise capacity, neuroendocrine activation, and impaired quality of life.

Motor performance deteriorates with simultaneously performed cognitive tasks in geriatric patients.

OBJECTIVE: To investigate whether simultaneous cognitive tasks influence maximal motor performance in frail geriatric patients with a history of injurious falls and different levels of cognitive function. DESIGN: Experimental 3-group design. SETTING: Geriatric rehabilitation hospital. PARTICIPANTS: Twenty-two healthy, young adults (mean age +/- standard deviation, 27.7 +/- 9y) and 23 geriatric patients (mean age, 80.9 +/- 5.4y) with a history of injurious falls with (Mini-Mental State Examination [MMSE] score, 20.5 +/- 1.6) and without (MMSE score, 28.1 +/- 1.2) cognitive impairment. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Motor performance: peak and integral of maximal isometric strength of leg extensors. Cognition: semiautomated calculation steps (serial 2 forward) and nonautomated calculation steps derived from the MMSE (serial 7 retro). Motor and cognitive performances were examined as single and dual tasks. RESULTS: In frail geriatric patients, especially in patients with cognitive impairment, maximal motor performance decreased significantly during all dual tasks. Cognitive performance was reduced, depending on the task and group. CONCLUSION: In frail or cognitively impaired geriatric patients, additional tasks can substantially decrease maximal motor performance. Insufficient resources on dual tasking may thus be a link in connecting the high incidence of falls with frailty and cognitive impairment in geriatric patients with a history of injurious falls.