A 30-year follow-up of the Dallas Bedrest and Training Study: II. Effect of age on cardiovascular adaptation to exercise training. (25/330)

BACKGROUND: Aerobic power declines with age. The degree to which this decline is reversible remains unclear. In a 30-year longitudinal follow-up study, the cardiovascular adaptations to exercise training in 5 middle-aged men previously trained in 1966 were evaluated to assess the degree to which the age-associated decline in aerobic power is attributable to deconditioning and to gain insight into the specific mechanisms involved. Methods and Results-- The cardiovascular response to acute submaximal and maximal exercise were assessed before and after a 6-month endurance training program. On average, VO(2max) increased 14% (2.9 versus 3.3 L/min), achieving the level observed at the baseline evaluations 30 years before. Likewise, VO(2max) increased 16% when indexed to total body mass (31 versus 36 mL/kg per minute) or fat-free mass (44 versus 51 mL/kg fat-free mass per minute). Maximal heart rate declined (181 versus 171 beats/min) and maximal stroke volume increased (121 versus 129 mL) after training, with no change in maximal cardiac output (21.4 versus 21.7 L/min); submaximal heart rates also declined to a similar degree. Maximal AVDO(2) increased by 10% (13.8 versus 15.2 vol%) and accounted for the entire improvement of aerobic power associated with training. CONCLUSIONS: One hundred percent of the age-related decline in aerobic power among these 5 middle-aged men occurring over 30 years was reversed by a 6-month endurance training program. However, no subject achieved the same maximal VO(2) attained after training 30 years earlier, despite a similar relative training load. The improved aerobic power after training was primarily the result of peripheral adaptation, with no effective improvement in maximal oxygen delivery.  (+info)

Cranial subdural haematoma after spinal anaesthesia. (26/330)

Intracranial subdural haematoma is an exceptionally rare complication of spinal anaesthesia. A 20-yr-old male underwent appendicectomy under partial spinal and subsequent general anaesthesia. A week later, he presented with severe headache and vomiting not responding to bed rest and analgesia. Magnetic resonance imaging showed a small acute subdural haematoma in the right temporo-occipital region. The patient improved without surgical decompression. The pathogenesis of headache and subdural haematoma formation after dural puncture is discussed and the literature briefly reviewed. Severe and prolonged post-dural puncture headache should be regarded as a warning sign of an intracranial complication.  (+info)

Deep venous thrombosis in postoperative vascular surgical patients: a frequent finding without prophylaxis. (27/330)

PURPOSE: The place of routine perioperative thromboprophylaxis for vascular surgical patients remains controversial, because the incidence of postoperative deep venous thrombosis (DVT) is said to be quite low. This study was designed to measure the incidence of lower limb DVT after vascular surgical procedures. METHODS: All consenting, consecutive patients who came to a metropolitan veterans hospital for abdominal or lower-limb arterial surgery were studied. Clinical and operative data were recorded. Lower-limb color flow duplex scans were performed before and after surgery. RESULTS: Fifty patients, age 75 +/- 1 (mean +/- SEM) years, were studied. Abdominal procedures were performed on 22 patients, and lower-limb procedures were performed on 28 patients. A postoperative DVT was noted in 14 patients (32%), 9 patients (41%) in the abdominal surgical group and 5 patients (18%) in the lower-limb group. Calf DVTs were four times more common than femoropopliteal DVTs. CONCLUSION: The incidence of postoperative lower-limb DVTs in this cohort of vascular surgical patients was high. The small size of the study population precludes generalized recommendations, but the results indicate an urgent need for definitive investigation.  (+info)

Does bed rest after cervical or lumbar puncture prevent headache? A systematic review and meta-analysis. (28/330)

BACKGROUND: Headache after cervical or lumbar puncture has long been attributed to early mobilization; however, there is little evidence for this. We performed a systematic literature review and meta-analysis of randomized controlled trials to assess whether longer bed rest is better than immediate mobilization or short bed rest in preventing headache. METHODS: We searched EMBASE (1988 to March 2001), MEDLINE (1966 to May 2001), Pascal Biomed (1996 to February 2001), Current Contents (1997 to September 1999), PsycINFO (1966 to May 2001), the Cochrane Controlled Trial Register (last search May 15, 2001), textbooks and references of the papers selected. Studies were eligible if patients underwent cervical or lumbar puncture for any reason and were randomly assigned to either a long or a short period of bed rest. Data were abstracted independently by 2 investigators to a predefined form. RESULTS: We found 16 randomized controlled trials involving 1083 patients assigned to immediate mobilization or a short period of bed rest (up to 8 hours) and 1128 patients assigned to a longer period of bed rest (0.5 to 24 hours). Puncture was performed for anesthesia (5 trials), myelography (6 trials) and diagnostic reasons (5 trials). None of the trials showed that longer bed rest was superior to immediate mobilization or short bed rest for preventing headache after puncture. When pooling the results of the trials in the myelography group and the diagnostic group, the relative risks of headache after puncture were 0.93 (95% confidence interval [CI] 0.81-1.08) and 0.97 (95% CI 0.79-1.19) respectively. We did not pool the results from the trials in the anesthesia group because of clinical heterogeneity, but shorter bed rest appeared to be superior. INTERPRETATION: There was no evidence that longer bed rest after cervical or lumbar puncture was better than immediate mobilization or short bed rest in reducing the incidence of headache.  (+info)

Intravitreal injection of tissue plasminogen activator for central retinal vein occlusion. (29/330)

PURPOSE: This pilot study evaluated the feasibility of intravitreal injections of tissue plasminogen activator (tPA) in eyes with central retinal vein occlusion (CRVO). METHODS: Between August 1997 and October 2000, 9 eyes with CRVO were treated with intravitreal injection of tPA, 100 micrograms (50 micrograms/0.1 mL), and paracentesis. After the injection, each patient was placed at strict bed rest in the supine position for 6 hours. Each patient was administered one baby aspirin daily. Best corrected visual acuity with Light House charts was obtained at each visit. A change of 3 or more lines of vision from pretreatment levels at 6 months' follow-up or a change in one level (i.e., counting fingers to hand motions) was deemed significant. RESULTS: All patients were followed up for at least 6 months. Four of 9 eyes (44%) showed 3 or more lines improvement at 6 months. In this group, the average improvement was 7 lines. Two eyes showed 6 or more lines loss of vision at 6 months. Four eyes showed dramatic improvement in visual acuity within 1 month of injection. There were no adverse effects related to treatment. Three eyes subsequently developed retinal or anterior-segment neovascularization requiring panretinal photocoagulation; all were graded as ischemic CRVO on fluorescein angiography at baseline. CONCLUSION: Intravitreal tPA can be injected safely and easily. Local injection of tPA should spare the patient the serious systemic risks of intravenous tPA administration, such as stroke. Given the morbidity of CRVO, further investigation with this therapy to establish both efficacy and safety seems warranted.  (+info)

Utility of ADL index for partially dependent older people: discriminating the functional level of an older population. (30/330)

In the present study, the ADL index for the partially dependent older people (Demura et al., 1999) was applied to 218 bedridden (BED), 466 partially dependent (PD) and 245 independent living (IL) people in older groups. The purposes of this study were to clarify the meaning of the evaluation of this index and to examine how ADL items are useful in determining each older group. It is suggested that a perfect score with our ADL index means independent living level, and a score of zero means bedridden level. The results of discriminant analysis indicated that four items with low-difficulty, such as "eating," "going to the toilet," "tossing about in bed" and "writing," are useful in determining if the PD is becoming bedridden. While five items with high-difficulty, such as "putting on slacks," "putting on trousers," "standing up from a sitting posture," "going up stairs" and "washing the whole body," are useful in determining if the PD is becoming independent living. Furthermore, it is inferred that the possibility of falling into a bedridden situation increases when the total score is 5 or less, while the functional level is close to independent living when the total score is 13 or more. These findings make clear the meaning of the evaluation of our ADL index. Furthermore, the functional level of older population may be screened using evaluation of total and item scores of this ADL index.  (+info)

Influence of bright light during daytime on sleep parameters in hospitalized elderly patients. (31/330)

Nurses frequently care for sleepless elderly patients on bed rest in a hospital environment. Our previous study with young adults showed that bright light exposure during the daytime affected the induction of nocturnal deep sleep. The purpose of this study is aimed at finding whether similar research could be observed with hospitalized elderly patients. Seven patients (mean age 67; range 57-77 yrs, males 3: females 4) served as participants and their informed written consent was obtained. A fluorescent lamp fixed in the bed frame near the head of the patient was turned on at 10:00 h and off at 15:00 h each day for 1 week (BL). Moreover, each patient was required to stay near this light during this period. The patients lived in a room facing north, where the ambient light intensities ranged from 50 to 300 lx during the daytime. Their activities were continuously measured using an Actiwatch (model-AWL, Mini-Mitter, USA). Salivary samples were collected at midnight for the measurement of melatonin. The findings were compared between 2 days before BL exposure (baseline) and the last 2 days during BL exposure, respectively. The bright light exposure during the daytime prolonged "Time in Bed" (p < 0.05), increased "Immobile Minutes" (p < 0.05), and delayed "Get up Time" (p < 0.01). The average melatonin secretion at midnight in four patients increased from 7.5 +/- 2.6 pg/ml to 13.3 +/- 9.2 pg/ml. These findings suggest that diurnal bright light exposure for hospitalized elderly patients lying in bed under dark condition during the daytime may favor clinically the induction of nocturnal deep sleep. Attention should be given to the illumination conditions for elderly patients in hospitals to improve their impaired sleep.  (+info)

Role of skin blood flow and sweating rate in exercise thermoregulation after bed rest. (32/330)

Two potential mechanisms, reduced skin blood flow (SBF) and sweating rate (SR), may be responsible for elevated intestinal temperature (T(in)) during exercise after bed rest and spaceflight. Seven men underwent 13 days of 6 degrees head-down bed rest. Pre- and post-bed rest, subjects completed supine submaximal cycle ergometry (20 min at 40% and 20 min at 65% of pre-bed rest supine peak exercise capacity) in a thermoneutral room. After bed rest, T(in) was elevated at rest (+0.31 +/- 0.12 degrees C) and at the end of exercise (+0.33 +/- 0.07 degrees C). Percent increase in SBF during exercise was less after bed rest (211 +/- 53 vs. 96 +/- 31%; P < or = 0.05), SBF/T(in) threshold was greater (37.09 +/- 0.16 vs. 37.33 +/- 0.13 degrees C; P < or = 0.05), and slope of SBF/T(in) tended to be reduced (536 +/- 184 vs. 201 +/- 46%/ degrees C; P = 0.08). SR/T(in) threshold was delayed (37.06 +/- 0.11 vs. 37.34 +/- 0.06 degrees C; P < or = 0.05), but the slope of SR/T(in) (3.45 +/- 1.22 vs. 2.58 +/- 0.71 mg x min-1 x cm-2 x degrees C-1) and total sweat loss (0.42 +/- 0.06 vs. 0.44 +/- 0.08 kg) were not changed. The higher resting and exercise T(in) and delayed onset of SBF and SR suggest a centrally mediated elevation in the thermoregulatory set point during bed rest exposure.  (+info)