Prediction of infarct size from serial CK determinations: Evaluation by clinical studies and computer simulation

To assess reduction of infarct size by therapeutic intervention, a high predictive accuracy is mandatory. The CK release in the circulation (CKr) was studied in 12 consecutive patients after uncomplicated myocardial infarction, admitted within 5 h after onset of symptoms. Despite improvement of existing methods, such as a more frequent sampling, CK-MB determination instead of total CK determination and use of a gamma-exponential instead of a log-normal curvefitting technique, the correlation between CK, predicted from measurements within 7 h after the start of CK rise and CKr calculated after completion of the CK curve remained poor. Computer simulations were done to investigate measurement errors as a cause of this failure. Normally distributed noise, with standard deviations ranging from 0.2% to 8.0% of peak CK-MB, was added to the first points of an ideal gamma-exponential CK-MB curve and predictions were made from these "noisy" points. A small noise already produced a great variation in prediction: 0.8% noise resulted in a deviation of predicted CKr from calculated CKrranging from -20 to + 6%. It is concluded that adequate prediction of infarct size from serial CK determinations in the first 7 h after onset of the CK rise must fail if the precision of the biochemical determination is not less than 0.4%

New insight into rectal function in pediatric defecation disorders: disturbed rectal compliance is an essential mechanism in pediatric constipation

OBJECTIVE: To evaluate rectal sensitivity in patients with pediatric constipation (PC) and nonretentive fecal soiling (FNRFS) using pressure-controlled distention (barostat). STUDY DESIGN: Thresholds for rectal sensitivity (first sensation, urge to defecate, and pain), and rectal compliance were determined using a barostat. RESULTS: A total of 69 patients with PC (50 males; mean age, 10.9 +/- 2.2 years) and 19 patients with FNRFS (15 males; mean age, 10.0 +/- 1.9 years) were compared with 22 healthy volunteers (HVs) (11 males; mean age, 12.7 +/- 2.6 years). Sensitivity thresholds were not significantly different among the 3 groups. Rectal compliance was increased in 58% of the patients with PC (P < .0001 vs HVs). Rectal compliance did not differ between patients with FNRFS and HVs. Children with PC with abnormal rectal function required significantly larger rectal volumes at urge to defecate. CONCLUSIONS: Increased compliance is the most prominent feature in patients with PC. Because of higher compliance in these children, larger stool volumes are required to reach the intrarectal pressure of the urge to defecate. Children with FNRFS have normal rectal functio

Influence of heat and moisture exchanger respiratory load on transcutaneous oxygenation in laryngectomized individuals: a randomized crossover study

High-resistance heat and moisture exchangers (HMEs) have been reported to increase transcutaneous oxygenation (tcpO(2)) values in laryngectomized individuals and to negatively influence patient compliance. The goal of the present study was to validate earlier published results on short-term transcutaneous oxygenation changes by high-resistance HMEs. We conducted a randomized crossover study, monitoring the influence of an HME on tcpO(2) over a 2-hour time interval in 20 subjects. No evidence of an immediate HME effect (95% CI: -14.9-13.3 mm Hg, p = .91), or a time-dependent HME effect (95% CI: -.121 - .172 mm Hg/minute, p = .74), on tcpO(2) was found. After fitting the statistical model without time dependency, again no evidence of HME presence was seen (95% CI: -.5 mm Hg - 3.6 mm Hg, p = .15). In contrast to earlier suggestions, there is no evidence of increased tcpO(2) levels by high-resistance HMEs in laryngectomized individuals. Thus, using such HMEs has no added clinical value in this respec

Isolated limb perfusion prolongs the limb recurrence-free interval after several episodes of excisional surgery for locoregional recurrent melanoma

BACKGROUND: The influence of isolated limb perfusion (ILP) on the limb recurrence-free interval (LRFI) and the number of lesions per recurrence was studied for patients with frequently recurring regional in-transit metastases previously managed by excisional surgery. METHODS: All 43 patients who had their first ILP for a third or further limb recurrence were selected from our computer database of 451 patients who underwent therapeutic ILP for recurrent extremity melanoma in our centers. Eighteen patients had resectable and 25 had locally unresectable lesions at the time of ILP. The patients had a total of 269 intervals between treatment of their primary melanoma and last recurrence or last follow-up. Median follow-up was 35 months (interquartile range, 14-64 months). RESULTS: The median LRFI decreases over time from primary melanoma to the third or further recurrence for which ILP was performed (P < 0.001). The median LRFI is 4.7 times longer (95% confidence interval [CI], 2.8-7.9; P < 0.001) after ILP in comparison with the last interval before ILP. Patients with resectable lesions have a median LRFI that is 5.9 times longer (95% CI, 2.7-13; P < 0.001). In all patients, the number of lesions increases by 22% per recurrence number (95% CI, 10%-35%; P = 0.02). At the same recurrence number, patients before ILP have a 2.6-fold higher (95% CI, 1.6-4.5) mean number of lesions than do patients after ILP (P < 0.001). CONCLUSIONS: ILP lengthens the LRFI and decreases the number of lesions per recurrence significantly in patients with repeatedly recurrent limb melanoma. Therefore, ILP could be a valuable adjunct to excisional surgery for in-transit metastases in these patients whose LRFIs tend to shorten over tim

Long term cerebral and vascular complications after irradiation of the neck in head and neck cancer patients: a prospective cohort study: study rationale and protocol

BACKGROUND: Successful treatment options for cancer result in more young long-term survivors prone for long-term complications. Carotid artery vasculopathy is a potential long-term complication after radiotherapy of the neck, resulting in cerebrovascular events and probably deficits in cognitive and motor functioning. Better insight into the underlying pathofysiology of radiotherapy induced carotid artery vasculopathy is needed for prognostic purposes and to develop preventive strategies. METHODS/DESIGN: The current study is a prospective cohort study on the long-term cerebral and vascular complications after radiotherapy of the neck, in 103 patients treated for head and neck cancer, included in our study database between 2002 and 2008. Baseline protocol (before radiotherapy) included screening for cerebrovascular risk factors and intima media thickness measurement of carotid arteries by ultrasonography. Follow-up assessment more than 5 years after radiotherapy included screening of cerebrovascular risk factors, cerebrovascular events, neurological examination with gait and balance tests, extensive neuropsychological examination, self-report questionnaires, ultrasonography of the carotid arteries with measurement of intima media thickness and elastography, magnetic resonance imaging of the brain and magnetic resonance angiography of the carotid arteries. DISCUSSION: The current study adds to the understanding of the causes and consequences of long-term cerebral and vascular changes after radiotherapy of the neck. These data will be helpful to develop a protocol for diagnostic and preventive strategies for long-term neurological complications in future head and neck cancer patients with anticipated radiotherapy treatment