Observations on the anemia of cryptogenetic splenomegaly. I. Hemolysis

Excessive hemolysis has been shown to occur in patients with cryptogeneticsplenomegaly. This is corrected by splenectomy.

The survival of normal red cells transfused to such patients is greatlyreduced. Following splenectomy normal red cells so transfused survive normally.

The survival of red cells from such patients upon transfusion to healthyrecipients, including a splenectomized recipient, is greatly reduced. Following splenectomy the survival of red cells from such patients upon transfusion to healthy recipients is significantly increased, although still significantly less than normal. However, upon transfusion into splenectomized butotherwise healthy recipients the survival time is normal.

Study of osmotic fragility before splenectomy demonstrates the existenceof a mixed population showing both increased and decreased fragility tohypotonic saline. Following splenectomy there emerges a population withincreased resistance to hypotonic saline.

It is concluded that prior to splenectomy the pathologic spleen exerts aneffect upon circulating erythrocytes including transfused normal red cellswhich results in marked reduction in their survival. Following splenectomya second defect in the erythrocytes becomes apparent and this also resultsin reduction in life-span, although the presence of the spleen would appearnecessary for this reduction to occur. It is suggested that this second defectdevelops as the result of liver damage.

Submitted on February 12, 1957 Accepted on December 25, 1957     

Creatine supplementation for patients with COPD receiving pulmonary rehabilitation: A systematic review and meta‐analysis

Background and objective: Creatine improves muscle strength in exercising healthy individuals, and in patients with neuromuscular disease and heart failure. The aim of this study was to assess whether creatine supplementation improves pulmonary rehabilitation (PR) outcomes in patients with COPD. Methods: A systematic review and meta‐analysis was performed of randomized controlled trials published between January 1966 and February 2009 that evaluated the effect of creatine compared with placebo on exercise capacity, muscle strength and health‐related quality of life (HR‐QoL) in patients undergoing PR for COPD. The pooled estimates were expressed as mean differences (MD) or standardized mean differences (SMD). Results: Four randomized controlled trials that included 151 patients were identified. There was no effect of creatine supplementation on exercise capacity (SMD ?0.01, 95% CI: ?0.42 to 0.22, n = 151). Creatine supplementation did not improve lower extremity muscle strength (SMD 0.03, 95% CI: ?0.55 to 0.61, n = 140) or upper limb muscular strength (SMD 0.02, 95% CI: ?0.33 to 0.38, n = 128) compared with placebo. Two studies (n = 48) assessed quality of life using the St. George's Respiratory Disease Questionnaire. There were no differences in HR‐QoL according to domain or total scores. Overall, creatine appeared to be safe and was well tolerated. Quality assessment of the studies showed important limitations. Conclusions: Creatine supplementation does not improve exercise capacity, muscle strength or HR‐QoL in patients with COPD receiving PR. However, important limitations were identified in the quality of the available evidence, suggesting that further research is required in this area.     

The Relationship Between Electrogram Cycle Length and Dominant Frequency in Patients with Persistent Atrial Fibrillation

Introduction: Sites of complex fractionated atrial electrograms (CFAE) with a short mean cycle length (MCL) and sites with a high dominant frequency (DF) have been advocated as targets for ablation in patients with persistent atrial fibrillation (AF). However, there are little data on the relationship between theses 2 markers. This study assessed the relationship between the DF and electrogram MCL after pulmonary vein (PV) isolation in patients with persistent AF. Methods and Results: A total of 44 patients with persistent AF were studied. Four‐second bipolar electrograms were obtained with a multielectrode mapping catheter at regions throughout the left atrium after isolation of the pulmonary veins, with analysis of the MCL and DF at each site. The DF was defined as the largest frequency peak within a 2.5‐ to 16‐Hz spectral profile generated with fast Fourier transformation of the electrogram. A total of 9,262 electrograms from the 44 patients were analyzed. The average MCL and DF post‐PV isolation were 135 ± 24 ms and 6.1 ± 0.6 Hz, respectively. There was a statistically significant but weak correlation between the MCL and DF (r = 0.21, P < 0.001). Additionally, analysis of this relationship within each patient did not demonstrate a strong correlation (range of r values per patient =?0.18 to 0.47). Conclusions: There is a poor correlation between the electrogram MCL and DF in patients with persistent AF. Ablation strategies targeting DF and those targeting CFAE are therefore unlikely to direct ablation toward similar left atrial sites. Comparative studies are necessary to determine the effectiveness of each strategy in guiding catheter ablation of persistent AF.     

A review of long‐term prophylaxis in the rare inherited coagulation factor deficiencies

Summary. The rare inherited coagulation factor deficiencies (deficiencies of factors I, II, V, VII, XI, XIII, combined FV + FVII deficiency, combined deficiency of the vitamin K dependent factors and von Willebrand disease type 3) have an aggregate prevalence of approximately 1:100 000. They may cause recurrent life or function threatening haemorrhage. In this article we review the available literature on long‐term prophylaxis and, where possible, make recommendations on this important area.     

Bacterial colonization of indwelling vascular catheters in newborn infants

Objective : To determine the incidence of bacterial colonization of intravascular catheters, to compare the incidence of colonization of intra-arterial (IA), intravenous (IV) and central venous catheters (CVC), and to determine the association, if any, between catheter withdrawal and bacterial sepsis.
Methodology : A prospective observational study was carried out at the neonatal intensive care unit of a university-affiliated regional referral centre. A total of 155 catheters (45 IA, 54 IV and 56 CVC) were obtained from 96 infants admitted to the unit and the distal 0.75 cm studied under the scanning electron microscope. The adjoining 0.75 cm was cultured for bacteria.
Results : Scanning electron microscopy revealed that 46% of catheters had bacteria on the internal surface and 13% had bacteria on the outer surface. Greater numbers of CVC were colonized with bacteria compared to IA and IV catheters ( P < 0.01). Bacterial colonization of intravascular catheters was not significantly associated with the duration the catheter remained in situ or local reaction at the site of entry of the catheter. Colonization of the external surface of the catheter was significantly associated with bacterial septicaemia ( P = 0.0466). Eighty-three per cent of 155 catheters studied had coagulum on the inner or outer surface. Only 53% of these were colonized with bacteria. Bacterial colonization occurred in the absence of a coagulum in only three instances. Catheter withdrawal was not associated with bacterial sepsis. Lack of coagulum on the internal surface of the catheter was strongly associated with septicaemia during the 7 days after catheter withdrawal.
Conclusions : Although significant numbers of intravascular catheters were colonized with bacteria, only colonization with the external surface was associated with catheter-related sepsis.     

Umbilical artery flow velocity waveforms in labour

Summary. Doppler signals were recorded from the umbilical arteries in 103 women during labour. The pulsatility index (PI) did not alter with progress in labour. During uterine contractions the PI showed a change only if there was a deceleration in the fetal heart rate. Low birthweight (<10th centile) and delivery by caesarean section for fetal distress were significantly more frequent in patients with abnormal PI values (defined as >2 SD above the mean in normal labours). Fetal scalp blood pH was measured in 24 patients. The PI was abnormal in only one case, but none of the 24 had a pH <7·20.     

The effects of oral iron supplementation on zinc and magnesium levels during pregnancy

Summary. Serial changes in serum zinc and magnesium concentrations have been studied before conception, throughout pregnancy and at 12 weeks postpartum in 15 normal healthy women not receiving iron supplementation, 10 women receiving iron supplementation but other-wise having healthy pregnancies and five insulin-dependent diabetics who also received oral iron . Relative to pre-pregnancy values zinc concentrations progressively decreased throughout pregnancy reaching a nadir at 36 weeks gestation followed by an increase; pre-pregnancy values were achieved by 12 weeks postpartum. Magnesium concentrations also decreased throughout pregnancy reaching a nadir at 32 weeks gestation increasing thereafter again with pre-pregnancy values achieved by 12 weeks postpartum. Iron supplementation in non-diabetic and diabetic women had no significant effect upon the changes in serum concentration of either zinc or magnesium. These results suggest that the decrease in the concentrations of both elements is a normal physiological adjustment to pregnancy and that iron supplementation does not influence these changes