Prevalence and 6-month recovery of olfactory dysfunction: a multicentre study of 1363 COVID-19 patients.

OBJECTIVE: To investigate prevalence and recovery of olfactory dysfunction (OD) in COVID-19 patients according to the disease severity. METHODS: From 22 March to 3 June 2020, 2581 COVID-19 patients were identified from 18 European hospitals. Epidemiological and clinical data were extracted at baseline and within the 2-month post-infection. RESULTS: The prevalence of OD was significantly higher in mild form (85.9%) compared with moderate-to-critical forms (4.5-6.9%; P = 0.001). Of the 1916 patients with OD, 1363 completed the evaluations (71.1%). A total of 328 patients (24.1%) did not subjectively recover olfaction 60 days after the onset of the dysfunction. The mean duration of self-reported OD was 21.6 ± 17.9 days. Objective olfactory evaluations identified hyposmia/anosmia in 54.7% and 36.6% of mild and moderate-to-critical forms, respectively (P = 0.001). At 60 days and 6 months, 15.3% and 4.7% of anosmic/hyposmic patients did not objectively recover olfaction, respectively. The higher baseline severity of objective olfactory evaluations was strongly predictive of persistent OD (P < 0.001). CONCLUSION: OD is more prevalent in mild COVID-19 forms than in moderate-to-critical forms. OD disappeared in 95% of patients regarding objective olfactory evaluations at 6 months.

The diagnostic accuracy of bleeding assessment tools for the identification of patients with mild bleeding disorders: A systematic review.

INTRODUCTION: The bleeding assessment tool (BAT) has been developed to standardize and interpret bleeding history for mild bleeding disorders. However, a critical appraisal addressing the quality and results of validation studies is lacking. AIM: We performed a systematic review of diagnostic studies assessing the performance of the BAT in patients referred for evaluation of bleeding symptoms. METHODS: The electronic database PubMed was searched from inception through July 27, 2017. Eligible publications were original studies that assessed and validated the diagnostic accuracy of bleeding questionnaires for identification of adults with mild bleeding disorders. For each study, sensitivity, specificity and diagnostic odds ratio (DOR) were calculated. Quality was assessed using the Quality Assessment of Diagnostic studies-2 tool. To assess the influence of specific study characteristics on DOR, univariate meta-regression analyses were performed. RESULTS: Nine studies were included. Five studies investigating the ISTH-BAT or other bleeding questionnaires had a moderate to low DOR. Four studies investigating Vicenza-based BATs had a high DOR, with high specificity (>90%) and sensitivity of 59%-85%. Study characteristics such as case-control design, retrospective data collection and differences in reference standard were associated with optimistic estimates of diagnostic performance. Three of four studies with a high DOR had these study characteristics. Studies with good methodological quality mainly had a low DOR. CONCLUSION: The main advantage of the BAT is that it offers a complete and structured interview. However, the BAT is of limited diagnostic value to the workup of patients referred for bleeding evaluation in clinical practice.

The practice of diagnosing and reporting transfusion-associated circulatory overload: a national survey among physicians and haemovigilance officers.

OBJECTIVES: This study aims at identifying factors that disciplines consider when diagnosing and reporting transfusion-associated circulatory overload ('TACO'). BACKGROUND: TACO is a clinical diagnosis based mainly on subjective factors. Therefore, TACO could be an underreported complication of blood transfusion. METHODS: A survey was conducted among critical care physicians, anaesthesiologists, haematologists, transfusion medicine physicians and haemovigilance officers using case vignettes and a questionnaire. Factors that may affect diagnosing TACO were investigated using conjoint analysis. A positive B-coefficient indicates a positive preference for diagnosing TACO. Participants rated factors influencing reporting TACO on a 0- to 100-point scale. RESULTS: One hundred and seven surveys were returned (62%). Vignettes showed preferences in favour of diagnosing TACO with the onset of symptoms within 2 h [ß 0·4(-0·1-1·0)], positive fluid balance [ß 0·9(0·4-1·5)] and history of renal failure [ß 0·6(0·1-1·2)]. Compared with transfusion of a single unit of red blood cells (RBC), respondents showed a preference for diagnosing TACO following a single unit of solvent/detergent (S/D) plasma or pooled platelet concentrate (PPC) [ß 0·3(-0·2-0·7) resp. 0·5(-0·1-1·2)]. Multiple transfusion (6 RBC + 4 S/D plasma) was a strong preference for diagnosing TACO compared to 1 RBC and 1 S/D plasma [ß 0·3(-0·8-1·3)]. Respondents did not fully take into account new hypertension and tachycardia when reporting TACO [median 70 (IQR 50-80) resp. 60 (IQR 50-80)]. No differences were observed between disciplines involved. CONCLUSION: When diagnosing and reporting TACO, physicians and haemovigilance officers do consider known risk factors for TACO. Reporting could be improved by increasing the awareness of haemodynamic variables in future education programmes.

Underdiagnosing of antibody-mediated transfusion-related acute lung injury: evaluation of cellular-based versus bead-based techniques.

BACKGROUND AND OBJECTIVES: Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related mortality. To support the diagnosis of antibody-mediated TRALI, HLA and HNA antibodies are tested in involved blood donors. Identification of antibody positive donors is important as exclusion of these donors is part of preventative strategies against TRALI. We compared cellular-based versus bead-based techniques for diagnosis of antibody-mediated TRALI. MATERIALS AND METHODS: All reported TRALI cases in the Netherlands during a 5-year period were evaluated. Donors were screened for the presence of HLA class I and class II antibodies using both cellular-based and bead-based techniques. RESULTS: In total, 100 TRALI cases were reported of which 91 were fully tested. In 113 donors, HLA antibodies were detected of which 84 were only detected by bead-based techniques, 12 only by cellular-based tests and 17 by both assays. Antibody-mediated TRALI was diagnosed in 44 of 91 reported cases. Twenty-one (48%) of these cases would not have been identified using only cellular-based assays. CONCLUSION: Bead-based techniques show a higher sensitivity for detecting incompatible donors in TRALI cases than cellular-based assays. These results suggest that the use of bead-based assays will result in a significant reduction of future TRALI reactions as more antibody positive donors will be excluded from future donations.

Increased coagulation and fibrinolytic potential of solvent-detergent plasma: a comparative study between Omniplasma and fresh frozen plasma.

BACKGROUND AND OBJECTIVES: In this study, differences in levels of proteins involved in coagulation and fibrinolysis were compared between fresh frozen (quarantine plasma) and Omniplasma. Furthermore, thawing conditions and plasma stability after thawing were studied. MATERIALS AND METHODS: 10 Omniplasma and 10 quarantine plasma units were used to study different procoagulation, anticoagulation and fibrinolytic parameters. Analysis took place at different time-points during plasma storage at 2-6°C. RESULTS: At baseline, significant reduced levels of factor V, free protein S, α2-antiplasmin and tPA-induced ROTEM lysis time were observed in Omniplasma as compared to quarantine plasma. Moreover, thrombin generation, IXa-AT complex levels and factor XIa were significantly increased in Omniplasma. The majority of the parameters studied remained stable in Omniplasma 48 h after thawing, with the exception of factor VIII (decrease) and IXa-AT (increase). CONCLUSION: Our results suggest an increased coagulation potential, presumingly as a result of contact activation during the production process and also, an increased fibrinolytic potential in Omniplasma. The stability of Omniplasma, based upon the different parameters studied, is comparable to Q-plasma. A maximum post-thawing time of 48 hfor Omniplasma can be suggested.

Triple red blood cell alloantibody formation after bone-allograft transplantation.

In this case report, we provide evidence for the possibility of red blood cell alloimmunization after bone-allograft transplantation. Here, we present a 13-year-old boy who received a bone allograft due to impending hip-luxation. Five months later he was shown to have developed three different alloantibodies: anti-D, anti-C and anti-E, which were induced by the bone allograft. Red blood cell alloimmunization is a possible adverse event when a patient is exposed to allogenic red blood cells. These antibodies may cause transfusion reactions when incompatible blood is administered. More importantly, these antibodies may cause severe, or even fatal, hemolytic disease of the fetus or newborn, stretching the importance of preventing antibody formation, especially in young women. This case demonstrates the importance of selecting rhesus phenotype compatible bone allografts.

Allo-exposure status and leucocyte antibody positivity of blood donors show a similar relation with TRALI.

INTRODUCTION: The fraction of transfusion-related acute lung injury (TRALI) cases preventable by deferral of allo-exposed donors has previously been estimated, under the assumption this indirectly estimated the contribution of leucocyte antibodies to the occurrence of TRALI. Our aim was to estimate the fraction preventable by deferral of leucocyte antibody positive donors and to investigate the validity of allo-exposure as a marker for leucocyte antibodies. METHODS: All donors involved in a series of previously published TRALI patients were tested for leucocyte antibodies. The observed number of antibody positive donors was compared to the expected number. From this comparison we estimated the contribution of leucocyte antibodies to the occurrence of TRALI and compared this to the previously reported estimate for allo-exposed donors. RESULTS: Sixty-one TRALI patients were included. Of 288 involved donors 43 were expected and 67 were observed to be leucocyte antibody positive. The observed percentage of positive donors was 8.3% (95% confidence interval (CI): 5.1-11.5%) in excess of the expected. Overall 59% (95% CI: 34-85%) of TRALI cases was estimated to be preventable by the exclusion of all leucocyte antibody positive donors. For plasma-poor products this was 16% (95% CI: -5.0 to 36%). CONCLUSIONS: These estimates were similar to those previously published for allo-exposed donors. This suggests allo-exposure status can effectively be used in donor deferral strategies.

The observation of bleeding complications in haemato-oncological patients: stringent watching, relevant reporting.

BACKGROUND: The reported percentage of haemato-oncological patients experiencing bleeding complications is highly variable, ranging from 5 to 70%, posing a major problem for comparison of clinical platelet transfusion trials using bleeding complications as a primary endpoint. In a pilot study we assessed the impact of the design of scoring of bleeding on the percentage of patients with WHO grade 2 or higher bleeding grades. STUDY DESIGN AND METHODS: We performed a prospective, observational study using a rigorous bleeding observation system in thrombocytopenic patients with haemato-oncological disorders. Endpoints of the study were the percentage of patients and days with bleeding WHO grade ≥ 2 comparing designs in which skin bleeding represent a continuation of a previous bleed or a new bleed. RESULTS: In four participating hospitals 64 patients suffering 870 evaluable thrombocytopenic days (platelet count < 80 × 10(9) L(-1)) were included. At least one episode of bleeding grade ≥ 2 occurred in 36 patients (56%). Most grade 2 bleeding complications occurred mucocutaneously. The percentage of days with bleeding of grade ≥ 2 was 16% but decreases to 8% when only newly developed skin bleeding was included. CONCLUSION: Rigorous daily observation results in a bleeding incidence that is comparable to recent reportings applying the same method. The results of this study show that censoring for stable skin bleeding has a profound effect on bleeding incidence per day. The clinical relevance of rigorous or clinically judged bleeding scores as an endpoint remains to be defined.

[Transfusion-related acute lung injury (TRALI) in the Netherlands in 2002-2005]. / Transfusiegerelateerde acute longbeschadiging (TRALI) in Nederland in 2002-2005.

OBJECTIVE: To determine the number of reported cases of transfusion-related acute lung injury (TRALI) in the Netherlands in 2002-2005 and to determine how many cases were associated with incompatibility between leukocyte-reactive antibodies in the donor plasma and leukocytes or antigens in the recipient. DESIGN: Retrospective national case review. METHOD: Cases of TRALI reported in 2002-2005 were assessed according to the national clinical definition of TRALI, and the relationship between TRALI and transfusion was assessed. Additional clinical details were requested from the treating hospital as necessary. The results of leukocyte serological tests from donors and recipients were linked to clinical cases. For cases with positive leukocyte serological tests, the relevant blood components and the sex of the donor were recorded. RESULTS: Of the 46 cases reported, 6 had insufficient information. 8 cases did not meet the definition or had another more likely diagnosis. There was a trend toward an increase in the number of reports: 12 cases were reported in 2005, corresponding with 1:60,000 blood components. Of the 40 evaluable cases, 32 (80%) met the definition of TRALI and were deemed to be definitely (n = 16), probably (n = 5) or possibly (n = 11) related to transfusion. Severity ranged from moderate to life-threatening, and there was one TRALI-related death. Leukocyte serology was fully investigated in 18 cases: 13 (72%) had leukocyte incompatibility and in 5 cases exclusively fresh frozen plasma from a female donor was implicated.

[Haemolysis: role of the direct antiglobulin test and eluate]. / Hemolyse: rol van directe antiglobulinetest en eluaat.

Haemolytic anaemia is the result of an abnormal breakdown of red blood cells. The direct antiglobulin test (DAT), also known as the direct Coombs test, can be used to determine the cause of the haemolysis. The DAT distinguishes between immune and non-immune causes of haemolysis. However, the DAT should not be used in screening for haemolysis. When the DAT is performed without an indication for in vivo haemolysis, there is a high risk of false-positive results. To increase the specificity of the DAT, the eluate can be tested to determine the specificity of the autoantibodies. In this article we present two cases of haemolytic anaemia in which the DAT gives further indication of the cause of haemolysis.

Antithrombotic medication in cancer-associated thrombocytopenia: Current evidence and knowledge gaps.

In cancer patients, antithrombotic medications (i.e. anticoagulation or antiplatelet therapy) are frequently prescribed for prior or new indications such as venous thromboembolism or stoke prevention in atrial fibrillation. Balancing the risks of bleeding and thrombosis during periods of thrombocytopenia represents a significant challenge. Management is informed mainly by expert opinion and several recent retrospective studies on venous thromboembolism. The main management options include no change, temporarily withholding antithrombotic therapy, reducing dose, changing the regimen, and increasing the platelet transfusion threshold. Important recent advances in knowledge include the prognostic importance and apparent safety of aspirin in acute myocardial infarction and thrombocytopenia and data suggesting a low risk of recurrent venous thromboembolism in autologous stem cell transplantation patients who had anticoagulation withheld. This paper will review the literature on antithrombotic medication in thrombocytopenic patients with cancer. The significant knowledge gaps will be summarized and considerations for practice and research will be provided.

OC-08 - Multiple functional defects in platelets from thrombocytopenic cancer patients undergoing chemotherapy.

INTRODUCTION: Severe thrombocytopenia (≤50×10(9) platelets/L) is often the consequence of hematological malignancies and intensive chemotherapy. The risk of clinically significant bleeding is increased in these patients, despite the use of prophylactic platelet transfusions. The fact that there is no clear correlation between the platelet count and the risk of hemorrhage, suggests that there are other contributing factors. The contribution of impairments in platelet and coagulant function remains poorly understood. AIM: In patients with chemotherapy-induced thrombocytopenia due to hematological malignancies, we evaluate platelet and coagulant functions and determine the effects of platelet transfusion. Ultimately, we can identify specific hemostatic factors that aid in the prediction of bleeding. MATERIALS AND METHODS: In total 58 patients were included and blood was collected before and, if indicated (≤10×10(9) platelets/L), 1 hour after transfusion with platelet concentrate. Platelet function was assessed using flow cytometry by determining: 1) integrin αIIbß3 activation (PAC-1 antibody), 2) P-selectin expression (anti-P-selectin antibody), 3) phosphatidylserine exposure (Annexin-V) and 4) intracellular calcium (Fluo-4 AM). Factor levels were determined in plasma. Thrombus and fibrin formation was assessed by perfusion of whole blood over a collagen-tissue factor surface at a shear rate of 1,000 s-1. RESULTS: Platelets from the thrombocytopenic patients before transfusion showed markedly reduced integrin αIIbß3 activation and P-selectin expression in response to thrombin, collagen-related peptide and ADP, compared to healthy donor platelets. Also, agonist-induced intracellular calcium fluxes were greatly reduced. However, calcium fluxes with thapsigargin, a SERCA pump inhibitor, were similar in patient and control platelets, suggesting a normal calcium store content in the patient platelets. Furthermore, phosphatidylserine exposure was increased in unstimulated patient platelets compared to control platelets (8.2 vs. 1.8%, p<0.0001). Coagulation factor levels were within the normal range, with the exception of von Willebrand factor and fibrinogen levels, which were elevated. Platelet transfusion partly recovered the platelet integrin αIIbß3 activation and P-selectin expression induced by agonists. Platelet deposition (6.7 vs. 1.7%, p<0.0001) and fibrin formation (7.6 vs. 0.9%, p=0.0005) under flow conditions were substantially improved after platelet transfusion. CONCLUSIONS: Platelets from cancer patients undergoing chemotherapy appear to display impaired functional responses to activating stimuli. Platelet transfusion partly restores these functional defects, resulting in improved thrombus and fibrin formation.

Gastric emptying, absorption, and carbohydrate oxidation during prolonged exercise.

This study was designed to examine aspects of digestive function that may limit assimilation of water and oxidation of orally ingested carbohydrate (CHO) during exercise. Eight males completed a crossover study in which each cycled on four occasions for 80 min at 70% maximal O2 consumption. Beverage was consumed at 0, 20, 40, and 60 min. Beverages were water, 4.5% glucose (4.5G), 17% glucose (17G), and 17% maltodextrin (17MD). CHO beverages contained 20 meq/l NaCl and were 13C enriched to measure exogenous CHO oxidation. Gastric (beverage) volume was measured at 80 min. Water uptake was estimated by including 2H2O in the beverage and measuring 2H accumulation in blood. Jejunal perfusion tests were conducted at rest with the same subjects and beverages. In 60 min, 1,294 +/- 31 (SE) ml were ingested; at 80 min, volumes emptied with H2O (1,257 +/- 32 ml) and 4.5G (1,223 +/- 32 ml) were greater than with 17G (781 +/- 56 ml) and 17MD (864 +/- 71 ml; P less than 0.05). Total CHO oxidized was similar with all beverages, but there was a greater increase in exogenous CHO oxidation over time with 17G and 17MD than with 4.5G; 54, 19, and 18% of the CHO ingested with 4.5G, 17G, and 17MD, respectively, was oxidized. This represents 57, 32, and 27%, respectively, of the CHO emptied from the stomach. 2H accumulation in the blood was more rapid with H2O and 4.5G than with 17G or 17MD. Net jejunal water absorption was greater from 4.5G than from water. Net water absorption was also observed from 17MD, whereas net secretion was observed with 17G.(ABSTRACT TRUNCATED AT 250 WORDS)

Is the gut an athletic organ? Digestion, absorption and exercise.

Digestion is a process which takes place in resting conditions. Exercise is characterised by a shift in blood flow away from the gastrointestinal (GI) tract towards the active muscle and the lungs. Changes in nervous activity, in circulating hormones, peptides and metabolic end products lead to changes in GI motility, blood flow, absorption and secretion. In exhausting endurance events, 30 to 50% of participants may suffer from 1 or more GI symptoms, which have often been interpreted as being a result of maldigestion, malabsorption, changes in small intestinal transit, and improper food and fluid intake. Results of field and laboratory studies show that pre-exercise ingestion of foods rich in dietary fibre, fat and protein, as well as strongly hypertonic drinks, may cause upper GI symptoms such as stomach ache, vomiting and reflux or heartburn. There is no evidence that the ingestion of nonhypertonic drinks during exercise induces GI distress and diarrhoea. In contrast, dehydration because of insufficient fluid replacement has been shown to increase the frequency of GI symptoms. Lower GI symptoms, such as intestinal cramps, diarrhoea--sometimes bloody--and urge to defecate seem to be more related to changes in gut motility and tone, as well as a secretion. These symptoms are to a large extent induced by the degree of decrease in GI blood flow and the secretion of secretory substances such as vasoactive intestinal peptide, secretin and peptide-histidine-methionine. Intensive exercise causes considerable reflux, delays small intestinal transit, reduces absorption and tends to increase colonic transit. The latter may reduce whole gut transit time. The gut is not an athletic organ in the sense that it adapts to increased exercise-induced physiological stress. However, adequate training leads to a less dramatic decrease of GI blood flow at submaximal exercise intensities and is important in the prevention of GI symptoms.

Effects of dehydration on gastric emptying and gastrointestinal distress while running.

Gastrointestinal distress is commonly reported by athletes after ingestion of a beverage. We speculate that ingestion may be occurring after dehydration has taken place. The high prevalence of GI disorders in marathon runners who have lost greater than or equal to 4% body weight supports this theory. To test this theory, the effects of dehydration, and dehydration in combination with endurance running, on gastric emptying (GE) and frequency of gastrointestinal (GI) complaints were tested in this experiment. A complete cross-over study was designed. Sixteen subjects ingested 8 ml.kg BW-1 of a 7% carbohydrate (296 mOsm.kg-1), solution after a euhydration or dehydration regime. Dehydration (4% BW loss) was produced by 60% maximal speed running at 30 degrees C or by intermittent sauna exposure at 100 degrees C. Euhydration experiments were conducted with a 2 h rest period with water administered at 20 and 40 min. Gastric drink volumes were measured every 10 min for 40 min. Emptying curves were compared using semi-log transformation of the percentage emptying data and simple linear regression. The slope of each line was used as a measure of average GE rate. Dehydration-exercise resulted in slower GE than in all other treatments (P less than 0.05). ANOVA revealed significant effects of dehydration (P less than 0.05) and exercise (P less than 0.05), these two effects being additive in delaying GE. GI complaints were reported by 37.5% of the subjects during dehydration-exercise experiments. No GI disturbance was reported in other tests.(ABSTRACT TRUNCATED AT 250 WORDS)

Exercise and training effects on gastric emptying of carbohydrate beverages.

Carbohydrate containing drinks are commonly consumed as an ergogenic aid during endurance sports activities. The efficacy of a given drink is limited by the rate of absorption, which is in turn limited by gastric emptying. A myriad of factors influence gastric emptying. The influence of several of these factors (training status, exercise intensity, and carbohydrate composition) was investigated by repeated experiments using a nasogastric tube and a modification of the technique of George. A group of well-trained bicyclists and a group of untrained subjects performed similar experiments. Three different carbohydrate containing drinks (15 g.100 ml-1 glucose (G), 15 g.100 ml-1 maltodextrin plus 3 g.100 ml-1 fructose (MD), 7 g.100 ml-1 sucrose (I] and artificially sweetened water were compared during rest and 50 and 70% Wmax bicycling. Experimental design was crossover. There was a trend for the carbohydrate drinks to empty initially more slowly under the influence of exercise. Differences in drink volume remaining in the stomach were significant (P less than 0.05), with I at 10 min (70%, mean = 48.9%; rest, mean = 30.5%) and at 20 min (70%, mean = 28.9%; rest, mean = 23.8%) and with MD at 10 min (70%, mean = 71.1%; rest, mean = 55.9%). A similar trend was also seen with 50% Wmax exercise; however, this trend was only significant with MD at 10 min (50%, mean = 72.1%; rest, mean = 55.9%). Drink composition was a much stronger inhibitor of gastric emptying. However, all drinks emptied exponentially with fast-phase initial emptying rates. No differences in gastric emptying or secretion were observed between trained and untrained subjects.

Effects of electrolytes in carbohydrate beverages on gastric emptying and secretion.

Two experiments were done at rest to examine gastric residue and secretion volume and electrolyte composition after ingestion of beverages of varying composition. In the first experiment the effects of two different sport drinks, one isotonic (7% carbohydrate, primarily sucrose) (I) and one hypertonic (18% carbohydrate, primarily maltodextrin) (H), and a control beverage (0.08 g.l-1 aspartame in water) (C) on titratable acid, pH, osmolality, gastric emptying and secretion volume, and Na+, K+, and Cl- content were measured. In a second experiment five solutions were tested all containing 150 g.l-1 maltodextrin, with 28 meq.l-1 Na+ (low Na), 140 meq.l-1 Na+(high Na), 28 meq.l-1 K+(K), or 140 meq.l-1 Na+ and 28 meq.l-1 K+(high NaK). Beverages H and C, and distilled water (W) were also tested. Samples were taken via a nasogastric tube. A dye dilution technique for serial sampling was employed to determine beverage and secretion volumes. After receiving a bolus of 8 ml.kg-1 body weight, samples of gastric residue were taken at 0, 10, 20, 30, 40, 60, and 80 min. Gastric secretion of Na+, K+, and Cl- was fairly constant despite large differences in beverage composition. Changes in gastric residue pH, titratable acid, osmolality, and electrolyte composition reflected the increasing proportion of the residue that was from gastric secretions. The effects of varying concentrations of Na+ and K+ (in a 150 g.l-1 maltodextrin solution) on gastric emptying were not significant. The high carbohydrate concentration and/or the large volume ingested may have overridden any effect of sodium or potassium. No differences were observed between W and C. Secretion was decreased in these two solutions versus all the others. Although nonsignificant, there was a trend for greater secretion in H versus the other carbohydrate containing solutions in experiment 2. This may be a result of the higher pH maintained after ingestion of this beverage.

Daily variation in gastric emptying when using the double sampling technique.

The purpose of this study was to establish the intra-individual variation in the rate of gastric emptying (GE) by using the double sampling technique of George. Eight healthy male volunteers, all familiar with gastric intubation and testing, participated in four GE tests, using an isotonic fluid as a test meal. Conditions were kept constant during all four tests, and each test was separated by at least 48 h. The within-subjects coefficient of variation proved to be 29%. The findings demonstrate that, given standard conditions, GE is reproducible from day to day.

Osmolarity does not affect the gastric emptying rate of oral rehydration solutions.

BACKGROUND: The objective of this study was to determine the effect of either carbohydrate content or osmolarity on gastric emptying rate in normal healthy subjects. METHODS: In total 12 test drinks were ingested as a single 8 mL/kg per body weight bolus on an empty stomach. Six of these drinks had a different carbohydrate content, increasing stepwise from 45 to 90 g/L, but all with the same osmolarity (330 mOsm/kg). The other six drinks all contained 60 g carbohydrate/L but differed stepwise in osmolarity because of the use of maltodextrins with a difference in chain length (243 to 374 mOsm/kg). RESULTS: The results show a significant negative relation between carbohydrate content and gastric emptying in the six drinks with a uniform osmolarity but progressively increasing carbohydrate content. The six drinks, which had the same carbohydrate-energy content but different osmolarities, emptied all at the same rate from the stomach. The delivery of carbohydrate-energy per minute from the stomach to the small intestine was the same for all drinks. CONCLUSIONS: From these data we conclude that the rate of gastric emptying of carbohydrate-containing solutions is triggered by the carbohydrate-energy drink content or by the delivery rate of carbohydrate-energy to the gut. Osmolarity in the range studied here had no effect.

Intravascular hemolysis by IgA red cell autoantibodies.

A 66-year-old male patient with severe intravascular hemolysis is presented. Laboratory investigation revealed initially a negative direct antiglobulin test (DAT), suggesting a Coombs-negative hemolytic anemia. Additional testing with monospecific anti-IgA was strongly positive. IgA autoantibodies with anti-e specificity and nonspecific IgA autoantibodies were identified. A diagnosis of IgA-only-associated warm AIHA was made. Treatment included transfusion of multiple e-negative typed red cell concentrates and administration of high-dose prednisone. The pathophysiologic mechanism of the rare IgA-induced warm AIHA is discussed.