Cross-sectional study of the prevalence, causes and management of hospital-onset diarrhoea.

BACKGROUND: The National Health Service in England advises hospitals collect data on hospital-onset diarrhoea (HOD). Contemporaneous data on HOD are lacking. AIM: To investigate prevalence, aetiology and management of HOD on medical, surgical and elderly-care wards. METHODS: A cross-sectional study in a volunteer sample of UK hospitals, which collected data on one winter and one summer day in 2016. Patients admitted ≥72 h were screened for HOD (definition: ≥2 episodes of Bristol Stool Type 5-7 the day before the study, with diarrhoea onset >48 h after admission). Data on HOD aetiology and management were collected prospectively. FINDINGS: Data were collected on 141 wards in 32 hospitals (16 acute, 16 teaching). Point-prevalence of HOD was 4.5% (230/5142 patients; 95% confidence interval (CI) 3.9-5.0%). Teaching hospital HOD prevalence (5.9%, 95% CI 5.1-6.9%) was twice that of acute hospitals (2.8%, 95% CI 2.1-3.5%; odds ratio 2.2, 95% CI 1.7-3.0). At least one potential cause was identified in 222/230 patients (97%): 107 (47%) had a relevant underlying condition, 125 (54%) were taking antimicrobials, and 195 (85%) other medication known to cause diarrhoea. Nine of 75 tested patients were Clostridium difficile toxin positive (4%). Eighty (35%) patients had a documented medical assessment of diarrhoea. Documentation of HOD in medical notes correlated with testing for C. difficile (78% of those tested vs 38% not tested, P<0.001). One-hundred and forty-four (63%) patients were not isolated following diarrhoea onset. CONCLUSION: HOD is a prevalent symptom affecting thousands of patients across the UK health system each day. Most patients had multiple potential causes of HOD, mainly iatrogenic, but only a third had medical assessment. Most were not tested for C. difficile and were not isolated.

Local public knowledge of blood donation systems in Trinidad and Tobago and in other places

OBJECTIVE: To investigate the Trinidad and Tobago (TRT) public’s knowledge of donation procedures locally and in the United States (USA) and United Kingdom (UK) and its effect on willingness to donate blood locally. DESIGN AND METHODS: A cross sectional study was conducted on a convenience sample from adults in TRT concerning knowledge and attitudes towards blood donation. Data was collected using an interviewer-administered questionnaire. 529 responses were received. Analysis was performed using SPSS Statistics 21. Chi-squared testing was done to determine statistical significance. RESULTS: Of 529 respondents, 141 (26.7%) had donated previously, 34 (6.4%) had been excluded and 354 (66.9%) had never donated. 76.8% of those who had donated did so for a friend or family member. 53.6% of respondents rated their knowledge of TRT’s system, and 86.2% rated that of the US and UK, as ‘poor’ or ‘very poor’. Knowledge of the local system was directly correlated to willingness to donate blood in TRT (p<0.001). No relation was found concerning knowledge of the foreign systems and local willingness to donate (p=0.423). Factors deemed most ‘likely’ or ‘very likely’ to influence people to donate included: if donation was for an ill family member (87.7%) or friend (77.9%); if the blood donation system in place was a replacement system (70.9%) and if more information was given to the public about blood donation (67.3%). CONCLUSION: Public knowledge of the blood donation system of TRT affected willingness to donate while knowledge of the US and UK systems had no effect.

Outbreak of invasive group A streptococcus infection: contaminated patient curtains and cross-infection on an ear, nose and throat ward.

BACKGROUND: Outbreaks of group A streptococcus (GAS) infections may occur in healthcare settings and have been documented in surgical, obstetrics and gynaecology, and burns units. The environment may serve as a reservoir and facilitate transmission via contaminated equipment. AIM: To describe the investigation and control of an outbreak of healthcare-associated GAS infection on an ear, nose and throat (ENT) ward in a tertiary referral centre. METHODS: Two patients with laryngeal cancer developed invasive GAS infection (bacteraemia) with associated tracheostomy wound cellulitis within a 48 h period. The outbreak team undertook an investigation involving a retrospective review of GAS cases, prospective case finding, healthcare worker screening and sampling of patient curtains. Immediate control measures included source isolation, a thorough rolling clean with a chlorine-based disinfectant and hydrogen peroxide decontamination of patient equipment. FINDINGS: Prospective patient screening identified one additional patient with carriage of GAS from a tracheostomy wound swab. Staff screening identified one healthcare worker who acquired GAS during the outbreak and who subsequently developed pharyngitis. Environmental sampling demonstrated that 10 out of 34 patient curtains on the ward were contaminated with GAS and all isolates were typed as emm-1. CONCLUSION: This is the first outbreak report to demonstrate patient curtains as potential source for GAS cross-transmission, with implications in relation to hand hygiene and frequency of laundering. Based on this report we recommend that during an outbreak of GAS infection all patient curtains should be changed as part of the enhanced decontamination procedures.

A systematic review: The use of desmopressin for treatment and prophylaxis of bleeding disorders in pregnancy.

Desmopressin (DDAVP) is commonly used for treatment and prevention of bleeding complications in patients with bleeding disorders including haemophilia A, von Willebrand's disease (VWD) and other less common disorders. This article reviews the current evidence for the use of DDAVP in pregnancy to clarify its efficacy and safety with regard to maternal and foetal outcome. A search of the literature found 30 studies that reported DDAVP use in pregnancy for prophylaxis or treatment of bleeding complications with 216 pregnancies reported in total. The most common indication was prophylaxis for prevention of bleeding during pregnancy and postpartum haemorrhage. DDAVP was used successfully in the first and early second trimester for bleeding prophylaxis in 50 pregnancies. No postpartum bleeding complications were reported in 167 out of 172 pregnancies when DDAVP was used for peripartum haemostatic cover. Twenty-nine studies reported no significant adverse events as a result of treatment with DDAVP. One case of water intoxication seizure and one case of premature labour following the use of DDAVP was reported in a single study. Other maternal side effects included facial flushing and headache and were reported by one study. These side effects were generally well tolerated by patients. There were no other significant adverse events reported in any of the studies as a result of DDAVP use. Foetal outcome was recorded in ten studies with no adverse foetal outcomes. In conclusion, this review shows that DDAVP in selected cases is effective in reducing bleeding complications associated with pregnancy and childbirth with a good safety record. Further research is needed to confirm these findings as they are based on the currently available evidence from small studies and case series only.

Charge trapping phenomena of tetraethylorthosilicate thin film containing Si nanocrystals synthesized by solid-state reaction.

In this work, we report on the fabrication of tetraethylorthosilicate (TEOS) thin dielectric film containing silicon nanocrystals (Si nc), synthesized by solid-state reaction, in a capacitor structure. A metal-insulator-semi-conductor (MIS) capacitor, with 28 nm thick Si nc in a TEOS thin film, has been fabricated. For this MIS, both electron and hole trapping in the Si nc are possible, depending on the polarity of the bias voltage. A V(FB) shift greater than 1 V can be experienced by a bias voltage of 16 V applied to the metal electrode for 1 s. Though there is no top control oxide, the discharge time for 10% of charges can be up to 4480 s when it is biased at 16 V for 1 s. It is further demonstrated that charging and discharging mechanisms are due to the Si nc rather than the TEOS oxide defects. This form of Si nc in a TEOS thin film capacitor provides the possibility of memory applications at low cost.

Training prehospital personnel in saphenous vein cutdown and adult intraosseous access techniques.

OBJECTIVE: To compare the success rates, complication rates, and times required for paramedic students to perform saphenous vein cutdown and adult intraosseous infusion using the bone injection gun (BIG). METHODS: This was a prospective, randomized crossover study of 13 senior-level students in a baccalaureate degree paramedic program. Study subjects were instructed in adult intraosseous and saphenous vein cutdown techniques through lecture and laboratory exercises and then randomized into two groups. Group 1 performed saphenous vein cutdown at the ankle, followed by intraosseous infusion using the BIG. Group 2 performed the same procedures but in reverse order. All procedures were performed on preserved cadavers and videotaped. Using a standardized scoring sheet, the authors evaluated the study subjects at the time of the procedures to determine success rates, errors, and complications. Videotapes were later reviewed to verify the time required to complete the procedures. RESULTS: The normalized mean procedure scores were 96.15 (SD 4.28) and 83.83 (SD 15.52) for the intraosseous infusion and saphenous vein cutdown procedures, respectively (95% CI for difference in means, -12.34 to -1.3; p = 0.020). Success rates for establishing venous access were higher for the intraosseous route (92.3%) than the cutdown technique (69.2%), but did not achieve statistical significance (p = 0.250). The times required to initiate fluid flow were 3.91 minutes (SD 0.82) by the intraosseous route and 7.57 minutes (SD 1.80) by venous cutdown (95% CI for difference in means, 2.43 to 5.55; p = 0.000). One critical error and 11 noncritical errors were encountered during the intraosseous procedure, compared with ten critical errors and 29 noncritical errors during the cutdown procedure ( p = 0.195). CONCLUSION: In a group of inexperienced paramedic students working on a preserved human cadaver model, intravenous access was gained more rapidly, with a higher success rate, and with fewer complications using the bone injection gun than by the saphenous vein cutdown procedure. Further study is needed to evaluate these procedures in the field setting and to compare their feasibility with other alternative venous access techniques such as femoral, external jugular, and central venous cannulation.

Influence of tobacco and alcohol on the stage of laryngeal cancer at diagnosis.

OBJECTIVE: This study sought to examine the influence of cigarette smoking and alcohol consumption on the stage of laryngeal cancer at diagnosis. STUDY DESIGN: A retrospective review of 499 laryngeal cancer patients diagnosed between 1978 and 1997 was conducted. METHODS: Parameters that included smoking history, history of alcohol consumption, and the tumor stage and location at diagnosis were analyzed using the proportional odds model, correlation coefficient, and Student t test. RESULTS: Three hundred sixteen patients met the inclusion criteria, and 180 (56%) had advanced-stage disease at the time of presentation. The statistical model demonstrated a small but significant relationship between tobacco and alcohol on the stage of laryngeal cancer at diagnosis. Patients diagnosed with an advanced-stage tumor (stage III or IV) smoked a significantly greater amount and were more likely to be heavy drinkers than those diagnosed with a localized laryngeal cancer. CONCLUSIONS: Our results demonstrate that for every incremental increase in pack years of smoking, there is a small but measurable increase in the odds that a patient's laryngeal cancer will be stage III or IV at diagnosis. Likewise, being a "heavy" drinker as opposed to a "social" drinker raises the likelihood of an advanced tumor. Given the preventable nature of these risk factors, the moderation of alcohol consumption and cessation of smoking is prudent advice that should be conveyed to all patients.

Indications for the surgical repair of unilateral aural atresia in children.

OBJECTIVE: This study aimed to clarify the indications for elective surgical repair of unilateral aural atresia in children and to review the rates of successful repair in the literature. DATA SOURCES: A search of the published English language literature, 1966-1997, was conducted using the key words aural atresia. STUDY SELECTION: Articles were selected on the basis of their inclusion of the authors' indications for surgical repair of aural atresia or the inclusion of surgical series that showed outcomes. DATA EXTRACTION: Articles reviewed in the review had to either provide specific guidelines for surgical repair of unilateral aural atresia or provide postoperative pure-tone averages, air-bone gaps, or speech reception thresholds. DATA SYNTHESIS: The authors compiled the relevant data into summary tables and extracted conclusions from these data. CONCLUSIONS: Elective surgical repair of unilateral aural atresia should only be attempted in children who meet specific anatomic criteria that predict that they are the most likely to benefit from the results of surgery. Otherwise, repair should be delayed until the age at which the patient can make an informed decision, knowing the risks, benefits, and consequences of this difficult surgery. Parents and surgeons must have a realistic expectation of the surgical results and the practiced benefit to be expected with a normal, contralateral ear.

Peripheral nerve regeneration: comparison of laminin and acidic fibroblast growth factor.

PURPOSE: In an effort to show the differences between neurotrophic factors, laminin and acidic fibroblast growth factor (aFGF) were compared in terms of their abilities to regenerate axons in vivo over an extended distance. MATERIALS AND METHODS: The sciatic nerve was transected in 15 Sprague-Dawley rats. A 15-mm Silastic tube (Dow Corning, Midland, MI) was placed between the ends of the cut nerve and filled with either laminin, aFGF, or buffer applied to collagen sponges. RESULTS: Ten weeks postimplantation, mean axon counts showed that both laminin (2432) and aFGF (1612) produced significantly higher numbers of axons than controls (1009) (P < .05) and that laminin showed significantly more nerve regeneration than aFGF (P < .05). CONCLUSION: These results indicate that laminin and aFGF enhance peripheral nerve regeneration across a large gap, presumably through their neurotrophic effects and mitogenic properties on supporting cells. Furthermore, it is concluded that the transient nature of aFGF's effect on the regenerative environment limits its effectiveness at regenerating axons over a prolonged period of time.

The coming globalization of health care.

In Phase One of the global economy, international marketing of goods was paramount. In Phase Two, the marketing of services is becoming an increasingly important force. And one of the industries best positioned to profit from the globalization of services is U.S. health care. For years, a small number of providers with international reputations has catered to foreign patients. But the competition for this potentially lucrative market is on the verge of exploding. It's been estimated that the number of foreign patients visiting the U.S. for health care will quadruple in the next few years. How is this new global phenomenon unfolding, who are the potential players in the market, and what obstacles and opportunities exist? Is it so preposterous to imagine Egyptians undergoing heart bypasses in Boston? The fact is, it's already starting to happen.

Expression and distribution of renal vacuolar proton-translocating adenosine triphosphatase in response to chronic acid and alkali loads in the rat.

Renal hydrogen ion excretion increases with chronic acid loads and decreases with alkali loads. We examined the mechanism of adaptation by analyzing vacuolar proton-translocating adenosine triphosphatase (H+ ATPase) 31-kD subunit protein and mRNA levels, and immunocytochemical distribution in kidneys from rats subjected to acid or alkali loads for 1, 3, 5, 7, and 14 d. Acid- and alkali-loaded rats exhibited adaptive responses in acid excretion, but showed no significant changes in H+ ATPase protein or mRNA levels in either cortex or medulla. In contrast, there were profound adaptive changes in the immunocytochemical distribution of H+ ATPase in collecting duct intercalated cells. In the medulla, H+ ATPase staining in acid-loaded rats shifted from cytoplasmic vesicles to plasma membrane, whereas in alkali-loaded rats, cytoplasmic vesicle staining was enhanced, and staining of plasma membrane disappeared. In the cortical collecting tubule, acid loading increased the number of intercalated cells showing enhanced apical H+ ATPase staining and decreased the number of cells with basolateral or poorly polarized apical staining. The results indicate that both medulla and cortex participate in the adaptive response to acid and alkali loading by changing the steady-state distribution of H+ ATPase, employing mechanisms that do not necessitate postulating interconversion of intercalated cells with opposing polarities.

Sodium handling by deep nephrons and the terminal collecting duct in glomerulonephritis.

The present study was designed to characterize the effects of anti-glomerular basement membrane (anti-GBM) glomerulonephritis (GN) on sodium handling by surface nephrons, deep nephrons and the terminal collecting duct segment. Studies were performed in rats during hydropenia and volume expansion. In hydropenia, the glomerular filtration rate (GFR) and sodium excretion tended to be lower in rats with GN than in controls. However, the major differences between the control and GN animals were seen in volume expansion. In the volume expanded groups fractional excretion of sodium was greater in controls (3.20 +/- 0.51%) than in GN (1.20 +/- 0.36%, P less than 0.01). Despite this, delivery to end proximal sites was similar in the two groups in absolute terms and higher in the expanded GN group compared to the expanded controls. Absolute sodium delivery to the bend of the loop of Henle in the expanded GN rats was decreased in absolute terms but increased in fractional terms compared to expanded controls. However, fractional delivery of sodium to the base of the terminal collecting duct was less in GN (3.71 +/- 1.39%) than in controls (7.19 +/- 0.96%, P less than 0.002). In both groups, fractional delivery between tip of the collecting duct fell compared to base (P less than 0.05) but delivery to the tip was again greater in controls (5.49 +/- 1.08%) than in GN (1.51 +/- 0.47%). In GN 62.6 +/- 5.0% of delivered sodium was reabsorbed between collecting duct sites, nearly twofold that of controls (28.8 +/- 9.4%, P less than 0.01). Thus, fractional sodium reabsorption in the collecting duct was enhanced by GN.

Three peptides from the ANF prohormone NH(2)-terminus are natriuretic and/or kaliuretic.

The present investigation was designed to determine whether peptides derived from the NH(2)-terminal portion of the 126-amino acid prohormone (pro) of atrial natriuretic factor (ANF) have natriuretic and diuretic properties similar to ANF. Three peptides consisting of amino acids 1-30 [(proANF-(1-30)], 31-67 [proANF-(31-67)], and 79-98 (proANF-(79-98)] of the ANF prohormone were tested and compared with the COOH-terminus peptide (ANF) with respect to their ability to increase urine volume, urine sodium and potassium excretion, and glomerular filtration rate (GFR) in anesthetized Munich-Wistar rats. Each of these peptides except proANF-(79-98) caused a significant diuresis (P less than 0.05) when infused at their respective 100 ng.kg body wt-1.min-1 concentrations for 120 min. ProANFs-(1-30), (31-67), (79-98), and (99-126) (ANF) increased sodium excretion by 231, 973, 167, and 1,405%, respectively. The fractional excretion of sodium compared with control was significant at P less than 0.05, P less than 0.01, and P less than 0.05 for proANFs (1-30), (31-67), and (99-126), respectively. ProANF-(79-98) did not significantly increase the fractional excretion of sodium, but it was the only peptide from the NH(2)-terminus of the prohormone that significantly increased the fractional excretion of potassium's ProANF-(31-67) did not increase urinary potassium excretion. ProANF-(1-30), (79-98), and ANF significantly (P less than 0.05) increased urinary potassium excretion. None of these peptides significantly enhanced GFR. In conclusion, three peptides from the NH(2)-terminus of the ANF prohormone as well as ANF (the COOH-terminus) have either natriuretic, kaliuretic, and/or diuretic properties, but the respective ability of each of these peptides to produce these effects varies considerably.

Contribution of the distal tubule to potassium excretion in experimental glomerulonephritis.

The renal adaptations that maintain potassium homeostasis in diffuse forms of glomerular disease are not well defined. Thus, handling of potassium by superficial nephron segments was examined in a rat model of antiglomerular basement membrane nephritis. Sampling the same nephron successively from the end and beginning of the distal tubule and the end of the proximal tubule allowed a segmental analysis. Despite a 40% reduction in GFR, potassium excretion in the glomerulonephritis animals was normal due to an increase in FEK. The proximal tubule and loop segment did not contribute to the enhanced FEK seen in these animals. In contrast, potassium entry along the distal tubule was significantly greater in the experimental group averaging 13.7 +/- 4.3 pmol/min compared to 1.2 +/- 1.7 pmol/min in controls (P less than 0.01). Multiple linear regression analysis showed that distal tubule potassium entry at any level of flow was enhanced in glomerulonephritis compared to controls (P less than 0.0001). Plasma aldosterone levels were similar in both groups of animals. Thus, the adaptation to potassium excretion seen in glomerulonephritis is partly achieved by the distal tubule through flow-rate independent mechanisms and appears to be independent of plasma aldosterone levels.

Transport of ammonia in the rabbit cortical collecting tubule.

Nonionic diffusion and diffusion equilibrium of ammonia have been generally accepted as the mechanism of urinary ammonium excretion. However, these characteristics have not been examined directly in vitro. In the present studies, nonionic diffusion and diffusion equilibrium of ammonia were examined in rabbit cortical collecting tubules perfused in vitro. Collected fluid ammonium and pH were measured in tubules exposed to chemical gradients of NH3/NH+4. In tubules perfused with an acid perfusate free of ammonia and bathed with solutions containing NH4Cl, collected fluid ammonia failed to equilibrate across the epithelium except at slow flow rates. The estimated apparent permeability coefficient to NH3 was approximately 5 X 10(-3) cm/s. Predominant nonionic diffusion of NH3, rather than transport of NH+4, was indicated by alkalinization of luminal fluid in tubules exposed to peritubular NH4Cl and by the relative influence of peritubular NH+4 and NH3 on ammonia entry. In tubules perfused with an acid solution containing NH4Cl, little loss of ammonium was detectable, indicating a low permeability to NH+4. In contrast to the restricted diffusion of NH3 in cortical collecting tubules, proximal convoluted tubules exhibited a much higher apparent permeability to NH3. In conclusion, nonionic diffusion of NH3 accounted for most ammonium transport in the proximal convoluted tubule and in the cortical collecting tubule. However, there was relatively restricted diffusion in the collecting tubules; this may account for the failure of whole kidney ammonium excretion to obey quantitatively the predictions of nonionic diffusion and diffusion equilibrium of ammonia.

Effect of reduced renal mass on ammonium handling and net acid formation by the superficial and juxtamedullary nephron of the rat. Evidence for impaired reentrapment rather than decreased production of ammonium in the acidosis of uremia.

Papillary and surface micropuncture were used to study the handling of ammonium and the formation of net acid by surface nephrons, deep nephrons, and the terminal segment of collecting duct (CD) after renal mass was reduced by two-thirds. Net acid excretion by the remnant kidney (RK) was significantly reduced, averaging 794+/-81 neq/min (SE) compared with 1,220+/-105 neq/min after sham operation (P < 0.001), due to a decrease in ammonium excretion (494+/-54 vs. 871+/-79 nmol/min in controls, P < 0.001). Urinary pH and titratable acid excretion were not different in the two groups of animals. After RK formation, ammonium delivery to the end of the proximal tubule increased nearly threefold and averaged 66.2+/-5.6 compared with 18.4+/-2.9 pmol/min in controls, (P < 0.001). This greater delivery of ammonium was primarily due to renal tubule entry rather than to changes in the filtered load and was only partially related to the differences in flow rate. Ammonium processing by deep nephrons was profoundly affected by a reduction in renal mass. Although absolute delivery of ammonium was greater to the bend of Henle's loop (BHL), the difference could be accounted for on the basis of an increase in nephron size. Thus, fractional delivery (FD(NH+4)) to this site was not different for the two groups of animals, averaging 1,567+/-180% in controls and 1,400+/-181% in the group with the RK. Hydrogen secretion in the proximal segments of deep and surface nephrons did not increase in proportion to the decrease in renal mass and as a consequence bicarbonate delivery to the end of the proximal tubule of surface nephrons and to the BHL of deep nephrons was increased. When renal mass was reduced FD(NH+4) to the base of the terminal CD doubled but did not change by the tip. In both groups FD(NH+4) to the base of the CD was greater than to the end of the distal tubule. However, the increase was the same. On the other hand, the increase in the net acid index between the end of the distal tubule and the base of the CD was profoundly greater in rats with an RK. This difference was primarily due to bicarbonate reabsorption rather than enhanced ammonium reentry. Indeed, >400% of the fractional ammonium delivered to the end of the proximal tubule was lost from the tubule fluid. The data suggest that the decrease in acid excretion by the RK is due to two factors. First, hydrogen secretion in the proximal segments of both nephron populations fails to increase in the proportion to the reduction in renal mass. Second, a reduced reentrapment of ammonia, rather than its impaired production, causes ammonium excretion to decrease.

Segmental analysis of the renal tubule in buffer production and net acid formation.

Papillary and surface micropuncture in Munich-Wistar rats was used to assess the role of proximal segments of superficial and juxtamedullary (JM) nephrons, the distal tubule of superficial nephrons, and the terminal collecting duct in acid excretion. The relative role of these segments in ammonium production, bicarbonate reclamation, and net acid formation was assessed under hydropenic conditions and after a chronic acid load. In these two settings the proximal segment of both kinds of nephrons is the major site of ammonium production and bicarbonate reclamation. However, this segment's contribution to net acid formation was only significant during acidosis. On the other hand, segments beyond the distal tubule appear to be the major site of acid formation. In situ pH measurements were lower in these nephron segments and fell even more after the induction of an acidosis. Ammonia appears to enter fluid between the end of the distal tubule and the base of the collecting duct. In vivo pH measurements made near the bend of Henle's loop of JM nephrons were more alkaline than near the end of the proximal tubule of superficial nephrons. It is postulated that this difference in pH allows ammonium to dissociate, permitting the movement of ammonia out of the tubule lumen and into collecting duct fluid where it is protonated and, therefore, reentrapped. This process is enhanced by the ingestion of a chronic acid load.