Impact of gastrointestinal polymerase chain reaction panels on antibiotic utilization in hospitalized adult patients

Multiplex stool polymerase chain reaction (PCR) panels offer rapid comprehensive testing for patients with infectious diarrhea. We compared antibiotic utilization among hospitalized patients with suspected infectious diarrhea who underwent diagnostic testing with either a stool culture or stool PCR panel. No significant differences in antibiotic utilization were identified.

185. Implementation of Multiplex Polymerase Chain Reaction in Clinical Practice: Impact on Antimicrobial Management In Infectious Diarrhea

Background

Stool culture and stool polymerase chain reaction (PCR) panels are both used to evaluate patients with suspected infectious diarrhea. Stool PCR panels are especially advantageous because of their ability to detect a broad array of infectious pathogens in less than one hour. Our study assessed how the use of stool PCR panels instead of stool culture impacted antibiotic days of therapy (DOT) and length of therapy (LOT) in hospitalized patients with suspected infectious diarrhea.

Methods

In December 2021, an intervention was implemented in our hospital in which all electronic orders for stool cultures were automatically switched to stool PCR testing. The pre-intervention group was comprised of 75 hospitalized adult patients who had a stool culture obtained from September to November 2021. The post-intervention group was comprised of 81 adult patients who had a stool PCR obtained from December 2021 to February 2022. The DOT and LOT for antibiotics prescribed specifically for infectious diarrhea were determined for each patient; DOT and LOT were compared between the pre- and post- intervention groups.

Results

The median DOT in the pre- and post-intervention groups was 0 with a range of 0-10 and 0-8, respectively. The median LOT in the pre- and post-intervention groups was 0 (range 0-5 for both groups). No significant difference in the median DOT (Wilcoxon rank sum test, p-value = 0.967) or LOT (Wilcoxon rank sum test, p-value = 0.993) was found between the pre- and post-intervention groups (Figure 1). After adjusting for patient days present, no significant change in DOT or LOT incidence rate was found between the pre- and post-intervention groups. The DOT incidence rate ratio (RR) was 0.71 (95% CI 0.42, 1.22), and the LOT incidence RR was 0.67 (95% CI 0.36, 1.24). Figure 1.

ID: 113: THE ENDOTHELIAL PHD2/HIF-2 AXIS REGULATES PULMONARY ARTERY PRESSURE IN MICE

Background

Pulmonary hypertension (PH), a common clinical problem characterized by increased pulmonary artery (PA) pressure, is frequently triggered by hypoxia. Key mediators of cellular hypoxia responses are hypoxia-inducible factors (HIF)-1 and -2, the activity of which is regulated by prolyl-4-hydroxylase domain (PHD) proteins, with PHD2 being the main oxygen sensor that controls HIF activity under normoxia. Although both transcription factors are expressed in the lung, little is known about their cell type-specific roles in the pathogenesis of PH.

Methods and Results

Here we used a genetic approach to investigate the role of endothelial PHD2/HIF axis in the regulation of PA pressure. Endothelial cell specific HIF activation was achieved by crossing Vecadherin (Cdh5)-Cre transgenics to Phd2 floxed mice (ePhd2), while the contribution of each HIF isoform was assessed by generating double mutants lacking Phd2 and Hif-2 (ePhd2Hif2) or Phd2 and Hif-1 (Phd2Hif1). Right ventricular systolic pressure (RVSP) was measured via insertion of a 1.4F Mikro-tip catheter transducer into a surgically exposed right internal jugular vein. ePhd2 mice showed activation of HIF-signaling as shown by immunoblot analysis of lung tissue for HIF-1 and HIF-2. These mice developed spontaneous PH (RVSP, ePhd2: 54.3±6.9 vs Cre-: 24.8±2.2 mm Hg, P=0.005), which was associated with right ventricular hypertrophy (RVH) (Fulton Index, ePhd2: 0.52 vs Cre-: 0.28, P=0.0004) and early mortality. While morphologic analysis of ePhd2 lungs did not demonstrate plexiform or lumen-obliterating lesions, enhanced muscularization of peripheral PAs was detected in mutants compared to controls, as indicated by an increase in the number of arteries with diameters <100 µm that stained positive for αSMA (22.1±1.6 vs. 7.6±1.5 muscularized vessels/10 hpf, P<0.0001). The PH phenotype was maintained in ePhd2Hif1 mutants but was reversed in ePhd2Hif2 mutants. To assess the contribution of endothelial HIF-2 in hypoxia induced PH, endothelial Hif2 single mutants or Cre-littermates were exposed to normobaric hypoxia (10% O2) for 4 weeks. In contrast to controls, eHif2 mutants were protected from development of PH and RVH. Bone marrow transplantation studies showed no contribution from hematopoietic HIF-2 in hypoxia induced PH. Because hypoxia regulates endothelin 1 (EDN1), a potent vasoconstrictor but also apelin (APLN), a vasodilatory peptide acting through binding to the apelin G-protein-coupled receptor (APLNR), we assessed the role of endothelial HIF-2 axis in the regulation of these molecules. Endothelial deletion of Phd2 resulted in 6.4-fold induction of pulmonary Edn1 mRNA (P=0.029), but not Apln mRNA. In contrast, Aplnr was downregulated by 2.5-fold in ePhd2 mutants (P=0.037). A similar pattern of expression was detected in ePhd2Hif1 mice, whereas simultaneous deletion of Hif2a and Phd2 reversed these changes. To investigate the differences between acute and chronic hypoxia, we examined the effects of acute HIF activation on Edn1 and Apln/Aplnr gene expression in vivo. To model acute hypoxia, we subjected WT mice to 8% O2 for 48 hrs and maintained controls in room air. Acute hypoxia resulted in a 4.3-fold and 1.6-fold up-regulation of Edn1 and Apln transcripts respectively (P=0.0011 for Edn1, P=0.08 for Apln) while Aplnr was reduced by 4.3-fold (P=0.0005). We observed similar gene expression changes in mice treated with a prolyl-4-hydroxylase inhibitor (PHI) that results in global HIF activation.

Conclusions

Our studies identify endothelial HIF-2 as a key transcription factor in the pathogenesis of PH and suggest that HIF-2 regulates PA pressure by modulating the expression of vasoactive molecules. Our findings identify the PHD2/HIF2 axis as a potential target for PH therapies.

Impedance nadir values correlate with barium bolus amount

We examined the value of impedance monitoring in measuring bolus volume compared with videoesophagram. Eighty consecutive subjects were studied with simultaneous impedance-manometry-videoesophagram. A catheter with both an impedance electrode pair and a pressure transducer at four sites (5, 10, 15, 20 cm above lower esophageal sphincter) was passed per nares. Six 10-cc boluses of 45% barium mixed with 0.9% NaCl were swallowed at 20- to 30-second intervals. When impedance fell to below 1000 ohms, other than that occurring during administered swallows, the videofluoroscopic image corresponding to the time of impedance nadir was reviewed. If barium was present at the impedance site, barium area was calculated. The video was reviewed for the cause of abnormal barium transit causing barium presence. We found 38/80 subjects had a total of 169 impedance falls to below 1000 ohms. Ninety-seven percent (164/169) of impedance falls had barium present at the impedance site, and there was good correlation (r = 0.83, P < 0.001) between impedance nadir value and barium area. The impedance nadir value : barium area relationship was similar for the three causes of barium presence identified by video: failed bolus clearing; gastroesophageal reflux; and esophageal escape. Impedance nadir values 700-999 ohms usually had a small barium area. In contrast, nadir values <400 ohms had a large barium area covering all or most of the catheter and filling the esophagus at the impedance site. Impedance falls from >1000 ohms to a low nadir value from all forms of abnormal esophageal bolus transit imply a large bolus amount.

Acid and non-acid reflux in patients with persistent symptoms despite acid suppressive therapy: a multicentre study using combined ambulatory impedance-pH monitoring

BACKGROUND AND AIMS

Empiric proton pump inhibitor (PPI) trials have become increasingly popular leading to gastroenterologists frequently evaluating gastro-oesophageal reflux disease (GORD) patients only after they have "failed" PPI therapy. Combined multichannel intraluminal impedance and pH (MII-pH) monitoring has the ability to detect gastro-oesophageal reflux (GOR) episodes independent of their pH and evaluate the relationship between symptoms and all types of GOR. Using this technique, we aimed to characterise the frequency of acid and non-acid reflux (NAR) and their relationship to typical and atypical GOR symptoms in patients on PPI therapy.

METHODS

Patients with persistent GORD symptoms referred to three centres underwent 24 hour combined MII-pH monitoring while taking PPIs at least twice daily. Reflux episodes were detected by impedance channels located 3, 5, 7, 9, 15, and 17 cm above the lower oesophageal sphincter (LOS) and classified into acid or non-acid based on pH data from 5 cm above the LOS. A positive symptom index (SI) was declared if at least half of each specific symptom events were preceded by reflux episodes within five minutes.

RESULTS

A total of 168 patients (103 (61%) females and 65 (39%) males; mean age 53 (range 18-85) years) underwent combined MII-pH monitoring while taking PPIs at least twice daily. One hundred and forty four (86%) patients recorded symptoms during the study day and 24 (15%) patients had no symptoms during testing. Sixty nine (48%) symptomatic patients had a positive SI for at least one symptom (16 (11%) with acid reflux and 53 (37%) with NAR) and 75 (52%) had a negative SI. A total of 171 (57%) typical GORD symptoms were recorded, 19 (11%) had a positive SI for acid reflux, 52 (31%) for NAR, and 100 (58%) had a negative SI. One hundred and thirty one (43%) atypical symptoms were recorded, four (3%) had a positive SI for acid reflux, 25 (19%) had a positive SI for NAR, and 102 (78%) had a negative SI.

CONCLUSION

Combined MII-pH identifies the relation of reflux of all types to persistent symptoms and the importance of NAR in patients taking PPIs.

"We're living what we're learning": student perspectives in distance learning degree and certificate programs in public health

The authors used surveys and interviews to study participants' motivations for enrolling and perceptions of the weaknesses and strengths of two distance learning programs administered by the University of North Carolina at Chapel Hill School of Public Health (SPH): the MPH in Public Health Leadership and a certificate program organized collaboratively with the Mahidol University SPH in Thailand. Chief motivations were career advancement, job performance improvement, convenience, and obtaining a degree from a reputable institution. Strengths included the curriculum, networking opportunities, and administrative and technical support. Concerns included quality of interaction with faculty and instructional methods.

Compliance curves during peritoneal dialysate infusion are like a distensible tube and are similar at multiple UGI sites

OBJECTIVE

Disorders from increased intraabdominal pressure (IAP) result from filling the abdominal cavity beyond its capacity. The aims of this study were 1) to examine pressure:volume curves as fluid is infused into the intraabdominal cavity, and 2) to ascertain the best UGI site for indirect IAP measurements.

METHODS

Chronic ambulatory peritoneal dialysis patients were studied (n = 4) supine. On day 1, manometry catheters measured IAP indirectly (intragastric and intrarectal) and intraesophageal (three sites) pressure. On day 2, antral-duodenal-jejunal manometry was performed to compare indirectly measured IAP at multiple sites. On both days, dialysate was infused at 200 ml/min until IAP was > or = 15 mm Hg or patient experienced severe discomfort.

RESULTS

Filling had three phases: 1) an initial small increase in IAP as infusion began; 2) minimal further increase in IAP during infusion to about 3 L concurrent with a progressive increase in abdominal girth and mild abdominal discomfort; and 3) a linear increase in IAP with infusion > 3 L concurrent with intense abdominal discomfort and little increase in abdominal girth. During study day 2, intragastric, intraduodenal, and intrajejunal pressures were usually similar.

CONCLUSIONS

The compliance curve of the abdomen with filling is similar to that of the bladder and large veins. Compliance curves with provocative meals may be useful in evaluating postprandial abdominal pain, dyspepsia, and bloating.

Nonprofit organizations and innovation: a model of neighborhood-based collaboration to prevent child maltreatment

Public policymakers increasingly are contracting with nonprofit organizations (NPOs) for innovations in the creation of new service systems in low-income communities. Interorganizational collaboration and cooperation are essential to such innovation. Neighborhood-based institutional arrangements require social work practitioners to work across multiple systems simultaneously--skills that most are not trained to possess. This article develops a theoretical and conceptual framework for neighborhood-based collaboration by NPOs; analyzes the main concepts of innovation in the design and implementation of a collaboration to prevent child maltreatment in an undervalued neighborhood; and draws implications for social policy, social work practice, and social work research.

Triazolam pharmacokinetics and pharmacodynamics in Caucasians and Southern Asians: ethnicity and CYP3A activity

A threefold higher area under the plasma drug concentration-time curve (AUC) of nifedipine, a substrate of cytochrome P4503A (CYP3A), has been shown in Southern Asians when compared with Caucasians. To determine if these differences are specific to nifedipine or apply to other substrates of CYP3A, we examined the pharmacokinetics and pharmacodynamics of 0.375 mg triazolam, another substrate of CYP3A, in eight healthy Caucasians and eight healthy Southern Asians in a double-blind placebo-controlled study. When compared with Caucasians, Southern Asians achieved higher maximum plasma concentration (Cmax) (8.0 +/- 2.6 vs 4.8 +/- 1.9 ng ml-1; the 95% confidence interval (CI) of the mean difference was 0.76 to 5.7; P < 0.01) and had a shorter time to reach maximal concentration (tmax) (45 min (range 30-75) vs 90 min (range 60-145); the 95% CI of the mean difference was -69 to -20; P < 0.002). Triazolam AUC, clearance and partial metabolic clearance did not differ significantly between Southern Asians and Caucasians. Significant differences were found in postural sway after triazolam when compared with placebo in both Caucasians (double stance: eyes open (DSEO): 172.9 +/- 82.9 vs 1138.9 +/- 1182.4; the 95% CI of the mean difference was -1897.2 to -34.4; P < 0.04; and Southern Asians (DSEO: 216.2 +/- 80.9 vs 1086.0 +/- 827.1; the 95% CI of the mean difference was -1564.2 to -175.6; P = 0.02; double stance: eyes closed (DSEC): 207.5 +/- 89.8 vs 1156.9 +/- 932.1; the 95% CI of the mean difference was -1718.5 to -178.5; P = 0.02; with no significant difference between the two ethnic groups. These results suggest that the large inter-ethnic difference in nifedipine clearance are not generalizable to all CYP3A4 substrates.

Evaluating a community intervention to reduce the risk of child abuse: methodological strategies in conducting neighborhood surveys

Building on the ecological approach to child abuse, the National Center on Child Abuse and Neglect is supporting a number of community-based prevention initiatives. One such program, based in Boston, is designed to build a caring community in which families can be empowered to break patterns of abusive and neglectful behavior. Independent evaluation is central to the program. A multi-level strategy has been designed, incorporating information from census and other databases, from random household surveys, and from families participating directly in services provided. This paper reports on the second level of the evaluation, designed to assess community social support, attitudes about parenting, perceptions of the neighborhood, and ways in which these may relate to child abuse. Perceptions of the extent of danger and disorganization in the neighborhood were significantly related to a sense of attachment to the community, and to disciplinary strategies. Parents who perceived more danger were stricter. They also tended to be born locally rather than being immigrants. Place of birth was associated with variation in parenting styles, suggesting that patterns of in- and out-migration are important variables in planning and executing a community based child abuse prevention program.

Institute for Nursing Excellence: A Retention Model

In 1989, the General Assembly funded initiatives for the recruitment and retention of nurses, including two pilot "Institutes for Nursing Excellence" designed to develop, recognize, and reward excellent staff nurses. The Wake Area Health Education Center (AHEC) implemented the pilot projects. In 1991, additional funding was obtained to replicate the pilot projects. The grant was awarded to the Wake AHEC from the General Assembly, through the newly established Center for Nursing. This cooperative effort between the legislature and nursing is considered a model of its kind in this state and possibly the nation. The purpose of the Institute was to develop mentoring, role-modeling, change, and lifelong learning skills in an atmosphere of renewal, rejuvenation, and trust.

Effect of i.v. anaesthesia with propofol on drug distribution and metabolism in the dog

We have studied the effect of i.v. anaesthesia with propofol in the emulsion (Intralipid) formulation on drug distribution and metabolism in six dogs using dual-route administration of propranolol as a model compound. Each dog was studied on two consecutive days: day 1 awake and day 2 during propofol anaesthesia (6 mg kg-1 followed by an infusion of 0.8 mg kg-1 min-1). Propofol anaesthesia was associated with reduced intrinsic clearance by 40% (P less than 0.05) but no significant difference in systemic clearance or hepatic plasma flow. Propofol produced marked changes in drug distribution; volume of distribution (Vss) of propranolol increased 54% from 82.5 (SEM 7.3) litre awake to 127.3 (27) litre during propofol anaesthesia (P less than 0.05). This change was accompanied by an increase (P less than 0.05) in the free fraction of propranolol from 8.5 (0.7) % in awake to 14.0 (0.7) % in propofol-anaesthetized dogs. The combination of the effects of both drug clearance and protein binding resulted in a 65% decrease in the intrinsic clearance of unbound drug (P less than 0.05). In contrast with the effects of propofol on drug distribution, infusion of Intralipid alone in another group of six dogs had no significant effects on drug distribution, protein binding or drug metabolism. We conclude that propofol is a modest inhibitor of drug metabolism, but has major effects on propranolol distribution, possibly by changing plasma protein binding.

The effect of halothane on morphine disposition: relative contributions of the liver and kidney to morphine glucuronidation in the dog

The present study determined the effect of halothane on the disposition of morphine by defining the effect of halothane anesthesia on the systemic, renal, and hepatic clearance of the parent compound, morphine, and on the generation of the primary metabolite, morphine-3-glucuronide (M3G) in the dog. Unlabeled morphine, 3H-morphine, and 14C-morphine were simultaneously administered into the portal vein, femoral vein, and renal artery, respectively, first during pentobarbital anesthesia and second during halothane (1.5 MAC) anesthesia; blood samples were taken for estimation of unlabeled plasma morphine and M3G concentrations by high performance liquid chromatography (HPLC). 3H- and 14C-morphine concentrations and corresponding M3G concentrations were determined by dual-channel liquid scintillation counting of the eluant corresponding to the appropriate peak on the HPLC. The portal clearance of morphine was not altered by halothane. However, intravenous (iv) morphine clearance (CLs) decreased (P less than 0.05) by 40% from 963 +/- 131 to 579 +/- 91 ml/min during halothane anesthesia, accompanied by an increase (P less than 0.05) in half-life from 78 +/- 8 to 106 +/- 8 min. The reduction in CLs of morphine occurred putatively on the basis of a halothane-induced decrease in hepatic blood flow, whereas morphine metabolism, reflected by morphine portal (intrinsic) clearance, was not significantly decreased by halothane. There was no significant effect of halothane on the partial metabolic clearance of morphine to M3G, and the ratio of area under the plasma concentration-time curve (AUC)-M3G to AUC unchanged morphine was not significantly altered by halothane, indicating that morphine glucuronidation is unaffected by halothane anesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)

Halothane inhibition of propranolol metabolism is stereoselective

Propranolol, like many drugs, is used clinically as a racemic mixture. The major pharmacodynamic effects of propranolol, however, are mediated by the (-)-isomer, which is 100 times as potent as the (+)-isomer. The two isomers also differ in their pharmacokinetic characteristics. To determine whether halothane anesthesia stereo-selectively inhibits the metabolism of racemic propranolol, eight male mongrel dogs were studied. On the first day of the study, 40 mg racemic propranolol was infused into the portal vein and arterial blood samples were obtained over the following 4 h for the measurements of (+)- and (-)-propranolol concentrations by HPLC. The study was repeated 24 h later during 2 MAC halothane anesthesia, when the intrinsic clearance of total propranolol was decreased by 67.5 +/- 5%, from 6.14 +/- 1.1 1/min to 1.84 +/- 0.4 1/min (P less than 0.05). The decrease in intrinsic clearance was stereoselective, (-)-propranolol being affected to a greater extent than (+)-propranolol; thus, the decrease in the clearance of (-)-propranolol, from 10.96 +/- 2.71/min to 2.6 +/- 0.71/min (73 +/- 5%) was significantly (P less than 0.05) greater than the decrease in the clearance of (+)-propranolol, (62 +/- 3%) from 4.3 +/- 0.8 1/min to 1.5 +/- 0.3 1/min. Furthermore, the ratio of the intrinsic clearance of (-)-propranolol to the intrinsic clearance of (+)-propranolol was significantly (P less than 0.05) reduced by halothane anesthesia, from 2.42 +/- 0.29 to 1.69 +/- 0.11. Stereoselective inhibition of propranolol metabolism results in proportionally higher concentrations of (-)-propranolol during halothane anesthesia than are present in awake dogs.(ABSTRACT TRUNCATED AT 250 WORDS)

Lack of effect of spinal anesthesia on drug metabolism

The effect of spinal anesthesia on drug disposition was determined in six dogs with chronically implanted vascular catheters using propranolol as a model compound. On the first study day, 40 mg of unlabeled propranolol and 200 microCi of [3H]propranolol were injected into the portal and femoral veins respectively. Arterial blood samples were taken for 4 hr for measurement of plasma concentrations of labeled and unlabeled propranolol by high-pressure liquid chromatography (HPLC) and of [3H]propranolol by liquid scintillation counting of the HPLC eluant corresponding to each propranolol peak. Twenty-four hr later, spinal anesthesia was induced with tetracaine (mean dose 20.7 +/- 0.6 mg) with low sacral to midthoracic levels and the propranolol infusions and sampling were then repeated. Spinal anesthesia had no significant effect on either the intrinsic clearance of propranolol (2.01 +/- 0.75 L/min before and 1.9 +/- 0.7 L/min during spinal anesthesia), or on mean hepatic plasma flow (2.01 +/- 0.5 L/min before and 1.93 +/- 0.5 L/min during spinal anesthesia). The systemic clearance and elimination half-life of propranolol were also unchanged by spinal anesthesia (0.9 +/- 0.23 L/min on the first day, 0.7 +/- 0.1 L/min during spinal anesthesia; and 101 +/- 21 min on the first day, 115 +/- 16 min during spinal anesthesia, respectively). The volume of distribution (Vd) of propranolol was similarly unaffected by spinal anesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of cimetidine on anesthetic metabolism and toxicity

Because the H2-receptor antagonist cimetidine has been shown to inhibit drug metabolism, the effects of cimetidine on anesthetic metabolism and toxicity were investigated in a rat model. Cimetidine decreased inorganic plasma fluoride production after methoxyflurane administration both in 21% oxygen (P less than 0.001) and in 100% oxygen (P less than 0.001). Phenobarbital produces an increased fluoride formation after methoxyflurane anesthesia, and this fluoride formation is also reduced by cimetidine (P less than 0.005). There was no significant difference between the plasma fluoride levels in rats anesthetized with halothane or enflurane. Although cimetidine inhibited the in vivo defluorination of methoxyflurane, fluoride levels were still within the nephrotoxic range, and cimetidine is not likely to play a role as part of a preanesthetic regimen that would permit the increased clinical use of methoxyflurane. Cimetidine also inhibited the oxidative metabolism of halothane; cimetidine decreased (P less than 0.05) trifluoroacetic acid concentrations after halothane anesthesia in 21% oxygen and in 100% oxygen and decreased (P less than 0.05) bromide concentrations after halothane anesthesia in 100% oxygen. Trifluoroacetic acid levels were less (P less than 0.02) after halothane anesthesia in 14% oxygen as compared with 100% oxygen, indicating a reduction in oxidative metabolism under hypoxic conditions. However, bromide concentrations were maximal after halothane anesthesia in 21% oxygen, and significantly (P less than 0.001) less after halothane anesthesia in 14% and 100% oxygen. Bromide production, therefore, seems to be inhibited by both hypoxia and hyperoxia.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of a home-based microcomputer to analyze community data from reported cases of child abuse and neglect

A personal microcomputer data base program was used to study 184 substantiated 1981 child abuse and neglect cases in the city of Lansing, Michigan. Data on 18 variables were entered directly into the microcomputer from the agency case closing forms in 7 1/2 hours. The microcomputer can sort by one or more variables. In analyzing the data, the following questions were addressed: Who reports the child abuse cases? In what types of families does abuse occur? Who are the perpetrators in relation to the child? Who are the victims by age and race? What types of abuse are substantiated? How many of the cases are repeats? Where are substantiated cases located? This study was both simple and inexpensive, requiring minimal staff time, a microcomputer with a data base program, and data already available in agency files. This study could be duplicated in any area by noncomputer persons to help professionals, community organizers, and others to better understand their community and help the abusive family.