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Biomedical subjects

C Sachs

Publications and source records attributed to C Sachs.

At least 19 recordsLinked to original sources
PubMed1998

Pulse oximetry as a fifth vital sign in emergency geriatric assessment.

OBJECTIVE: To determine the utility of pulse oximetry as a routine fifth vital sign in emergency geriatric assessment. METHODS: Prospective study using pulse oximetry to measure O2 saturation in geriatric patients presenting to ED triage. Saturation values were disclosed to clinicians only after they had completed medical evaluations and were ready to release or admit each patient. The authors measured changes in medical management and diagnoses initiated after the disclosure of pulse oximetry values. The study included 1,963 consecutive adults aged > or = 65 years presenting to triage at a university ED. Measurements included changes in select diagnostic tests: chest radiography, complete blood count (CBC), spirometry, arterial blood gases (ABGs), pulse oximetry, and ventilation-perfusion scans; treatments: antibiotics, beta-agonists, and supplemental O2; and hospital admission and final diagnoses that occurred after complete ED evaluation when physicians were informed of triage pulse oximetry values. RESULTS: 397 (20.2%) geriatric patients had triage pulse oximetry values <95%. Physicians ordered repeat oximetry for 51 patients, additional chest radiography for 23, CBC for 16, ABGs for 15, spirometry for 5, and ventilation-perfusion scans for none. Physicians ordered 49 new therapies for 44 patients, including antibiotics for 14, supplemental O2 for 29, and beta-agonists for 6. Nine patients initially scheduled for ED release were subsequently admitted to the hospital. Physicians changed or added diagnoses for 27 patients. CONCLUSIONS: Using pulse oximetry as a routine fifth vital sign resulted in important changes in the diagnoses and treatments of a small proportion of emergency geriatric patients.

Aged↗
PubMed1997

Nitric oxide and the renin angiotensin system: contributions to blood pressure in the young rat.

The present study was designed to investigate the effects of chronic administration of the arginine analogue L-Name (50 mg/kg body weight), the angiotensin converting enzyme inhibitor, perindopril (2 mg/kg body weight), and perindopril (2 mg/kg) plus L-Name (50 mg/kg) on blood pressure, plasma renin activity, plasma angiotensinogen, and hepatic angiotensinogen mRNA levels in young and adult rats. The drugs were given daily from birth to day 21 to puppies and for 15 days to adults. Analytical procedures were performed on day 21 for the puppies and at 10 weeks for the adults. In puppies, blood pressure did not change with L-Name, it decreased to 45% of control values (P < 0.001) with perindopril, and decreased to 77% of control values (P < 0.05) with perindopril plus L-Name. In adults, blood pressure increased to 129% of control values (P < 0.02) with L-Name, decreased to 80% of control values (P < 0.05) with perindopril, and did not change with perindopril plus L-Name. Compared with controls, plasma renin activity was unchanged in puppies and adults with L-Name, undetectable in puppies and slightly increased in adults with perindopril, undetectable in puppies and slightly decreased in adults with perindopril plus L-Name. With L-Name, angiotensinogen mRNA levels were unchanged in puppies and slightly increased in adults, while plasma angiotensinogen levels were decreased (P < 0.05) in puppies and increased (P < 0.01) in adults; with perindopril, angiotensinogen mRNA levels were unchanged in puppies and slightly decreased in adults, while plasma angiotensinogen levels were undetectable in puppies and decreased (P < 0.05) in adults; with perindopril plus L-Name, angiotensinogen mRNA levels were unchanged in puppies while plasma angiotensinogen levels were undetectable in puppies and decreased (P < 0.01) in adults. This study suggests that during the early postnatal period (1) nitric oxide does not exert a basal vasodilator tone but contributes to the hypotensive state induced by perindopril, (2) angiotensin II is essential to maintain blood pressure, (3) and angiotensinogen mRNA levels are not influenced by nitric oxide or angiotensin II.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1997

Pulse oximetry as a fifth pediatric vital sign.

PURPOSE: To determine the utility of pulse oximetry as a routine fifth vital sign in acute pediatric assessment. DESIGN: Prospective study using pulse oximetry to measure oxygen saturation in children presenting to emergency department triage. Saturation values were disclosed to clinicians only after they had completed medical evaluations and were ready to discharge or admit each child. We measured changes in medical treatment and diagnoses initiated after the disclosure of pulse oximetry values. SETTING AND PARTICIPANTS: The study included 2127 consecutive children presenting to triage at a university emergency department. MEASUREMENTS: Changes in select diagnostic tests: chest radiography, complete blood count, spirometry, arterial blood gases, pulse oximetry, and ventilation-perfusion scans; treatments: antibiotics, beta-agonists, supplemental oxygen; and hospital admission and final diagnoses that occurred after disclosure of triage pulse oximetry values. RESULTS: Of 305 children having triage pulse oximetry values less than 95%, physicians ordered second oximetry for 49, additional chest radiography for 16, complete blood counts for 7, arterial blood gas measurements for 4, spirometry for 2, and ventilation-perfusion scans for 2. Physicians ordered 39 new therapies for 33 patients, including antibiotics for 15, supplemental oxygen for 11, and beta-agonists for 8. Five patients initially scheduled for hospital discharge were subsequently admitted. Physicians changed or added diagnoses in 25 patients. CONCLUSIONS: Using pulse oximetry as a routine fifth vital sign resulted in important changes in the treatment of a small proportion of pediatric patients.

Adolescent↗
PubMed1997

The European Register for Clinical Chemists. (European Communities Confederation of Clinical Chemistry, Working Group on Registration).

To ensure freedom of movement in the European Union, a limited number of professions is regulated by a so-called Sectorial Directive; all other disciplines, including clinical chemistry, fall under a General Directive. However, clinical chemists in the EU wish their specialty to be more specifically regulated; this means that common standards of education, training, experience and compliance with continuing professional developments must be guaranteed. Therefore, the European Communities Confederation of Clinical Chemistry (EC4) is about to implement the European Register for clinical chemists, and has composed a guide to this Register. The document describes the conditions for entry to specialty training, the minimum standards for registration (university education and postgraduate vocational training with a minimum total of eight years), the competencies of those qualifying for registration, and the operation of the register. Registration guarantees professional and managerial competencies; the title conferred is "European Clinical Chemist". EC4 recognises the existing national registers as far as they are based on the minimal requirements as indicated. An EC4 Register Commission (EC4RC) will maintain and control the European Register, supported by National Clinical Chemistry Registration Committees (NCCRC). An NCCRC controls the quality of the education in each country and assesses candidates. An individual (EU citizen or non-EU citizen trained in an EU country) applies privately for the European Register to EC4RC and, where applicable, the application is accompanied by a document from the NCCRC of the country of registration, stating that the applicant has the necessary qualifications. For EU citizens trained outside the EU the final decision is with EC4RC; non-EU citizens not trained in an EU country are not eligible for registration. Registration is renewed once every five years.

Chemistry, Clinical↗
PubMed1996

A comparison of pulse oximetry and respiratory rate in patient screening.

OBJECTIVE: To examine how well respiratory rate correlates with arterial oxygen saturation status as measured by pulse oximetry, and determine whether respiratory rate measurements detect oxygen desaturation reliably. METHODS: Respiratory rate (RR) and oxygen saturation (SaO2) were measured prospectively on 12,096 consecutive adult emergency department triage patients at a university medical center. Respiratory rate was measured by counting ausculated breath sounds for 1 min. Pulse oximetry was used to measure SaO2. Measurements were analysed by age (with one group for 18-19 year olds, groups for every 10 yr from age 20 to age 60, and groups for every 5 yr for subsequent ages). Pearson correlation coefficients were calculated for each age group as well as the weighted average coefficient. Cases having oxygen saturation below 90% were examined to determine how frequently they exhibited increased RR (increased RRs were defined as any rate in the upper five percentile by age. RESULTS: Correlation coefficients ranged from 0.379 to -0.465 with a weighted mean of -0.160. Coefficients for ages 18 through 70 years (representing 10,740 patients) all had magnitude < 0.252. Overall, only 33% of subjects with oxygen saturation below 90% exhibited increased RR. CONCLUSIONS: Respiratory rate measurements correlate poorly with oxygen saturation measurements and do not screen reliably for desaturation. Patients with low SaO2 do not usually exhibit increased RR. Similarly, increased RR is unlikely to reflect desaturation.

Adolescent↗
PubMed1996

Evaluation of syringes for ionized calcium measurements.

UNLABELLED: Commercially available ready to use syringes (Radiometer, Sarstedt, Ciba-Corning and Portex), containing heparinate as an anticoagulant have been tested to evaluate the magnitude of induced preanalytical errors. Tonometered serum pools adjusted to four Ca2+ concentrations were sampled anaerobically. MEASUREMENTS: Ca2+ and pH (ICA2 with 3 digits, Radiometer Medical A/S, Denmark; Heparin: anti-Xa factor activity on a chromogenic substrate. Results were expressed as means of 10 measurements and as percentages of the reference values. Sarstedt syringes, (Li-heparinate), yielded a negative bias (-3%). However for 0.5 or 1 mL samples the bias reached -4% to -6%. Radiometer syringes (QS50 and QS90; calcium titrated heparinate) demonstrated biases below -2%. The bias in the Ciba-Corning (Gas-Lyte) syringe was below 2%. Portex (Pulsator) syringes showed biases above +4% even for nominal sampling volumes. All syringes (except Pulsator) released anticoagulant amounts corresponding to the expected values. Radiometer and Ciba-Corning were the only recommendable devices.

Anticoagulants↗
PubMed1995

Fetal urinary insulin-like growth factor I and binding protein 3 in bilateral obstructive uropathies.

Fetal urinary concentrations of insulin-like growth factor I (UIGF-I) and binding protein 3 (UIGFBP-3) were determined in patients with prenatal diagnosis of bilateral obstructive uropathy. Patients were retrospectively assigned to three groups, on the basis of outcome: group 1, termination of pregnancies (n = 11) with sonographic evidence of severe oligohydramnios or renal dysplasia, confirmed at histological examination; group 2, patients (n = 10) with postnatal plasma creatinine > 50 mumol/l at the age of 1 year (1 yr-pCreat); and group 3, patients (n = 16) with 1 yr-pCreat < or = mumol/l. The results show a significant increase in UIGF-I and UIGFBP-3 in groups 1 (18,159 +/- 9083 pg/ml; 2657 +/- 669 ng/ml) and 2 (1574 +/- 847 pg/ml; 176 +/- 50 ng/ml) in comparison with group 3 (35 +/- 6 pg/ml; 21 +/- 2 ng/ml). UIGF-I and UIGFBP-3 were significantly correlated with postnatal plasma creatinine, and were both sensitive (90 per cent; 80 per cent) and specific (88 per cent; 88 per cent) for prediction of elevated 1 yr-pCreat (> 50 mumol/l). Fetal urinary IGF-I and IGFBP-3 are increased in severe fetal bilateral obstructive uropathy, possibly reflecting tubular dysfunction or/and increased synthesis consequent upon fetal kidney injury. Their predictive value for postnatal renal function needs further assessment.

Electrolytes↗
PubMed1995

Mechanisms of dopamine effects on Na-K-ATPase activity in Madin-Darby canine kidney (MDCK) epithelial cells.

Dopamine decreases tubular sodium reabsorption, attributed in part to Na-K-ATPase inhibition in the proximal convoluted tubule (PCT). Because the final regulation of sodium excretion occurs in the collecting duct, where specific dopamine DA1 binding sites have been demonstrated, we examined the effects of dopamine, as well as of DA1 and DA2 receptor agonists on Na-K-ATPase activity and on the number of units in Madin-Darby canine kidney (MDCK) cells, which retain differentiated properties of the renal cortical collecting tubule epithelium. Dopamine (10(-5) M) inhibited pump activity (by 50%) and reduced the number of units. This effect was reproduced by the DA1 agonist SKF 38393, which inhibited pump activity in a dose- and time-dependent manner (maximum, 10(-5) M). The DA2 agonist quinpirole hydrochloride was without effect, either alone or in combination with SKF 38393. Inhibition of pump activity by dopamine was totally abolished by H7 (100 microM), an inhibitor of protein kinase (PK), but partially by 2',5'-dideoxy-adenosine (DDA) and H4, respective inhibitors of cAMP production and PKA, which suggests that the dopamine effect on Na-K-ATPase activity may be linked to activation of both PKC and PKA. In these cells, amiloride addition during preincubation did not alter the effect of dopamine on Na-K-ATPase activity; in contrast, furosemide increased further the inhibitory effect of dopamine on the enzyme activity. Monensin addition (10(-3) M) reversed the inhibitory effect of dopamine after a 30-min preincubation.(ABSTRACT TRUNCATED AT 250 WORDS)

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1995

Deleterious effects of inhibition of the renin-angiotensin system in neonatal rats.

The angiotensin I converting enzyme inhibitor (ACEI) perindopril (2 mg/kg body weight), the peripheral vasodilator dihydralazine (DHL) (25 mg/kg body weight) or distilled water was given daily from birth to day 14 to neonatal rats. Blood pressure, plasma creatinine, plasma renin activity (PRA), substrate (PRS) and concentration (PRC) and renin content of kidney tissue sections were evaluated on days 14 and 28. By day 14, a high mortality in the ACEI group was observed. ACEI, but not DHL, led to a significant fall (P < 0.01) in blood pressure, 57 +/- 11 versus 89 +/- 25 in the DHL group and 103 +/- 24 mmHg in controls, and to a dramatic increase in plasma creatinine. PRA and PRS were undetectable in ACEI-treated rats; in contrast, PRC and renal staining with anti-renin antibody were significantly increased in ACEI rats. On day 28, the blood pressure was normal in all groups and plasma creatinine returned to the normal range in ACEI rats. PRA, PRS and PRC were not significantly different in the ACEI group and controls. These results suggest that the renin-angiotensin system (RAS) plays a major postnatal role in the neonatal rat. Inhibition of the RAS during the first 2 weeks of life leads to high mortality, severe hypotension, reversible renal failure and a defect in circulating angiotensinogen.

Aging↗
PubMed1995

Effect of routine emergency department triage pulse oximetry screening on medical management.

PURPOSE: To determine the utility of routine triage pulse oximetry screening in emergency department (ED) patients. DESIGN: Prospective study using pulse oximetry to measure oxygen saturation of ED patients at triage. Saturation values were disclosed to physicians only after they completed medical evaluations and were ready to discharge or admit each patient. We measured changes in medical management initiated after disclosure of pulse oximetry values. SETTING AND PARTICIPANTS: The study included 14,059 consecutive patients presenting to triage at a university ED. MEASUREMENTS: Changes in select diagnostic tests: chest radiography, CBC count, spirometry, arterial blood gases, pulse oximetry, and ventilation-perfusion scans; treatments: antibiotics, beta-agonists, supplemental oxygen; and hospital admission and final diagnoses that occurred after disclosure of triage pulse oximetry values. RESULTS: Of 1,175 patients having triage pulse oximetry values less than 95%, physicians ordered repeat pulse oximetry on 159 (13.5%), additional chest radiography on 5.4%, CBC count on 3.1%, arterial blood gases on 2.9%, spirometry on 0.9%, and ventilation-perfusion scans on 0.3%. Physicians ordered 178 new therapies on 134 patients (11.4%), including supplemental oxygen for 6.5%, antibiotics for 3.9%, and beta-agonists for 1.8%. Thirty-five patients (3.0%) initially scheduled for hospital discharge were subsequently admitted. Physicians changed or added diagnoses in 77 patients (6.6%). CONCLUSIONS: Providing physicians with routine triage pulse oximetry measurements resulted in significant changes in medical treatment of these patients.

Adolescent↗
PubMed1994

Endothelin-1 in children with chronic renal failure.

Endothelin-1 (ET-1) was measured after extraction from plasma of normal adults (5.9 +/- 1.9 pg/ml, n = 22), normal children (7.1 +/- 1.86 pg/ml, n = 29), non-haemodialysed children with chronic renal failure (CRF) (11.1 +/- 1.8 pg/ml), n = 10), renal graft recipients (9.5 +/- 3.4 pg/ml, n = 37), haemodialysed children 24 h after a haemodialysis session (20.02 +/- 10.9 pg/ml, n = 26) and haemodialysed children before and after a haemodialysis session (15.31 +/- 10.6 and 13.8 +/- 8.5 respectively, n = 14). A sensitive and specific radioimmunoassay was used. ET-1 was significantly higher in non-haemodialysed CRF children and in renal graft recipients than in normal children (P < 0.001 and P < 0.01, respectively) and significantly higher in haemodialysed children when compared with normal children, non-haemodialysed CRF children and renal graft recipients (P < 0.001). ET-1 concentrations were similar in normal children and normal adults. ET-1 was inversely correlated with glomerular filtration rate in non-haemodialysed CRF children (r = -0.39, P < 0.01) and positively correlated with extracellular volume in haemodialysed children (r = 0.435, P < 0.03). After haemodialysis, ET-1 increased in 6 and decreased in 8 of the 14 children studied before and after a haemodialysis session.

Adolescent↗
PubMed1994

Effects of lipoxygenase products of arachidonate metabolism on parathyroid hormone secretion.

High extracellular Ca2+ (Ca2+ ec) stimulates the formation of inositol phosphates and diacylglycerol and activates phospholipase A2 in porcine parathyroid cells. Ca2+ ec action is also coupled to the formation of arachidonic acid, the precursor of both the cyclooxygenase and lipoxygenase (LO) pathways. We previously reported that LO pathway products might act as second messengers and play a part in regulating PTH secretion by Ca2+ ec. We have now investigated the effects of hydroxyeicosatetranoic acids (HETEs) on PTH secretion. Collagenase-dispersed porcine parathyroid cells were incubated in low [Ca2+] (0.5 mM, maximal stimulation) with or without HETEs for three 15-min periods. 12- and 15-HETEs inhibited PTH secretion in a dose-dependent manner from 10(-12) to 10(-9) M. Maximal inhibition was with 10(-9) M. Since 12- and 15-HETEs are the metabolic reduction products of 12- and 15-HPETEs, we also examined the effect of those precursors on PTH release. 12- and 15-hydroxyperoxyeicosatetranoic acids (HPETEs) were more potent inhibitors of PTH secretion. The threshold concentrations of both HPETEs that inhibited PTH release were lower than those for HETEs: 10(-9) M suppressed PTH secretion. This effect is comparable to that of high [Ca2+] (2 mM). This provides new evidence that products of 12-LO and 15-LO pathways are potent inhibitors of PTH secretion.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1993

Creation of experimental urethral obstruction in utero: evaluation of fetal renal function.

Management of obstructive uropathy diagnosed in utero would be markedly enhanced by the availability of a simple, safe and quantitative fetal renal function test to predict postnatal renal function. In order to allow experimental evaluation of such a parameter, we adjusted a model of complete urethral obstruction with urachal ligation in 30 fetal lambs at 79 or 99 days of gestation. The method described allows obstruction in male and female fetuses as early as 79 days of gestation, with an overall high survival rate (control: 12/14; obstructed: 23/29), although lower (6/12) when obstruction is performed early (79 days) during gestation. Consequences of obstruction were examined on the 121st day of gestation. Severe hydronephrosis, ureteral and calyceal dilatation, with or without ascites and pulmonary hypoplasia were observed in all fetuses; creatinine clearance determined in utero was decreased in both groups with obstruction (early and late) vs control group: 1.15 +/- 0.5, NS, and 0.58 +/- 0.4, p < 0.01 vs 1.61 +/- 0.8 ml/min/kg respectively. In both obstructed groups, fetuses with ascites displayed lower plasma creatinine concentration and higher creatinine clearance values when compared to fetuses without ascites. In conclusion, the experimental model of obstructive uropathy described appears efficient and easily reproducible, allowing therefore the evaluation of a predictive parameter of postnatal renal function. Our preliminary results suggest that renal fetal function is more dependent on the degree of obstruction than on the term of its creation.

Animals↗
PubMed1993

Acute and early effects of aldosterone on Na-K-ATPase activity in Madin-Darby canine kidney epithelial cells.

The time course and mechanism of early effects of aldosterone on renal Na-K-adenosinetriphosphatase (Na-K-ATPase) activity and number of units were studied in MDCK cells. Aldosterone induced a time- and dose-dependent stimulation of Na-K-ATPase activity. The stimulatory effect of aldosterone on activity and number of pump units increased progressively and was inhibited by spironolactone. In presence of cycloheximide, the stimulatory effect of aldosterone on activity and number of catalytic sites persisted to the same extent until 30 min and decreased by 20% after 60 min. In these cells, dimethylamiloride addition during preincubation abolished the aldosterone-induced stimulation in Na-K-ATPase activity up to 60 min. In contrast, furosemide addition did not alter the effect of aldosterone on Na-K-ATPase activity. The present study demonstrates an early effect of aldosterone on Na-K-ATPase activity that can be separated into the following two successive periods: 1) increase in pump number due to insertion of presynthetized units secondary to Na entry through an amiloride-sensitive apical pathway; and 2) an increase in pump number by de novo protein synthesis.

Aldosterone↗
PubMed1993

Attrition from an evening alcohol rehabilitation program.

In recent years many groups have become interested in the potential cost savings and efficacy of outpatient treatment for chemical dependency. This study was originally conceived to answer questions of both patients and staff concerning graduation and attrition rates in an evening outpatient alcohol treatment program. Of particular interest were gender effects, rates of attrition across two progressive program levels, and whether alcohol-only users and self-initiated clients fared better in treatment than did polysubstance users and patients who were referred by others. Medical records were available for 103 of the 107 treated patients, and of these, 27 remained in the program until graduation. Women were more likely to graduate and remain in the program longer than men. Alcohol users were more likely to graduate than subjects with additional substance use disorders. Graduation rates did not differ significantly between contact initiators and noninitiators; however, the former dropped out of treatment more quickly. The study is an example of the potential use of data obtained from an existing agency data base.

Adult↗