Study Period In Groups Research Articles

Comparison of Hemodynamic Changes After Acute Normovolemic Hemodilution Using Ringer’s Lactate Versus 5% Albumin in Patients on β-Blockers Undergoing Coronary Artery Bypass Surgery

Acute normovolemic hemodilution (ANH) is used cautiously in coronary artery disease (CAD) patients because of concerns of compromised coronary blood flow. This study aimed to compare hemodynamic changes by using either Ringer's lactate or albumin for ANH in CAD patients receiving beta-blockers. Prospective, randomized study. Postgraduate teaching hospital. Thirty patients undergoing coronary artery bypass graft surgery (CABG) (hemoglobin >12 g/dL, on chronic beta-blocker therapy). Monitoring, induction, and anesthesia followed a routine protocol for CABG surgery including pulmonary artery catheter placement. Patients were randomly included in group 1 (ANH by Ringer's lactate) or in group 2 (ANH by 5% albumin). A hemodynamic calculation software program was used for parameters recorded before and after ANH. ANH could not be completed in 5 patients (33%) in group 1 because of a fall in mean arterial pressure (MAP) of more than 25% from baseline. In both groups posthemodilution MAP, heart rate, systemic vascular resistance, and oxygen delivery index decreased, whereas stroke volume index, cardiac index, and tissue oxygen extraction increased significantly as compared to baseline values (p < 0.05). Hemodynamic parameters were better maintained during the study period in group 2 than group 1. Hemodynamic stability was better maintained by 5% albumin than Ringer's lactate for ANH in chronic beta-blocked CAD patients. Despite an increase in cardiac index, systemic oxygen delivery was decreased irrespective of the hemodiluting fluid used. ANH to a hemoglobin value of 10 g/dL in chronically beta-blocked CAD patients was well tolerated.

Effizienz der Bestandesbetreuung in Milchviehbetrieben

A retrospective analysis of the reproductive parameters was conducted in 15 dairy farms using a herd health monitoring system between 1995 and 1998. Five of these farms have used this monitoring process for many years (group 1) while 10 of them only initiated the process in 1996 (group 2). It was the aim of this study to evaluate the economic gain of the farms in each group due to the herd health monitoring program throughout the three year study period, by using Value Based Management (VBM), a model from the economic sciences. The mean calving to conception interval decreased from 93.3 to 84.0 days and from 104.9 to 86.7 days throughout the study period in groups 1 (P>0.05) and 2 (P < 0.05), respectively. The mean percentage of cows with calving to conception intervals below 115 days varied between 68.2% and 82.0% in group 1, while there was an increase form 65.2% to 78.6% in group 2 (P<0.05). There were no apparent trends in the reproductive culling rate throughout the study period (P>0.05), and the majority fell below 10%. Likewise, the first service conception rate varied between 52.7% and 56.6% and between 41.2% and 50.0%, in group 1 and 2, respectively. The number of services per conception varied between 1.6 and 1.8 and between 1.8 and 1.9, in groups 1 and 2, respectively. The number of days between calving and first service varied between 62.7 and 64.8 days in group 1, while it decreased significantly from 69.2 to 59.2 in group 2 (P<0.05). The time between first service and conception decreased from 30.6 to 22.0 days, and from 35.7 to 28.0 days in groups 1 and 2, respectively (P<0.05). Although there was an apparent increase of the detection rate of oestrus from 57.8% to 68.2% throughout the study period in group 1, it was not significant (P > 0.05). In group 2, however, the oestrus detection rate increased significantly from 53.0% to 69.9% (P < 0.05). The percent of detected oestrus within 42 days post partum increased from 33.1% to 38.1%, and from 24.1% to 40.9% in groups 1 and 2, respectively (P < 0.05). By 1998, four out of five farms in group 1, and five out of the eight farms where information was avail- year study period of CHF 25.- to CHF 609.- per cow and year. The calving to conception interval and the reproductive culling rate were the two most important parameters to determine the reproductive performance of the herd and the economic benefit of the herd health monitoring program. These findings support the implementation of a herd health monitoring program.

The effect of montelukast on eosinophil apoptosis: induced sputum findings of patients with mild persistent asthma

Background Apoptosis may be important in limiting airway eosinophilia. Treatment with leukotriene antagonists decreases the number of eosinophils in both peripheral blood and sputum. Aim To assess the effect of montelukast on eosinophil apoptosis in a group of patients with mild persistent asthma (MPA) and to compare this effect with the apoptotic effect of fluticasone propionate (FP). Methods Randomly selected patients with MPA (n = 22) who had not taken anti-inflammatory therapy within the preceding 12 months were included in the study. The sputum induction procedure was performed and the patients were divided into two groups: group 1 (n = 10) received FP 250 μg/day and group 2 (n = 22) received montelukast 10 mg/day orally for 4 weeks. Sputum induction was repeated after the treatment period. The resulting cytospin slides were stained by Wright's stain and morphologic changes in apoptotic eosinophils were assessed by the use of light microscopy by two blinded expert pathologists. Serum soluble Fas ligand (sFasL) concentrations were measured by an ELISA method at baseline and after treatment in both groups, as well as in a group of healthy subjects. Results In within-group comparisons, the apoptotic ratio (AR) increased at the end of the study period in group 1 (p = 0.05). In the group treated with FP the ratio of sputum eosinophils significantly decreased (p = 0.02), and the AR significantly increased (p < 0.005). No differences were found in the two study groups in serum sFasL levels at the end of the treatment period compared with baseline values (p > 0.05). Conclusion Our findings demonstrate that 4 weeks’ treatment with a CysLT receptor antagonist (montelukast) resulted in an increase in eosinophil apoptosis comparable to that produced by FP, suggesting that induction of apoptosis may be a potential mechanism for the mode of action of CysLT receptor antagonists in asthma.

Usefulness of epidural anesthesia in gynecologic laparoscopic surgery for infertility in comparison to general anesthesia

Although the advantages of epidural anesthesia in open surgery have been established, its usefulness in the setting of laparoscopic surgery remains to be studied. Patients undergoing laparoscopic surgery for infertility were randomly administered epidural anesthesia (group A, n = 11) or general anesthesia (group B, n = 9). The operation was performed under 4 mmHg pneumoperitoneum and in the 20 degrees Trendelenburg position. Respiratory function tests using a spirometer and blood gas analysis were performed during the intra- or perioperative period. Pain status was evaluated with visual analog scale scoring. The number of postoperative recovery days needed to resume daily activities was obtained by a questionnaire. Respiratory rate, minute volume, P(a)CO2, % vital capacity (VC), and forced expiratory volume in 1 s (FEV1) % were virtually constant throughout the study period in group A, whereas %VC was decreased immediately after operation in group B (p < 0.05). Minute volume immediately after operation was significantly increased in group B compared with group A (p < 0.01), suggesting shallow respiration in women undergoing general anesthesia. Observed pain scores on abdominal pain, shoulder pain, and dyspnea were very low during operation in group A. Pain scores immediately and 3 h after operation were also minimal in group A, whereas abdominal pain scores at these points were significantly higher in group B than those in group A (both p < 0.01). The number of days required for a half reduction in wound pain, trotting, and full recuperation for group A were less than those for group B (p < 0.05). Epidural anesthesia, when used in laparoscopic surgery for infertility treatment, has advantages over general anesthesia in terms of analgesic effects, postoperative respiratory function, and a return to preoperative daily activities.

The juxtaglomerular apparatus in young type-1 diabetic patients with microalbuminuria. Effect of antihypertensive treatment.

Our goal was to investigate the effect of antihypertensive drugs on the juxtaglomerular apparatus (JGA) in young type-1 diabetic patients with microalbuminuria. Twelve patients were allocated to treatment with either an angiotensin-converting enzyme inhibitor (group 1, six subjects) or a beta-receptor blocker (group 2, six subjects). A comparable group of nine patients without antihypertensive treatment provided reference values (group 3, nine subjects). Renal biopsies were taken at baseline and after a median of 40 months (groups 1 and 2) and 30 months (group 3). Using light microscopy with 1microm serial sections of the plastic-embedded biopsies, volumes of the JGA and glomerulus and areas of the macula densa and lumina of the afferent and efferent arterioles were obtained. A significant decrease of the volume of the JGA (P=0.026) and of the volume of the JGA relative to that of its corresponding glomerulus (P=0.0005) was noted in the reference group only. Negative correlations existed between the increase in the luminal area of the afferent arteriole and mean diastolic blood pressure in the study period in group 1 (P=0.024) and group 2 (P=0.032). Our results showed that a decrease in the size of the JGA is offset by antihypertensives. The negative correlation between the change in the luminal area of the afferent arteriole and mean diastolic blood pressure in groups 1 and 2 suggest that renal protection in antihypertensive treatment may be through a better constriction of the afferent arteriole protecting the glomerulus from systemic blood pressure.

A new prototype of an electronic jet-ventilator and its humidification system.

BACKGROUND: Adequate humidification in long-term jet ventilation is a critical aspect in terms of clinical safety. AIM: To assess a prototype of an electronic jet-ventilator and its humidification system. METHODS: Forty patients with respiratory insufficiency were randomly allocated to one of four groups. The criterion for inclusion in this study was respiratory insufficiency exhibiting a Murray score above 2. The four groups of patients were ventilated with three different respirators and four different humidification systems. Patients in groups A and B received superimposed high-frequency jet ventilation (SHFJV) by an electronic jet-ventilator either with (group A) or without (group B) an additional humidification system. Patients in group C received high-frequency percussive ventilation (HFPV) by a pneumatic high-frequency respirator, using a hot water humidifier for warming and moistening the inspiration gas. Patients in group D received conventional mechanical ventilation using a standard intensive care unit respirator with a standard humidification system. SHFJV and HFPV were used for a period of 100 h (4days). RESULTS: A significantly low inspiration gas temperature was noted in patients in group B, initially (27.2 +/- 2.5 degrees C) and after 2 days (28.0 +/- 1.6 degrees C) (P < 0.05). The percentage of relative humidity of the inspiration gas in patients in group B was also initially significantly low (69.8 +/- 4.1%; P < 0.05) but rose to an average of 98 +/- 2.8% after 2 h. The average percentage across all four groups amounted to 98 +/- 0.4% after 2 h. Inflammation of the tracheal mucosa was found in patients in group B and the mucosal injury score (MIS) was significantly higher than in all the other groups. Patients in groups A, C and D showed no severe evidence of airway damage, exhibiting adequate values of relative humidity and temperature of the inspired gas. CONCLUSION: The problems of humidification associated with jet ventilation can be fully prevented by using this new jet-ventilator. These data were sustained by nondeteriorating MIS values at the end of the 4-day study period in groups A, C and D.

Control of hypertension during isoflurane or sevoflurane anesthesia with continuous infusion of nicardipine hydrochloride

In a multicenter study, the efficacy and tolerability of nicardipine hydrochloride (NIC) were examined when the drug was used to control hypertension during isoflurane or sevoflurane anesthesia in patients with or without a preoperative history of hypertension. Retrospectively, the 124 study patients were divided into four groups: patients without (group 1) or with (group 2) a preoperative history of hypertension who received isoflurane anesthesia, and those without (group 3) or with (group 4) a preoperative history of hypertension who received sevoflurane anesthesia. NIC infusion was started when systolic pressure exceeded 160 mm Hg or 30% above the control value determined before the induction of anesthesia. The ability of NIC to control hypertension was analyzed for 30 minutes after starting the infusion. Arterial pressure, heart rate, and urine volume were examined in each group. Mean doses of NIC infused during the 30-minute study period in groups 1, 2, 3, and 4 were 2.23, 2.13, 2.43, and 2.19 μg · kg −1 · min −1, respectively. There were no significant differences between the four groups in the amount of NIC infused. In the four groups, no significant changes were seen in heart rate, and blood pressure was effectively controlled (group 1: 149.5/86.4 mm Hg and 113.3/63.0 mm Hg before and after the 30-minute study period, respectively; group 2: 156.6/91.2 mm Hg and 118.2/71.0 mm Hg; group 3: 153.4/90.1 mm Hg and 119.0/71.1 mm Hg; and group 4: 160.6/98.7 mm Hg and 124.1/76.8 mm Hg). The final blood pressure measurements were considered within normal ranges for the patients studied. A decrease in blood pressure was slightly delayed in both sevoflurane groups (groups 3 and 4) and in the isoflurane group with a preoperative history of hypertension (group 2). While urine output tended to increase in all groups, a significant increase was found only in group 1 (from 0.019 ± 0.011 mL · kg −1 · min −1 before treatment to 0.087 ± 0.041 mL · kg −1 · min −1 after treatment). In conclusion, NIC was effective and well tolerated in controlling hypertension during isoflurane or sevoflurane anesthesia

EARLY ENTERAL FEEDING PROTOCOLS FOR PRETERM INFANTS. † 1908

We evaluated the use of early enteral feeding protocols (EEFP) for preterm infants with birth weights of 751 - 1200 g (Group I) and 1201 - 1500 g (Group II) during study (S) and retrospective periods (R). Infants were evaluated for growth and nutritional intake at birth and weekly intervals throughout the neonatal period. Hypothesis: EEFP will lead to earlier institution of enteral nutrition (EN), improved caloric intake and growth, and shorter duration of parenteral nutrition (PN). Results are summarized below(M±SD): Table The age at which EN was started was significantly less during the study period in each group; however, the age at which full EN (120 kcal/k/d) was reached was similar within groups. The ages when parenteral carbohydrate (CHO) and protein were added were similar within groups, whereas lipid was added significantly sooner during Group I S. At d7, PN kcal/k/d were significantly higher during the study period in each group, with significantly higher lipid kcal/k/d during the study period in Group II, d7 (19.1±6.4 vs. 12.8±5.0, p=.032) and Group I, d14(25.8±8.1 vs. 16.4±11.3, p=.011). This improved caloric intake did not persist on days 21 and 28. Weight, length, and head circumference were similar within groups at all time periods. The duration of PN nutrition was not significantly less during the study period. Conclusions: Routine utilization of EEFP contributed to more uniform, earlier onset of EN; however, caloric intake and growth were not significantly improved throughout the neonatal period, nor was the duration of PN significantly reduced at our institution.

Short courses of high-dose inhaled budesonide and serum IgG subclass levels in healthy volunteers

BACKGROUND:The incidence of systemic side effects of inhaled budesonide increases at doses exceeding 2000 μg/day. OBJECTIVE: This study was carried out to investigate whether high-dose inhaled budesonide affects serum IgG subclass concentrations in healthy adult volunteers. METHODS: Two groups of 10 subjects each inhaled 2.4 mg of budesonide per day in a double-blind, crossover study of morning (8:00 AM F, group A) and diurnal (8:00 AM and 8:00 PM, group B) dosing schedules for 4 weeks each, separated by a 2-week washout period. The budesonide was inhaled through a pressurized metered-dose inhaler, mounted on a 750 ml Nebuhaler (ASTRA Pharmaceuticals, Lund, Sweden). The IgG subclass levels were determined at baseline and every 2 weeks until the end of the study period (10 weeks). RESULTS: There were no statistically significant changes in the serum IgG subclass concentrations over the 10-week study period in group A, group B, or groups A and B combined. CONCLUSION: Inhalation of budesonide, 2.4 mg/day, through a large-volume spacer for repeated 1-month periods does not influence serum IgG subclass concentrations in healthy adults, suggesting that budesonide does not cause systemic humoral immunosuppression when given at therapeutic doses. (J A LLERGY C LIN I MMUNOL 1996;97:113-8.)

Internal potassium shift in premature infants: Cause of nonoliguric hyperkalemia

To study the pathophysiology of nonoliguric hyperkalemia, we measured serum potassium concentration and external K balance (intake and excretion), and estimated internal K balance (a shift from intracellular space to extracellular space) in 24 nonoliguric premature infants during the first 72 hours after birth. Data were analyzed from two aspects: gestational age (group 1, 24 to 28 weeks, n = 9; group 2, 29 to 32 weeks, n = 9; group 3, 33 to 36 weeks, n = 6) and postnatal age (0 to 72 hours). Serum K concentration rose from baseline (0 hour) to 24 hours in groups 1 and 2 ( p < 0.01) but did not rise in group 3. The external K balance was negative in all groups during the study period, and was more negative in the more premature infants (group 1 > group 2 > group 3) during the second 24 hours. There was a significant difference ( p < 0.01) between the internal K balance of the three groups during the first 24 hours (group 1 > group 2 > group 3), and the K shift decreased significantly ( p < 0.05) during the study period in groups 1 and 2. The more premature the infants, the larger the K shift and the larger the rise in serum K concentration during the first 24 hours, and the more negative the external K balance after 24 hours. These data indicate that K loading caused by the K shift associated with prematurity produces a rapid rise in serum K concentration, resulting in an increase in urinary K excretion. We conclude that an internal K shift inversely proportional to gestational and postnatal age is the primary cause of nonoliguric hyperkalemia in very premature infants. (J P EDIATR 1995;126:109-13)

Plasma volume expansion and PEEP in a canine model of acutePseudomonas pneumonia

Four groups of anesthetized, ventilated dogs (n = 6 in each group) inoculated endotracheally with Pseudomonas aeruginosa were studied over 5 h as bilateral, hemorrhagic pneumonia developed. Groups I and II were ventilated with zero end-expiratory pressure (ZEEP) and groups III and IV with positive end-expiratory pressure (PEEP) (8 cmH2O). Hetastarch (6%) in saline was infused intravenously to maintain similar transmural pulmonary wedge pressures (Pwtm) in groups I and III (approximately 5 mmHg) and groups II and IV (approximately 10 mmHg) throughout the experiment. The effects of plasma volume expansion were analyzed by comparing groups I and III with groups II and IV and of PEEP by comparing groups I and II with groups III and IV. The number of lobes with gross consolidation was greater in groups II (4.8 +/- 1.2) and IV (5 +/- 0.9) than in groups I (2 +/- 1.1) and III (3.3 +/- 1). The mean lung wet weight/body weight ratio was greater in groups II (40 +/- 11 g/kg) and IV (48 +/- 12 g/kg) than in groups I (19 +/- 3 g/kg) and III (32 +/- 6 g/kg) and in groups III and IV than in groups I and II. Plasma volume expansion, in the absence of PEEP (group II vs. group I), dramatically increased intrapulmonary shunt (Qs/Qt 5 h after inoculation: group II, 62 +/- 13%; group I, 25 +/- 12%). However, overall gas exchange 5 h after inoculation was not significantly different between PEEP-treated groups and ZEEP-treated groups despite more extensive disease in the former. Despite maintenance of Pwtm, cardiac output fell significantly over the 5 h study period in groups III (4.3 +/- 0.7 to 3.3 +/- 1.0 L/min) and IV (7.2 +/- 1.7 to 3.8 +/- 2.4 L/min) compared to groups I (3.8 +/- 1.0 to 3.5 +/- 1.2 L/min) and II (6.9 +/- 3.2 to 7.3 +/- 2.6 L/min). We conclude that plasma volume expansion, within the normal physiological range of Pwtm, increases the extent of pneumonia. Positive end-expiratory pressure with maintenance of Pwtm also independently increases pneumonia size, possibly by increasing pulmonary capillary hydrostatic pressure, but masks this effect by maintaining arterial oxygenation through recruitment of additional lung units for gas exchange. The data also suggest that PEEP adversely affects cardiac performance in this model of acute pneumonia.

Serial changes in left ventricular wall motion by two-dimensional echocardiography following anterior myocardial infarction

To evaluate the time course of spontaneous changes in wall motion following anterior infarction, we prospectively performed serial apical four-chamber two-dimensional echocardiography on 45 consecutive long-term survivors of initial transmural anterior infarction. Studies were performed on admission (1 ± 1 days), 1 week after admission (6 ± 2 days), at discharge (15 ± 8 days), and at long-term follow-up (235 ± 186 days). Ventricular size was expressed as end-diastolic area in square centimeters. Wall motion for this tomographic section was evaluated as the percent change in left ventricular area from end diastole to end systole (% LVA). Patients were grouped on the basis of significant differences for %LVA between the first and fourth studies. Group I (n = 14) had improved wall motion (23 ± 5% to 38 ± 9%); group II (n = 23) did not change (22 ± 9% to 23 ± 11%); and group III (n = 8) had worsened wall motion (28 ± 6% to 18 ± 7%). End-diastolic area did not change over the study period for groups I and II but increased significantly for group III (30 ± 6 to 35 ± 4 cm 2, p < 0.05). Most of the increase in end-diastolic area for group III was between the third and fourth study. The percent improvement (%IMP) in wall motion for patients in group I who did not have ventricular fibrillation outside the hospital expressed in days (t) following infarction fit an exponential curve (%IMP = 100−100e −(.108t) that predicts that 70% of eventual recovery will occur in the first 15 days post-infarction. We conclude that changes in left ventricular size and wall motion occur following anterior infarction with improvement or worsening occurring spontaneously in some patients. If improvement occurs, it should be evident within 2 weeks of infarction; infarct expansion in this select group of long-term survivors occurred primarily after discharge.

Effects of indomethacin on systemic and coronary hemodynamics in patients with coronary artery disease

The effects and possible mechanisms of actions of indomethacin on systemic and coronary hemodynamics were studied in 17 patients with coronary artery disease. Group I patients (12) were given either indomethacin or placebo in the absence of prior cyclooxygenase inhibition and group II (five) were given indomethacin after prior treatment with 2600 mg of aspirin. In group I, systolic blood pressure rose from a baseline of 136 ± 5 mm Hg to a peak level of 158 ± 8 mm Hg 5 minutes after drug ( p < 0.01). This was associated with a fall in coronary blood flow and a rise in coronary vascular resistance from a baseline of 1.36 ± 0.4 mm Hg/ml/min to 1.99 ± 0.7 mm Hg/ml/min 5 minutes after indomethacin ( p < 0.01). Immunoreactive thromboxane B 2 levels fell from 191 to 1.4 ng/ml. No changes were noted in plasma renin activity, angiotensin II, or catecholamine levels. Immunoreactive thromboxane B 2 levels were undetectable throughout the study period in group II patients and the blood pressure response to indomethacin was attenuated. Baseline coronary blood flow was significantly higher ( p < 0.01) and baseline coronary vascular resistance significantly lower ( p < 0.01) than in group I. At all time points after indomethacin, the fall in coronary blood flow was greater and the increase in coronary vascular resistance less in group II versus group I ( p < 0.001). These findings suggest a dissociation between the effect of indomethacin on systemic and coronary hemodynamics, the former apparently being more prostaglandin-dependent than the latter.