Methylprednisolone reduces postoperative nausea in total knee and hip arthroplasty.

WHAT IS KNOWN AND OBJECTIVE: Total knee and hip joint replacement has a high risk of postoperative nausea and vomiting (PONV), and steroid cover is used for cases associated with autoimmune diseases. Our aim is to evaluate the antiemetic efficacy of methylprednisolone as steroid cover in patients undergoing the surgery. METHODS: A prospective cohort study design was used. Sixty-eight patients, aged between 20 and 80 years, were scheduled for a standardized general anaesthetic technique. Patients who were given methylprednisolone were assigned as the steroid cover group, and those who were not given methylprednisolone formed the non-steroid cover group. PONV were assessment by direct questioning or spontaneous complaints by patients 1 week after surgery. Postoperative pain was evaluated using Visual Analog Scale (VAS) 1 and 3 days after surgery. RESULTS AND DISCUSSION: The incidence of nausea in the steroid cover group was significantly less than that in the non-steroid cover group (adjusted odds ratio, 0·17, P = 0·021), but there was no significant difference in vomiting between the two groups. Postoperative pain VAS score was not significantly different between groups. WHAT IS NEW AND CONCLUSION: In total knee and hip arthroplasty, methylprednisolone is effective in preventing postoperative nausea; however, higher doses of methylprednisolone may be needed to prevent vomiting.

Space plasma physics: space experiments with particle accelerators.

Electron and plasma beams and neutral gas plumes were injected into the space environment by instruments on Spacelab 1, and various diagnostic measurements including television camera observations were performed. The results yield information on vehicle charging and neutralization, beam-plasma interactions, and ionization enhancement by neutral beam injection.

The frequencies of diabetic complications in elderly non-insulin dependent diabetic patients in Himeji.

Data on 746 patients with non-insulin-dependent diabetes mellitus (NIDDM) were collected from the Internal Medical Association in Himeji by questionnaire, and the patients were divided into six groups according to the duration of illness. Frequencies of various complications according to the duration of illness and risk factors of complications were compared between men and women. Although the number of male patients was 417, significantly more than the 329 female patients, many female patients were elderly, and the age at initial onset was about 10 years older than that of the male patients. Fasting blood sugar and hemoglobin A1c levels increased with the duration of illness. The female patients showed a greater tendency to suffer from hypertension, hyperlipidemia and obesity than the male patients. There was positive correlation between the incidence of complications and duration of illness. This tendency was more marked in the female patients than in the male patients. Both male and female patients showed a tendency for microangiopathy to appear earlier than macroangiopathy. The increase in the frequency of complications accompanying the increase in the duration of illness was more marked for microangiopathy than for macroangiopathy.

The sensitivity of intracoronary injection of acetylcholine in inducing coronary spasm differs in patients with stable and unstable angina.

In an attempt to clarify the role of coronary artery spasm in the pathogenesis of unstable angina, acetylcholine (20 and 50 micrograms) was injected directly into the coronary arteries of 19 patients with unstable effort angina (group 1), 30 patients with unstable spontaneous angina (group 2), and 15 patients with stable effort angina due to coronary artery organic stenosis (greater than or equal to 75%) (group 3). Coronary spasm was defined as severe vasoconstriction (greater than or equal to 90% of luminal diameter) with chest pain and/or ischemic ST-segment changes. Intracoronary injection of acetylcholine induced spasm of at least one coronary artery in 19 patients (100%) of group 1 and 28 (93%) of group 2 but only 3 (20%) of group 3 (p less than 0.01). When acetylcholine was injected into the left and right coronary arteries separately, multivessel spasm (spasm of both coronary arteries) was induced in 5 of 12 (42%) patients of group 1 and in 9 of 23 (39%) patients of group 2. In contrast, intracoronary acetylcholine did not cause multivessel coronary spasm in any of 15 patients of group 3 (0%). These results suggest that coronary arteries in patients with unstable effort angina as well as spontaneous angina are susceptible to spasm and that coronary artery spasm may be responsible at least in part for the genesis of attacks in these patients.

Importance of non-stenosed donor coronary arteries for collateral flow reserve.

To elucidate whether the presence of significant stenoses in donor coronary arteries compromises collateral flow reserve, coronary arteriography was performed in 22 patients with stable effort angina who had a complete obstruction in one of the major coronary arteries. The patients were divided into two groups according to the absence (group I: n = 11) or presence (group II: n = 11) of significant stenoses (> or = 75% stenosis of the luminal diameter) in donor arteries. After conventional cardiac catheterization, coronary arteriography was repeated before and during rapid atrial pacing. Coronary collateral circulation was evaluated by means of angiographic contrast appearance time (CAT) which was defined as the time (s) until the epicardial segments distal to the site of complete occlusion were opacified after the injection of contrast medium into the donor artery. The pressure gradient across the collateral circulation (mean aortic pressure minus left ventricular end-diastolic pressure) remained unchanged before and during rapid atrial pacing (group I: 95 +/- 14 vs. 99 +/- 15 mmHg; group II: 91 +/- 18 vs. 94 +/- 16 mmHg). Rapid atrial pacing decreased the contrast appearance time in group I from 1.73 +/- 0.34 to 1.47 +/- 0.37 s (P < 0.01), but was not changed in group II from 1.68 +/- 0.36 to 1.73 +/- 0.51 s (P = n.s.). It was concluded that coronary collateral circulation is further augmented in response to an increase in myocardial oxygen demand in patients with non-stenosed donor coronary arteries and significant stenoses in donor arteries compromise an increase in collateral blood flow.

Coronary collateral development after acute myocardial infarction.

In 31 patients without a history of preinfarction angina, coronary collateral circulation to the completely obstructed coronary artery was evaluated by coronary angiography during a convalescent period of their first myocardial infarction. Collateral visualization (collateral index) was found to be significantly greater in patients with involvement of the right coronary artery (2.1 +/- 1.1, SD) than in those with obstruction of the left anterior descending coronary artery (1.2 +/- 1.0, p less than 0.05). The time interval from the onset of symptoms of acute myocardial infarction to angiographic evaluation did not affect the extent of collateral visualization or the degree of coronary artery disease. These findings indicate that the collateral vessels develop after acute myocardial infarction regardless of the extent of coronary artery disease and accomplish the proliferative process within one month. It is also suggested that the collateral visualization is dependent on the size of perfusion territory of the infarct-related coronary artery.

Comparative sensitivity of intracoronary injection of acetylcholine for the induction of coronary spasm in patients with various types of angina pectoris.

To elucidate the possible contribution of coronary artery spasm to the pathogenesis of angina pectoris, coronary arterial responses to intracoronary injection of acetylcholine were examined in patients with various types of angina pectoris. Coronary artery spasm with chest pain and/or electrocardiographic ischemic changes was angiographically demonstrated in 50 (85%) of 59 patients with angina pectoris. The sensitivity for coronary spasm was 92% (24 of 26) in patients with rest angina, 100% (16 of 16) in patients with both rest and effort angina, and 59% (10 of 17) in patients with effort angina, while it was only 6% (1 of 16) in patients without coronary artery disease. When patients with effort angina were subdivided according to the variability of anginal threshold for exertional angina, the sensitivity for coronary spasm was as high as 90% (9 out of 10) in patients with variable-threshold angina. In contrast, coronary spasm was less frequently (p less than 0.05) induced in patients with fixed-threshold angina (1 of 7, 14%). These results suggest that coronary arteries in patients with angina pectoris are quite susceptible to acetylcholine except in those patients with stable exercise tolerance or anginal threshold. Thus coronary artery spasm appears to play a significant role for the pathogenesis of angina pectoris in a large proportion of patients with effort angina as well as in patients with rest angina.

Biphasic changes (initial increase and late decrease) in coronary sinus venous oxygen saturation during anginal attacks induced by intracoronary acetylcholine in patients with variant angina.

In order to evaluate the effects of intracoronary acetylcholine on coronary resistance vessels, oxygen saturation in coronary sinus blood was continuously measured to compare its dynamic changes during intracoronary injection of acetylcholine in both patients with variant angina and control subjects. Group 1 consisted of 6 patients without coronary artery disease. Group 2 consisted of 10 patients with variant angina and spasm in the left anterior descending coronary artery. A fiberoptic reflection oximetry system was used for the continuous measurement of coronary sinus venous oxygen saturation. Acetylcholine (20 micrograms) was injected directly into the left coronary artery over 30 s. In the group 1 patients, coronary sinus venous oxygen saturation was increased from 39 +/- 2% (mean +/- SEM) to 54 +/- 3% at 30 s, continuously climbed to 70 +/- 3% at 60 s and then gradually decreased to 53 +/- 5% at 120 s after the initiation of intracoronary injection of acetylcholine. In contrast, in the group 2 patients, coronary sinus venous oxygen saturation was transiently increased from 39 +/- 2% to 56 +/- 4% at 30 s, reversed, decreased to 52 +/- 4% at 60 s and then rapidly decreased to 36 +/- 3% at 120 s with the onset of chest pain associated with electrocardiographic ischemic changes. Coronary arteriography during attacks demonstrated a total or subtotal occlusion of the left anterior descending coronary artery due to severe spasm in all of the 10 patients. The extent of increases in coronary sinus venous oxygen saturation at 30 s after acetylcholine injection was not significantly different between the two groups (group 1: 15 +/- 4%, group 2: 17 +/- 3%). Heart rate, blood pressure and rate-pressure product were essentially unchanged at 30 s after intracoronary injection of acetylcholine in both groups. These data suggest that in control adult humans, coronary blood flow was increased through dilatation of resistance vessels by acetylcholine, while in patients with variant angina, coronary blood flow was transiently increased by dilatation of resistance vessels, after which it was suddenly decreased by spasm of an epicardial artery induced by this agent. Relaxant responses to acetylcholine of coronary resistance vessels appear to be preserved well in patients with variant angina.

Importance of regurgitant fraction for left ventricular end-systolic wall stress to end-systolic volume ratio in patients with chronic mitral regurgitation.

End-systolic wall stress to end-systolic volume index (ESWS/ESVI) ratio is an index of myocardial contractility. In the presence of mitral regurgitation (MR), this ratio may be modified by the unloading effect of a leakage of flow into the low pressure left atrium. Therefore, to evaluate whether or not this ratio is an index of myocardial function in patients with MR, we compared the ratio with conventional measurements of myocardial performance in 11 patients with moderate to severe MR. The ESWS/ESVI ratio was 3.9 +/- 1.6 kdyn/cm5 per m2 in MR and slightly lower than the control value of 4.6 +/- 0.6 kdyn/cm5 per m2. The correlation between ESWS/ESVI ratio and ejection fraction was poor (r = 0.05, p:NS), while there was a close inverse correlation between the ratio and regurgitant fraction (r = 0.76, p less than 0.01). These results strongly suggest that ESWS/ESVI ratio is a better indicator of myocardial function than ejection fraction in MR; however, this ratio could be affected by not only the inotropic state of the ventricle, but also by the extent of mitral regurgitation.

Usefulness of intracoronary injection of acetylcholine as a provocative test for coronary artery spasm in patients with vasospastic angina.

In order to examine both the sensitivity and specificity of coronary artery spasm induced by intracoronary injection of acetylcholine in patients with vasospastic angina, incremental doses of acetylcholine (20, 30, and 50 micrograms) were injected directly into each coronary artery in 21 patients with variant angina (group A), in 28 patients with other types of vasospastic angina (group B), and in 20 patients without any significant coronary artery disease (group C). Coronary artery spasm was defined as severe vasoconstriction (greater than or equal to 90% of reduction in luminal diameter) with chest pain and/or ischemic changes in the electrocardiogram. Intracoronary injection of acetylcholine induced spasm of at least one coronary artery in 20 patients (95%) of group A, in 27 patients (96%) of group B, and in only 2 patients (10%) of group C. The low dose of acetylcholine (20 micrograms) induced coronary spasm more frequently in group A patients (81%) than in group B patients (43%) (P less than 0.05). ST-segment elevation associated with anginal attacks was significantly (P less than 0.05) more frequent in group A (71%) than in group B (39%). When acetylcholine was injected separately into the left and right coronary arteries, spasm of both coronary arteries was observed in 7 out of 14 of group A (50%), in 8 out of 22 of group B (36%), and in none of the 20 of group C. We concluded that intracoronary injection of acetylcholine is a sensitive and reliable method for the induction of coronary spasm in patients with vasospastic angina as well as in those with variant angina.

A sensitive assay of sialidase activity with fluorogenic oligosaccharide derivatives.

Fluorogenic oligosaccharide derivatives, lactityl-aminopyridine and sialyllactityl-aminopyridines, were synthesized by reductive amination of lactose and sialyllactose with 2-aminopyridine in the presence of sodium cyanoborohydride. Lactityl-aminopyridine showed bluish-white fluorescence at 390 nm by excitation with ultraviolet light at 320 nm, and the intensity of the fluorescence was proportional to the concentration of lactityl-aminopyridine within a range from 20 to 9800 pmole/ml. Two isomers of sialyllactityl-aminopyridine were enzymatically hydrolyzed to sialic acid and lactityl-aminopyridine by the action of both microbial and mammalian sialidases, and their suitability as substrates for sialidase was investigated. The result showed that sialidase activity was determined with about 55-fold higher sensitivity than that of ordinarily used colorimetric methods.

Significance of collateral circulation in reversible left ventricular asynergy by nitroglycerin in patients with relatively recent myocardial infarction.

To evaluate the functional role of coronary collateral circulation in reversible asynergy of the left ventricle, cineventriculography was performed before and after the administration of sublingual nitroglycerin in 19 patients with complete occlusion of the proximal part of the left anterior descending coronary artery. In nine patients who had significant collateral circulation to the infarct-related coronary artery (group A), there was significant improvement in both the left ventricular ejection fraction (53% to 60%, p less than 0.05) and regional wall motion in the infarct zone (8% to 18%, p less than 0.01 in the anterolateral area) with administration of nitroglycerin. In contrast, in the remaining 10 patients without significant collateral perfusion (group B), there were no detectable changes in either global function (49% versus 50%) or regional wall motion (6% versus 8% in the anterolateral area) before and after nitroglycerin. Changes in heart rate and left ventricular peak systolic and end-diastolic pressures with nitroglycerin were comparable in both groups. These results suggest that angiographically demonstrable collaterals preserve viable myocardium, which can improve its contraction when the supply-demand relationship is favorably affected because of increased collateral flow and/or more favorable loading conditions produced by nitroglycerin.

Determinants of beneficial effect of heparin exercise treatment on treadmill capacity and long-term efficacy of the therapy in patients with chronic effort angina.

The purpose of the present study was to evaluate the factors which influence the effect of heparin exercise treatment on treadmill capacity, and to examine the long-term efficacy of the treatment in 16 patients with chronic effort angina. Treadmill exercise was performed 20 times for 2 to 3 weeks according to standard Bruce protocol. A single intravenous dose of heparin (5,000 IU) was given 10 min before each exercise period. Exercise with heparin pretreatment increased the total exercise duration from 6.6 +/- 1.6 (SD) to 9.4 +/- 1.9 min (p < 0.05) and the maximal rate-pressure product from 19,200 +/- 4,700 to 24,700 +/- 5,900 mmHg.beats/min (p < 0.05). The rate-pressure product at the onset of angina was also increased by 32% (p < 0.05). The ST segment depression at the same exercise time as in control exercise was ameliorated from 0.16 +/- 0.05 to 0.12 +/- 0.06 mV (p < 0.05). Multivariate analysis of the determinants of the effect of the treatment on treadmill capacity indicated that the treatment is more effective in patients without previous myocardial infarction. All of the above-mentioned variables of treadmill capacity did not change significantly during a follow-up period of 13 +/- 7 months (range; 4-24 months). These findings lend further support to heparin exercise treatment as a possible therapeutic approach in patients with chronic stable effort angina, and particularly in those without previous infarction.

Adult respiratory distress syndrome in a patient with uncomplicated acute myocardial infarction.

A 53-year-old woman was admitted with a diagnosis of acute extensive anterior myocardial infarction. Pulmonary capillary wedge pressure was 17 mmHg, and cardiac index 2.4 l/min.m2. The patient was successfully treated with diuretics and nitrates but on the fifth hospital day moist rales were noted over the entire lung field. A chest roentgenogram showed diffuse bilateral pulmonary infiltration with unchanged cardiac silhouette. Arterial oxygen partial pressure was reduced to 45 mmHg under 3 liters of nasal oxygen inhalation. Pulmonary capillary wedge pressure was 8 mmHg. Diffuse infiltration was not ameliorated by intravenous injection of diuretics. The diagnosis of adult respiratory distress syndrome was finally established by successful treatment with steroids.

Development of collateral circulation after acute myocardial infarction: its role in preserving left ventricular function.

The present study evaluated the effects of coronary collateral circulation developing after acute myocardial infarction on global and regional left ventricular function during the chronic stage. The study group consisted of 16 patients with initial myocardial infarction having total occlusion of the proximal left anterior descending coronary artery. To eliminate the effects of collateral circulation existing at the onset of infarction, patients with pre-infarction angina were excluded from this study. The patients were categorized in two groups depending on the extent of their collateral circulation (collateral index: CI 0-3): group A--patients with significant collateral circulation (CI = 2 or 3) to the infarct-related coronary artery; group B--patients without significant collateral circulation (CI = 0 or 1). Their heart rate, left ventricular peak systolic and end-diastolic pressures and cardiac index were similar in the two groups. The left ventricular end-systolic volume index in the group B was significantly greater than that in the group A (60 +/- 21 ml/m2 vs 34 +/- 9 ml/m2, p less than 0.05). Left ventricular ejection fraction in the group A was significantly greater than that of the group B (55 +/- 9% vs 39 +/- 15%, p less than 0.05), and a significant difference was observed in the percentage of segment shortening in the infarct area between the groups A and B (10.8 +/- 9.2% vs -0.2 +/- 5.4%, p less than 0.01). It was concluded that coronary collateral circulation which develops after acute myocardial infarction exerts beneficial effects on global and regional left ventricular function during the chronic stage.

Importance of coronary collateral circulation for increased treadmill exercise capacity by nitrates in patients with stable effort angina pectoris.

The purpose of this study was to elucidate the mechanism that induces an improvement in exercise capacity by nitrates in patients with stable effort angina pectoris. The study population was composed of 19 patients: group A, 10 patients with chronic stable effort angina who had a well-developed coronary collateral circulation to the potentially ischemic region; group B, 9 patients with chronic stable effort angina who had no collateral circulation to the jeopardized myocardium. Treadmill exercise was performed according to the standard Bruce protocol with and without pretreatment with orally administered 10 mg isosorbide dinitrate. Percent increases (mean +/- SE) in exercise duration were not significantly different between groups A and B (25 +/- 6 vs. 14 +/- 6%). Percent increases in the maximal rate-pressure product tended to be greater in group A than in group B (27 +/- 6 vs. 10 +/- 6%). Percent increases in the rate-pressure product at the onset of angina pectoris were significantly greater in group A than in group B (37 +/- 7 vs. 7 +/- 6%; p less than 0.01). Percent increases in the rate-pressure product at 0.1 mV S-T segment depression were also significantly greater in group A than in group B (26 +/- 6 vs. 1 +/- 5%; p less than 0.01). These results suggest that isosorbide dinitrate dilates epicardial collateral vessels with smooth muscle layers, but fails to dilate the coronary arteries with significant organic stenoses.

[Significance of collateral circulation in reversible asynergy].

The functional role of collateral circulation in reversible asynergy of the left ventricle was evaluated. Cineventriculograms were obtained before and after the administration of sublingual nitroglycerin (0.3 mg) in 19 patients with complete occlusion of the proximal portion of the left anterior descending coronary artery. In nine patients with well-developed collateral circulation, both left ventricular ejection fraction and regional wall motion were significantly improved by nitroglycerin. By contrast, in 10 patients without significant collateral circulation, there were no detectable changes in both global and regional wall motions before and after nitroglycerin. The left ventricular hemodynamic changes caused by nitroglycerin were comparable in both groups. These findings support the view that the improvement in asynergy caused by nitroglycerin appears to depend mainly on the extent of collateral circulation, rather than on decreases in both preload and afterload.

Effects of heparin treatment on collateral development and regional myocardial function in acute myocardial infarction.

To define the effects of heparin treatment during the acute stage of the first anterior myocardial infarction on coronary collateral development and regional myocardial function, we evaluated angiographically the extent of a collateral visualization (collateral index: 0-3) to the completely obstructed infarct-related coronary artery and regional wall motion in 18 patients during convalescence after infarction. The patients were divided into two groups depending on the presence (group I) or absence (group II) of heparin treatment (170 to 220 IU/kg per day) during the acute phase of infarction. The collateral index was significantly higher in group I (1.5 +/- 0.9) than in group II (0.4 +/- 0.4; p less than 0.05). The left ventricular ejection fraction tended to be greater in group I than in group II (49 +/- 12% vs 38 +/- 16%), and there was a significant difference in regional wall motion of the infarct area that was evaluated by the percentage of segment shortening between the two groups (group I:7.4 +/- 9.2%, group II:-0.8 +/- 4.5%, p less than 0.05). These findings indicate that heparin treatment for patients with acute myocardial infarction is worthwhile in terms of the preservation of left ventricular function as a result collateral development.