Is there a Need for Luteinizing Hormone (LH) Estimation in Patients Undergoing Ovarian Stimulation with Gonadotropin-Releasing Hormone (GnRH) Antagonists and Recombinant Follicle-Stimulating Hormone (rFSH)?

AIM: To find out effect of serum luteinizing hormone (LH) levels on Day 1 (Day 2 of cycle) and Day 5 of stimulation and Day of trigger hCG in controlled ovulation stimulation with antagonist protocol of IVF-ICSI cycle on cycle outcome. MATERIALS AND METHODS: This retrospective study was conducted in a University Hospital setting. One hundred and 62 patients underwent 165 cycles of controlled ovarian stimulation (COS) with recombinant Follicle stimulating hormone (rFSH) and Gonadotropin releasing hormone (GnRH) antagonist protocol in one year were included. Serum LH levels estimated on Day 1, Day 5 and the day of trigger hCG injections were divided into three groups based on the percentile and outcome measured. RESULTS: The average number of follicles >18 mm in size were significant in the patients with LH levels between 25th to 75th percentile group on Day 1, Day 5 and Day of trigger hCG. The fertilization rate was significant (p= 0.04) in the patients with LH levels < 25thpercentile on the day of trigger hCG. Oocyte recovery rate, oocyte maturation rate and average number of best quality embryos (Grade 1) were not affected significantly in all three groups. CONCLUSION: In GnRH antagonist and rFSH protocols, low serum LH concentrations on the day of trigger hCG has better fertilization rate. LH levels between 25th and 75th percentile have an influence on the average number of > 18 mm size follicles. However, the LH level on Day 1, Day 5 and Day of hCG does not affect the cycle outcome in COS with antagonist protocol of IVF cycle. Hence, LH estimation is not mandatory in ART cycles with GnRH antagonist protocol.

Flow graphs: interweaving dynamics and structure.

The behavior of complex systems is determined not only by the topological organization of their interconnections but also by the dynamical processes taking place among their constituents. A faithful modeling of the dynamics is essential because different dynamical processes may be affected very differently by network topology. A full characterization of such systems thus requires a formalization that encompasses both aspects simultaneously, rather than relying only on the topological adjacency matrix. To achieve this, we introduce the concept of flow graphs, namely weighted networks where dynamical flows are embedded into the link weights. Flow graphs provide an integrated representation of the structure and dynamics of the system, which can then be analyzed with standard tools from network theory. Conversely, a structural network feature of our choice can also be used as the basis for the construction of a flow graph that will then encompass a dynamics biased by such a feature. We illustrate the ideas by focusing on the mathematical properties of generic linear processes on complex networks that can be represented as biased random walks and their dual consensus dynamics, and show how our framework improves our understanding of these processes.

Safety and effectiveness of combining carotid artery stenting with cardiac surgery: preliminary results of a single-center experience.

AIM: Optimal strategy (staged or combined) for the treatment of patients with concurrent severe carotid and cardiac disease is still controversial. Moreover, carotid artery stenting (CAS), has become a valid alternative to carotid endarterectomy (CEA) and has been proposed for the treatment of cardiac patients. The authors report the preliminary results of a new therapeutic strategy consisting in combined CAS and cardiac surgery. METHODS: An initial series of 22 patients underwent combined CAS and cardiac surgery in the same operating room and under general anesthesia. All filter-protected CAS procedures were performed under only heparin and aspirin. A cervical approach (3-cm cervicotomy) was used in patients with documented vessel tortuosity or severe aorto-iliac occlusive arteriopathy. In all the other cases a femoral access was used. A double antiplatelet regimen was initiated in the early postoperative period, once major bleedings were excluded. RESULTS: Among the 22 patients who underwent this combined procedure, no deaths, no myocardial infarctions and one controlateral stroke (overall complication rate: 4.5%) were observed. This stroke was observed after transcervical CAS, coronary artery bypass and mitral valve replacement. No major postoperative bleedings nor stent thrombosis were observed. CONCLUSIONS: Combined carotid stenting and cardiac surgery, performed in the same operating room under only heparin and aspirin, seems a safe and effective strategy for the treatment of patients with concomitant carotid and cardiac disease.

Community structure of cortical networks in spinal cord injured patients.

In the present study, we estimated the cortical networks were from high-resolution EEG recordings in a group of spinal cord injured patients and in a group of healthy subjects, during the preparation of a limb movement. Then, we use the Markov Clustering method to analyse the division of the network into community structures. The results indicate large differences between the injured patients and the healthy subjects. In particular, the networks of spinal cord injured patient exhibited a higher density of clusters. In the Alpha (7-12 Hz) frequency band, the two observed largest communities were mainly composed by the cingulate motor areas with the supplementary motor areas, and by the pre-motor areas with the right primary motor area of the foot. This functional separation could reflect the partial alteration in the primary motor areas because of the effects of the spinal cord injury.

Factors influencing immediate and long-term results after button's technique.

BACKGROUND: Aim of this study was to evaluate the factors influencing immediate and long-term results in patients undergoing aortic root replacement with a composite graft. METHODS: Between January 1989 and February 1999, 105 patients (83 males, 22 females) who underwent Bentall technique were studied. Preoperative diagnosis was annulo-aortic ectasia in 54, aortic dissection in 27, atherosclerotic aneurysm in 21, and aortitis in 3 cases. Seventeen patients were affected by Marfan's syndrome. All cases, elective, urgent, and emergency were included. Button technique was performed and the associated surgical procedures were coronary artery bypass grafting in 21, total aortic arch replacement in 15, proximal hemi arch in 5, and mitral valve replacement in 5 cases. RESULTS: The overall hospital mortality rate was 7.6% (n=8). Univariate analysis using chi(2) and/or two-sample "t"-test showed that dissection, aortitis, aneurysm rupture into-pleura or pericardium, emergency status, redo, prolonged pump times and circulatory arrest, were predictors influencing in-hospital mortality. Coagulopathy, low cardiac output, stroke, perioperative myocardial infarction, surgical bleeding leading to reoperation, were significantly related to in-hospital mortality (by correlation analysis). A multivariate analysis showed that, emergency status (p=0.027), aortic dissection (p=0.029), perioperative myocardial infarction (p=0.0021), reoperation for bleeding (p=0.0023), and pump time >180 min (p=0.011), were significant. The actuarial survival rate at 10 years follow-up was 84.7%. There were 8 late deaths. The Kaplan-Meier showed significant differences when considering dissection vs non-dissection (p=0.018), but did not reach significance in Marfan vs non-Marfan groups (p=0.83). NYHA class IV (p=0.052), previous cardiac surgery procedure (p=0.041), concomitant CABG (p=0.021), total aortic arch reconstruction (p=0.001), and mitral valve replacement (p=0.016), were identified as significant by Log Rank test. CONCLUSIONS: The Bentall procedure for aortic root replacement is safe and durable; in hospital mortality in elective status it was 1.28%; early and long-term mortality higher in patients with acute dissection. Six late deaths were procedures related. Sixty-six patients (76.4%) were in NYHA I class at follow-up. The incidence of late outcomes, thromboembolism (1.03%), graft infection (2.06%), pseudoaneurysm (0%), reoperation in ascending aorta or aortic valve (3.1%), operations on the remaining aorta (6.7%), and hemorrhage due to anticoagulant therapy (1.03%), are very low.

Clinical evaluation of St Jude Medical Hemodynamic Plus versus standard aortic valve prostheses: The Italian multicenter, prospective, randomized study.

OBJECTIVE: Hemodynamic and clinical performances of 21-mm and 23-mm St Jude Medical Hemodynamic Plus aortic valves (St Jude Medical, Inc, St Paul, Minn) were compared with those of 21-mm and 23-mm St Jude Medical standard cuff aortic valves in the first such multicenter, prospective, randomized study. Hemodynamic Plus valves are mechanical, bileaflet prostheses suitable for the small aortic anulus. METHODS: Patients with 21-mm and 23-mm anulus diameters were randomized to receive either a Hemodynamic Plus or a standard cuff valve. Postoperatively and at 6 months after the operation, patients underwent 2-dimensional Doppler echocardiography. Ejection fraction, cardiac output, peak gradient, mean gradient, effective orifice area, effective area index, and performance index were calculated. Postoperative and 6-month echocardiographic measurements and their variations across observation times were analyzed statistically. RESULTS: Of the 140 patients enrolled, 5 died at operation and 1 died of aortic dissection during the follow-up period. Eight patients were lost to follow-up. A total of 125 patients completed the study. In 1 patient a sewing cuff escaped intraoperatively. At 6 months the 21-mm and 23-mm Hemodynamic Plus valves showed significantly lower peak gradients and mean gradients than those of the 21-mm and 23-mm standard cuff valves. The 21-mm Hemodynamic Plus valves had gradients similar to those of the 23-mm Hemodynamic Plus valves. The effective orifice area did not differ significantly between the Hemodynamic Plus and standard cuff valves at either measurement. No valve mismatch was found in the 4 groups of patients. A more enhanced decrease of peak gradients and mean gradients and a more enhanced increase of effective orifice areas, effective area indices, and performance indices were found across observation times for patients with Hemodynamic Plus valves compared with those with standard cuff valves. CONCLUSIONS: Clinical hemodynamic performances of 21-mm and 23-mm St Jude Medical Hemodynamic Plus valves correspond closely with those of standard cuff valves, and gradients are substantially better than those of standard cuff valves of the same diameter. Therefore, use of this valve may minimize the need for aortic anulus enlargement. Early follow-up results with the Hemodynamic Plus valves were excellent, although more time is required to confirm this outcome.

A novel technique for giant left atrium reduction.

We herein describe a safe and reproducible technique for left atrial volume reduction in patients with a giant left atrium. In a 56-year-old patient undergoing redo mitral valve replacement, the left atrium measured 18 x 20 x 17 cm occupying the middle-lower segment of the right hemithorax with compression of the adjacent organs. The left atrial volume was reduced by triangular resections of the atrial wall and the mitral valve was replaced using a mechanical prosthesis. The postoperative course was uneventful and the left atrial diameter was 11.2 cm at the latest control.

Long-term histologic features of synthetic chordal replacement for mitral valve repair: a case report.

Expanded polytetrafluoroethylene (e-PTFE) sutures have been used with increasing frequency to replace chordae tendineae in mitral valves prolapsing because of myxoid change. A case is reported where fibrosis and calcification of the endocardial overgrowth covering the synthetic chordae led to severe mitral regurgitation 7 years after plastic repair and required mechanical prosthetic valve implantation.

Emergency operation for acute type A aortic dissection: neurologic complications and early mortality.

BACKGROUND: Acute type A aortic dissection is a surgical emergency still associated with high postoperative complications. The aim of this study was to investigate factors for hospital mortality and neurologic deficit in patients undergoing emergency operation for acute type A aortic dissection. METHODS: Eighty-five consecutive patients (age range, 20 to 82 years) operated on for acute type A aortic dissection over a 6-year period were evaluated. Univariate and stepwise multiple logistic regression analyses were conducted among 32 perioperative variables. RESULTS: All patients underwent surgical procedures under deep hypothermic circulatory arrest. Antegrade or retrograde cerebral perfusion was used in 23 patients (27.1%) and 18 patients (21.2%), respectively. Forty-three patients underwent arch/hemiarch replacement and the ascending aorta was replaced in 42 patients. Overall mortality rate was 25.9% (22 of 85 patients). Multiple logistic regression analysis showed that lack of cerebral perfusion (p = 0.021) and postoperative renal failure (p = 0.006) were the best predictors for hospital death. Twenty-one patients (24.7%) experienced neurologic accidents. The risk factor for postoperative neurologic complication was lack of cerebral perfusion (p = 0.013). Hospital mortality was 13% (3 of 23 patients) and 16.7% (3 of 18 patients) in the antegrade and retrograde cerebral perfusion groups (p > 0.05) and neurologic deficit was 13% (3 of 23 patients) and 11.1% (2 of 18 patients), respectively (p > 0.05). CONCLUSIONS: Hospital mortality and neurologic complications in patients undergoing emergent operation for acute type A aortic dissection were reduced when cerebral perfusion was used with deep hypothermic circulatory arrest.

Non-invasive assessment of coronary flow velocity reserve before and after angioplasty in a patient with mammary graft stenosis.

We report the diagnosis of mammary artery graft dysfunction by high-resolution transthoracic Doppler and venous adenosine infusion. The patient was treated by percutaneous balloon angioplasty, with optimal angiographic results. Coronary flow reserve in the distal left anterior descending artery was abnormal before angioplasty, and recovered soon after the procedure. The utility of this new non-invasive technique in the diagnosis of flow-limiting stenoses and follow-up of coronary angioplasty is described.

Sterility of epidural solutions--recommendations for cost-effective use.

BACKGROUND AND OBJECTIVES: Specific recommendations or guidelines for duration of use or "hangtime" for epidural solutions have not been established. Presently, most hospital policies limit expiration dating of these solutions to 24 hours at room temperature. Extending expiration dating would reduce or eliminate the manipulation of the epidural system during the course of therapy. The objective of this study was to assess the bacteriologic status over time of pharmacy-prepared epidural solutions to determine if longer expiration dating could be safely instituted. METHODS: Samples from both previously administered and nonadministered bags of epidural infusate solutions were retrieved for bacteriologic testing and maintained at room temperature. These solutions were tested every 5 to 7 days beginning 24 to 48 hours after preparation. RESULTS: Samples of 54 infusion bags were tested for a median duration of 63 days. One hundred fifteen samples were tested. Only 5 samples of 4 solutions reported positive cultures; no growth was reported for multiple subsequent cultures of these solutions. CONCLUSIONS: Samples of pharmacy-prepared epidural solutions remained sterile for greater than 42 days. A change from epidural solution expiration dating of 24 hours to 48 or 72 hours would translate into a cost savings of $36,375 to $48,450 at our institution.

Sternal wound infection revisited.

Sternal wound infections (SWIs) can be subdivided into two types, superficial or deep, that require different treatments. The clinical diagnosis of superficial SWI is normally easy to perform, whereas the involvement of deep tissues is frequently difficult to detect. Therefore, there is a need for an imaging study that permits the assessment of SWIs and is able to distinguish between superficial and deep SWI. The present work was a prospective study aiming to evaluate the role of technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) labelled leucocyte scan in SWI management. Twenty-eight patients with suspected SWIs were included in the study. On the basis of clinical examination they were subdivided into three groups: patients with signs of superficial SWI (group 1), patients with signs of superficial SWI and suspected deep infection (group 2) and patients with suspected deep SWI without superficial involvement (group 3). Ten patients previously submitted to median sternotomy, but without suspected SWI, were also included in the study as a control group (group 4). All patients with suspected SWI had bacteriological examinations of wound secretion, if present. In addition 99mTc-HMPAO labelled leucocyte scan was performed in all patients. The patients of groups 1, 2 and 3 were treated on the basis of the clinical signs and microbiological findings, independently of the scintigraphic results. The patients of group 4 did not receive treatment. The final assessment of infection was based on histological and microbiological findings or on long-term clinical follow-up. Sensitivity, specificity, accuracy and positive and negative predictive values for scintigraphic and non-scintigraphic results were calculated. In the diagnosis of superficial and deep SWI, clinical and microbiological examination (combined) yielded, respectively, a sensitivity of 68.7% and 100%, a specificity of 77.3% and 80.8%, an accuracy of 73.7% and 86.8%, a positive predictive value of 68.7% and 70.6% and a negative predictive value of 77.3% and 100%. The scintigraphic results obtained in superficial SWI yielded a sensitivity of 56.2%, a specificity of 90.9%, an accuracy of 76.3%, a positive predictive value of 81.8% and a negative predictive value of 74.1%, while, by contrast, in deep SWI all of these values were 100%. Therefore, one can conclude that 99mTc-HMPAO labelled leucocyte scan permits accurate diagnosis of deep SWI, solving the main clinical problem in this field. In the present study the categorisation of patients without taking into account 99mTc-HMPAO labelled leucocyte planar scan findings caused a non-negligible number of cases of superficial SWI to be treated as though they were deep SWI. This "overestimation" led to unnecessary surgery, increased and prolonged use of antibiotics with more (higher) toxicity and additional expense.

The decreasing incidence and severity of retinopathy of prematurity.

PURPOSE: We sought to determine whether the incidence of retinopathy of prematurity (ROP) at our institution has changed since the Cryo-ROP recruitment period 10 years ago. METHODS: We determined the incidences of threshold ROP, prethreshold ROP, less-than-prethreshold ROP, and no disease for each of 3 birth weight classes (<750 g, 750 to 999 g, and 1000 to 1250 g) of infants born between July 1, 1995, and June 30, 1996, and cared for in the Vanderbilt Neonatal Intensive Care Unit. We then compared these with the rates from our institution during the Cryo-ROP study recruitment period (January 1, 1986, to November 30, 1987). RESULTS: The current incidence and severity of ROP have decreased substantially overall and for each weight group compared with the 1986-87 incidence (P < .001, Cochran-Mantel-Haenszel test). The incidence of "any ROP" decreased by 27% for infants with birth weights less than 750 g, by 51% for infants 750 to 999 g, and by 71% for infants 1000 to 1250 g. The incidence of "prethreshold or greater ROP" decreased by 70% for the 750 to 999 g and 77% for the 1000 to 1250 g weight groups. Although the decrease in "prethreshold or greater ROP" was not as dramatic (25%) for the infants less than 750 g, only 1 infant (10%) progressed to threshold disease in this group, whereas 7 (47%) did in 1986-87. The incidence of threshold ROP decreased by 84% for infants less than 750 g and by 66% for infants 750 to 999 g. No infant with birthweight greater than 999 g progressed to threshold ROP. CONCLUSIONS: The incidence of all levels of ROP has decreased substantially for all infants with birth weights less than 1251 g at Vanderbilt University Medical Center during the past decade. Putative factors responsible for this decrease may include surfactant use, continuous pulse oximetry, aggressive use of antenatal steroids, and improved neonatal nutritional support.

Visual capacity and Prader-Willi syndrome.

PURPOSE: Prader-Willi syndrome (PWS) refers to a genetic disorder induced by an anomaly on chromosome 15 occurring with a frequency of one in 10,000 to 20,000. It is characterized by a unique set of features including infantile hypotonia, obesity in childhood, small hands and feet, hypogonadism, and mental retardation. Reported here are the results of ophthalmic examinations of persons with PWS, together with results from controls comparable in age, percentage of body fat, and intelligence. These data bear on the hypothesis that the ocular anomalies in PWS are unique to this syndrome. METHOD: A comprehensive investigation of PWS brought children and adults to Vanderbilt University for extended testing, which included an ophthalmic examination. Genetic analysis determined unequivocally the PWS diagnosis and identified subgroups-deletion and maternal disomy. A group of persons without PWS but generally comparable in age, body composition, and intelligence served as controls. RESULTS: Significant differences between the deletion and disomy subgroups were not found for the clinical ophthalmic measures. The incidence of anomalies in the combined PWS was similar to those reported in previous studies. A similar pattern was present in the control group except for myopia and stereopsis. An effect of genetic subgroup, however, was observed for random element stereopsis with the maternal disomy group having a greater degree of impairment. CONCLUSION: The overall similarity between the PWS and control groups on all measures except myopia and stereopsis suggest that many of the anomalies in PWS found in prior studies are due to factors inherent in a general dysfunctional population, rather than reflective of an ocular signature unique to PWS.

Preoperative identification of viable myocardium: effectiveness of nitroglycerine-induced changes in myocardial Sestamibi uptake.

In order to predict tissue viability in infarcted myocardial areas, changes induced by nitroglycerine infusion on Sestamibi myocardial uptake were evaluated in 37 patients with previously confirmed myocardial infarction undergoing coronary artery bypass grafting, and compared with echocardiographic and perfusional changes occurring after the operation. The improvement of Sestamibi uptake after nitroglycerine correctly classified 24/26 (92%) patients showing postoperative improvement of wall motion in the infarcted area, whereas 24/31 (77%) patients with nitroglycerine-induced increase in Sestamibi uptake had improved wall motion after operation. The presence of collateral flow to the infarcted area was associated with a significantly (P < 0.01) higher increase in Sestamibi uptake both during nitroglycerine infusion and postoperatively. An increase in wall motion score after operation was associated with a significantly higher (P < 0.05) increase in Sestamibi uptake score during nitroglycerine infusion. Thus, the results of this study suggest that Sestamibi perfusional myocardial scintigraphy during nitroglycerine infusion is capable of assessing viable but chronically hypoperfused myocardium and predicting postoperative wall motion and perfusional improvement, to yield the best results in patients with evidence of collateral circulation that supplies the infarcted area.

Left ventricular aneurysmectomy; comparison between two techniques; early and late results.

OBJECTIVE: The aim of the present study was to evaluate early and late results of two different surgical techniques for left ventricular aneurysms repair. The conventional aneurysmectomy and direct closure of the ventricular wall and the endoventricular patch plasty. METHODS: We retrospectively reviewed 118 patients operated on for postinfarction left ventricular aneurysm from 1981 to 1994. Eighty-seven patients (Group A) were operated upon between 1981 and 1991 with the conventional technique and 31 patients (Group B) between 1992 and 1994 with the endoventricular patch plasty technique. Preoperative clinical, hemodynamic and echocardiographic evaluation with operative procedures and early postoperative results of all patients are reported. We also analyzed results of late clinical and echocardiographic controls of 34 patients of Group A and all patients of Group B after a mean follow-up of 42 and 28 months, respectively. RESULTS: Mean number of by-pass grafts was 1.9 in Group A and 2.6 in Group B (P = 0.01). The left anterior descending coronary artery was revascularized in 27 patients of Group A (34.6%) and 26 of Group B (89.7%) (P < 0.001); the left internal mammary artery was used in seven patients of Group A (8.9%) and 24 of Group B (82.8%) (P < 0.001). Hospital mortality in Group A was 10.3% (9/87), in Group B there was no hospital mortality (P > 0.05). Thirty-two patients of Group A (36.8%) and 3 of Group B (9.7%) suffered of low cardiac output syndrome (P = 0.01). At late control, improvements observed in NYHA and CCS classes, left ventricular ejection fraction (all P < 0.001 in both groups versus preoperative values) and left ventricular end-diastolic diameter (P > 0.05 in Group A and P < 0.001 in Group B) proved to be statistically higher in patients of Group B. CONCLUSIONS: Endoventricular patch plasty associated with a complete myocardial revascularization, in particular of the anterior descending coronary, and a larger use of the internal mammary artery, permits, by means of reconstruction of the left ventricular geometry, a better outcome for patients undergoing left ventricular aneurysmectomy.

Postoperative analgesia with parenteral opioids: does continuous delivery utilizing a transdermal opioid preparation affect analgesic efficacy or patient safety?

STUDY OBJECTIVES: To compare, in patients who underwent major orthopedic surgical procedures, the efficacy of intravenous (IV) patient-controlled analgesia (PCA) with morphine combined with continuous administration of two doses of fentanyl or placebo via transdermal therapeutic system with fentanyl (TTSF) patches. DESIGN: Randomized, double-blind, placebo-controlled study. SETTING: University teaching hospital. PATIENTS: 62 patients aged 18 to 65 years, presenting for elective orthopedic surgery and general anesthesia. INTERVENTIONS: Patients were randomized to one of three groups: group 1 received two placebo patches; group 2 received a 20 cm2 active patch delivering 50 micrograms/hr of fentanyl and a 30 cm2 placebo patch; group 3 received a 30 cm2 active patch delivering 75 micrograms/hr of fentanyl and a 20 cm2 placebo patch. All patches were placed approximately two hours prior to induction of general anesthesia. General anesthesia was induced with thiopental, intubation facilitated by the use of vecuronium or pancuronium, and anesthesia was maintained with isoflurane in an oxygen/nitrous oxide mixture (O2/N2O). Following surgery, IV morphine was provided using IV PCA with 1.5 mg of morphine with a 6-minute lockout and a 4-hour maximum dosage of 30 mg. MEASUREMENTS AND MAIN RESULTS: The time and dosage of morphine administered was recorded. Vital signs, pain intensity at rest, level of sedation, and arterial oxygen saturation (SpO2) were measured at intervals throughout the 72-hour study period and at 6 and 12 hours following patch removal. The presence of side effects was noted. Visual analog pain scores throughout the 72 hours of the study were not significantly different among groups. Patients receiving active TTSF required less IV PCA morphine at all time intervals. However, total opioid consumption was comparable among groups. The incidence of side effects was similar in all groups. CONCLUSIONS: There is no significant advantage to the routine use of continuous transdermal opioid delivery in patients receiving IV PCA after major orthopedic surgery.

Subarachnoid meperidine-morphine combination. An effective perioperative analgesic adjunct for cesarean delivery.

BACKGROUND AND OBJECTIVES: Low-dose subarachnoid morphine provides effective perioperative analgesia but may be associated with a transient period of inadequate pain relief between the regression of local anesthetic block and the onset of morphine's analgesic effect. We hypothesized that this period of suboptimal analgesia could be avoided by adding meperidine, a rapid-acting, intermediate-duration opioid. METHODS: In a double-blind, randomized trial, 49 patients scheduled for elective cesarean delivery received subarachnoid 0.75% bupivacaine, 12 mg in 8.25% dextrose, with either meperidine 10 mg, morphine 0.15 mg, or meperidine 10 mg plus morphine 0.15 mg. Visual analog scale scores for pain and satisfaction were obtained at skin incision, delivery, uterine exteriorization, on arrival in the postanesthesia care unit, and 2, 4, 6, 12, and 24 hours after drug administration. Neonatal Apgar scores and adverse effects were also noted. Postoperative intravenous patient-controlled analgesia (PCA) requirements were recorded for 24 hours. The data were analyzed by chi-square analysis Fisher's exact test, the Wilcoxon rank sum test, and analysis of variance with Tukey's adjustment for multiple comparisons. RESULTS: There were no significant differences in the incidence and severity of side effects, including nausea, vomiting, pruritus, and sedation. Respiratory depression was not observed. Patients treated with morphine alone were least comfortable (P < .006), expressed the lowest satisfaction scores at early observations (P < .002), and required more PCA meperidine (P < .001) than any other group. Patients treated with meperidine alone were comfortable at early observations but required the greatest total amount of PCA meperidine over the first 24 hours (P < .05). Patients in the meperidine-morphine combination group reported the lowest pain scores and highest satisfaction scores at 4-hour and 6-hour observations (P < .03) and required the least total amount of PCA meperidine. CONCLUSION: The subarachnoid combination of meperidine-morphine provided more uniform analgesia, higher satisfaction, and a lower requirement for intravenous narcotic supplementation than either morphine or meperidine alone in patients recovering from cesarean delivery.

Felodipine protects human atrial muscle from hypoxia-reoxygenation dysfunction: a force-frequency relationship study in an in vitro model of stunning.

AIMS: We aimed at investigating contractile changes after hypoxia-reoxygenation and dobutamine challenge in superfused human atrial pectinate muscle to see whether high versus low stimulation rate during hypoxia might account for outcome differences compatible with the definition of an in vitro model of myocardial stunning and whether pretreatment with the dihydropyridine Ca2+ entry blocker felodipine might afford protection. METHODS: Human right atrial trabeculae obtained from adult patients were superfused in an organ bath with oxygenated (O2 content 16 ml/l) and modified (NaHCO3 25.7 mmol/l) Tyrode's solution at 37 degrees C. Dobutamine (1 nmol/l to 10 micromol/l) was superfused in 10 oxygenated preparations to select the optimal drug concentration to be used in another 22 which were randomized. Group (A) consisted of time-related controls (Tyrodes's solution for 225 min at cycle length (CL) 1600 ms and no dobutamine). There were two test groups, respectively: (B) low (1600 ms CL) and (C) high (400 ms CL) stimulation rate. After 60 min of stabilization, in groups B and C, hypoxic superfusion (O2 content 5 ml/l) lasted 60 min, then reoxygenation (60 min) and dobutamine challenge (1 micromol/l, 15 min) were performed. Analysis of variance for repeated measures with the Greenhouse-Geisser correction, and a repeated measures model with structured covariance (preparation mass, length, width and time-varying time to peak tension) matrices were used whereby grouping (G), time (T) and G x T interaction were weighted. Force-frequency relationship and post-pausal potentiation were studied after each phase. Electrophysiology, histomorphometry and electron microscopy were carried out (n=6). Felodipine (0.1 micromol/l, n=5) pretreatment (15 min before hypoxia) was given in parallel experiments. RESULTS: Time-related controls showed approximately 10% per hour decrease of developed tension and the Paradise test provided approximately 80% of control values. In test groups (as compared to baseline values) contractility was decreased approximately 65% after hypoxia-reoxygenation and it increased approximately 25% after dobutamine (G, 0.0065