Melricflash/CW_MedAbstractsAlt huggingface dataset:
Intraoperative blood pressure. What patterns identify patients at risk for postoperative complications? While monitoring blood pressure is a routine part of intraoperative management, several methods have been proposed to characterize intraoperative hemodynamic patterns as predictors of postoperative complications. In this prospective study of a high-risk population of hypertensive and diabetic patients undergoing elective noncardiac surgery, one objective was to compare different approaches to the assessment of intraoperative hemodynamic patterns to identify those patterns most likely to be associated with postoperative complications. Twenty-one per cent of the 254 patients sustained cardiac or renal complications after operation. Patients with more than 1 hour of greater than or equal to 20-mmHg decreases in mean arterial pressure (MAP) or patients with less than 1 hour of greater than or equal to 20-mmHg decreases and more than 15 minutes of greater than or equal to 20-mmHg increases were at highest risk for postoperative complications. Together these two patterns had a 46% sensitivity rate and a 70% specificity rate in predicting postoperative complications. Using 20% change in intraoperative MAP produced results nearly identical to 20-mmHg changes. When the duration of 20-mmHg changes was accounted for, changes of a greater magnitude (e.g., 40 mmHg) were not significant independent predictors of complications. The use of the mean difference from preoperative MAP was misleading because patients who experienced both high and low MAPs tended to have nearly normal mean MAPs, but high complication rates. The absolute magnitude of intraoperative MAPs, regardless of the preoperative levels, also was evaluated. The overall mean intraoperative MAP was not a significant predictor of complications. Specific intraoperative MAPs (e.g., less than 70 mmHg and more than 120 mmHg) also were evaluated. While neither was a significant predictor, there was a trend for increased complications among patients whose MAPs decreased to less than 70 mmHg. Intraoperative blood pressure should be analyzed in relation to the patient's preoperative blood pressure. Prolonged changes of more than 20 mmHg or 20% in relation to preoperative levels were significantly related to complications. 

Category: cardiovascular diseases
Timing and topography of cerebral blood flow, aura, and headache during migraine attacks. Ten years of study has resulted in considerable but fragmented knowledge about regional cerebral blood flow in migraine with aura (classic migraine). In the present study, the number of repeatedly studied patients (n = 63) was large enough to determine statistically significant sequences of events and statistically significant spatial relations. The first observable event was a decrease of regional cerebral blood flow posteriorly in one cerebral hemisphere. Further development of this pathological process was accompanied by the aura symptoms. Thereafter headache occurred while regional cerebral blood flow remained decreased. During the headache phase, regional cerebral blood flow gradually changed from abnormally low to abnormally high without apparent change in headache. In some patients headache disappeared while regional cerebral blood flow remained increased. Although regional cerebral blood flow reduction and aura symptoms in the great majority of patients were unilateral, one-third had bilateral headache. Unilateral headache usually localized to the side on which regional cerebral blood flow was reduced and from which the aura symptoms originated (i.e., aura symptoms were perceived to occur contralaterally but presumably originated in the hypoperfused hemisphere). Our results suggest a simple model for migraine attacks: A pathological disturbance in one cerebral hemisphere causes the aura symptoms and after a time delay, it also causes the headache by stimulating local vascular nociceptors. Bilateral headache caused by a unilateral cerebral disturbance may be explained by recent neuroanatomical and neurophysiological findings. 

Category: nervous system diseases
Temporal relationship between the decrease in arterial pressure and sodium retention in conscious spontaneously hypertensive rats with carbon tetrachloride-induced cirrhosis. It has been proposed that the initial event of sodium retention in cirrhosis is a peripheral arteriolar vasodilation causing underfilling of the arterial vascular compartment and stimulation of the renin-aldosterone and sympathetic nervous systems. To test this hypothesis, systolic blood pressure, sodium balance and urinary excretion of sodium and aldosterone were sequentially measured in 13 conscious spontaneously hypertensive rats submitted to a cirrhosis induction program with carbon tetrachloride and phenobarbital and in 14 control hypertensive animals. No significant differences were found between control and cirrhotic rats in any of the measured parameters during the first 7 wk of the study. The eighth week sodium retention developed in cirrhotic rats as indicated by a positive sodium balance and a marked decrease of sodium excretion. At the same time a significant reduction in systolic blood pressure and a great increase in urinary excretion of aldosterone were detected. These changes were more marked the ninth week of the study. In cirrhotic rats there was a highly significant direct correlation between systolic blood pressure and urinary sodium excretion. Postmortem examination showed a histological picture of cirrhosis in all animals given carbon tetrachloride and ascites in six of them. These results indicate that the onset of hyperaldosteronism and sodium retention in conscious spontaneously hypertensive rats with carbon tetrachloride-induced cirrhosis is chronologically related to a significant decrease in arterial pressure, thus supporting the "peripheral arterial vasodilation hypothesis" of ascites. 

Category: digestive system diseases
Reduced platelet aggregability and thromboxane release after rebleeding in patients with subarachnoid hemorrhage. Serial blood samples were obtained from 80 patients with subarachnoid hemorrhage (SAH) to study adenosine diphosphate-induced platelet aggregation and associated thromboxane B2 release. The goal of the investigation was to detect whether reduced platelet function is involved in rebleeds. Seventeen patients (21%) suffered a rebleed, six of those experiencing their first rebleed within 24 hours after SAH. Therefore, most platelet function studies were performed after rebleeds. Thromboxane release was lower in patients with rebleeds than in the others, both before and after rebleeding, although statistical significance was reached only in samples collected after rebleeds. Patients rebleeding within 24 hours after SAH had lower platelet aggregability (p = 0.037) than patients without a rebleed in the samples taken within 3 days after SAH. The results suggest that reduced platelet aggregability and thromboxane release are involved in rebleeds following primary SAH. 

Category: cardiovascular diseases
Mechanical circulatory support as a bridge to transplantation: current status of total artificial heart in 1989 and determinants of survival. Since April 1986, 40 total artificial hearts (TAH) were implanted as a bridge to transplantation in our institution. In an attempt to identify factors affecting survival of TAH recipients we reviewed our experience over 1000 days of mechanical support. There was no postoperative bleeding requiring surgery nor were there any clinical episodes of thromboembolic complications. Over a total functioning period greater than 3 years there were no mechanical failures in the driving system but one artificial ventricle had to be replaced because of mechanical dysfunction. Infections and multiple organ failure were the primary causes of morbidity and mortality during mechanical support. When the patients who underwent staged transplantation (no. 17) were compared with those who died during mechanical support (no. 23) there were no differences in TAH driving mode or hemodynamic variables between the groups. Although preoperative pulmonary, hepatic and renal functions were found to be similar between the groups, there were significant differences in the early evolution (3 days) of hepatic and renal functions following TAH implant (p less than 0.01). Urinary output was found to be the earliest variable discriminating recovery and survival (p less than 0.01). Finally, univariate analysis indicated age (less than 40 vs greater than 40 years) and modality of cardiac decompensation (acute vs chronic) as the most important factors affecting survival after TAH implantation. Since young patients (less than 40 years of age) with acute decompensation were successfully transplanted in 82% of cases while 100% of older patients with chronic decompensation died before or after transplantation, TAH should be advised in young patients with acute or chronic heart failure and in selected older candidates with recent, acute cardiac failure. 

Category: general pathological conditions
Comparison of STIR and spin-echo MR imaging at 1.5 T in 45 suspected extremity tumors: lesion conspicuity and extent. Short inversion time inversion recovery (STIR) imaging and a double-echo spin-echo (SE) sequence at 1.5 T in 45 sequential patients with suspected extremity tumors were compared to assess the number of lesions detected, subjective conspicuity of lesions, approximate volume of abnormality detected in each lesion, and identification of peritumoral brightening in tissues adjacent to each lesion. STIR sequences enabled detection of all 45 lesions; 44 were detected with the SE sequence. Tumor appeared most conspicuous on STIR images in 35 patients (78%) and was most conspicuous on SE images in 10 patients (22%). Peritumoral brightening, which indicated either peritumoral edema or microscopic tumor infiltration, was detected in 20 patients but was detected only with STIR sequences in nine patients. It is concluded that, although STIR and SE sequences are comparable for lesion detection in the extremities, most lesions appear more conspicuous with STIR. STIR may enable detection of a greater volume of abnormality than SE sequences and may therefore have important implications for local staging and surgical and radiation therapy planning. 

Category: neoplasms
In vitro and in vivo effects within the coronary sinus of nonarcing and arcing shocks using a new system of low-energy DC ablation. DC shocks within the coronary sinus have been abandoned because of the risk of cardiac rupture and tamponade. Catheter ablation using DC energy to electrodes straddling the ostium of the coronary sinus, when used clinically, has been reported to result in cardiac tamponade in as many as 16% of patients. A new system of energy delivery maximizes voltage while decreasing the undesirable effects caused by barotrauma. This system includes 1) a low-energy ablation power supply with a brief time-constant capacitive discharge that delivers up to 40 J and 3,000 V and 2) a low-energy ablation catheter with a contoured distal electrode. We performed in vitro and in vivo studies of this new system and compared arcing shocks with nonarcing shocks. Ablations were performed using unipolar distal shocks (D) and unipolar shocks to both electrodes made electrically common (P-D). In vitro studies were done in a large tank filled with physiological saline while recording voltage, current, and pressure. High-speed cinematography (32,000 frames/sec) of shocks of 10-40 J permitted detailed analysis of the vapor globe. Anodal shocks of less than 20 J showed no arcing or only minimal vapor globe formation. For D and P-D anodal shocks of 40 J, the diameters of the vapor globe were 31 and 22 mm, respectively, corresponding to pressure recordings of 11 and 4.9 atm. The pressure rise lasted less than 50 mu sec. In vivo studies involved 18 dogs that received nonarcing shocks (one to six shocks of 15 J) and 18 dogs that received arcing shocks (one to three shocks of 40 J). Each group was divided between D and P-D shocks; catheter ablation was performed at a mean +/- SEM distance of 2.94 +/- 0.92 cm within the coronary sinus. All dogs tolerated the procedure without cardiac rupture or tamponade. When killed 2-4 days later, the dogs had edema and hyperemia or hemorrhage in the area of the coronary sinus. We compared the effects of multiple (three to six) nonarcing shocks with the effects of one to three arcing shocks. Disruption or rupture of the coronary sinus within the epicardial fat space occurred in two of 12 dogs (17%) with multiple nonarcing shocks but in 13 of 18 dogs (72%) with arcing shocks (p less than 0.003). Occlusion of the coronary sinus occurred in two of 12 dogs (17%) with multiple nonarcing shocks and in nine of 18 dogs (50%) with arcing shocks (p less than 0.06).(ABSTRACT TRUNCATED AT 400 WORDS). 

Category: cardiovascular diseases
From Leningrad to the day-care center. The ubiquitous Giardia lamblia. Giardiasis is recognized as a worldwide public health problem. Seroprevalence data from both the developing and developed world show high rates of carriage in populations at risk for fecal-oral transmission, such as children in day-care centers. Outbreak investigation has expanded our understanding of reservoirs for Giardia lamblia and of the routes of transmission. Various host factors have been associated with infection. The pathogenesis of giardial infections is being elucidated, in particular the role of lectin activation in producing disease. Three standard chemotherapeutic agents are available in the United States. The institution of community-wide prevention measures is equally important. Current areas of investigation including antigenic composition and enzymatic variants should result in effective forms of immunotherapy, while more effective forms of chemoprophylaxis could assist in eradicating the pathogen from institutional settings. 

Category: digestive system diseases
Sleep disturbances in HIV-infected homosexual men. To provide a better understanding of the etiology of subjective sleep complaints in HIV-infected individuals, a study to evaluate sleep/wake disturbances in 10 healthy HIV-infected male volunteers was performed. All subjects were HIV-infected but had no history of AIDS-related infections, and considered clinically asymptomatic. Interviews and sleep questionnaires revealed sleep complaints in nine subjects. Five healthy HIV-seronegative male subjects, with no history of sleep complaints, were also evaluated. Sleep architecture analyses detected that, in comparison to published normative data and to negative controls, there was a significant increase in the total percentage of slow wave sleep (SWS) and an increase in the percentage of SWS in the later sleep cycles. When compared with normative data, an increase in stage 1 shifts, rapid eye movement (REM) periods, and arousals were also observed in the HIV-infected group. Significant decreases in sleep latency, total percentage stage 2 sleep, and average REM durations were also observed in the HIV-infected group compared with normative data. These sleep architecture abnormalities could not be attributed to known sole primary sleep disorders, first night effect, medications, anxiety or depression. This study indicates that sleep disturbances occur early in the course of HIV infection and suggests that the observed alterations of sleep physiology may be a consequence of central nervous system involvement and/or immune defense mobilization in the early phases of HIV infection. 

Category: nervous system diseases
The management of pseudomyxoma peritonei. The management of nine patients with pseudomyxoma peritonei was reviewed. Aggressive surgical resection of tumor is the standard of treatment, with many patients requiring multiple laparotomies. Chemotherapy, including the use of cisplatin is not effective. Long-term nutritional support provides a better quality of survival for select patients. 

Category: neoplasms
Hospital admissions from the Surgical Day Care Centre of Vancouver General Hospital 1977-1987. The admissions to Vancouver General Hospital from its Surgical Day Care Centre were reviewed for the period 1977 to 1987. The overall mean rate of admission for the period was 0.28 per cent, for surgically-related admissions 0.22 per cent and for anaesthesia-related admissions 0.07 per cent. The principal reasons for surgery-related admissions were postoperative bleeding, complications, the need for further surgery, the requirement for prolonged postoperative care, and pain. Urology had a particularly high percentage of admissions compared with its workload, because of the diagnostic nature of much of the work. Anaesthesia-related admissions included "syncope," lack of an accompanying adult, aspiration pneumonitis and coincident acute disease. Twelve of the 14 patients admitted with syncope had surgery in the afternoon and had received less than ideal amounts of intravenous fluid. Seven of the 12 ASA physical status II patients admitted had an admission diagnosis related to the coincident disease. 

Category: nervous system diseases
Epidural haematoma requiring surgical decompression following repeated cervical epidural steroid injections for chronic pain. We report a case of epidural haematoma following a steroid injection into the cervical epidural space. The complication occurred on the seventh such injection over a 2 year period for chronic spinal pain. Surgical decompression over the seventh cervical and the upper 3 thoracic vertebrae was required to alleviate the symptoms of paralysis and anaesthesia. The patient subsequently required skin grafting to the surgical site and two trans-urethral resections of the prostate gland during his 6 week hospital admission. He made a full recovery. 

Category: nervous system diseases
Usefulness of tomographic thallium-201 imaging for detection of restenosis after percutaneous transluminal coronary angioplasty. The role of tomographic thallium-201 exercise and redistribution imaging in the detection of restenosis after percutaneous transluminal coronary angioplasty (PTCA) was evaluated in 116 patients: 61 (53%) with 1- and 55 (47%) with multivessel PTCA, with a total of 185 dilated vessels. Complete revascularization was performed in 89 (77%) and partial revascularization in 27 (23%) of the patients. Restenosis was angiographically demonstrated in 69 (60%) of the patients and 85 (46%) of the vessels 6.4 +/- 3.1 months after PTCA. Disease progression in previously normal vessels was noted in 11 patients. The results were: (1) for detection of restenosis in the group of patients, single-photon emission computed tomographic (SPECT) versus exercise electrocardiographic sensitivity was 93 vs 52% (p less than 0.001), specificity 77 vs 64%, and accuracy 86 vs 57% (p less than 0.001). The results were similar in the complete and partial revascularization groups. (2) SPECT was 86% sensitive, specific and accurate for restenosis detection in specific vessels with comparable results for 1-versus multivessel PTCA and complete versus partial revascularization. Sensitivity, specificity and accuracy were: 89, 95 and 92% for the left anterior descending coronary artery; 88, 79 and 82% for the right coronary artery; and 76, 83 and 85% for the left circumflex coronary artery. Eighty-one percent of the diseased nondilated vessels were correctly identified. (3) Disease progression to greater than 50% stenosis was detected with 91% sensitivity, 84% specificity and 85% accuracy. SPECT thallium-201 imaging is an excellent tool for the detection of restenosis and disease progression after PTCA in the settings of 1- and multivessel angioplasty and complete and partial revascularization. 

Category: general pathological conditions
Posttraumatic torticollis. We report six cases of torticollis precipitated by neck trauma. The dystonia began 1 to 4 days after the trauma and differed clinically from idiopathic torticollis by marked limitation of range of motion, lack of improvement after sleep ("honeymoon period"), and absence of geste antagonistique. Worsening with action was not present; nor was there improvement with support as seen with idiopathic torticollis. Onset of pain immediately after the trauma and marked spasms of the paracervical muscles were other predominant features. Anticholinergic therapy was without benefit; however, some improvement occurred with botulinum toxin injection. It is concluded that torticollis can be caused by peripheral trauma and that it has unique clinical characteristics. 

Category: nervous system diseases
Exercise intolerance in patients with heart failure and preserved left ventricular systolic function: failure of the Frank-Starling mechanism Invasive cardiopulmonary exercise testing was performed in 7 patients who presented with congestive heart failure, normal left ventricular ejection fraction and no significant coronary or valvular heart disease and in 10 age-matched normal subjects. Compared with the normal subjects, patients demonstrates severe exercise intolerance with a 48% reduction in peak oxygen consumption (11.6 +/- 4.0 versus 22.7 +/- 6.1 ml/kg per min; p less than 0.001), primarily due to a 41% reduction in peak cardiac index (4.2 +/- 1.4 versus 7.1 +/- 1.1 liters/min per m2; p less than 0.001). In patients compared with normal subjects, peak left ventricular stroke volume index (34 +/- 9 versus 46 +/- 7 ml/min per m2; p less than 0.01) and end-diastolic volume index (56 +/- 14 versus 68 +/- 12 ml/min per m2; p less than 0.08) were reduced, whereas peak ejection fraction and end-systolic volume index were not different. In patients, the change in end-diastolic volume index during exercise correlated strongly with the change in stroke volume index (r = 0.97; p less than 0.0001) and cardiac index (r = 0.80; p less than 0.03). Pulmonary wedge pressure was markedly increased at peak exercise in patients compared with normal subjects (25.7 +/- 9.1 versus 7.1 +/- 4.4 mm Hg; p less than 0.0001). Patients demonstrated a shift of the left ventricular end-diastolic pressure-volume relation upward and to the left at rest. Increases in left ventricular filling pressure during exercise were not accompanied by increases in end-diastolic volume, indicating a limitation to left ventricular filling. 

Category: cardiovascular diseases
Serial neurobehavioral assessments in preterm infants. The purpose of this study was to compare serial neurobehavioral assessments in a sample of preterm infants with intraventricular hemorrhage (IVH) to those of a group of unaffected preterm infants. Of the 30 infants included in the study, 5 infants had a grade III or IV/VI intraventricular hemorrhage. Infants with IVH demonstrated more abnormalities in mental status and a cluster of abnormal neurologic findings (persistent ankle clonus, tremulousness, and brisk deep tendon reflexes). Of the 30 infants, 20 infants were included in a brain metabolism study. Infants who had experienced an IVH had significantly different brain metabolism findings, as measured by nuclear magnetic resonance spectroscopy (NMR). There was a significant correlation between one measure of brain metabolism (PCr/PI) and the neurobehavioral assessment rating for infants with IVH. 

Category: general pathological conditions