Effects of tracheal extubation on coronary blood flow,myocardial metabolism and systemic haemodynamic responses

Global coronary blood flow and metabolism were measured in seven patients on the first postoperative day following coronary revascularization to test the hypothesis that tracheal extubation produces adverse haemodynamic responses akin to those observed during tracheal intubation. Regional coronary flow and metabolic measurements were made in five of the seven patients. Extubation from a continuous positive airway pressure (CPAP) of 5 cm H₂O was associated with a statistically significant rise in cardiac index from 3.44 ± 0.23 L · min^-1 · m^-2 to 3.73 ± 0.15L·min^-1 ·m^-2 related to an increase in stroke index, without significant changes in heart rate, mean arterial and pulmonary capillary wedge pressure. Consequently the changes in myocardial oxygen consumption (8.52 ± 0.55 to 8.85 ± 0.93 ml · min^-1) and coronary blood flow (172 ± 18 to 179 ± 17 ml·min^-1) were less prominent than those reported during intubation, where substantial rises in myocardial oxygen consumption and coronary flow occurred. Two patients experienced cardiac lactate production but there were no changes in systemic or coronary haemodynamics, nor were there clinical or electrocardiographic signs of ischaemia. We conclude that extubation does not appear to be associated with adverse systemic or coronary haemodynamic responses in patients following coronary bypass grafting. However, the revascularized myocardium may remain vulnerable to anaerobic metabolism in the immediate postoperative period. Pour savoir si comme ľintubation, ľextubation de la trachée provoque des perturbations hémodynamiques, on a mesuré le métabolisme et la circulation coronarienne globale chez sept patients, au lendemain ďun pontage aorto-coronarien. On a aussi calculé les valeurs régionales de ces mêmes variables pour cinq ďentre eux. Ľindex cardiaque de 3.44 ± 0.23 L · min^-1 · m^-2 sous pression positive en respiration spontanée (CPAP) de 5 cm. H₂O s’est élevé à 3.73 ± 0.15 L · min^-1 · m^-2 post-extubation avec une augmentation significative du volume ďéjection. La fréquence cardiaque et les pressions artérielles moyennes et capillaires pulmonaires n’ont pas changé. Ainsi ľaugmentation de la consommation ďoxygène du myocarde de 8.52 ± 0.55 à 8.85 ± 0.93 ml · min^-1 et celle du flot coronarien de 172 ± 18 à 179 ± 17 ml · min^-1 ont été moindres que celles, importantes, déjà observées lors de ľintubation. On a noté chez deux patients une production de lactate par le myocarde, sans changement de ľhémodynamic systémique et coronarienne non plus que de signe clinique ou électrocardiographique ďischémie. Donc, après un pontage coronarien, ľextubation ne semble pas causer ďeffet néfaste sur les circulations systémique et coronarienne, toutefois, le myocarde revascularisé peut demeurer sensible au métabolisme anaérobique.     

Reversal of stress-induced anhedonia by the dopamine receptor agonist,pramipexole

Chronic exposure to mild unpredictable stress has previously been found to depress the consumption of a palatable (1%) sucrose solution, and to attenuate food-induced place preference conditioning. In this study the effects of pramipexole (SND-919), a dopamine D₂ agonist, were studied during 7–9 weeks of chronic treatment. Pramipexole (1.0 mg/kg per day) reversed the suppression of sucrose intake in stressed animals, increasing sucrose intakes above the levels seen in untreated nonstressed controls. Pramipexole also increased sucrose intake in nonstressed animals; these effects were accompanied by increases in water intake and tended to correlate with weight loss. Drug-treated stressed animals also lost weight, but in this case water intake was unaffected. A second group of animals received a higher dose of pramipexole (2.0 mg/kg per day). The effects of the two doses were very similar. After three weeks of treatment, these animals were switched to a lower dose of pramipexole (0.1 mg/kg per day). Increases in sucrose intake were maintained over three weeks of treatment at the lower dose, with significant recovery of body weight. Two further groups received the same doses of pramipexole (1.0 mg/kg for 6 weeks or 2.0 mg/kg for 3 weeks followed by 0.1 mg/kg thereafter), but received intermittent (twice-weekly) drug treatment. Intermittent pramipexole treatments also tended to increase sucrose intakes, but the results were less consistent from week to week. Following 6–8 weeks of pramipexole treatment, food-induced place preference conditioning was studied in all animals. Untreated stressed animals showed no evidence of place conditioning. Normal conditioning was seen in both groups of stressed animals treated daily with pramipexole (at 1.0 and 0.1 mg/kg) and in the group treated twice weekly at the higher dose (1.0 mg/kg); intermittent treatment at the lower dose (0.1 mg/kg) was ineffective. The results indicate that pramipexole exerts rapid anti-anhedonic effects in the chronic mild stress model. This conclusion is complicated, but not undermined, by drug-induced weight loss and by the presence of significant drug effects in nonstressed control animals.     

Quality of air contrast barium enema performed the same day as incomplete colonoscopy with air insufflation.

The quality of 17 air contrast barium enemas performed the same day as incomplete colonoscopies using air insufflation was compared with 21 air contrast barium enemas performed on a different day from incomplete colonoscopies. A gastrointestinal radiologist blinded to the timing of the procedures reviewed the barium studies scoring them as 1 (unsatisfactory) to 4 (excellent) in four areas. The mean overall quality score for the air contrast barium enemas done the same day as incomplete colonoscopy was 3.29 vs. 2.97 for those done on a different day (p = 0.24). There were no significant differences in quality scores between same-day versus different-day air contrast barium enemas for the specific parameters of quality of distention, barium coating, and amount of spasm. We conclude that when colonoscopy using air insufflation is incomplete because of looping or angulation, air contrast barium enema can be done the same day without impairing the quality of the barium study.     

Wireless capsule endoscopy detects small bowel ulcers in patients with normal results from state of the art enteroclysis

BACKGROUND: Wireless capsule endoscopy (WCE) is a new technology for small bowel imaging. AIM: To report our initial experience with sensitivity of high quality enteroclysis in patients with small bowel ulcers detected by WCE. METHODS: Medical records of all patients referred for WCE from December, 2001 to April, 2002 at our institution were reviewed. All patients had negative upper and lower endoscopies and small bowel barium studies before WCE. RESULTS: There were 40 patients (19 female, mean age 57.3 yr) during this study period. Three patients had multiple small bowel ulcers detected by WCE. One with ileal ulcers and abdominal pain had an enteroclysis at another hospital before WCE. Review of the study at our institution showed that it was of excellent quality and was normal. Two patients with chronic iron deficiency anemia had multiple small bowel ulcers and were referred after WCE for a repeat small bowel barium study by biphasic enteroclysis performed by experienced GI radiologists. The radiologists were told in advance of the WCE findings. Both studies were considered technically to be of perfect quality. Despite this, both studies were negative. All 3 patients improved after therapy for Crohn's disease. CONCLUSIONS: Our data indicates that WCE may be more sensitive for small bowel ulcers than the best enteroclysis available.     

Coronary heart disease attack rate, incidence and mortality 1975-1994 in Goteborg, Sweden

MATERIAL AND METHODS: Data from the Göteborg myocardial infarction register wereused to investigate trends in attack rate, incidence of non-fatalmyocardial infarction and mortality from coronary heart diseasein persons aged 64 and below during the period 1975–1994. RESULTS: Myocardial infarction was defined according to strict criteriawhich remained the same throughout the study period. Attackrate and incidence were 3–5 times higher among men thanwomen. The ratio of recurrent infarcts out of all attacks increasedwith increasing age and was 14%, 20% and 24% for men aged 35–44,45–54, and 55–64, respectively. Corresponding ratesfor women were 8%, 14%, and 22%, respectively. Both attack rateand incidence decreased significantly by 2·1–3·9%per year during the study period for most age groups. The 28-dayfatality rate (hospitalized as well as non-hospitalized cases)tended to decline, but significantly so only in the oldest men.The same was true for 28-day fatality among hospitalized patients.The majority of all coronary heart disease deaths occurred outsidehospital in people unaware they had coronary heart disease.Mortality from coronary heart disease decreased by 2·0–68%per year during the study period. In-hospital treatment of myocardialinfarction with intravenous beta-blockers followed by oral treatment,nitroglycerin and thrombolytics increased during the study period.Coronary surgery and angioplasty were used in less than 5% ofpatients during the study period, but increased substantiallyin 1994. CONCLUSION: Coronary heart disease and mortality in ages below 65 yearsare now decreasing in Sweden. Decreasing short-term mortalityis almost certainly due to more efficient treatment in hospital,but as the majority of coronary heart disease deaths occur outsidehospital and in people unaware they have coronary heart disease,primary prevention is still very important.     

Preoperative Biliary Drainage of Severely Jaundiced Patients Increases Morbidity of Pancreaticoduodenectomy: Results of a Case-Control Study

Background

Recent studies have indicated that preoperative biliary drainage (PBD) should not be routinely performed in patients suffering from obstructive jaundice before surgery. The severity of jaundice that mandates PBD has yet to be defined. Our aim was to investigate whether PBD is truly justified in severely jaundiced patients before pancreaticoduodenectomy. The parameters evaluated were overall morbidity, length of hospital stay, and total in-hospital mortality.

Methods

From January 2000 to December 2012, a total of 240 patients underwent pancreaticoduodenectomy for periampullary tumors. Group A comprised 76 patients with preoperative serum bilirubin ≥15 mg/dl who did not undergo PBD before surgery. Group B comprised another 76 patients, matched for age and tumor localization (papillary vs. pancreatic head) who underwent PBD 2–4 weeks before pancreaticoduodenectomy and were identified from the same database.

Results

Less operative time was required in the ‘no PBD’ group compared with the ‘PBD’ group (210 vs. 240 min). Total intraoperative blood loss and blood transfusions were also significantly less in the ‘no PBD’ group. There was no difference detected in the rate of pancreatic fistula or biliary fistula formation. Group A patients demonstrated significantly lower morbidity than group B (24 vs. 36 %, respectively) and therefore required briefer hospitalization (11 vs. 16 days). Mild infectious complications appear to be the main factor that enhanced morbidity in the PBD group. However, total in-hospital mortality was not significantly different between the two groups.

Conclusions

Even severe jaundice should not be considered as an indication for PBD before pancreaticoduodenectomy, as PBD increases infections and postoperative morbidity, therefore delaying definite treatment.     

Activation of natriuretic peptide receptor-C attenuates the enhanced oxidative stress in vascular smooth muscle cells from spontaneously hypertensive rats: implication of Gialpha protein

We have recently shown that vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR) exhibit enhanced expression of Giα proteins, which was attributed to the enhanced oxidative stress. Since C-ANP_4-23 that specifically interacts with natriuretic peptide C (NPR-C) receptor has been shown to decrease the expression of Giα protein in VSMC, the present study was undertaken to examine if C-ANP_4-23 can also decrease the enhanced expression of Giα protein in VSMC from SHR and whether it is attributed to its ability to attenuate the enhanced oxidative stress. Aortic VSMC from 12-week-old SHR and their age-matched Wistar-Kyoto (WKY) rats were used for the present studies. VSMC from SHR exhibited enhanced expression of Giα-2 and Giα-3 proteins, different subunits of NADPH oxidase such as Nox⁴ and p^47phox proteins but not of p^22phox, enhanced production of superoxide anion as well as NADPH oxidase activity as compared to age-matched WKY rats. Treatment of VSMC from SHR with C-ANP_4-23 decreased towards control levels the enhanced expression of Giα proteins, enhanced superoxide anion production and enhanced NADPH oxidase activity as well as the enhanced expression of Nox⁴ and p^47phox. However, C-ANP_4-23-induced attenuation of the enhanced level of O₂⁻ and NADPH oxidase activity occurs at 4 h before the decrease in the enhanced expression of p^47phox that occurs at 16 h of C-ANP_4-23 treatment. The decreased expression of NADPH oxidase in SHR was also associated with further decrease in O₂⁻ and NADPH oxidase activity. Furthermore, treatment of VSMC from SHR with pertussis toxin (PT) decreased the enhanced levels of superoxide anion as well as NADPH oxidase activity; however, the enhanced levels of different subunits of NADPH oxidase were not attenuated by PT treatment. These results suggest that C-ANP_4-23 decreases the enhanced oxidative stress in SHR by attenuating the enhanced expression of Giα proteins and also the enhanced levels of NADPH oxidase.     

Psychosocial risk factors for myocardial infarction among Swedish railway engine drivers [corrected

BACKGROUND: Several earlier investigations have found an increased incidence of myocardial infarction among male drivers and, not least, among railway engine drivers. In a previous study we found that increased serum cholesterol, blood pressure or tobacco smoking did not explain this increased risk. OBJECTIVE: To investigate psychosocial factors and primarily work-related factors among male engine drivers. DESIGN: Engine drivers were compared with random population samples in a cross-sectional study. METHOD: Two thousand three hundred and eighteen engine drivers aged 25-59 years were compared with 331 randomly selected men who were mainly from the G?teborg MONICA population study. Job demands and job decision latitude as well as social support were the main factors compared. RESULTS: Job demands were reported as being significantly lower by both younger and older engine drivers compared to their referents (P = 0.002 and P = 0.0001, respectively). Decision latitude was reported as being lower by both younger and older engine drivers than among controls (P = 0.0001 for both groups). Engine drivers experienced deficient support from their superiors compared to the referents (P = 0.0001 for younger as well as older engine drivers). Low decision latitude was associated with significantly higher diastolic blood pressure (r = -0.11 and P = 0.0001), but otherwise there were no significant relationships between psychosocial work characteristics and somatic risk factors. CONCLUSIONS: The combination of low decision latitude and low social support seems to be a key factor in the increased risk of myocardial infarction among railway engine drivers. They generally undertake shift work which may be an additional risk factor for myocardial infarction.