No convincing association between post-operative delirium and post-operative cognitive dysfunction: a secondary analysis

BACKGROUND

Post-operative delirium and post-operative cognitive dysfunction (POCD) are both common but it has not been clarified how closely they are associated. We aimed to assess the possible relationship in a secondary analysis of data from the 'Surgery Depth of anaesthesia and Cognitive outcome'- study.

METHODS

We included patients aged ≥ 60 years undergoing non-cardiac surgery planned for longer than 60 min. Delirium was assessed according to the Diagnostic and Statistical Manual of Mental Disorders IV criteria in the post-anaesthesia care unit (PACU) as well as within the first week after surgery. Cognitive function was assessed with a neuropsychological test battery. Multivariable analysis of POCD was performed with consideration of predisposing and precipitating factors.

RESULTS

Of 1277 randomized patients, 850 (66.6%) had complete data. Delirium was found in 270 patients (32.9% of 850). We detected POCD in 162 (20.9% of 776) at 1 week and in 52 (9.4% of 553) at 3 months. In multivariable analysis (n = 808), delirium had no overall effect on POCD (P = 0.30). Patients with no delirium in PACU but with postoperative delirium within 7 days had an increased risk of POCD at 3 months (OR = 2.56 (95%-confidence interval: 1.07-6.16), P = 0.035). No significant association was found for the other subgroups.

CONCLUSIONS

There is no clear evidence that postoperative delirium is independently associated with POCD up to 3 months.

Autoantibodies to the Atheroma Component Beta2-Glycoprotein I and Risk of Symptomatic Peripheral Artery Disease

Peripheral artery disease (PAD) is mostly related to atherosclerosis. Autoimmunity and, in particular, antibodies to cardiolipin (aCL) and phospholipid cofactors such as beta2-glycoprotein I (beta2-gpI) might influence the development of atheroma. Beta2-glycoprotein I (beta2-gpI) has been found in atheroma. It has previously been shown that immunoglobulin A (IgA) anti-beta2-gpI antibodies are associated with a risk of cerebral ischemia and myocardial infarction. This case control study aimed to determine whether elevated levels of aCL/anti-beta2-gpI antibodies are associated with a risk of symptomatic PAD (sPAD). Cases comprised a nonselected population of patients with sPAD (intermittent claudication or critical ischemia). Patient recruitment was based on arteriography changes. Controls were selected from patients admitted to orthopedic wards as a result of fractures or muscle-ligamentous disorders. Age, sex, race, hypertension, smoking, diabetes mellitus, and hypercholesterolemia were evaluated as risk factors in both groups. IgG/IgM/IgA aCL and anti-beta2-gpI were detected by enzyme-linked immunoabsorbant assays (ELISA). To estimate the grade of association of antibodies with sPAD, odds ratios (OR) were calculated. Logistic regression was utilized for adjustment of confounding factors. Seventy-seven cases and 93 controls were studied. The mean age was 61.5 years for cases and 47.5 years for controls (p <0.001). Among the risk factors evaluated, the presence of hypertension showed the strongest association with sPAD (OR 12.1; 95%CI 5.8—30). The presence of IgA anti-beta2-gpI was independently associated with sPAD (OR 5.4; 95%CI 1.8—15.8; p = 0.01). IgA aCL was strongly associated with the outcome (nonadjusted OR 11.5 after Agresti correction). IgA aCL and IgA anti-beta2-gpI antibodies were not associated with any known risk factors for sPAD or with arteriography changes. The occurrence of these autoantibodies might represent one of the links between autoimmunity and atherosclerosis in patients with sPAD.

[Ways to psychosomatic rehabilitation--differential treatment selection between psychosomatic acute care and rehabilitation]

Consecutive admissions to the psychosomatic departments of 5 hospital units in southwest Germany registered between October 2012 and October 2013 were asked to participate in a study investigating the treatment selection process for psychosomatic rehabilitation. 527 patients were included in the study, 269 outpatients and 258 inpatients at the end of their inpatient treatment. 52 patients (10.1%) received the recommendation for rehabilitation. 47 (90.4%) could be followed up 3 months later. 22 patients had applied for a rehabilitation treatment, 11 (50%) had obtained an approval for their rehabilitation, 5 had still no answer and for 6 patients the request was refused. 4 of the latter had objected their refusal and were still waiting for an answer. Only one patient was already admitted to a rehabilitation center. Possible reasons for the low permeability at the interface between hospital care and rehabilitation are discussed.

[Influence of body weight on the natural history of and the therapeutic approaches to type 1 diabetes]

Obesity, whose prevalence is increasing in industrialized countries, is recognized as a major risk factor for the development of type 2 diabetes. In contrast, the role of excess adiposity in the natural history of type 1 diabetes (T1DM) and its impact on therapeutic approaches are by far less known and most probably largely underestimated. The following items will be most particularly considered: 1) the accelerator role of obesity in the development of T1DM in young predisposed individuals; 2) the difficult diagnosis in presence of hybrid or double diabetes combining insulin secretory defect and insulin resistance; 3) the problem of managing both body weight and glucose control, especially in young females and adolescents; 4) the possible deleterious effects of intensive insulin therapy on body weight and some markers of the metabolic syndrome; 5) the worse cardiovascular prognosis of T1DM patients when obesity is present; 6) the possible role of other medications as adjunct therapy to insulin in insulin resistant obese T1DM patients; and finally 7) the expected benefit of bariatric surgery in some well selected T1DM patients with severe obesity.

[Metabolic surgery: an increasing place in the management of diabetes]

Bariatric surgery becomes more and more important in the management of the obese patient with type 2 diabetes, especially in case of failure of medical approaches. Metabolic improvement results not only from weight loss and the subsequent reduction in insulin resistance, but also from modifications of digestive hormones (especially incretins) that contribute to promote insulin secretion. This new paradigm, moving from bariatric surgery to metabolic surgery, opens new perspectives. The present article briefly describes innovative surgical techniques focusing on endocrine and metabolic improvement rather than on weight loss, the preliminary results of metabolic surgery in patients with type 2 diabetes and a body mass index <35 kg/m2 and, finally, some data regarding the surgical management of obese patients with type I diabetes not well treated with classical medical means.

Incidence and Risk Factors for Cognitive Dysfunction in Patients with Severe Systemic Disease

OBJECTIVE: To determine the relevance of surgery and other causative factors to the incidence of postoperative cognitive dysfunction (POCD) in patients with severe systemic disease. METHODS: This observational study included 107 noncardiac surgical patients and 26 nonsurgical control subjects, all of whom had an American Society of Anesthesiologists physical classification status of 3. Cognitive assessment was performed preoperatively and 7 days postoperatively, or with a 7-day interval for the control group. POCD was calculated as a combined Z-score. Mini Mental State Examination (MMSE) was used to exclude patients with pre-existing cognitive deficit (MMSE score ≥ 23). Surgical and other factors including duration of surgery/anaesthesia and length of stay in the intensive care unit (ICU) were recorded. RESULTS: After 7 days, POCD was found in 40/107 (37.4%) surgical patients compared with 4/26 (15.4%) nonsurgical controls. Preoperative MMSE score, duration of surgery/anaesthesia, and length of stay in the ICU and hospital were associated with POCD. Logistic regression analysis revealed that preoperative MMSE score was an independent predictor of POCD. CONCLUSION: Lower baseline MMSE score was the only independent predictor for POCD in patients with severe systemic disease.

Documented Intraoperative Hypotension According to the Three Most Common Definitions Does Not Match the Application of Antihypotensive Medication

This observational study investigated which of the three most common definitions of intraoperative hypotension (IOH), reported in a published systematic literature review, were associated best with anaesthetists' administration of antihypo-tensive medication (AHM). IOH and AHM use in anaesthetic procedures in a mixed surgical population ( n = 2350) were also reviewed. The definitions were: arterial systolic blood pressure (SBP) < 100 mmHg or a fall in SBP of > 30% of the preoperative SBP baseline; arterial SBP < 80 mmHg; a fall in SBP of > 20% of the preoperative SBP. Accuracy of predicting AHM using these three definitions was 67%, 54% and 65%, respectively. Prediction by a new fourth definition, using an optimal threshold of minimal SBP falling to < 92 mmHg or by > 24% of preoperative baseline, was 68% accurate. In multivariate logistic analysis, age, volatile versus intravenous anaesthetics, medical history of arterial hypertension and all four definitions of IOH were associated with intraoperative AHM, however IOH was not associated with postoperative in-patient stay. The three original definitions correlated poorly with the anaesthetist's judgement about applying AHM. Anaesthetists make complex decisions regarding the relevance of IOH, considering various perioperative factors in addition to SBP. Age, physical status and duration and type of surgery showed better correlations with postoperative in-patient stay than IOH.

Risk factors for inadequate emergence after anesthesia: emergence delirium and hypoactive emergence

AIM

Inadequate emergence after anesthesia in the adult patient may be distinguished by the patients' activity level into two subtypes: emergence delirium and hypoactive emergence. The aim of this study was to determine the incidence of inadequate emergence in its different forms, to identify causative factors and to examine the possible influence on postoperative length of stay in the recovery room and in the hospital.

METHODS

In this prospective observational study, 1868 non-intubated adult patients who had been admitted to the recovery room were analyzed. Inadequate emergence was classified in its different forms according to the Richmond agitation and sedation scale (RASS) 10 minutes after admission to the recovery room. Emergence delirium was defined as a RASS score >or=+1, and hypoactive emergence was defined as a RASS score <or=-2.

RESULTS

Of the 1,868 patients, 153 (8.2%) displayed symptoms of inadequate emergence: 93 patients (5.0%) screened positive for emergence delirium, and 60 patients (3.2%) showed hypoactive emergence. Significant risk factors for emergence delirium were premedication with benzodiazepines, induction of anesthesia with etomidate, younger as well as older age (age below 40 years and over 64 years), higher postoperative pain scores (NRS 6-10) and musculoskeletal surgery. Risk factors for hypoactive emergence were younger age, long duration of surgery and intraabdominal surgery. Patients with hypoactive emergence had a significantly increased length of stay in the hospital.

CONCLUSION

Inadequate emergence after anesthesia is a frequent complication. Preventable risk factors for emergence delirium were induction of anesthesia with etomidate, premedication with benzodiazepines and higher postoperative pain scores. Hypoactive emergence was less frequent than emergence delirium and was associated with a longer postoperative hospital stay.

Documentation of Post-operative Nausea and Vomiting in Routine Clinical Practice

This study investigated the quality of documentation of post-operative nausea and vomiting (PONV) by comparing incidences collected by a research team with those reported routinely by nursing personnel. A total of 560 patients passing through an interdisciplinary recovery room were included in the study. The overall recorded incidence of PONV over 24 h was 30.7%, which was in agreement with the predicted value of 32% calculated using incidences from published randomized controlled trials. Out of the total number of 86 cases of PONV in the recovery room only 36 (42%) were detected by nursing staff. Similarly, out of the total number of 129 cases of PONV on the ward over 24 h, only 37 (29%) were recognized by nursing staff during routine care. In conclusion, PONV in routine clinical care is likely to be under-reported. To use PONV as a valid quality measure, patients need to be actively asked about nausea and vomiting at frequent intervals in a standardized fashion. A considerable proportion of patients experience PONV after discharge from the recovery room, so the assessment of PONV should cover at least 24 h post-operatively

Comparison of three scores to screen for delirium in the recovery room

BACKGROUND

Delirium is often seen in the recovery room and is a predictor for postoperative delirium on the ward. However, monitoring to detect delirium in the recovery room as a basic prerequisite for early intervention is rarely used. The aim of this study was to identify a valid and easy-to-use test for early screening of delirium in the recovery room.

METHODS

One hundred and fifty-four adult patients admitted to the recovery room during regular working hours were included. A screening assessment for delirium was performed in the recovery room by a trained research team at the time when the patient was judged to be 'ready for discharge'. Delirium monitoring was performed with the Confusion Assessment Method (CAM), the Delirium Detection Score (DDS), and the Nursing Delirium Screening Scale (Nu-DESC). The Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV criteria were used as the gold standard.

RESULTS

Delirium in the recovery room was seen in 21 patients (14%) with the DSM-IV criteria, in 11 patients (7%) with the CAM, in four patients (3%) with the DDS, and in 37 patients (24%) with the Nu-DESC. Sensitivity and specificity were 0.43 and 0.98 for the CAM, 0.14 and 0.99 for the DDS, and 0.95 and 0.87 for the Nu-DESC, respectively.

CONCLUSIONS

All scores used were very specific, but the CAM and the DDS were less sensitive compared with the gold standard. Overall, the Nu-DESC was the most sensitive test in the recovery room to detect delirium.

Motivation of trauma patients to stop smoking after admission to the emergency department

Every smoker should be offered smoking cessation treatment when they present for clinical care. The Readiness to Change-Smokers (RTC-S) questionnaire and the Heidelberg Smoking History (HSH) are brief questionnaires that divide patients into three stages. The purpose of this study was to prospectively compare the performance of each questionnaire at identifying patients who will successfully quit smoking within one year of Emergency Department (ED) discharge. Out of 1292 injured ED patients nearly half (n = 599, 46.4%) were identified as current smokers. Both questionnaires were given to all 599 subjects, and used to divide patients into three stages. At 12-months postdischarge 306 patients (51.1%) were contacted to determine smoking status. Patients were similarly classified by both tests in only 36% of cases. Concordance between tests was poor (kappa = 0.33). The RTC-S classified fewer patients as ready to quit (A = 13% vs. 22.2%). At 12 month follow-up, 55 patients (17.9%) had stopped smoking. The HSH was more successful to predict quitters. Multivariate logistic regression with respect to smoking cessation resulted in significant impact of HSH (p = 0.024).

Could the pale, soft, and exudative condition be explained by distinctive histological characteristics?1

Pork quality depends on various genetic and environmental factors. Despite the improvement of slaughter conditions, the PSE type is still one of the main concerns in this field. This study was conducted on nonstressed animals to evaluate the tissue characteristics of some muscles usually involved during stress compared with a reference muscle, the M. triceps brachii, which is actually not subject to stress-caused damages. Samples of M. triceps brachii, M. longissimus dorsi, M. biceps femoris, and M. semimembranosus were taken from pigs exhibiting 1 of the 3 HAL genotypes (NN, Nn, or nn) and 2 of the 3 RN genotypes (rn+rn+ or rn+RN-). Histoenzymology and immunohistochemistry were used to compare the fiber typing and capillary network in these muscles within these different stress susceptibility genotypes. In comparison with the reference muscle, M. triceps brachii, the combination of a high value of the number of type IIb fibers and a low vascular network showed a primary effect on muscles usually involved during stress. This led to the definition of a PSE index. A dramatic increase (P < 0.001) in this PSE index was systematically found in muscles usually involved in the PSE-type condition. These results show that distinctive histological characteristics were associated with the vulnerability of some muscles independently of the genotypes. Moreover, this study highlights the distinctive histological features of each genotype and is likely to suggest some interactions between them.

[Ovarian tissue vitrification: Cortex and whole ovary in sheep]

OBJECTIVE

The aim of this study was to evaluate a cryopreservation technique by vitrification of cortex or whole ovaries in sheep, using two cryoprotectant solutions: VS1 and VS4 and to study their physical properties to avoid ice crystallisation by vitrification of whole sheep ovaries permeated with a cryoprotectant solution.

ANIMALS AND METHODS

From 6-month-old ewes, whole sheep ovaries with their vascular pedicles were collected at the slaughterhouse or at the veterinary school and prepared for cryoprotectant toxicity tests and freezing procedure. Follicle viability was measured by trypan blue test and histological examination of ovary. The hemi-ovarian cortex was stored in liquid nitrogen. Four to six weeks after the first laparotomy, the controlateral ovary was removed and the vitrified-warmed hemi-ovary was sutured. Thermal properties of a cryoprotectant solution called VS4 (critical cooling rates [Vccr], vitreous transition temperature [Tg], end of melting temperature [Tm]) were measured by differential scanning calorimetry.

RESULTS

No significant difference in follicle viability or normal follicle rates was observed between ovarian cortex exposed or non-exposed to cryoprotectant solutions. Nor was any significant difference observed before and after vitrification. Three pregnancies occurred, from which four lambs were born after autografts of vitrified ovarian cortex. With whole ovary, the decrease in the number of normal follicles was lower when frozen-thawed ovaries were treated with VS4 (P = 0.04). There were less nuclear anomalies (P = 0.02). The Vccr of VS4 has been estimated to be 14.3+/-1.1 degrees C/min and Tg was -125.0+/-0.2 degrees C. Because the penetration of cryoprotectants was very low, Vccr was very high and the cooling speed did not allow cortex to vitrify.

DISCUSSION AND CONCLUSIONS

Cryopreservation of cortex or whole ovary by vitrification seems a promising technique in reproductive medicine. The best histologic results were obtained with the VS4 cryoprotectant when whole ovary was vitrified.

Hypothyroidism after medium exposure to the fungicide maneb in the rabbit Cuniculus lepus

Dithiocarbamate are widely used as fungicides because of their efficacy against a broad spectrum of fungi and their associated plant diseases. Maneb is one of Ethylenebisdithiocarabamate (EBDCs). Males domestic rabbits received (by gavage) 2, 3, 5 and 8 mg/kg body weight of maneb, for a period of 5 weeks. Total body weights were measured at 48 h interals. At the end of the experimental period, animals were sacrified and some of organs such as, liver, testes, spleen and the kidney were weighted. The obtained data reveal that the used fungicide induces a remarkable increase in body weight of all the treated animals, particularly with the higher dose as compared with control group. An increase in plasma triglycerides, glucose and of cholesterol levels has been recorded. Moreover, a reduction in the weight of kidneys and testes in animals receiving 5 and 8 mg/kg, while a remarkable increase in the weight of the liver has been observed. Thyroxin concentrations underwent a significant reduction in treated individuals. A very significant reduction in, the number, speed and mobility of spermatozoa accompanied with a high ratio of spermatozoa deformation in the treated groups was noticed. In conclusion, administration of maneb causes thyroid pathology and affects the biology of sperms with histological deformation of testes.

Follicular viability and morphology of sheep ovaries after exposure to cryoprotectant and cryopreservation with different freezing protocols

OBJECTIVE

To test the toxicity of cryoprotectant in sheep ovarian tissue and to determine optimal conditions for freezing hemiovary cortex.

DESIGN

Small follicles (<60 microm in diameter) were isolated enzymatically for viability testing. Dead and live follicles were identified by using trypan blue staining, and follicle morphology was examined histologically.

SETTING

Centre hospitalo-universitaire de Biologie de la Reproduction, Hôpital Edouard Herriot, Lyon, France.

ANIMAL(S)

Lambs 5 to 6 months of age.

INTERVENTION(S)

Two-millimeter slices of hemiovarian cortex were prepared for cryoprotectant toxicity tests and freezing procedures.

MAIN OUTCOME MEASURE(S)

Follicular mortality and histologic structure.

RESULT(S)

For freezing procedures, the concentration of cryoprotectant was increased to 2 M on the basis of results of cryoprotectant toxicity tests in fresh tissues. Follicular mortality rates were 4.6% with of 2 M dimethyl sulfoxide (DMSO) and 3.8% with 2 M of propylene glycol (PROH). After freezing with semiautomatic seeding, follicular mortality rates were 8.4% (2 M of DMSO) and 12.4% (2 M of PROH). Tissue morphology was well preserved with 1.5 M of DMSO or PROH. With 1.5 M DMSO, results of the slow cooling protocol (2 degrees C/min) without seeding and the standard very slow cooling protocol (0.3 degrees C/min) were similar.

CONCLUSION(S)

Optimal survival of primordial follicles in the sheep was obtained by using a slow cooling protocol with semiautomatic seeding at 2 M of DMSO.

Better preservation of endothelial function and decreased activation of the fetal renin-angiotensin pathway with the use of pulsatile flow during experimental fetal bypass

OBJECTIVE

Pulsatile flow was shown to overcome the progressive rise in peripheral and placental vascular resistances observed during steady-flow bypass, this rise being counteracted by inhibition of nitric oxide synthase. This study quantifies the release of endothelial vasoactive substances during a 60-minute in utero model of fetal bypass.

METHODS

Fetuses were randomly allocated into 1 of 2 groups (steady flow, n = 8, or pulsatile flow, n = 13) and subjected to bypass through central cannulation and perfusion with either a centrifugal or pulsatile (125 beats x min(-1)) blood pump.

RESULTS

Lactate concentration was high, starting at fetal exteriorization and increasing during fetal preparation in the 2 groups. Once bypass was established, the rise was significant only in the steady-flow group. Plasma nitric oxide metabolites, similar before bypass, reached higher levels during pulsatile flow at the end of bypass (99+/-9 vs. 82+/-23 micromol x L(-1); P =.037). Levels of urinary nitric oxide metabolites were significantly higher in the pulsatile-flow than in the steady-flow group (764+/-143 vs. 508+/-240 micromol x L(-1); P =.005). Plasma cyclic guanosine monophosphate levels increased after 30 minutes of bypass in the pulsatile-flow group (25+/-18 vs. 12+/-8 pmol x mL(-1); P =.004), and urinary cyclic guanosine monophosphate excretion was higher in the pulsatile-flow group (517+/-450 vs. 118+/-78 pmol x mL(-1); P =.024). Plasma endothelin-1 levels increased in the 2 groups and were higher in the steady-flow group at 30 minutes (27+/-5 vs. 23+/-2 pg x mL(-1); P =.04) and 60 minutes of bypass (39+/-7 vs 32 +/- 6 pg x mL(-1); P =.04). Plasma renin concentration increased significantly during bypass only in the steady-flow group (26+/-10 vs. 57+/-42 in ng A1 x mL(-1) x h(-1); P =.04).

CONCLUSIONS

Improved placental and peripheral perfusion during fetal pulsatile-flow bypass may be mediated by preservation of fetal/maternal endothelial nitric oxide biosynthetic mechanisms and/or decreased activation of the fetal renin-angiotensin pathway.

Restoration of ovarian steroid secretion and histologic assessment after freezing, thawing, and autograft of a hemi-ovary in sheep

OBJECTIVE

To evaluate the effects of freezing, thawing, and autograft of a hemi-ovary on steroid secretion, endometrial maturation, and ovarian histology in ewes.

DESIGN

Experimental animal study.

SETTING

Laboratoire de Zootechnie, Ecole Nationale Vétérinaire, Marcy l'Etoile, France.

ANIMAL(S)

Six lambs aged 6 months to 1 year old.

INTERVENTION(S)

Hemi-ovaries were prepared and frozen from the right ovary of six lambs and autografted 4 weeks later to the contralateral ovarian hilus. The autografts and the uterus were recovered 1 year later. Blood tests were performed each week to measure P concentration.

MAIN OUTCOME MEASURE(S)

Number of primordial follicles; levels of plasma P.

RESULT(S)

Histologic examination of ovarian slices after freezing showed no destruction of primordial, primary, secondary, or cavitary follicles. The frozen ovarian autograft showed good recovery of the macroscopic and microscopic ovarian structure. After autografting, histologic examination revealed primordial to cavitary follicles. Secretion of P started to rise 4 weeks after the autograft. Histologic analysis of the endometrium showed numerous glands, vessels, and mucous secretion.

CONCLUSION(S)

Frozen ovarian autografts achieved P secretion and endometrial maturity.

Neonatal Soave endorectal pull-through for Hirschsprung's disease

In October 1994 we changed our management of neonatal Hirschsprung's disease from a staged procedure after initial colostomy to a neonatal single-stage Soave endorectal pull-through (SERPT) without a colostomy. We report on our experience with the first 12 neonatal SERPTs, comparing them retrospectively with a consecutive series of 12 patients managed with initial colostomy, followed by a SERPT months later. A neonatal SERPT proved to be an easier and quicker procedure than the same procedure in the older child. Patients could be discharged earlier and fewer complications were encountered; in addition a colostomy was avoided. The cosmetic result and parental acceptance were excellent. At the same time the cost was less than half compared with the staged group. At this stage of follow-up functional results are comparable with previous staged pull-through procedures.

Pulmonary embolism and cor pulmonale in a cat

A 14-year-old male neutered cat experienced pulmonary embolism 15 days following surgical debridement of a recurrent dorsolumbar abscess. Clinical signs were dominated by respiratory distress. Pulmonary embolism was suggested from the lateral thoracic radiograph by the presence of an abruptly attenuated lobar artery and a contiguous oligaemic area in the caudal lung lobe. Pulmonary hypertension was demonstrated on Doppler echocardiography by right pulmonary artery dilation and tricuspid regurgitation raising the pulmonary arterial pressure to 56 mmHg. Chronic pulmonary hypertension, assumed from right ventricular wall hypertrophy, and hypokinesia, indicating chronic cor pulmonale, was suggestive of chronic rather than acute pulmonary embolism. Postmortem histological evidence of pulmonary arteriolar occlusion confirmed the diagnosis of pulmonary embolism.

Echocardiographic appearance of flail aortic valve in a dog with infective endocarditis

A 4-year-old female Boxer was suffering from aortic valve endocarditis with perforation of the right coronary cusp resulting in a flail aortic cusp and subsequent acute aortic insufficiency. This flail aortic cusp was observed on M mode and two-dimensional endocardiograms as a free linear echostructure in the left ventricular outflow tract. Although rarely observed, a free linear echostructure seems more specific of a flail aortic valve than a shaggy echostructure, which can represent a free moving vegetation and thus be confusing. Severe acute aortic insufficiency resulted in an uncommon abnormal mitral valve motion in the absence of early mitral diastolic opening. The absence of early mitral valve opening was thought to be a consequence of coupled aortic regurgitation, reduced left ventricular compliance, and presumably delayed mitral valve opening secondary to coronary artery occlusion. An exaggerated septal diastolic dip accounted for the decreased transmitral inflow. All the usual contractility parameters were within normal range; subsequently, mitral valve motion alterations seem to be more reliable indicators of left ventricular dysfunction during acute aortic insufficiency.

Effects of various flow types on maternal hemodynamics during fetal bypass: is there nitric oxide release during pulsatile perfusion?

OBJECTIVE

This study investigates the role of various flow conditions on maternal hemodynamics during fetal cardiopulmonary bypass.

METHODS

Normothermic fetal bypass was conducted under pulsatile, or steady flow, for a 60-minute period. Fetal lamb preparations were randomly assigned to 1 of the 3 groups: steady flow (n=7), pulsatile flow (n=7), or pulsatile blocked flow bypass (n=7), where fetuses were perfused with Nomega-nitro-L-arginine after the first 30 minutes of pulsatile flow to assess the potential role of endothelial autacoids.

RESULTS

Maternal oximetry and pressures remained unchanged throughout the procedure. Under fetal pulsatile flow, maternal cardiac output increased after 20 minutes of bypass and remained significantly higher than under steady flow at minute 30 (8.8+/-0.7 L x min(-1) vs 5.9+/-0.5 L x min(-1), P=.02). Maternal cardiac output in the pulsatile group also remained higher than in both steady and pulsatile blocked flow groups, reaching respectively 8.7+/-0.9 L x min(-1) vs 5.8+/-0.4 L x min(-1) (P=.02) and 5.9+/-0.3 L min(-1) (P=.01) at minute 60. Maternal systemic vascular resistances were significantly lower under pulsatile than under steady flow after 30 minutes and until the end of bypass (respectively, 9.1+/-0.6 IU vs 12.7+/-1.1 IU, P=.02 and 8.9+/-0.5 IU vs 12.9+/-1.2 IU, P=.01). Infusion of Nomega-nitro-L-arginine was followed by an increase in systemic vascular resistances from 9.3+/-0.7 IU, similar to that of the pulsatile group, to 13.5+/-1 IU at 60 minutes, similar to that of the steady flow group.

CONCLUSIONS

Maternal hemodynamic changes observed under fetal pulsatile flow are counteracted after infusion of Nomega-nitro-L-arginine, suggesting nitric oxide release from the fetoplacental unit under pulsatile fetal flow conditions.

The hemodynamic effects of hypoxemia in anesthetized pigs: a comparison between right heart catheter and echocardiography

During hypoxemia, hypoxic pulmonary vasoconstriction and tachycardia are often observed in association with increases in pulmonary artery pressure and cardiac output. Nevertheless, the hemodynamic consequences of hypoxemia have never been evaluated by echocardiography and simultaneously compared with invasive hemodynamic variables. Fourteen open-chest, anesthetized piglets (weight 29-36 kg) were submitted to progressive hypoxemia and reoxygenation. Usual invasive hemodynamic variables were obtained from peripheral and central heart catheters. Direct epicardial echocardiography was used to measure right and left ventricular areas on a short-axis view at mid-papillary level. The mean pulmonary artery pressure (MPAP) increased with pulmonary vascular resistance in a dose-related manner as the fraction of inspired oxygen (FIO2) declined from 0.5 to 0.12. The MPAP correlated with right ventricular end-diastolic area (RVEDA) only at FIO2 0.08. There was a 49% reduction in left ventricular end systolic wall stress (LVESWS) between FIO2 0.5 and 0.08. Left ventricular ejection fraction area (LVEFA) increased by 33% above baseline and correlated with the decrease in LVESWS. No correlation was observed between left ventricular end-diastolic area and pulmonary artery occlusion pressure or left atrial pressure and between cardiac output and LVEFA. Systemic vascular resistance underestimates the magnitude of changes in LVESWS but overestimates the afterload compared with LVESWS. This study demonstrates that, for the lowest FIO2 (0.08), changes in MPAP correlated with changes in RVEDA but not in pulmonary vascular resistance. Moreover, LVESWS decreases significantly in a dose-related manner under progressive hypoxemia and normalizes immediately after reoxygenation. This study also shows that, under hypoxemic conditions, echocardiography enhances understanding of hemodynamic changes compared with right heart catheterization alone.

IMPLICATIONS

Acute hypoxemia in pigs is responsible for pulmonary vasoconstriction-induced pulmonary hypertension (which is restricted by the right ventricular failure), as well as a PaO2-dependent decrease in left ventricular afterload. These changes are better displayed by echocardiography than by right heart catheter.

Freezing, thawing, and autograft of ovarian fragments in sheep: preliminary experiments and histologic assessment

OBJECTIVE

To evaluate the effects of freezing and thawing on the histologic changes in ovarian fragments from sheep and to determine the feasibility of ovarian autografts.

DESIGN

Histologic evaluation of follicles that survived after freezing at -196 degrees C for 2 weeks. Histologic evaluation of ovarian fragments 6 months after the autografts.

SETTING

Laboratoire de Zootechnie, Ecole National Véterinaire, Marcy l'Etoile, France.

ANIMAL(S)

Six ewes aged 6 months to 1 year.

INTERVENTION(S)

Cortical fragments were prepared from the right ovary of 6 lambs and were grafted immediately to the contralateral ovarian hilus or were cooled slowly to -196 degrees C in medium containing dimethyl sulfoxide for 2 weeks. The autografts were recovered 6 months later.

RESULT(S)

Histologic examination of ovarian slices after freezing showed no destruction of primordial, primary, secondary, or cavitary follicles. The ovarian autograft showed good recovery of the macroscopic and microscopic ovarian structure. After autografting, histologic examination revealed primordial to cavitary follicles.

CONCLUSION(S)

Freezing of ovarian fragments is possible without damaging the follicles. Ovarian autografts showed good recovery of ovarian structure.

Cranial vena caval thrombosis secondary to invasive mediastinal lymphosarcoma in a cat

A 12-year-old female cat was diagnosed with a cranial vena caval thrombosis in association with a mediastinal lymphosarcoma. The cause of the cranial vena caval thrombosis was thought to be invasion of the venous wall by neoplastic lymphoid cells. Clinical signs of cranial vena caval thrombosis, such as swelling and oedema of the submandibular area, the ventral part of the neck and the forelimbs, were related to a space-occupying mediastinal lymphosarcoma, which also induced respiratory distress and cyanosis. Non-selective angiocardiography demonstrated the occlusion of the cranial vena cava and abnormal venous collateral vessels feeding the heart which are accepted as the venographic hallmark of clinically overt cranial vena caval syndrome. At postmortem examination, an intracaval thrombus, 5 cm in length, was seen extending from the costocervical vein to the sulcus terminalis of the right atrium.

Experimental right ventricle to pulmonary artery discontinuity: outcome of polyurethane valved conduits

OBJECTIVE

The ideal substitute for the treatment of ventricle-pulmonary artery discontinuity remains a topic of controversy, because of calcifications and degeneration of biologic substitutes leading to subsequent reoperations. Because polyurethane valves used in ventricular assist devices show a satisfactory biocompatibility, the aim of this study was to evaluate a valved conduit composed of a Dacron graft incorporating a trileaflet 25 mm polyurethane valve.

METHODS

The conduit was implanted between the right ventricle and the main pulmonary artery in adult sheep, with ligation of the proximal pulmonary artery. The animals received no medications. Serial hemodynamic data were collected at the time of implantation and at postoperative intervals of 6 and 12 months.

RESULTS

The peak pressure gradient across the valve increased significantly between implantation (0.17 +/- 5.6 mm Hg) and 6 months after operation (7.3 +/- 3 mm Hg, p = 0.0007) and remained stable thereafter (6.7 +/- 3 mm Hg at 12 months), whereas the cardiac output remained unchanged (4.6 +/- 0.6 L/min at implantation, 4 +/- 0.6 L/min at 6 months, and 3.9 +/- 1.1 L/min at 12 months). At the completion of the study, valve samples were processed and vapor coated with carbon for microscopic examination. There was one instance of nonadherent thrombus formation inside a cusp but no structural failures. The other valves were free of calcium deposits and no significant amounts of phosphorus could be detected by scanning electron microscopy and energy dispersive spectrometry.

CONCLUSIONS

These data demonstrate the good hemodynamic performance, low thrombogenicity, and acceptable durability of the polyurethane valves implanted in the right side of the heart in a chronic sheep model.

Flow-induced release of endothelium-derived relaxing factor during pulsatile bypass: experimental study in the fetal lamb

OBJECTIVE

This study was initiated to test the hypothesis that fetal hemodynamic changes observed under pulsatile flow bypass might be related to the release of endothelium-derived relaxing factor through oscillating shear stress.

METHODS

Normothermic bypass was instituted in utero in 21 preterm fetal lambs for a 1-hour period through the right atrium and main pulmonary artery. Ultrasonic flowmeters were positioned around the descending aorta and the umbilical artery. The circuit consisted of an oxygenator and a pump set to either continuous flow (n = 7) or pulsatile flow (n = 7) and adjusted to maintain a fetal main arterial pressure of 50 mm Hg. In seven other animals, endothelium-derived relaxing factor was blocked by a continuous infusion of N omega-nitro-L-arginine after 30 minutes of pulsatile flow.

RESULTS

During the first 30 minutes of bypass, pump flows were significantly lower in the continuous-flow group than in the pulsatile-flow or blocked-flow groups (respectively, 612 +/- 144, 907 +/- 153 and 987 +/- 228 ml/min), with similar changes in aortic and umbilical flows. Systemic vascular resistances were significantly lower in the pulsatile-flow and blocked-flow groups than in the continuous-flow group (550 +/- 106 vs 821 +/- 212 dynes/sec/cm-5). However, after blockade of endothelium-derived relaxing factor, resistances increased gradually in the blocked-flow group to reach the level of that of the continuous-flow group at the end of bypass (943 +/- 77 vs 556 +/- 143 dynes/sec/cm-5 in the pulsatile-flow group).

CONCLUSIONS

Blockade of endothelium-derived relaxing factor after 30 minutes of pulsatile flow returns fetal hemodynamics to continuous flow conditions. The specific inhibitor of endothelium-derived relaxing factor used in this experiment suggests that nitric oxide may be released by fetal endothelium during pulsatile bypass.

[Effects of active synchronized prolonged coronary perfusion in the animal]

The efficacy of a system of active diastolic synchronised coronary perfusion was studied during prolonged balloon angioplasty in 8 sheep. In the first part of the study (group 1) including 5 animals, the aim was to study the effects of high and constant flow (48 ml/min) for 90 minutes perfusion on haemolysis, the arterial wall and the perfused myocardium. The second part of the study (group 2), including 3 animals, assessed whether flow adapted to the extent of the vascular bed perfused (24 to 40 ml/min) could protect the myocardium for an interval of 60 minutes. In group 1, after 90 minutes of perfusion (48 ml/min), there was no haemolysis, or jet lesion of the arterial wall distal to the catheter tip. On the other hand, the creatinine phosphokinase levels increased at the 60th minute (188 vs 119 i.u./l for controls) and at the 90th minute (238 vs 119 i.u./l; p < 0.05). Moreover, the perfused myocardium was the site of histological lesions. These observations showed myocardial changes due to the "overflow phenomenon". In group 2, the flow rate was adapted to each animal, increasing progressively until disappearance of electrocardiographic signs of ischaemia (ST elevation) and maintained for 60 minutes. No signs of haemolysis, jet lesions or myocardial changes were observed, with absence of creatinine phosphokinase elevation and histological abnormalities. These preliminary results show that the system investigated allowed myocardial protection after arterial occlusion for an interval of 60 minutes.

Awareness of blood pressure: interoception or contextual judgement?

Most patients with mild to moderate hypertension are asymptomatic but some patients report symptoms and seem to be aware of their blood pressure. The research question is whether the estimation of blood pressure is primarily derived from interoception or is inferred by contextual judgement. A psychophysiological ambulatory assessment was conducted with 51 male hypertensive patients and 30 either normotensive or hypotensive student subjects employing (1) a multichannel recording system for blood pressure, heart rate and physical activity; and (2) a pocket computer for assessing estimated BP, setting variables and self-ratings of subjective state. Within-subject correlations revealed that there was no significant relationship between estimated BP and concurrently recorded systolic BP. Estimated BP is, however, related to self-ratings of feeling physically tense and self-ratings of physical activity. Blood pressure awareness appears to be a rather inconsistent and subjective phenomenon, based on contextual judgements and inferences instead of "perception", but it is a relevant methodological issue (and possible bias) in hypertension research.

[Which patients benefit from treatment with respiratory feedback?]

The physiological and psychological data of 82 patients with essential hypertension, who participated in the treatment group of a respiratory feedback (RFB) evaluation (Franck et al. 1994), were examined, using clusteranalysis, to detect and to describe therapy responders and nonresponders. For patients with usual personality characteristics, active coping strategies and interest in games and technics the best blood-pressure decrease (systolic bp: 13.05 mmHg, diastolic bp: 10.63 mmHg) was found. Furthermore patients, who stopped RFB-treatment have been compared with patients, who finished the treatment program. Patients, who stopped the RFB-treatment, had more psychological symptoms in the sense of psychosomatic complaints.

Pulsatility improves hemodynamics during fetal bypass. Experimental comparative study of pulsatile versus steady flow

BACKGROUND

The main advantage of pulsatile flow compared with steady flow during cardiopulmonary bypass is to prevent a rise in systemic vascular resistances. We hypothesized that pulsatile flow could overcome the progressive rise in peripheral and placental vascular resistances observed during fetal bypass and leading to progressive irreversible hypoxemia.

METHODS AND RESULTS

A study was undertaken in 17 fetal lambs (110 to 140 days of gestation). Fetal bypass was established for a 30-minute period through right atrial and main pulmonary artery cannulation. The circuit had no oxygenator. Flow was delivered by a standard roller pump for the continuous study (group 1, n = 9) or by a centrifugal pulsatile pump for the pulsatile study (group 2, n = 8). Oxymetric and hemodynamic parameters, along with organ blood flow determined by radiolabeled microspheres counting, were recorded before (T1) and after 10 minutes (T2) and 30 minutes (T3) of bypass. SaO2 and PaO2 were significantly higher in group 2 than in group 1 at T2 but thereafter deteriorated similarly in both groups, whereas PCO2 remained unchanged. Pump flow in group 2 was significantly higher than in group 1 at T2 and T3 (957.6 +/- 49 and 1104 +/- 152 versus 437.6 +/- 23 and 467.8 +/- 43 mL/min, respectively). Systemic vascular resistances during pulsatile bypass were also significantly lower than in group 1 at T2 (402 +/- 12 versus 930 +/- 79 dynes/sec/cm-5) and T3 (374 +/- 60 versus 1017 +/- 192 dynes/sec/cm-5). At T2 and T3, all individual blood flows except the brain but including the placenta were statistically higher in group 2 than in group 1. Placental vascular resistances gradually increased during bypass in group 1 to reach 2.9 +/- 0.2 mm Hg.mL-1.min-1.kg-1 at T3 and remained approximately stable in group 2 during 30 minutes of pulsatile bypass, varying from 0.35 +/- 0.02 to 1.26 +/- 0.14 from T2 to T3 (P < .01).

CONCLUSIONS

The data suggest that pulsatile flow for 30 minutes of bypass in a fetal lamb preparation temporarily prevents the progressive hypoxemia observed under steady-flow bypass. Pulsatile flow allows higher pump flow through a significant decrease in systemic vascular resistances. Individual organ blood flow, including placenta, was significantly higher under pulsatile bypass. With technical improvements in the design of pulsatile devices adapted to more physiological beat rates, pulsatility may become a valuable adjunct to overcome placental dysfunction observed during experimental fetal cardiac surgery.

[Relaxation therapy with respiratory feedback in patients with essential hypertension]

During a stationary rehabilitation program for four to six weeks 170 patients with essential hypertension participated in a respiratory feedback (RFB) evaluation. 91 patients were treated with this relaxation therapy and compared with 79 controls. Furthermore the anti-hypertensive medication was controlled. One treatment group (without antihypertensive medication) had a higher systolic blood-pressure decrease than controls. In both treatment groups psychological effects in the sense of more positive mood and less physical complaints were found.

Velocimetric and biochemical fetal effects of placental embolisation using microspheres in ewes

OBJECTIVE

To investigate the reliability of our animal model and study the fetal response to placental ischemia.

STUDY DESIGN

Eight monofetal pregnant ewes were fitted with appliances in conformity with a previously defined operating protocol which we have developed. Microspheres at different concentrations were injected through the fetal face of the placenta. The extent of this embolisation was evaluated using biochemical (acid-base balance) and velocimetric criteria (umbilical and carotid arteries).

RESULTS

Five fetuses received high concentrations of microspheres and developed acute fetal distress (pH = 6.8 +/- 0.05; PO2 = 6.7 +/- 0.4; (S - D)/S (U.A.) = 1.0; (S - D)/S (C.D.) = 0.58 +/- 0.05). Three fetuses received lower concentrations of microspheres and developed chronic fetal distress (pH = 7.2 +/- 0.02; PO2 = 15 +/- 1; (S - D)/S (U.A.) = 0.75 +/- 0.09; (S - D)/S (A.C.) = 0.62 +/- 0.04).

CONCLUSION

Our experimental model is able to reproduce acute and chronic fetal distress. The concentration of microspheres used to create chronic distress is currently understood. Long-term fetal compensation mechanisms prevent the evaluation of risks linked to each degree of chronic distress in utero. The subsequent aim is to obtain a correlation between velocimetric observations and acid-base balance data.

Cloning and characterization of a cold- and ABA-inducible Arabidopsis gene

We have identified by differential screening a novel Arabidopsis thaliana gene, called kin1, which is induced at +4 degrees C. The nucleotide sequences of both the genomic clone and the corresponding cDNA were determined. The deduced 6.5 kDa polypeptide has an unusual amino acid composition being rich in alanine, glycine and lysine. The gene belongs to a family of at least two genes. Northern blot analysis revealed that the level of kin1 mRNA is increased 20-fold in cold-treated plants. In addition to being expressed in cold, kin1 is also induced by water stress and the plant hormone abscisic acid (ABA) which has been suggested to be a common mediator for osmotic stress responses and cold acclimation in plants. Sequence comparisons showed that the kin1 gene product has similarities to fish antifreeze proteins (AFPs).