Nutrition education in medical schools (NEMS) project: Joining ESPEN and university point of view

BACKGROUND & AIMS

Nutrition education is not well represented in the medical curriculum. The aim of this original paper was to describe the Nutrition Education in Medical Schools (NEMS) Project of the European Society for Clinical Nutrition and Metabolism (ESPEN).

METHODS

On 19 January 2020, a meeting was held on this topic that was attended by 51 delegates (27 council members) from 34 countries, and 13 European University representatives.

RESULTS

This article includes the contents of the meeting that concluded with the signing of the Manifesto for the Implementation of Nutrition Education in the Undergraduate Medical Curriculum.

CONCLUSION

The meeting represented a significant step forward, moved towards implementation of nutrition education in medical education in general and in clinical practice in particular, in compliance with the aims of the ESPEN Nutrition Education Study Group (NESG).

Acute intestinal failure: International multicenter point-of-prevalence study

BACKGROUND & AIMS

Intestinal failure (IF) is defined from a requirement or intravenous supplementation due to failing capacity to absorb nutrients and fluids. Acute IF is an acute, potentially reversible form of IF. We aimed to identify the prevalence, underlying causes and outcomes of acute IF.

METHODS

This point-of-prevalence study included all adult patients hospitalized in acute care hospitals and receiving parenteral nutrition (PN) on a study day. The reason for PN and the mechanism of IF (if present) were documented by local investigators and reviewed by an expert panel.

RESULTS

Twenty-three hospitals (19 university, 4 regional) with a total capacity of 16,356 acute care beds and 1237 intensive care unit (ICU) beds participated in this study. On the study day, 338 patients received PN (21 patients/1000 acute care beds) and 206 (13/1000) were categorized as acute IF. The categorization of reason for PN was revised in 64 cases (18.9% of total) in consensus between the expert panel and investigators. Hospital mortality of all study patients was 21.5%; the median hospital stay was 36 days. Patients with acute IF had a hospital mortality of 20.5% and median hospital stay of 38 days (P > 0.05 for both outcomes). Disordered gut motility (e.g. ileus) was the most common mechanism of acute IF, and 71.5% of patients with acute IF had undergone abdominal surgery. Duration of PN of ≥42 days was identified as being the best cut-off predicting hospital mortality within 90 days. PN ≥ 42 days, age, sepsis and ICU admission were independently associated with 90-day hospital mortality.

CONCLUSIONS

Around 2% of adult patients in acute care hospitals received PN, 60% of them due to acute IF. High 90-day hospital mortality and long hospital stay were observed in patients receiving PN, whereas presence of acute IF did not additionally influence these outcomes. Duration of PN was associated with increased 90-day hospital mortality.

Economy matters to fight against malnutrition: Results from a multicenter survey

BACKGROUND AND AIM

Malnutrition represents a serious health care threat, as it increases morbidity, mortality and health care cost. The effective screening and treatment with enteral (EN) or parenteral (PN) nutrition are the key elements of the policy called Optimal Nutrition Care for All (ONCA). The study tried to analyze the impact of the state's economy on the implementation of EN and PN to define its role in ONCA.

MATERIAL AND METHODS

an international survey in twenty two European countries was performed between January and December 2014. An electronic questionnaire was distributed to 22 representatives of clinical nutrition (PEN) societies. The questionnaire comprised questions regarding country economy, reimbursement, education and the use EN and PN. Return rate was 90.1% (n = 20).

RESULTS

EN and PN were used in all countries surveyed (100%), but to different extent. The country's income significantly influenced the reimbursement for EN and PN (p < 0.05). It was also associated with the overall use of tube feeding and PN (p = 0.05), but not with the use of oral nutritional supplements (p = 0.165). The use of both, EN and PN at hospitals was not depended on the economy (p > 0.05). Education was actively carried out in all countries, however the teaching at the pre-graduate level was the least widespread, and also correlated with the country income (p = 0.042).

CONCLUSIONS

Results indicated that economic situation influences all aspects of ONCA, including education and treatment. The reimbursement for EN and PN seemed to be the key factor of effective campaign against malnutrition.

Advances in clinical nutrition in GI surgery

This review addresses recent relevant advances to clinical nutrition regarding gastrointestinal disease surgery. Medline Ovid, EMBASE and Central were searched systematically in April 2014. Inclusion criteria were randomized controlled trials, non-randomized controlled trials and observational studies evaluating nutritional support in gastrointestinal surgery published within 5 years. The review included 56 relevant studies. Themes were: nutrition screening and risk factors predict outcome; preoperative nutritional support; shortening fasting periods and including carbohydrate solutions; early nutrition after surgery; immune modulating nutrition; synbiotics, growth hormone, omega-3 and oral, enteral and parenteral nutrition in combination. Screening for nutritional risk is profound, with special focus on dietary intake in the past week. Age and severity of disease need to be included in the screening system. Patients at severe nutritional risk benefit from nutritional therapy before surgery. New standards are developing quickly and clinical guidelines on surgery should include updated knowledge within clinical nutrition.

ESPEN Guidelines on Parenteral Nutrition: pancreas

Assessment of the severity of acute pancreatitis (AP), together with the patient's nutritional status is crucial in the decision making process that determines the need for artificial nutrition. Both should be done on admission and at frequent intervals thereafter. The indication for nutritional support in AP is actual or anticipated inadequate oral intake for 5-7 days. This period may be shorter in those with pre-existing malnutrition. Substrate metabolism in severe AP is similar to that in severe sepsis or trauma. Parenteral amino acids, glucose and lipid infusion do not affect pancreatic secretion and function. If lipids are administered, serum triglycerides must be monitored regularly. The use of intravenous lipids as part of parenteral nutrition (PN) is safe and feasible when hypertriglyceridemia is avoided. PN is indicated only in those patients who are unable to tolerate targeted requirements by the enteral route. As rates of EN tolerance increase then volumes of PN should be decreased. When PN is administered, particular attention should be given to avoid overfeeding. When PN is indicated, a parenteral glutamine supplementation should be considered. In chronic pancreatitis PN may, on rare occasions, be indicated in patients with gastric outlet obstruction secondary to duodenal stenosis or those with complex fistulation, and in occasional malnourished patients prior to surgery.

Acute responses of muscle protein metabolism to reduced blood flow reflect metabolic priorities for homeostasis

The present experiment was designed to measure the synthetic and breakdown rates of muscle protein in the hindlimb of rabbits with or without clamping the femoral artery. l-[ring-(13)C(6)]phenylalanine was infused as a tracer for measurement of muscle protein kinetics by means of an arteriovenous model, tracer incorporation, and tracee release methods. The ultrasonic flowmeter, dye dilution, and microsphere methods were used to determine the flow rates in the femoral artery, in the leg, and in muscle capillary, respectively. The femoral artery flow accounted for 65% of leg flow. A 50% reduction in the femoral artery flow reduced leg flow by 28% and nutritive flow by 26%, which did not change protein synthetic or breakdown rate in leg muscle. Full clamp of the femoral artery reduced leg flow by 42% and nutritive flow by 59%, which decreased (P < 0.05) both the fractional synthetic rate from 0.19 +/- 0.05 to 0.14 +/- 0.03%/day and fractional breakdown rate from 0.28 +/- 0.07 to 0.23 +/- 0.09%/day of muscle protein. Neither the partial nor full clamp reduced (P = 0.27-0.39) the intracellular phenylalanine concentration or net protein balance in leg muscle. We conclude that the flow threshold to cause a fall of protein turnover rate in leg muscle was a reduction of 30-40% of the leg flow. The acute responses of muscle protein kinetics to the reductions in blood flow reflected the metabolic priorities to maintain muscle homeostasis. These findings cannot be extrapolated to more chronic conditions without experimental validation.

Propranolol decreases splanchnic triacylglycerol storage in burn patients receiving a high-carbohydrate diet

OBJECTIVE

To quantify the various components of splanchnic free fatty acid and very-low-density lipoprotein-triacylglycerol (VLDL-TAG) metabolism in order to gain insight into the mechanisms responsible for the development of fatty liver in severely burned patients, and to determine if decreasing free fatty acid availability by use of propranolol could potentially reduce hepatic fatty acid accumulation.

SUMMARY BACKGROUND DATA

Hepatic fat accumulation results from an imbalance between fatty acid uptake, oxidation, and release via VLDL-TAG. Fatty acid delivery is accelerated in burn patients because of stimulated lipolysis. Since propranolol decreases lipolysis, it should also decrease hepatic fatty acid uptake and thus TAG synthesis.

METHODS

Stable isotope-labeled tracers and regional catheterization enabled quantification of various parameters of lipid metabolism across the splanchnic bed in severely burned patients. The acute effects of propranolol treatment were studied in all patients, and in a subgroup of patients the chronic (3 weeks) effects of propranolol were assessed.

RESULTS

The rate of splanchnic uptake of palmitate was 1.68 +/- 1.3 micromol/kg/min, whereas the rates of oxidation and VLDL-TG secretion were only 0.12 +/- 0.11 and 0.003 +/- 0.02 micromol/kg/min, respectively. Propranolol significantly reduced palmitate delivery, and thus palmitate uptake, without significantly affecting oxidation or VLDL-TAG secretion. Thus, palmitate storage was reduced from 1.53 +/- 1.30 micromol/kg/min without propranolol to 0.76 +/- 0.58 micromol/kg/min after propranolol.

CONCLUSIONS

Hepatic fat storage in burn patients is due to low rates of both fatty acid oxidation and VLDL-TAG secretion. Propranolol can decrease hepatic fat storage by limiting fatty acid delivery.

Dietary fat composition alters pulmonary function in pigs

OBJECTIVES

We investigated the effect of various dietary fats on pulmonary surfactant composition and lung function changes that occur before and after endotoxin infusion in pigs.

METHODS

Eighteen pigs were assigned to three groups (n = 6 per group) to receive a diet of protein (20% of calories), carbohydrate (20% of calories), and fat (40% of calories). In one group the fat content consisted entirely of palmitic acid. In the second group, fat came from Intralipid, which provided predominantly linoleic acid. The third group was fed fish oil. Pigs were maintained on these diets for 21 d before the experiment. Cardiovascular and pulmonary functions were determined on day 22. Pigs then were infused with endotoxin (80 mg. kg(-1). min(-1)) until the pulmonary arterial pressure reached a pressure similar to that found in trauma victims (45 to 50 mmHg). Cardiovascular and pulmonary function tests were then repeated, the animals killed, and the lungs removed for study.

RESULTS

Compliance was reduced in the linoleate and fish-oil groups compared with the palmitate group before and after endotoxin. Compliance changes in pigs fed the linoleate and fish-oil diets were consistent with significant increases in lung wet:dry weight ratios, increased CO(2) retention, histologic evidence of vascular congestion, intra-alveolar edema, and alveolar septa thickening. Changes in surfactant phosphatidylcholine composition between groups were consistent with the notion that increased unsaturated fatty acids could affect surfactant function.

CONCLUSIONS

We concluded that the common practice of providing calories in the form of polyunsaturated fatty acids to critically ill patients carries the risk of being detrimental to lung function.

Anabolic action of insulin on skin wound protein is augmented by exogenous amino acids

To investigate the metabolic basis of skin wound healing, we measured in anesthetized rabbits the responses of protein kinetics in scalded skin to insulin and amino acids. L-[ring-(13)C(6)]Phe was infused on the 7th day after the ear was scalded, and the scalded ear was used as an arteriovenous unit to reflect protein kinetics in skin wound. The ipsilateral carotid artery was clamped to control the wound blood flow within four- to fivefold the normal skin rate to measure the enrichment difference in the scalded ear during hyperaminoacidemia. Neither insulin (2.5 mU x kg(-1) x min(-1)) nor amino acid (2.5 mg x kg(-1) x min(-1)) infusion alone improved net protein balance in the skin wound. In contrast, combined infusion of insulin and amino acids increased the net protein balance in skin wound from -6.5 +/- 4.5 to 1.4 +/- 5.2 micromol x 100 g(-1) x h(-1) (P < 0.01, control vs. insulin plus amino acids). We conclude that there is an interactive effect of insulin and sufficient amino acid supply on protein metabolism in skin wound, meaning that their combined anabolic effect is greater than the sum of their individual effects.

Both glucose-insulin-potassium and glutamine in warm blood cardioplegia increase the rates of myocardial glucose and free fatty acid oxidation

OBJECTIVE

We wanted to assess the effect of glucose-insulin-potassium (GIK) and glutamine on the oxidative metabolism during and after prolonged warm continuous blood cardioplegia (WB).

DESIGN

WB was given to 21 pigs divided into three equally sized groups: WB (control), WB and GIK, or WB and glutamine. Oxidation rates of radiolabeled glucose (14C) and free fatty acid (FFA) (3H) were assessed before, during, and at 30 and 60 min after 3 h of cardiac arrest with WB.

RESULTS

During standstill the substrate oxidation dropped markedly (<60%), glucose oxidation was highest in the WB + GIK group (p < 0.05) and FFA oxidation highest in the WB + glutamine group (NS). During recovery the GIK group had an elevated glucose oxidation (47 and 40% vs WB at 30 and 60 min recovery, respectively -p < 0.05). Following 30 min recovery the addition of GIK suppressed FFA oxidation some 60%. Glutamine increased the oxidation of both glucose (30%) and FFA (150%) following 60 min recovery (p < 0.05). During the whole recovery phase the relative FFA oxidation was significantly lowered in the GIK group. There were no differences between the groups regarding arterial levels or uptake of substrates, except for a higher myocardial oxygen consumption (MVO2) during cardioplegia in the glutamine group. All the hearts performed similarly.

CONCLUSION

Addition of GIK or glutamine to the well-perfused and oxygenated heart during WB led to a postcardioplegic increase in oxidative metabolism and MVO2. GIK resulted in a significant metabolic shift from FFA to glucose.

Alteration of hepatic fatty acid metabolism after burn injury in pigs

BACKGROUND

The primary goal of this study was to investigate hepatic fatty acid (FA) metabolism after severe thermal injury.

METHODS

Sixteen pigs were divided into control (n = 8) and burn (n = 8, with 40% full thickness total body surface area burned) groups. Catheters were inserted in the right common carotid artery, portal vein, and hepatic vein for blood sampling. Flow probes were placed around the hepatic artery and portal vein for blood flow measurements. Animals were given pain medication and sedated until the tracer study on day 4 after burn. The pigs were infused for 4 hours with U-13C16-palmitate in order to quantify hepatic FA kinetics and oxidation.

RESULTS

Liver triglyceride (TG) content was elevated from 162 +/- 16 (control) to 297 +/- 28 micromol TG/g dry liver wt. (p < .05). Hepatic FA uptake and oxidation were similar between the 2 groups, as were malonyl-coenzyme A (CoA) levels and activities of acetyl-CoA carboxylase and adenosine monophosphate (AMP)-activated protein kinase. In contrast, incorporation of plasma-free fatty acids into hepatic TG was elevated (p < .05) and very low density lipoprotein TG (VLDL-TG) secretion was decreased from 0.17 +/- 0.02 (control) to 0.03 +/- 0.01 micromol/kg per minute in burned pigs (p < .05).

CONCLUSIONS

The accumulation of hepatic TG in burned animals is due to inhibition of VLDL-TG secretion and to increased synthesis of hepatic TG. Fatty acids are not channeled to TG because of impaired oxidation.

Surfactant phosphatidylcholine in thermally injured pigs

OBJECTIVE

To investigate the effect of a thermal injury on pulmonary surfactant phosphatidylcholine kinetics.

DESIGN

Random, controlled study.

SETTING

University research laboratory.

SUBJECTS

Yorkshire swine (n = 8) with and without a 40% total body surface area burn.

INTERVENTIONS

A new isotope tracer methodology was used to quantify surfactant phosphatidylcholine kinetics. Four days after burn, [1,2-13C2]acetate and [U-(13)C16]palmitate were infused continuously for 8 hrs to quantify surfactant phosphatidylcholine synthesis, secretion, recycling, and irreversible loss.

MEASUREMENTS AND MAIN RESULTS

The total surfactant phosphatidylcholine pool size was reduced from the control value of 2.65 +/- 0.05 to 1.61 +/- 0.08 micromol/g wet lung in burned animals (p <.05), as was the proportional contribution of palmitate to lung surfactant phosphatidylcholine composition. This reduction was associated with a significant decrease in lung dynamic compliance from the control value of 66 +/- 6 to 55 +/- 6 mL/cm H2O for burned pigs (p <.05). The most prominent response of lung phosphatidylcholine kinetics was a decrease in the total lung phosphatidylcholine synthesis from a control value of 12.7 +/- 1.2 to 5.5 +/- 0.3 nmol phosphatidylcholine-bound palmitate x hr(-1) x g of wet lung(-1) in burned animals (p<.05).

CONCLUSIONS

Pulmonary phosphatidylcholine content and palmitate composition decrease after burn injury because of a decrease in the rate of phosphatidylcholine synthesis. These responses likely contribute to impaired lung compliance.

Caval backflow: a potential problem during blood sampling from the hepatic vein

A proper measurement of splanchnic metabolism involves sampling blood from the hepatic vein without backflow contamination of blood from the caval vein. We have investigated the potential problem of caval backflow in human volunteers with an indwelling hepatic vein catheter by sampling blood with different amounts of suction on the syringe (ie, sampling speeds). We also investigated the potential problem in pigs in which a balloon catheter was inserted in the hepatic vein. Pure hepatic vein samples were obtained with the balloon inflated and compared with samples obtained from the same catheter in the conventional manner. In overnight fasted humans, drawing blood samples from the hepatic vein with minimal suction ("slow" drawing) resulted in glucose values 9.6% higher than drawing the samples with greater suction ("fast" drawing). The calculated arterial-venous balance across the splanchnic bed was 4.8 times greater with "slow" blood drawing as compared with "fast" drawing. Values obtained from the pigs showed no concentration differences between pure hepatic vein samples and "slow" drawing from the hepatic vein. The current study indicates that it is possible to obtain a "true" hepatic vein sample, but backflow from the caval vein is a potential pitfall that can have a physiologically significant impact on calculated balance data.

Glucose effects on lung surfactant kinetics in conscious pigs

The primary goal of this study was to investigate the effects of glucose infusion on surfactant phosphatidylcholine (PC) metabolic kinetics in the lungs. A new stable isotope tracer model was used in which [1,2-(13)C(2)]acetate and uniformly labeled [U-(13)C(16)]palmitate were infused in 12 normal overnight-fasted pigs to quantify lung surfactant kinetics with or without glucose infusion (24 mg. kg(-1). min(-1)). With glucose infusion, the rate of surfactant PC incorporation from de novo synthesized palmitate increased from the control value of 2.1 +/- 0.2 to 15.5 +/- 1.9 nmol PC-bound palmitate. h(-1). g wet lung(-1) (P < 0.05), whereas the incorporation rate from plasma preformed palmitate decreased from the control value of 20.9 +/- 1.9 to 11.6 +/- 1.1 nmol palmitate. h(-1). g wet lung(-1) (P < 0.05). The palmitate composition in lamellar body surfactant PC increased from the control value of 61.7 +/- 2.1% to 75.9 +/- 0.6% (P < 0.05). The surfactant PC secretion rate decreased from the control value of 239.0 +/- 26.1 to 81.9 +/- 5.3 nmol PC-bound palmitate. h(-1). g wet lung(-1) (P < 0.05). We conclude that, whereas surfactant secretion was inhibited by glucose infusion, neither total surfactant PC synthesis nor the surfactant PC pool size was significantly affected due to an increased reliance on de novo synthesized fatty acids.

Myocardial metabolism and efficiency after warm continuous blood cardioplegia

BACKGROUND

Warm continuous blood cardioplegia (WCBCP) has been recommended during prolonged cardiac arrest to minimize functional deterioration. Myocardial metabolism and efficiency after this cardioplegic modality are not well described.

METHODS

Substrate oxidation, blood flow, and myocardial function were measured before, during, and after 3 hours of WCBCP in 7 pigs.

RESULTS

Free fatty acid and glucose oxidation decreased by 60% +/- 3.8% and 94% +/- 1.2%, respectively, during cardioplegia (both p < 0.05) and increased to 62% +/- 28% and 122% +/- 62% of baseline during the early recovery phase (p < 0.05 for glucose). One hour after WCBCP oxidation rates were similar to baseline. The transient postcardioplegic increase in substrate oxidation was associated with a 43% +/- 23% elevation of oxygen consumption (MVO2) compared with baseline and a 62% +/- 18% increase in myocardial blood flow. Cardiac output and mean arterial pressure did not change significantly after WCBCP, although myocardial function (stroke work, left ventricular end-systolic pressure, end-diastolic pressure, contractility, and efficiency) was depressed (p < 0.05). End-diastolic pressure and contractility improved from early to late phase of recovery, whereas the other indicators of ventricular function remained depressed.

CONCLUSIONS

Myocardial substrate oxidation was preserved after 3 hours of WCBCP, although ventricular function was moderately impaired. Thus, WCBCP with a seemingly normal substrate and oxygen supply was associated with a reduced cardiac efficiency.

Methysergide reduces nonnutritive blood flow in normal and scalded skin

Methysergide is a serotonin antagonist and has been demonstrated to reduce wound blood flow and edema formation. We have determined the effect of methysergide on protein kinetics in normal and scalded skin of anesthetized rabbits. L-[ring-(13)C(6)]- or L-[ring-(2)H(5)]phenylalanine was used to reflect skin protein kinetics by use of an ear model, and L-[1-(13)C]leucine was used to reflect whole body protein kinetics. The results were that infusion of methysergide (2-3 mg. kg(-1). h(-1)) reduced the blood flow rate in normal skin by 50% without changing skin or whole body protein kinetics. After scald injury on the ear, administration of methysergide for 48 h reduced the weight of scalded ears (43 +/- 4 vs. 30 +/- 5 g, P < 0.01) and ear blood flow rate (42.6 +/- 4.9 vs. 5.8 +/- 1.0 ml. 100 g(-1). min(-1), P < 0.0001) and did not change wound protein kinetics. Methysergide reduced arteriovenous shunting and maintained inward phenylalanine transport from the blood to the skin pool. Using the microsphere technique, we found that the infusion of methysergide decreased blood perfusion by 33-36% in both normal and scalded ear skin. We conclude that methysergide administration reduces nonnutritive, as opposed to nutritive, blood flow in normal and scalded skin.

Gut epithelial apoptosis after severe burn: effects of gut hypoperfusion

BACKGROUND

Severe cutaneous burn causes transient mesenteric vasoconstriction and altered gut mucosal integrity. We recently showed that burn also increases gut epithelial cell death by apoptosis. The goal of this study was to determine whether changes in gut perfusion after burn contribute to burn-associated gut apoptosis.

STUDY DESIGN

We first correlated superior mesenteric artery blood flow with measurement of gut perfusion at the tissue level by laser doppler in four nonburned rats before, during, and after arterial clamping to validate our measurements of gut perfusion. We then characterized gut perfusion sequentially over time after burn; gut perfusion was measured 3 cm from the ligament of Treitz before burn and hourly for 6 hours. A group of control rats underwent the exact same protocol without the burn to exclude effects of anesthesia and laparotomy on tissue perfusion (n = 4). We studied a third group of rats with hypoperfusion of the same duration and magnitude induced mechanically without burn (n = 7). Sections of the proximal gut from all three groups (control without burn, burn, and hypoperfusion without burn) were examined for epithelial apoptosis.

RESULTS

Linear regression analysis demonstrated a strong correlation between superior mesenteric artery blood flow and intestinal tissue perfusion measured by laser doppler under both low and high flow conditions (r = 0.85). Laser doppler measurements of gut perfusion after burn showed deceased gut perfusion that was maximal at 2 hours postburn (p < 0.05), and that persisted for 4 hours (p < 0.05). By 6 hours, gut perfusion returned to baseline. Apoptosis increased significantly in the burn group (2.11 +/- 0.17%) compared with control (0.52 +/- 0.2%) and the mechanically decreased perfusion group (0.51 +/- .03) (p < 0.001).

CONCLUSIONS

We conclude that burn-induced gut hypoperfusion is insufficient to cause burn-related increased gut epithelial apoptosis. We speculate that the signal for increased gut epithelial apoptosis is primarily related to proinflammatory mediators induced by the burn wound.

Comparison of wound culture and bronchial lavage in the severely burned child: implications for antimicrobial therapy

BACKGROUND

The relationship of the burn wound flora to microbial pathogens in the tracheobronchial tree has important implications for antimicrobial therapy in the severely burned patient. Management of septic complications is bolstered by surveillance quantitative wound cultures (QWC) and bronchial lavage fluid (BLF) cultures.

OBJECTIVES

To compare the organisms present in BLF with those found in QWC and to determine if QWC can predict BLF results.

DESIGN

Results of BLF cultures from all patients who underwent bronchial lavage from January 1, 1996, to December 31, 1996, at our institution were compared with QWC data from the same date. Criteria for a positive match included an identical antibiotic susceptibility pattern and biotype. Match rates were calculated qualitatively and quantitatively.

RESULTS

In 30 (48%) of the 62 BLF cultures, there was a match between the organism identified in the BLF and the QWC. When strict quantitative criteria were applied, the match rate was only 9 (14%) of 62. Burn size and inhalation injury had no significant effect on match rate.

CONCLUSIONS

Whereas the microbial pathogens were similar in the QWC and BLF, linear regression showed no value of QWC in predicting BLF culture results. The difference between qualitative and quantitative match rates suggests cross-colonization between the burn wound and tracheobronchial tree, but little to no cross-infection. The QWC and BLF cultures must be performed independently in determining antimicrobial specificity in the burned patient.

Is the general practitioner hospital a potential "patient trap"? A panel study of emergency cases transferred to higher level hospitals

OBJECTIVES

1. To find out whether a stay in local general practitioner hospitals (GP hospitals) prior to an emergency admission to higher level hospitals aggravated or prolonged the course of the disease, or contributed to permanent health loss for some patients. 2. To detect cases where a transitory stay in a GP hospital might have been favourable.

DESIGN

A retrospective expert panel study based on records from GP hospitals and general hospitals. The included patients had participated in a previous prospective study of consecutive admissions to GP hospitals during 8 weeks.

SETTING

Fifteen out of 16 GP hospitals in Finnmark county, Norway.

SUBJECTS

Seventy-three patients transferred to higher level hospitals from a total of 395 admitted to GP hospitals.

MAIN OUTCOME MEASURES

Three outcome categories were considered for each patient: "possible permanent health loss", "possible significantly prolonged or aggravated disease course", and "possible favourable effect on the disease course".

RESULTS

There was agreement about the possibility of negative effects in two patients (2.7%), while a possible favourable influence was ascribed to six cases (8.2%).

CONCLUSION

Negative health effects due to transitory stays in GP hospitals are uncommon and moderate, and balanced by benefits, particularly with regard to early access to life saving treatment for critically ill patients.

High cardioplegic perfusion pressure entails reduced myocardial recovery

OBJECTIVE

The cardioplegic solution is often given at high flow and pressure following aortic clamping clamping to ensure rapid diastolic arrest. With standard setup in clinical practice, it is easy to exceed 200 mmHg in the aortic root. To investigate whether cardioplegic solution delivery pressure has an influence on myocardial protection, intermittent infusions of crystalloid cardioplegia were given at two different pressures using an in vivo pig model.

METHODS

Fourteen pigs (48-57 kg) were put on cardiopulmonary bypass, aorta-clamped (2 h) and 500 ml St. Thomas' cardioplegia (4 degrees C) was delivered antegradely at either 75 mmHg (group 1, n = 7) or 175 mmHg (group 2, n = 7) pressure via 9-F aortic root cardioplegic needle. Every 20 min, 100 ml cardioplegic were delivered at either one of the two pressures. After 2 h, the aorta was unclamped and the hearts reperfused. Attempts were made to wean pigs from bypass following 20 min reperfusion or, if they were failing, after 40 min. If failing once again, the pigs were reperfused for the last 20 min on the heart-lung machine.

RESULTS

Hearts in group 1 (n = 7) needed significantly longer time to stop after aortic clamping (38 +/- 9 s) than did group 2 hearts (n = 7) (21 +/- 5 s) (P = 0.043). In group 1, all pigs were weaned from bypass, whereas in group 2 only 2 out of 7 pigs were able to sustain circulation without cardiopulmonary bypass (P = 0.01), and then with lower hemodynamic performances. At the end of cardiac arrest, group 1 had significantly higher adenosine triphosphate (19.4 +/- 1.1 mumol/g dry weight and 15.05 +/- 1.8 mumol/g dry weight, respectively) (P = 0.05) and significantly lesser fall in energy charge than group 2 (0.02 +/- 0.01 and 0.05 +/- 0.02, respectively) (P = 0.05). Also at the end of reperfusion, group 1 had significantly higher adenosine triphosphate (16.54 +/- 1.4 mumol/g dry weight and 12.53 +/- 0.95 mumol/g dry weight, respectively) (P = 0.016) than group 2.

CONCLUSIONS

Despite a swifter diastolic cardiac arrest, the high cardioplegic solution delivery pressure caused significantly poorer postischemic recovery than a moderate pressure with the same amount of cardioplegic solution.

Exogenous reactive oxygen species deplete the isolated rat heart of antioxidants

The effects of reactive oxygen species (ROS) on myocardial antioxidants and on the activity of oxidative mitochondrial enzymes were investigated in the following groups of isolated, perfused rat hearts. I: After stabilization the hearts freeze clamped in liquid nitrogen (n = 7). II: Hearts frozen after stabilization and perfusion for 10 min with xanthine oxidase (XO) (25 U/l) and hypoxanthine (HX) (1 mM) as a ROS-producing system (n = 7). III: Like group II, but recovered for 30 min after perfusion with XO + HX (n = 9). IV: The hearts were perfused and freeze-clamped as in group III, but without XO + HX (n = 7). XO + HX reduced left ventricular developed pressure and coronary flow to approximately 50% of the baseline value. Myocardial content of hydrogen peroxide (H2O2) and malondialdehyde (MDA) increased at the end of XO + HX perfusion, indicating that generation of ROS and lipid peroxidation occurred. Levels of H2O2 and MDA normalized during recovery. Superoxide dismutase, reduced glutathione and alpha-tocopherol were all reduced after ROS-induced injury. ROS did not significantly influence the tissue content of coenzyme Q10 (neither total, oxidized, nor reduced), cytochrome c oxidase, and succinate cytochrome c reductase. The present findings indicate that the reduced contractile function was not correlated to reduced activity of the mitochondrial electron transport chain. ROS depleted the myocardium of antioxidants, leaving the heart more sensitive to the action of oxidative injury.

Myocardial substrate oxidation during warm continuous blood cardioplegia

BACKGROUND

Although long-chain fatty acids are a major energy substrate utilized by the myocardium, changes in the substrate balance toward a predominating fatty acid utilization could jeopardize the myocardium during cardiac operative procedures.

METHODS

In the present study myocardial substrate utilization was examined during warm continuous blood cardioplegia (4 hours, 37 degrees C), using pigs undergoing cardiopulmonary bypass. Hearts were perfused antegradely in a closed extracorporeal circuit in which cardioplegic donor blood (hematocrit, 22%) containing 14C-glucose and 3H-oleate was delivered to the heart. Arterial and coronary sinus blood samples were taken at intervals for determination of plasma concentrations of energy substrates, as well as glucose and oleate oxidation rates (14CO2 and 3HOH production).

RESULTS

The concentration of fatty acids in the cardioplegic perfusate did not change significantly during the cardiac arrest period. The mean concentration of glucose showed a 30% decline (not significant), whereas the lactate concentration increased from a starting value of 3.12 +/- 0.27 to 6.31 +/- 0.72 mmol/L at the end (mean +/- standard error of the mean; n = 8; p < 0.05). Only fatty acid levels showed a significant (positive) arterial-coronary sinus difference. Myocardial oxidation of oleate varied between 302 +/- 71 and 650 +/- 66 nmol.min-1.heart-1, whereas the range of variation for glucose oxidation was 144 +/- 64 to 355 +/- 107 nmol.min-1.heart-1. However, the changes in fatty acid levels and glucose oxidation rates during the cardiac arrest period were not statistically significant. We calculated that overall glucose oxidation accounted for less than 5% of the total aerobic energy production.

CONCLUSIONS

The present results demonstrate overreliance on fatty acids as a source of energy during warm continuous blood cardioplegia, consistent with a condition of myocardial insulin resistance.

Normotherm continuous blood cardioplegia for 4 hours in an in vivo pig model

Warm, continuous blood cardioplegia should theoretically maintain cardiac arrest for hours without ischaemic or hypothermic injury. In the absence of in vivo studies of myocardial metabolism and ultrastructural and/or functional preservation during and after more than 2 hours of cardiac arrest and after weaning from bypass, we devised a porcine model with a closed extracorporeal circuit for the heart alone. Normothermic blood cardioplegia was administered antegrade and recirculated for 2 or 4 hours, each in seven pigs. After aortic declamping all were successfully weaned from bypass and reperfused for 1 hour. Thereafter we found no significant intergroup difference in haemodynamic characteristics (average fall in mean arterial pressure 31.7 +/- 3.2% and 26.9 +/- 2.6%) or blood analyses. After 5 and 60 minutes of cardiac arrest there was minimal lactate production (5.7 +/- 10.7 and 0.5 +/- 10.5 nmol/l, respectively), whereas in the remainder of the arrest period there was lactate uptake, indicating aerobic heart metabolism. Our setup avoids systemic hyperkalaemia, gives good cardiac protection with no deterioration between 2 and 4 hours and is well suited for studies on the quiescent, blood-perfused oxygenated heart.

Coronary autoregulation protects against harmful effects of commonly used cardioplegia delivery pressure

OBJECTIVE

Hearts or parts of hearts are often ischemic prior to infusion of the cardioplegic solution and have a more or less dilated coronary bed. We made an investigation whether coronary dilation just prior to induction of cardiac arrest by aortic clamping and infusion of crystalloid cardioplegic solution would influence cardioprotection.

METHODS

Isolated buffer-perfused rat hearts (100 cm H2O pressure (= 73.5 mmHg), 37 degrees C) were used. After a stabilization period the perfusion of 8 rats (group 1) was stopped and the hearts arrested with 5 ml CS (100 cm H2O, 12 degrees C). Equal amounts of cardioplegic solution were then delivered every 20 minutes for the entire 3 1/2 hour hypothermic ischemic period. Following ischemia the hearts were reperfused for 60 minutes. In group 2 (n = 8) 1 ml 10(-2) mmol Papaverine was given into the aortic root just prior to the first cardioplegic solution infusion in order to induce coronary vasodilation. The procedure was identical in the two groups during ischemia and reperfusion.

RESULTS

During the ischemic period coronary resistance increased in group 2. During reperfusion group 2 had lower coronary flow (P = 0.001), left ventricle developed pressure (P = 0.002) and a higher creatine kinase release (P = 0.003) than group 1 hearts. Group 2 also had a lower adenosine-triphosphate (6.51 +/- 0.40 mumol.g-1 and 14.03 +/- 0.59 mumol.g-1, respectively, P = 0.011), creatine phosphate (24.70 +/- 1.02 mumol.g-1 and 36.50 +/- 1.31 mumol.g-1, respectively, P = 0.020) and a larger fall in dry/wet-weight ratio (1.7 +/- 0.4 and 0.8 +/- 0.5, respectively, P = 0.043).

CONCLUSIONS

Vasodilation (i.e. ischemia) just prior to infusion of crystalloid cardioplegic solution may impair myocardial protection even when the cardioplegic solution is delivered at a relatively low and presumably safe pressure.

Delivery pressure of the cardioplegic solution influences myocardial protection

To investigate whether cardioplegic solution (CS) delivery pressure influences myocardial protection, intermittent infusions of CS at different pressures were used in an isolated Langendorff rat heart preparation. In group 1 the hearts were kept arrested for 210 min at 12 degrees C with intermittent infusions of 5 ml CS every 20 min at 30 cm H2O (22 mmHg) pressure, in group 2 the same volume of CS was infused at 100 cm H2O (73.5 mmHg) pressure, in group 3 at 145 cm H2O (106.5 mmHg) pressure and in group 4 at 238 cm H2O (175 mmHg) pressure. There was a significantly higher coronary resistance in groups 1 and 4 (7.3 +/- 0.2 RU and 6.9 +/- 0.2 RU) than in groups 2 and 3 (4.2 +/- 0.2 RU and 4.2 +/- 0.2 RU) (P < 0.05) during the ischemic period. There were no significant differences between group 2 and 3 in the reperfusion period. Groups 2 and 3 showed higher coronary flow and left ventricle developed pressure than group 1 and 4. Hearts from group 1 and 4 had lower adenosine triphosphate (7.88 +/- 0.44 mumol.g-1, 5.56 +/- 0.56 mumol.g-1) (P < 0.05) and creatine phosphate (24.66 +/- 0.47 mumol.g-1, 15.34 +/- 0.94 mumol.g-1) (P < 0.05) content at the end of the reperfusion period than group 2 (10.56 +/- 0.41 mumol.g-1, 30.06 +/- 0.38 mumol.g-1) and group 3 (14.13 +/- 0.69 mumol.g-1, 35.25 +/- 0.78 mumol.g-1).(ABSTRACT TRUNCATED AT 250 WORDS)

[Varices of the great saphenous vein]

During a 7-year period, 237 patients were treated surgically at Tromsø Hospital for varices of the great saphenous vein. At follow-up (mean 7.5 years) the overall results were excellent in 30%, good in 47%, and poor in 21% of the patients. The recurrence rate of varicose veins was 47%. However, 50% of these patients had no symptoms or only minor symptoms, from the recurrence. 37 patients noticed the occurrence of troublesome varicose veins within one year after operation. At clinical reexamination it was found that in 32 of these patients the surgery had been inadequate. This probably explains the rapid recurrence.