Foodborne botulism, a forgotten yet life-threatening disease: a case report

OBJECTIVE

Botulism is a very rare disease in Switzerland, with less than one case per year, an incidence of 0.01 cases for 100,000 inhabitants. Indeed, over the past ten years, 9 cases have been reported to Public Health registry. Foodborne botulism (FB) is caused by ingestion of preformed botulinum neurotoxin. Characteristic features should be rapidly recognized, and prompt treatment should be administered to avoid further progression towards respiratory failure and death.

CASE REPORT

We report the case of a patient who developed gastrointestinal symptoms just after a sandwich consumption followed by rapidly progressive cranial nerve impairment, truncal muscle weakness in a descending pattern and respiratory failure requiring mechanical ventilation. The diagnosis of foodborne botulism was delayed due to differential diagnosis considerations. Specific antitoxin therapy was administered immediately after firm clinical conviction of botulism, without waiting for serologic results that later confirmed the diagnosis. As expected, muscle weakness recovery was slow, with persistent chronic deficits nine years later.

CONCLUSIONS

This case highlights differential diagnosis issues of botulism. These include acute neuromuscular disorders such as myasthenia gravis, Guillain-Barré syndrome, or tick-borne encephalitis. The importance of careful medical history and repeated clinical evaluation to avoid misdiagnosis can be lifesaving. Our case highlights the typical warning signs.

Prevalence of hypophosphatemia in the ICU - Results of an international one-day point prevalence survey

BACKGROUND & AIMS

Hypophosphatemia (HypoP) is associated with organ dysfunction and mortality. Despite its potential severe consequences, HypoP remains poorly characterized in terms of real prevalence and timing of onset. The primary objective was to determine the prevalence of HypoP defined as blood phosphate <0.8 and < 0.65 mmol/l on one particular day at international level.

METHODS

One-day point prevalence survey conducted by the Section of Metabolism, Endocrinology and Nutrition (MEN) of the European Society of Intensive Care Medicine (ESICM) during week 11-2020.

RESULTS

In total, 56 adult and 4 paediatric ICUs, from 22 countries participated: 41 ICUs were mixed medico surgical, the 19 others being cardiac, medical or surgical. Phosphate measurements were performed daily in 21 ICUs, and 1-3 times per week in 39 ICUs. On D-Day 909 patients (883 adults) were present and 668/883 (75.7%) had serum/plasma phosphate determined, revealing a HypoP in 103 (15.4%) patients aged 62 [18 to 85] years. Of those, 49 patients presented phosphate <0.65 mmol/l: cases of hypophosphatemia were detected at any time of patient's ICU stay. No HypoP was observed in children. A treatment protocol existed only in 41.1% of adult ICUs, independently of ICU type, or size. Only 41/98 of the HypoP patients (29/41 of patients with phosphate <0.65 mmol/l) were receiving phosphate.

CONCLUSION

HypoP is present at least in 15.4% of ICU patients, and may occur at any time during the ICU stay. The absence of phosphate repletion protocols in 60% of participating ICUs is an unexpected finding, and confirms the necessity for the development of ICU phosphate protocols and guidelines.

CLINICALTRIALS IDENTIFIER

NCT04201899.

Pharmakologische Eigenschaften von Notfallmedikamenten unter Extrembedingungen

Notfallmedikamente kommen an nahezu allen Orten dieser Erde zum Einsatz. Damit werden sie unterschiedlichsten Umweltbedingungen (Kälte, Hitze, direkte Sonneneinstrahlung) ausgesetzt. Sämtliche Daten zur Pharmakokinetik, Pharmakodynamik, Medikamentensicherheit und -haltbarkeit werden jedoch unter standardisierten Bedingungen erhoben, die sich von den Anwendungsbedingungen in der Notfallmedizin erheblich unterscheiden können. Durch die Kälte bei Wintereinsätzen im Gebirge können ebenso wie bei Einsätzen in großer Hitze und bei direkter Sonnenexposition chemische Reaktionen entstehen, welche die Eigenschaften der Medikamente bis hin zur kompletten Wirkungslosigkeit verändern können. Zusätzlich können Unterkühlung oder Überhitzung des Patienten zu einer Zentralisation bzw. Vasodilatation führen und damit das pharmakologische Verteilungsvolumen erheblich verändern, woraus Unter- bzw. Überdosierungen resultieren können. Gleichzeitig kann durch einen temperaturbedingt veränderten Metabolismus die Konjugation und Elimination von Medikamenten beeinflusst sein und zu einer unvorhersehbaren Verlängerung der Medikamentenwirkung führen. Trotz der erheblichen klinischen Relevanz dieser Thematik existieren bisher kaum Daten zu den konkreten Effekten extremer Umweltbedingungen auf die pharmakologischen Eigenschaften von Notfallmedikamenten. Diese Übersicht soll dazu dienen, den aktuellen Kenntnisstand der notfallmedizinischen Pharmakotherapie unter Extrembedingungen darzustellen.

Does the type of parenteral lipids matter? A clinical hint in critical illness

BACKGROUND & AIMS

An altered lipid profile is common among intensive care unit (ICU) patients, but evidence regarding the impact of different fatty acid (FA) emulsions administered to patients requiring parenteral nutrition (PN) is scarce. This study aimed to compare the plasma triglycerides (TG) response to two types of commercial lipid emulsions: a structured mixture of long- and medium-chain triglycerides (LCT/MCT) or LCTs with n-9 FA (LCT+) in ICU patients.

METHODS

In this retrospective observational study conducted in a multidisciplinary ICU: two groups were defined by the type of emulsion used. Inclusion criteria were: consecutive patients on PN staying ≥4 days with one TG determination before commencing PN and at least one during PN. Recorded variables included energy intake, amount and type of nutritional lipids, propofol dose, glucose and protein intake, laboratory parameters, and all drugs received. Hypertriglyceridemia (hyperTG) was defined as TG >2 mmol/L.

RESULTS

The dynamic impact of the emulsion was analyzed in 187/757 patients completing the inclusion criteria (112 LCT/MCT and 75 LCT+). The demographic variables, severity indices, diagnostic categories, and outcomes did not differ between the two groups. Seventy-seven patients (41%) presented hyperTG. Both groups received similar daily energy (1604 versus 1511 kcal/day), lipids (60 versus 61 g/day), and glucose intake (233 versus 197 g/day). There was no increase of TG concentration in those receiving the LCT/MCT emulsion compared to those receiving the LCT+ emulsion (0 and 0.2 mmol/L, respectively, p < 0.05).

CONCLUSION

LCT/MCT emulsions are associated with a less pronounced increase of plasma TG levels than LCT+ emulsions.

Targets of perioperative fluid therapy and their effects on postoperative outcome: a systematic review and meta-analysis

Perioperative fluid management plays a fundamental role in maintaining organ perfusion, and is considered to affect morbidity and mortality. Targets according to which fluid therapy should be administered are poorly defined. This systematic review aimed to identify specific targets for perioperative fluid therapy. The PubMed database (January 1993-December 2013) and reference lists were searched to identify clinical trials which evaluated specific targets of perioperative fluid therapy and reported clinically relevant perioperative endpoints in adult patients. Only studies in which targeted fluid therapy was the sole intervention were included into the main data analysis. A pooled data analysis was used to compare mortality between goal-directed fluid therapy and control interventions. Thirty-six clinical studies were selected. Sixteen studies including 1224 patients specifically evaluated targeted fluid therapy and were included into the main data analysis. Three specific targets for perioperative fluid therapy were identified: a systolic or pulse pressure variation <10-12%, an increase in stroke volume <10%, and a corrected flow time of 0.35-0.4 s in combination with an increase in stroke volume <10%. Targeting any one of these goals resulted in less postoperative complications (pooled data analysis: OR 0.53; CI95, 0.34-0.83; P=0.005) and a shorter length of intensive care unit/hospital stay, but no difference in postoperative mortality (pooled data analysis: OR 0.61; CI95, 0.33-1.11; P=0.12). This systematic review identified three goals for perioperative fluid administration, targeting of which appeared to be associated with less postoperative complications and shorter intensive care unit/hospital lengths of stay. Perioperative mortality remained unaffected.

Early metabolic and splanchnic responses to enteral nutrition in postoperative cardiac surgery patients with circulatory compromise

OBJECTIVES

To assess the hemodynamic and metabolic adaptations to enteral nutrition (EN) in patients with hemodynamic compromise.

DESIGN AND SETTING

Prospective study in a university hospital surgical ICU, comparing baseline (fasted) with continuous EN condition.

PATIENTS

Nine patients requiring hemodynamic support by catecholamines (dobutamine and/or norepinephrine) 1 day after cardiac surgery under cardiopulmonary bypass.

INTERVENTION

Isoenergetic EN via a postpyloric tube while catecholamine treatment remained constant. Baseline (fasted) condition was compared to continuous EN condition.

MEASUREMENTS AND MAIN RESULTS

Cardiac index (CI), mean arterial pressure (MAP), pulmonary and wedge pressures, indocyanine green (ICG) clearance, gastric tonometry, plasma glucose and insulin, and glucose turnover (6,62H2-glucose infusion) were determined repetitively every 60 min during 2 h of baseline fasting condition and 3 h of EN. During EN CI increased (from 2.9 +/- 0.5 to 3.3 +/- 0.5 l min-1 m-2), MAP decreased transiently (from 78 +/- 7 to 70 +/- 11 mmHg), ICG clearance increased (from 527 +/- 396 to 690 +/- 548 ml/min), and gastric tonometry remained unchanged, while there were increases in glucose (158 +/- 23 to 216 +/- 62 mg/dl), insulin (29 +/- 23 to 181 +/- 200 mU/l), and glucose rate of appearance (2.4 +/- 0.2 to 3.3 +/- 0.2 mg min-1 kg-1).

CONCLUSIONS

The introduction of EN in these postoperative patients increased CI and splanchnic blood flow, while the metabolic response indicated that nutrients were utilized. These preliminary results suggest that the hemodynamic response to early EN may be adequate after cardiac surgery even in patients requiring inotropes.

Selenium losses in 10 burned patients

To determine the selenium (Se) losses and balances, 10 patients with burns of 32 +/- 9% (mean +/- SD) of total body surface and aged 36 +/- 9 years were studied from D1 (first post-injury) unitl D7. Cutaneous losses were extracted from the textiles surrounding the patients. Serum and urine were collected until D20. Exudative losses of nitrogen decreased progressively (mean 8.7 +/- 3.8 g/24H). Se was detectable in wound seepage only during excision-grafting: mean operative loss was 342 +/- 191 mug. Mean urinary Se excretion was 41 +/- 13 mug/24H. Operative cutaneous losses led to some negative balances. Serum Se and glutathione peroxydase (GSHPx) were depressed until D20. Serum Se was related to N intake (p < 0.001). The decreased Se and GSHPx levels reflect a deficiency state, which measured losses did not explain, but limitations of the measurement methods prevented detection of Se cutaneous losses 100 mug/24H.

[Burns--from trifle case to mass casualty]

Burn injuries are very frequent, most being trifle cases. Nevertheless every year about 200 patients need to be treated in one of the two specialised Swiss burns centres. Admission criteria are burns > 15% body surface or burns to critical areas (face neck, hands, genitalia, joints) and electrical injuries. The paper reviews the physiophathology of the burn wound which differs depending on the thermal or electrical aetiology. The airway may be threatened due to true inhalation, but also to burns to the face or neck. In major burns >20% body surface in adults, or > 10% in children, fluid resuscitation will be required; oral hydration is generally sufficient by smaller burns. Surgical treatment of 2nd and 3rd degree burns starts within the first 24 days after injury. While complex treatment is generally available in peace time, a major accident such as a disco-fire that can generate hundreds casualties in a few minutes, can threaten our system and force the adoption of triage rules, and simplified treatments. Attitudes to adopt in such conditions are discussed.

Fish oil after abdominal aorta aneurysm surgery

OBJECTIVE

Fish oil (FO) may attenuate the inflammatory response after major surgery such as abdominal aortic aneurysm (AAA) surgery. We aimed at evaluating the clinical impact and safety aspects of a FO containing parenteral nutrition (PN) after AAA surgery.

METHODS

Intervention consisted in 4 days of either standard (STD: Lipofundin medium-chain triglyceride (MCT): long-chain triglyceride (LCT)50%-MCT50%) or FO containing PN (FO: Lipoplus: LCT40%-MCT50%-FO10%). Energy target were set at 1.3 times the preoperative resting energy expenditure by indirect calorimetry. Blood sampling on days 0, 2, 3 and 4. Glucose turnover by the (2)H(2)-glucose method. Muscle microdialysis.

CLINICAL DATA

maximal daily T degrees, intensive care unit (ICU) and hospital stay.

RESULTS

Both solutions were clinically well tolerated, without any differences in laboratory safety parameters, inflammatory, metabolic data, or in organ failures. Plasma tocopherol increased similarly; with FO, docosahexaenoic and eicosapentaenoic acid increased significantly by day 4 versus baseline or STD. To increased postoperatively, with a trend to lower values in FO group (P=0.09). After FO, a trend toward shorter ICU stay (1.6+/-0.4 versus 2.3+/-0.4), and hospital stay (9.9+/-2.4 versus 11.3+/-2.7 days: P=0.19) was observed.

CONCLUSIONS

Both lipid emulsions were well tolerated. FO-PN enhanced the plasma n-3 polyunsaturated fatty acid content, and was associated with trends to lower body temperature and shorter length of stay.

[Toxic epidermal necrolysis]

The toxic epidermal necrolysis (TEN) is an immunologic reaction in the skin with apoptosis of kératinocytes: most cases are reactions against drugs. The main features of this reaction are a separation of the epidermis and erosions of the mucus membranes, associated with a reduction of the general condition with kidney and liver failure. This leads to problems similar to those observed in severely burned patients. The mortality high of patients with TEN can be reduced, if the responsible drug is immediately withdrawn and if the patient is treated in a specialized burns intensive care unit. The medical treatment to stop the chain reaction of apoptosis is still under discussion. Through a case report, this article will focus on the complexity of the treatment of patients with TEN and will point out the importance of a multidisciplinary approach.

Nutritional support during renal replacement therapy

BACKGROUND/AIMS

Malnutrition is common in critically ill patients with acute renal failure. The aim of this review is to describe the basis for nutritional support during renal replacement therapy.

METHODS

Review of the literature.

RESULTS

Techniques of nutritional support and nutritional requirements are described.

CONCLUSION

Early aggressive enteral, parenteral or combine nutritional support is required in critically ill patients on replacement therapy.

[Merging of two intensive care units: preliminary observations]

The merging of two intensive care units is a time of profound change, and constitutes a risk of mishaps. We report some aspects of such a project in our institution. The evaluation of various indicators reflecting the activity, patient's hospital pathways, mortality, as well as the use of specific techniques, has shown that no particular problem was observed during the first 9 months. Improvements in performance or productivity have not been demonstrated so far. The follow-up will permit to demonstrate long-term benefits. We believe that these observations may be of interest for other departmental or hospital reorganisations.

ESPEN Guidelines on Enteral Nutrition: Intensive care

Enteral nutrition (EN) via tube feeding is, today, the preferred way of feeding the critically ill patient and an important means of counteracting for the catabolic state induced by severe diseases. These guidelines are intended to give evidence-based recommendations for the use of EN in patients who have a complicated course during their ICU stay, focusing particularly on those who develop a severe inflammatory response, i.e. patients who have failure of at least one organ during their ICU stay. These guidelines were developed by an interdisciplinary expert group in accordance with officially accepted standards and are based on all relevant publications since 1985. They were discussed and accepted in a consensus conference. EN should be given to all ICU patients who are not expected to be taking a full oral diet within three days. It should have begun during the first 24h using a standard high-protein formula. During the acute and initial phases of critical illness an exogenous energy supply in excess of 20-25 kcal/kg BW/day should be avoided, whereas, during recovery, the aim should be to provide values of 25-30 total kcal/kg BW/day. Supplementary parenteral nutrition remains a reserve tool and should be given only to those patients who do not reach their target nutrient intake on EN alone. There is no general indication for immune-modulating formulae in patients with severe illness or sepsis and an APACHE II Score >15. Glutamine should be supplemented in patients suffering from burns or trauma.

[Perioperative evaluation of lung function]

Respiratory diseases contribute significantly to perioperative morbidity and mortality. Severe pulmonary complications usually emerge postoperatively. To minimise pulmonary risk, the perioperative evaluation of lung function is of major significance, allowing the identification of patient and surgery-related risk factors. In particular, the significance of the intraoperative assessment of lung function has gained in importance over the last few years. The following article describes the possibilities and frontiers of the perioperative assessment of lung function, and focuses especially on the significance of preoperative pulmonary function tests and the intraoperative interpretation of respiratory pressure, flow, and volume loops.

Safety and intestinal tolerance of high-dose enteral antioxidants and glutamine peptides after upper gastrointestinal surgery

OBJECTIVE

Safety and intestinal tolerance of an early high-dose enteral administration of antioxidative vitamins, trace elements, and glutamine dipeptides.

DESIGN

open intervention trial.

SETTING

Two university teaching hospitals.

PATIENTS

A total of 14 patients requiring jejunal feeding (64+/-14 y).

INTERVENTION

A measure of 500 ml/day Intestamin (FreseniusKabi: 250 kcal/1.050 kJ, 300 microg selenium, 20 mg zinc, 400 mug chromium, 1500 mg vitamin C, 500 mg vitamin E, 10 mg beta-carotene, 30 g glutamine) for 5 days beginning 6 h after surgery. Parenteral/enteral nutrition was provided to achieve energy target (25 kcal/kg/day).

ASSESSMENTS

Intestinal complaints, plasma nutrients, and glutathione.

RESULTS

Only minor signs of nausea, hiccups, flatulence (3/14). Plasma micronutrients (except beta-carotene) postoperatively decreased and increased to normal on day 5. Extracellular glutamine remained low (preop: 520+/-94; d1: 357+/-67; d5: 389+/-79 micromol/l); total glutathione decreased (d1: 9.4+/-3.8; d5: 3.6+/-2.5 micromol/l).

CONCLUSION

Study feed is well tolerated and metabolically safe representing a valuable tool for targeted pharmaconutrient supply.

Failure to detect enterovirus in the spinal cord of ALS patients using a sensitive RT-PCR method

OBJECTIVE

To assess the association of enteroviruses (EV) with ALS by applying a sensitive seminested reverse transcription (RT) PCR protocol to the detection of enteroviral RNA in a blinded set of archived tissues from ALS and control cases.

METHODS

The specimen set consisted of 24 frozen spinal cord samples from ALS cases, 17 frozen spinal cord samples from negative control (non-ALS) cases, and 5 frozen spinal cord positive control samples. The positive controls were two human spinal cord samples spiked with poliovirus (PV) and three spinal cords from PV-infected transgenic mice. A sensitive, EV-specific, seminested RT-PCR assay was used to detect EV genome in RNA extracted from the specimens and controls.

RESULTS

The assay detected EV RNA in a 10(-5) dilution of infected mouse tissue. EV RNA was not detected in the ALS specimens or in specimens from control cases, despite the presence of amplifiable RNA as assessed by amplification with control primers, whereas all of the positive control specimens yielded the expected PV amplification product.

CONCLUSION

The reported association between EV infection and ALS was not confirmed by testing this set of specimens with these sensitive methods.

Fractional hepatic de novo lipogenesis in healthy subjects during near-continuous oral nutrition and bed rest: a comparison with published data in artificially fed, critically ill patients

BACKGROUND AND AIMS

In critically ill patients, fractional hepatic de novo lipogenesis increases in proportion to carbohydrate administration during isoenergetic nutrition. In this study, we sought to determine whether this increase may be the consequence of continuous enteral nutrition and bed rest. We, therefore, measured fractional hepatic de novo lipogenesis in a group of 12 healthy subjects during near-continuous oral feeding (hourly isoenergetic meals with a liquid formula containing 55% carbohydrate). In eight subjects, near-continuous enteral nutrition and bed rest were applied over a 10 h period. In the other four subjects, it was extended to 34 h. Fractional hepatic de novo lipogenesis was measured by infusing(13) C-labeled acetate and monitoring VLDL-(13)C palmitate enrichment with mass isotopomer distribution analysis. Fractional hepatic de novo lipogenesis was 3.2% (range 1.5-7.5%) in the eight subjects after 10 h of near continuous nutrition and 1.6% (range 1.3-2.0%) in the four subjects after 34 h of near-continuous nutrition and bed rest. This indicates that continuous nutrition and physical inactivity do not increase hepatic de novo lipogenesis. Fractional hepatic de novo lipogenesis previously reported in critically ill patients under similar nutritional conditions (9.3%) (range 5.3-15.8%) was markedly higher than in healthy subjects (P<0.001). These data from healthy subjects indicate that fractional hepatic de novo lipogenesis is increased in critically ill patients.

Deformation-induced endothelin B receptor-mediated smooth muscle cell apoptosis is matrix-dependent

To maintain normal blood flow, pressure overload in both arteries and veins requires a structural adaptation of the vessel wall (remodelling) that involves smooth muscle cell (SMC) hypertrophy and/or hyperplasia. Due to its potent vasoconstrictor and growth-promoting effects, endothelin-1 (ET-1) is a likely candidate to initiate and/or promote remodelling in blood vessels exposed to a chronic increase in blood pressure. To test this hypothesis, isolated segments of the rabbit carotid artery and jugular vein were perfused at different levels of intraluminal pressure. In both types of segments, pressure overload (160 and 20 mmHg, respectively) resulted in an increase in endothelial prepro-ET-1 and SMC endothelin B receptor (ETB-R) expression. Moreover, in pressurised segments from the carotid artery an ETB-R antagonist-sensitive increase in SMC apoptosis in the media was observed, while in the vein medial SMC started to proliferate. Isolated SMC from these rabbit blood vessels as well as from the aorta and vena cava of the rat, when cultured on a collagen or laminin matrix, uniformly revealed an ETB-R-mediated increase in apoptosis upon exposure to mechanical deformation plus exogenous ET-1 (10 nmol/L). However, when grown on a fibronectin matrix, the cultured SMC did not respond with an increase in apoptosis under otherwise identical experimental conditions. These findings suggest that deformation-induced activation of the endothelin system in the vessel wall not only plays a crucial role in remodelling, but that the structural components of the vessel wall, in particular the cell-matrix interaction, determine how SMC respond phenotypically to these changes in gene expression.

Resuscitation, anaesthesia and analgesia of the burned patient

Burns resuscitation has evolved over the past few decades towards more evidence-based management. It has been shown that patients with major burns (i.e. involving more than 30% of the body surface) benefit from invasive monitoring, and physiological variable targeted resuscitation using vasoactive agents for cardiovascular support. The invasive approach results in a reduction of mortality rates. Since the introduction of the Parkland formula in 1968, there has been a trend towards the administration of fluid resuscitation far in excess of the volume predicted with this formula. This has led to an increase in complication rates, with more pulmonary oedema, and the appearance of abdominal compartment syndrome. Hypertonic saline solutions, whether with dextran or not, have shown no advantage over the classic Ringer's lactate solution. The colloid controversy has reached burns resuscitation, with the demonstration that the liberal use of albumin is associated with higher mortality rates. Fresh frozen plasma should only be used for specific coagulation disorders. On the other hand, artificial colloids, particularly gelatine, remain a useful tool in patients with major burns and haemodynamic instability, particularly, and can be given as early as 6 h after injury. Considering the actual evidence, using inotropes and vasopressors to reach supranormal haemodynamic endpoints seems preferable to delivering unrestricted amounts of fluid.

Influence of selenium supplements on the post-traumatic alterations of the thyroid axis: a placebo-controlled trial

OBJECTIVE

To investigate whether early selenium (Se) supplementation can modify the post-traumatic alterations of thyroid hormone metabolism, since the first week after trauma is characterised by low plasma Se and negative Se balances.

DESIGN

Prospective, placebo-controlled randomised supplementation trial.

SETTING

Surgical ICU in a tertiary university hospital.

PATIENTS

Thirty-one critically ill trauma patients aged 42 +/- 16 years (mean +/- SD), with severe multiple injury (Injury Severity Score 30 +/- 7).

INTERVENTION

Supplementation during the first 5 days after injury with either Se or placebo. The selenium group was further randomised to receive daily 500 microg Se, with or without 150 mg alpha-tocopherol (AT) and 13 mg zinc supplements. The placebo group received the vehicle. Circulating Se, AT, zinc, and thyroid hormones were determined on D0 (= day 0, admission), D1, D2, D5, D10, and D20.

RESULTS

Plasma Se, low on D0, normalised from D1 in the selenium group; total T4 and T3 increased more and faster after D2 (P = 0.04 and 0.08), reverse T3 rising less between D0 and D2 (P = 0.05).

CONCLUSIONS

Selenium supplements increased the circulating Se levels. Supplementation was associated with modest changes in thyroid hormones, with an earlier normalisation of T4 and reverse T3 plasma levels. The addition of AT and zinc did not produce any additional change.

Effects of cardiogenic shock on lactate and glucose metabolism after heart surgery

BACKGROUND

Hyperlactatemia is a prominent feature of cardiogenic shock. It can be attributed to increased tissue production of lactate related to dysoxia and to impaired utilization of lactate caused by liver and tissue underperfusion. The aim of this prospective observational study was to determine the relative importance of these mechanisms during cardiogenic shock.

PATIENTS

Two groups of subjects were compared: seven cardiac surgery patients with postoperative cardiogenic shock and seven healthy volunteers.

METHODS

Lactate metabolism was assessed by using two independent methods: a) a pharmacokinetic approach based on lactate plasma level decay after the infusion of 2.5 mmol x kg(-1) of sodium lactate; and b) an isotope dilution technique for which the transformation of [13C]lactate into [13C]glucose and 13CO2 was measured. Glucose turnover was determined using 6,62H2-glucose.

RESULTS

All patients suffered from profound shock requiring high doses of inotropes and vasopressors. Mean arterial lactate amounted to 7.8 +/- 3.4 mmol x L(-1) and mean pH to 7.25 +/- 0.07. Lactate clearance was not different in the patients and controls (7.8 +/- 3.4 vs. 10.3 +/- 2.1 mL x kg(-1) x min(-1)). By contrast, lactate production was markedly enhanced in the patients (33.6 +/- 16.4 vs. 9.6 +/- 2.2 micromol x kg(-1) x min(-1); p < .01). Exogenous [13C]lactate oxidation was not different (107 +/- 37 vs. 103 +/- 4 mmol), and transformation of [13C]lactate into [13C]glucose was not different (20.0 +/- 13.7 vs. 15.2% +/- 6.0% of exogenous lactate). Endogenous glucose production was markedly increased in the patients (1.95 +/- 0.26 vs. 5.3 +/- 3.0 mg x kg(-1) x min(-1); p < .05 [10.8 +/- 1.4 vs. 29.4 +/- 16.7 micromol x kg(-1) x min(-1)]), whereas net carbohydrate oxidation was not different (1.7 +/- 0.5 vs. 1.3 +/- 0.3 mg x kg(-1) x min(-1) [9.4 +/- 2.8 vs. 7.2 +/- 1.7 micromol x kg(-1) x min(-1)]).

CONCLUSIONS

Hyperlactatemia in early postoperative cardiogenic shock was mainly related to increased tissue lactate production, whereas alterations of lactate utilization played only a minor role. Patients had hyperglycemia and increased nonoxidative glucose disposal, suggesting that glucose-induced stimulation of tissue glucose uptake and glycolysis may contribute significantly to hyperlactatemia.

[Nutrition and stress]

Acute illness induces major physiological responses, which favor the adaptation of the organism to stress and injury. The metabolic response plays key roles in maintenance of vital functions and promotion of the healing mechanisms. All the components of energy expenditure are modified, particularly the resting metabolism. The regulation of carbohydrate metabolism is also markedly altered. Such patients are characterized by fasting and postprandial hyperglycemia, insulin resistance, and by a stimulation of the hepatic glucose production in fasted and fed states. Lipolysis and increased fat oxidation are typically observed. Ketogenesis processes are inhibited, concurring to alter the adaptation to starvation. Protein turnover is stimulated with a preponderance of the catabolic processes, even during full nutritional support. This induces a state of resistance to feeding, leading to a progressive depletion of the fat free mass. Such progressive tissue catabolism cannot be reversed by hypercaloric nutrition or growth factors. Specific nutrients (aminoacids, micronutrients, PUFA) may offer interesting perspectives in stimulating immunity, improving the antioxidant balance or modulating the inflammatory response.

Impact of a bicarbonated saline solution on early resuscitation after major burns

OBJECTIVE

The study aimed at assessing the impact of the introduction of a bicarbonated saline solution on total fluid load, weight gain and acid base status during acute burn resuscitation.

DESIGN

Based on a retrospective patient record review.

SETTING

Burn care centre of a surgical ICU in a tertiary university hospital.

PATIENTS

Two groups of adult patients (20/20), with thermal burns of 25% or more body surface area were studied.

INTERVENTION

Modification of the resuscitation fluid composition from lactated Ringer's solution (LR: Na 132 mmol/l, Cl 112 mmol/l, 263 mosm/l), to bicarbonated 0.9% saline (BS: Na 180 mmol/l, Cl 154 mmol/l, 340 mosm/l)

METHODS

Age, weight, burn size and depth, inhalation injury, fluid intakes over 48 h post-injury, plasma sodium, chloride, creatinine, albumin levels, blood gases and ventilation support were recorded.

RESULTS

The demographic characteristics of the patients (41 +/- 16 years) in the two groups were not different, with severe burns involving 44 +/- 17% body surface area. While the total fluid volumes administered did not differ, BS was associated with lower plasma pH, base excess and bicarbonate levels for 24 h and with hyperchloraemia. Clinical evolution did not differ.

CONCLUSIONS

Using bicarbonated saline solution for resuscitation causes a transient hyperchloraemic dilutional acidosis compared with LR, and has no other detectable clinical impact over the first 10 days after severe burn injury.

Intestinal absorption in patients after cardiac surgery

OBJECTIVES

We designed this study to assess intestinal absorption in patients with adequate or altered hemodynamic status after cardiac surgery and to test clinical tolerance to early enteral nutrition.

DESIGN

Prospective, descriptive study.

SETTING

Surgical intensive unit in a university teaching hospital.

PATIENTS

Cardiac surgery patients, age 64+/-10 yrs (mean +/-SD) were subdivided into two groups according to hemodynamic status: group I, 16 patients with adequate hemodynamic status; group II, 23 patients with hemodynamic failure. These groups were compared with healthy controls (group III, n = 6).

INTERVENTIONS

Paracetamol pharmacokinetic study on days 1 and 3 with nasogastric or postpyloric paracetamol administration. Early postpyloric or conventional gastric nutrition in group II.

MEASUREMENTS AND MAIN RESULTS

Plasma concentrations were measured on days 1 and 3, and area under the curve (AUC) was calculated. Absorption was strongly reduced on day 1 in all patients after gastric administration (lower peak paracetamol and AUC), but normal after postpyloric delivery. Duration of anesthesia and of circulatory bypass did not affect paracetamol absorption. On day 3, AUC was close to normal in case of hemodynamic failure. Peak absorption on day 1 was negatively correlated with opiate dose (r2 = 0.176, p = .008). Hypocaloric enteral nutrition was well tolerated.

CONCLUSIONS

The close-to-normal AUC, during low cardiac output, despite lower peak paracetamol, shows absorption was not suppressed, only delayed, because of decreased pyloric motility. The decrease on day 1 can be attributed to opiates, known to alter pyloric function and to slow down the intestinal transit.

Segmental bioelectrical impedance analysis to assess perioperative fluid changes

OBJECTIVES

Perioperative fluid accumulation determination is a challenge for the clinician. Bioelectrical impedance analysis (BIA) is a noninvasive method based on the electrical properties of tissues, which can assess body fluid compartments. The study aimed at assessing their changes in three types of surgery (thoracic, abdominal, and intracranial) requiring various regimens of fluid administration.

DESIGN

Prospective descriptive trial.

PATIENTS

A total of 26 patients scheduled for elective surgery were separated into three groups according to site of surgery: thoracic (n = 8), abdominal aortic (n = 8), and brain surgery (n = 10).

SETTING

University teaching hospital.

INTERVENTION

None.

MEASUREMENTS

Whole body, segmental (arm, trunk, and legs) BIA at multiple frequency (0.5, 50, 100 kHz) was used to assess perioperative fluid accumulation after surgery. The fluid balances were calculated from the charts.

RESULTS

The patients were aged 62+/-4 yrs. Fluid balances were 4.8+/-1.0 L, 4.1+/-0.5 L, and 1.9+/-0.3 L, respectively, in the three groups. In trunk surgery patients, fluid accumulation was detected as a drop in impedance in the operated area at all frequencies. In the operated area, there was an expansion of both intra- and extracellular compartments. A reduction in high frequencies' impedance in the legs was only detected after aortic surgery. Fluid accumulation and trunk impedance changes were strongly correlated. Neurosurgery only induced minor body fluid changes.

CONCLUSIONS

Segmental BIA is able to detect and localize perioperative fluid accumulation. It may become a bedside tool to quantify and to localize fluid accumulation.

Major reduction in plasma Lp(a) levels during sepsis and burns

Plasma levels of lipoprotein(a) [Lp(a)], an atherogenic particle, vary widely between individuals and are highly genetically determined. Whether Lp(a) is a positive acute-phase reactant is debated. The present study was designed to evaluate the impact of major inflammatory responses on plasma Lp(a) levels. Plasma levels of C-reactive protein (CRP), low density lipoprotein cholesterol, Lp(a), and apolipoprotein(a) [apo(a)] fragments, as well as urinary apo(a), were measured serially in 9 patients admitted to the intensive care unit for sepsis and 4 patients with extensive burns. Sepsis and burns elicited a major increase in plasma CRP levels. In both conditions, plasma concentrations of Lp(a) declined abruptly and transiently in parallel with plasma low density lipoprotein cholesterol levels and closely mirrored plasma CRP levels. In 5 survivors, the nadir of plasma Lp(a) levels was 5- to 15-fold lower than levels 16 to 18 months after the study period. No change in plasma levels of apo(a) fragments or urinary apo(a) was noticed during the study period. Turnover studies in mice indicated that clearance of Lp(a) was retarded in lipopolysaccharide-treated animals. Taken together, these data demonstrate that Lp(a) behaves as a negative acute-phase reactant during major inflammatory response. Nongenetic factors have a major, acute, and unexpected impact on Lp(a) metabolism in burns and sepsis. Identification of these factors may provide new tools to lower elevated plasma Lp(a) levels.

Elevated perfusion pressure upregulates endothelin-1 and endothelin B receptor expression in the rabbit carotid artery

To investigate the hypothesis that high blood pressure activates the endothelin system in the vessel wall, isolated segments of the rabbit carotid artery were subjected to different levels of perfusion pressure. Both preproendothelin-1 (ppET-1) mRNA abundance and intravascular ET-1 peptide content were strongly upregulated on raising the intraluminal pressure from 90 to 160 mm Hg for 3 to 12 hours, and this increase in ppET-1 mRNA occurred predominantly in the endothelial cells. Endothelin-converting enzyme-1 and endothelin A receptor (ET(A)-R) expression were pressure-insensitive, whereas that of the ET(B)-R in the smooth muscle cells was also significantly enhanced. Both the pressure-induced increase in ppET-1 and ET(B)-R expression required RNA synthesis because they were abolished by actinomycin D. The nuclear signaling mechanisms involved therein, however, appeared to be different. Thus, the pressure-induced expression of ppET-1 and activation of CCAAT-enhancer binding proteins beta and delta were blocked by the tyrosine kinase inhibitor herbimycin A, whereas ET(B)-R expression and the nuclear translocation of activator protein-1 were abolished by the protein kinase C inhibitor Ro 31-8220. One consequence of these presumably deformation-induced changes in gene expression was an increased rate of apoptosis of the smooth muscle cells in the media that if transferable to the situation in human blood vessels may contribute to hypertension-induced arterial remodeling.

Detection and cellular localization of enterovirus RNA sequences in spinal cord of patients with ALS

OBJECTIVE

To investigate the possible association of persistent enterovirus (EV) infection with the development of ALS.

BACKGROUND

Although ALS is a clinically well-defined motor neuron disease, little is known about the etiology and pathogenesis of the sporadic cases. Among the different causes that have been hypothesized, conflicting results have been reported about the possible role of persistent enteroviral infection.

METHODS

Reverse transcriptase-PCR (RT-PCR) and direct RT in situ PCR (RT-IS-PCR) were performed in formaldehyde-fixed spinal cord samples of 17 patients with confirmed ALS and 29 control subjects with no history of motor neuron disease. When obtained, PCR products were sequenced subsequently.

RESULTS

Using direct RT-IS-PCR, EV nucleic acid sequences were detected in 15 (88.3%) of 17 patients with ALS compared to 1 (3.4%) of 29 control subjects. PCR products were located in neuronal cell bodies of the anterior horns of the spinal cord. The RT-PCR products obtained in 13 of the 17 patients with ALS showed between 94% and 86% homology with echovirus 7 sequences.

CONCLUSION

The 88.3% rate of detection of enterovirus (EV) nucleic acids in the neuronal cell bodies within the gray matter of the spinal cord of patients with ALS strongly suggests association between persistent EV RNA and ALS. Further work is required to confirm that the persisting EV sequences we detected are somehow involved in the development of ALS.

Pressure-induced upregulation of preproendothelin-1 and endothelin B receptor expression in rabbit jugular vein in situ : implications for vein graft failure?

Upregulation of endothelin-1 (ET-1) synthesis in venous bypass grafts in response to arterial levels of blood pressure may play a major role in graft failure. To investigate this hypothesis, isolated segments of the rabbit jugular vein were perfused at physiological (0 to 5 mm Hg) and nonphysiological (20 mm Hg) levels of intraluminal pressure. As judged by reverse transcription-polymerase chain reaction analysis (mRNA level), neither endothelin-converting enzyme nor endothelin A receptor expression appeared to be pressure sensitive. In contrast, there was a profound and time-dependent increase in endothelial prepro-ET-1 mRNA and intravascular ET-1 abundance (by ELISA) as well as in smooth muscle endothelin B receptor mRNA and functional protein (by superfusion bioassay) on raising the perfusion pressure from 5 to 20 mm Hg, but not from 0 to 5 mm Hg, for up to 12 hours. Video microscopy analysis revealed that the segments were distended by 75% at 5 mm Hg and near maximally at 20 mm Hg compared with the resting diameter at 0 to 1 mm Hg. Treatment of the segments with actinomycin D (1 micromol/L), the specific protein kinase C inhibitor, Ro 31-8220 (0.1 micromol/L), or the c-Src family-specific tyrosine kinase inhibitor, herbimycin A (0.1 micromol/L), demonstrated that the pressure-induced expression of these gene products occurs at the level of transcription and requires activation of protein kinase C, but not c-Src. In venous bypass grafts such deformation-induced changes in gene expression may contribute not only to acute graft failure through ET-1-induced vasospasm but also to endothelin A receptor- and/or endothelin B receptor-mediated smooth muscle cell hyperplasia and graft occlusion.

Trace elements in trauma and burns

This review describes the place of trace elements in the management of critically ill injured patients. There has been a growing interest in trace elements as a result of their essential role in endogenous antioxidant defence mechanisms and in immunity. Burns and trauma are associated with increased free radical production and negative trace element balances, which contribute to the imbalance in endogenous antioxidant capacity and the extension of primary lesions. Supplementation trials have shown that early provision of large amounts of trace elements improve recovery after major burns and brain injury.

Trace element supplementation modulates pulmonary infection rates after major burns: a double-blind, placebo-controlled trial

Infections remain the leading cause of death after major burns. Trace elements are involved in immunity and burn patients suffer acute trace element depletion after injury. In a previous nonrandomized study, trace element supplementation was associated with increased leukocyte counts and shortened hospital stays. This randomized, placebo-controlled trial studied clinical and immune effects of trace element supplements. Twenty patients, aged 40 +/- 16 y (mean +/- SD), burned on 48 +/- 17% of their body surfaces, were studied for 30 d after injury. They consumed either standard trace element intakes plus supplements (40.4 micromol Cu, 2.9 micromol Se, and 406 micromol Zn; group TE) or standard trace element intakes plus placebo (20 micromol Cu, 0.4 micromol Se, and 100 micromol Zn; group C) for 8 d. Demographic data were similar for both groups. Mean plasma copper and zinc concentrations were below normal until days 20 and 15, respectively (NS). Plasma selenium remained normal for group TE but decreased for group C (P < 0.05 on days 1 and 5). Total leukocyte counts tended to be higher in group TE because of higher neutrophil counts. Proliferation to mitogens was depressed compared with healthy control subjects (NS). The number of infections per patient was significantly (P < 0.05) lower in group TE (1.9 +/- 0.9) than in group C (3.1 +/- 1.1) because of fewer pulmonary infections. Early trace element supplementation appears beneficial after major burns; it was associated with a significant decrease in the number of bronchopneumonia infections and with a shorter hospital stay when data were normalized for burn size.

Bedside determination of fluid accumulation after cardiac surgery using segmental bioelectrical impedance

OBJECTIVES

Bioelectrical impedance analysis (BIA) is based on the physical property of tissues to conduct electrical currents, impedance being inversely related to tissue fluid content. At high frequency, the electrical current flows across both intracellular and extracellular pathways, making the assessment of fat-free mass possible while a low-frequency current flows through the extracellular space. Similarly, segmental BIA may be used to assess segmental body fluid repartition. The aim of this study was to assess fluid accumulation after cardiac surgery by multiple frequency segmental BIA.

DESIGN

Observational, clinical study.

SETTING

A 17-bed, surgical intensive care unit in a university hospital.

PATIENTS

Twenty-six patients before and after open-heart surgery with cardiopulmonary bypass.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

After surgery, fluid accumulation resulted in a decrease in whole-body and segmental bioelectrical impedance in the arm and in the trunk. There was a good correlation between the fluid accumulation measured by fluid balance and by whole-body or segmental impedance changes. The major part (71%) of fluid accumulation occurred in the trunk. Multiple frequency measurements did not indicate a fluid shift between the intra- and extracellular compartments.

CONCLUSION

Cardiac surgery produced a significant decrease in segmental trunk BIA, reflecting fluid accumulation at the trunk level.

Demonstration of persistent enterovirus in the pancreas of diabetic mice by in situ polymerase chain reaction

BACKGROUND

Although Enterovirus (EV) do not persist in the tissue, which is essential to maintain autoimmunity, they have been associated as the cause of chronic autoimmunity in some cases of insulin dependent diabetes mellitus (IDDM). Convincing reports, demonstrating persistent EV infections in the pancreases, are rare.

OBJECTIVES

To determine the role of EV in IDDM, a mouse model was tested and i situ polymerase chain reaction (ISPCR) developed. The major problem of ISPCR are the high amounts of non-specific staining. In the current study we developed an ISPCR protocol which minimised non-specific staining and allowed the accurate localisation of the viral RNA in the tissue.

STUDY DESIGN

Five mice were infected with coxsackievirus group B4, sacrificed 7 weeks later and the pancreases were harvested. The EV nucleic acid were localised and detected in the pancreases by ISPCR.

RESULTS

In the current study non-specific staining of ISPCR, due to DNA repair and diffuse artefacts, were minimised and the EV nucleic acids were localised in the beta cells of the endocrine pancreases in all five diabetogenic mice.

CONCLUSION

This study demonstrates an association of viral RNA with the development of diabetes in mice and the usefulness of ISPCR to determine the role of EV in IDDM.