Cardiovascular Safety of Clonidine and Dexmedetomidine in Critically Ill Patients after Cardiac Surgery.

PURPOSE: The aim of this retrospective study was to assess the haemodynamic adverse effects of clonidine and dexmedetomidine in critically ill patients after cardiac surgery. METHODS: 2769 patients were screened during the 30-month study period. Heart rate (HR), mean arterial pressure (MAP), and norepinephrine requirements were assessed 3-hourly during the first 12 hours of the continuous drug infusion. Results are given as median (interquartile range) or numbers (percentages). RESULTS: Patients receiving clonidine (n = 193) were younger (66 (57-73) vs 70 (63-77) years, p=0.003) and had a lower SAPS II (35 (27-48) vs 41 (31-54), p=0.008) compared with patients receiving dexmedetomidine (n = 141). At the start of the drug infusion, HR (90 (75-100) vs 90 (80-105) bpm, p=0.028), MAP (70 (65-80) vs 70 (65-75) mmHg, p=0.093), and norepinephrine (0.05 (0.00-0.11) vs 0.12 (0.03-0.19) mcg/kg/min, p < 0.001) were recorded in patients with clonidine and dexmedetomidine. Bradycardia (HR < 60 bpm) developed in 7.8% with clonidine and 5.7% with dexmedetomidine (p=0.51). Between baseline and 12 hours, norepinephrine remained stable in the clonidine group (0.00 (-0.04-0.02) mcg/kg/min) and decreased in the dexmedetomidine group (-0.03 (-0.10-0.02) mcg/kg/min, p=0.007). CONCLUSIONS: Dexmedetomidine and the low-cost drug clonidine can both be used safely in selected patients after cardiac surgery.

[CME: Fusobacterium nucleatum/naviforme - a Rare but Serious Cause for Pyogenic Liver Abscesses]. / CME: Fusobacterium nucleatum/naviforme ­ eine seltene, aber nicht zu unterschätzende Ursache für pyogene Leberabszesse.

CME: Fusobacterium nucleatum/naviforme - a Rare but Serious Cause for Pyogenic Liver Abscesses Abstract. Pyogenic liver abscesses belong to the most common abdominal infections. Beside the most common pathogens, also rare forms like Fusobacteria, which can also be part of the natural oropharyngeal and enteral microbiome, may be considered to cause severe forms of abscesses of the liver. Since they may be more difficult to detect, they could become a challenge during diagnosis and therapy.

Heart rate elevations during early sepsis predict death in fluid-resuscitated rats with fecal peritonitis.

BACKGROUND: In sepsis, early outcome prediction would allow investigation of both adaptive mechanisms underlying survival and maladaptive mechanisms resulting in death. The aim of this study was to test whether early changes in heart rate monitored by telemetry could predict outcome in a long-term rat model of fecal peritonitis. METHODS: Male Wistar rats (n = 24) were instrumented with a central venous line for administration of fluids, antibiotics and analgesics. A telemetry transmitter continuously collected electrocardiogram signals. Sepsis was induced by intraperitoneal injection of fecal slurry, and the animals were observed for 48 h. Additional animals underwent arterial cannulation at baseline (n = 9), 4 h (n = 16), or 24 h (n = 6) for physiology and laboratory measurements. RESULTS: 48-h mortality was 33% (8/24), with all deaths occurring between 4 and 22 h. Septic animals were characterized by lethargy, fever, tachycardia, positive blood cultures, and elevated cytokine (IL-1, IL-6, TNF alpha) levels. An increase in heart rate ≥ 50 bpm during the first 4 h of sepsis predicted death with sensitivity and specificity of 88% (p = 0.001). CONCLUSIONS: In this long-term rat sepsis model, prognostication could be made early by telemetry-monitored changes in heart rate. This model enables the study of underlying mechanisms and the assessment of any differential effects of novel therapies in predicted survivors or non-survivors.

Is there a role for procalcitonin in differentiating uncomplicated and complicated diverticulitis in order to reduce antibiotic therapy? A prospective diagnostic cohort study.

AIMS OF THE STUDY: While studies show that antibiotic treatment for uncomplicated diverticulitis seems to have no benefit, most experts advocate antimicrobial therapy for complicated diverticulitis. However, even for uncomplicated diverticulitis, most clinicians are very reluctant to withhold antibiotics. Biomarkers could help to guide antibiotic therapy as this approach has been shown to be effective for acute respiratory infections. In this diagnostic cohort study we evaluated whether procalcitonin could be a biomarker to distinguish complicated from uncomplicated cases of diverticulitis. METHODS: Complicated diverticulitis was defined as having abscess formation or perforation diagnosed by abdominal computed tomography (CT) scan. In all patients with suspected diverticulitis, procalcitonin values were measured at admission and on day 2. These values were blinded for clinicians, and treatment was carried out according to the physician's judgement. Two groups (complicated vs uncomplicated diverticulitis) were defined. Patients who had received antibiotic treatment before admission were excluded. Difference in procalcitonin values was calculated for both groups using the Mann-Whitney test. Receiver operating characteristics (ROC) were calculated to determine cut-off values for procalcitonin according to the gold standard (abdominal CT scans). RESULTS: 115 patients were included for analysis. 35 patients (30%) suffered from complicated diverticulitis. The median procalcitonin value for uncomplicated diverticulitis was significantly lower compared to complicated diverticulitis (median 0.05, interquartile range [IQR] 0.05-0.06 ng/l vs median 0.13, IQR 0.05-0.23 ng/l; p <0.0001). In the ROC analysis, the sensitivity and specificity were 81% and 91% when the highest procalcitonin value (days 1 and 2) was considered, with a cut-off value of 0.1 ng/l. CONCLUSION: Procalcitonin was able to differentiate with a high sensitivity and specificity between complicated and uncomplicated cases of diverticulitis when combined with abdominal CT scans. As most clinicians still treat uncomplicated diverticulitis with antibiotics, procalcitonin could be an interesting parameter for guiding therapy and decreasing antibiotic usage. This should be further evaluated in randomised trials.

Improving animal welfare using continuous nalbuphine infusion in a long-term rat model of sepsis.

BACKGROUND: Sepsis research relies on animal models to investigate the mechanisms of the dysregulated host response to infection. Animal welfare concerns request the use of potent analgesics for the Refinement of existing sepsis models, according to the 3Rs principle. Nevertheless, adequate analgesia is often missing, partly because the effects of analgesics in this particular condition are unknown. We evaluated the use of nalbuphine, an opioid with kappa agonistic and mu antagonistic effects, in rats with and without experimental sepsis. METHODS: Male Wistar rats were anesthetized with isoflurane and instrumented with a venous line for drug administration. Arterial cannulation allowed for blood pressure measurements and blood sampling in short-term experiments of non-septic animals. Nalbuphine (or placebo) was administered intravenously at a dose of 1 mg/kg/h. Long-term (48 h) experiments in awake septic animals included repetitive clinical scoring with the Rat Grimace Scale and continuous heart rate monitoring by telemetry. Sepsis was induced by intraperitoneal injection of faecal slurry. Nalbuphine plasma levels were measured by liquid chromatography-high resolution mass spectrometry. RESULTS: In anesthetized healthy animals, nalbuphine led to a significant reduction of respiratory rate, heart rate, and mean arterial pressure during short-term experiments. In awake septic animals, a continuous nalbuphine infusion did not affect heart rate but significantly improved the values of the Rat Grimace Scale. Nalbuphine plasma concentrations remained stable between 4 and 24 h of continuous infusion in septic rats. CONCLUSIONS: In anaesthetised rats, nalbuphine depresses respiratory rate, heart rate, and blood pressure. In awake animals, nalbuphine analgesia improves animal welfare during sepsis.

Analgesia in clinically relevant rodent models of sepsis.

Postoperative analgesia in rodent sepsis models has been considerably neglected in the past. However, intentions to model clinical practice, increasing awareness of animal ethics, efforts to apply the 3Rs (replacement, reduction, refinement), and stricter legislation argue for a change in this respect. In this review, we describe different concepts of analgesia in rodent models of sepsis focusing on opioid agonists as well as non-opioid analgesics. Advantages and pitfalls in study design and side-effects are discussed. Score sheets should be used to adapt analgesia or to terminate experiments using humane endpoints. Further research is needed to differentiate behavioral changes caused by sepsis and pain or as a consequence of analgesia. Information on the efficacy of analgesia in sepsis models is scarce. Hence, studies are needed to identify the best ways to reduce suffering of research animals and thereby optimize the clinically relevant rodent models of sepsis.

The Effects of Fentanyl on Hepatic Mitochondrial Function.

BACKGROUND: Remifentanil interferes with hepatic mitochondrial function. The aim of the present study was to evaluate whether hepatic mitochondrial function is affected by fentanyl, a more widely used opioid than remifentanil. METHODS: Human hepatoma HepG2 cells were exposed to fentanyl or pretreated with naloxone (an opioid receptor antagonist) or 5-hydroxydecanoate (5-HD, an inhibitor of mitochondrial adenosine triphosphate (ATP)-sensitive potassium [mitoKATP] channels), followed by incubation with fentanyl. Mitochondrial function and metabolism were then analyzed. RESULTS: Fentanyl marginally reduced maximal mitochondrial complex-specific respiration rates using exogenous substrates (decrease in medians: 11%-18%; P = 0.003-0.001) but did not affect basal cellular respiration rates (P = 0.834). The effect on stimulated respiration was prevented by preincubation with naloxone or 5-HD. Fentanyl reduced cellular ATP content in a dose-dependent manner (P < 0.001), an effect that was not significantly prevented by 5-HD and not explained by increased total ATPase concentration. However, in vitro ATPase activity of recombinant human permeability glycoprotein (an ATP-dependent drug efflux transporter) was significantly stimulated by fentanyl (P = 0.004). CONCLUSIONS: Our data suggest that fentanyl reduces stimulated mitochondrial respiration of cultured human hepatocytes by a mechanism that is blocked by a mitoKATP channel antagonist. Increased energy requirements for fentanyl efflux transport may offer an explanation for the substantial decrease in cellular ATP concentration.

Dose response of endotoxin on hepatocyte and muscle mitochondrial respiration in vitro.

INTRODUCTION: Results on mitochondrial dysfunction in sepsis are controversial. We aimed to assess effects of LPS at wide dose and time ranges on hepatocytes and isolated skeletal muscle mitochondria. METHODS: Human hepatocellular carcinoma cells (HepG2) were exposed to placebo or LPS (0.1, 1, and 10 µg/mL) for 4, 8, 16, and 24 hours and primary human hepatocytes to 1 µg/mL LPS or placebo (4, 8, and 16 hours). Mitochondria from porcine skeletal muscle samples were exposed to increasing doses of LPS (0.1-100 µg/mg) for 2 and 4 hours. Respiration rates of intact and permeabilized cells and isolated mitochondria were measured by high-resolution respirometry. RESULTS: In HepG2 cells, LPS reduced mitochondrial membrane potential and cellular ATP content but did not modify basal respiration. Stimulated complex II respiration was reduced time-dependently using 1 µg/mL LPS. In primary human hepatocytes, stimulated mitochondrial complex II respiration was reduced time-dependently using 1 µg/mL LPS. In isolated porcine skeletal muscle mitochondria, stimulated respiration decreased at high doses (50 and 100 µg/mL LPS). CONCLUSION: LPS reduced cellular ATP content of HepG2 cells, most likely as a result of the induced decrease in membrane potential. LPS decreased cellular and isolated mitochondrial respiration in a time-dependent, dose-dependent and complex-dependent manner.

Interference of angiotensin II and enalapril with hepatic blood flow regulation.

Acute reduction of portal vein blood flow (Qpv) increases hepatic arterial perfusion (Qha) [the hepatic arterial buffer response (HABR)]. Angiotensin II (AT-II) reduces Qpv, but its effect on HABR is not known. We explored interactions of AT-II and enalapril with hepatic blood flow regulation. Twenty healthy anesthetized pigs were randomized to receive AT-II (n = 8) from 5 to 61 ng/kg per min, enalapril (n = 8) from 3 to 24 µg/kg per h, or saline (n = 4). HABR was assessed by occluding portal vein and expressed as 1) ratio between changes in Qha and Qpv, 2) hepatic arterial conductance (Cha). AT-II infusion increased mean arterial blood pressure from 74 (66-77) mmHg to 116 (109-130) mmHg (median, IQR; P < 0.0001) and decreased cardiac output, Qpv, and renal artery flow (-24%, -28% and -45%, respectively). The fraction of cardiac output of Qha, carotid, and femoral flows increased. With enalapril, blood pressure decreased, whereas cardiac output was maintained with flow redistribution favoring hepatic and renal arteries. In AT-II group, dQha/dQpv increased from 0.06 (0.03, 0.17) to 0.24 (0.13, 0.31) (P = 0.002), but Cha during acute portal vein occlusion decreased from 4.3 (1.6, 6.6) to 2.9 (1.2, 3.7) ml/mmHg (P = 0.003). Both variables remained unchanged in the enalapril group and in controls. AT-II infusion reduces portal flow in parallel with cardiac output and induces a dose-dependent redistribution of flow, favoring brain, hepatic artery, and peripheral tissues at the expense of renal perfusion. During HABR, AT-II decreases Cha but increases Qha compensation, likely as result of increased hepatic arterial perfusion pressure. Enalapril had no effect on HABR.

Angiotensin II in septic shock: effects on tissue perfusion, organ function, and mitochondrial respiration in a porcine model of fecal peritonitis.

OBJECTIVES: To compare effects of norepinephrine and angiotensin II in experimental sepsis on hemodynamics, organ function, and mitochondrial respiration. DESIGN: Randomized, controlled, study. SETTING: University experimental laboratory. SUBJECTS: Twenty-eight anesthetized, mechanically ventilated pigs. INTERVENTIONS: Sixteen pigs were randomized to receive after 12 hours of fecal peritonitis fluid resuscitation and either norepinephrine (group NE; n = 8) or angiotensin II (group AT-II; n = 8) for 48 hours. A separate group (n = 8), treated with enalapril for 1 week before peritonitis and until study end, received fluids and norepinephrine (group E). The blood pressure dose-response to angiotensin II was evaluated in additional four nonseptic pigs. MEASUREMENTS AND MAIN RESULTS: Blood pressure target (75-85 mm Hg) was reached in both NE and AT-II, and cardiac output increased similarly (NE: from 64 mL/kg/min [60-79 mL/kg/min] to 139 mL/kg/min [126-157 mL/kg/min]; AT-II from 79 mL/kg/min [65-86 mL/kg/min] to 145 mL/kg/min [126-147 mL/kg/min]; median, interquartile range). Renal plasma flow, prevalence of acute kidney injury, inflammation and coagulation patterns, and mitochondrial respiration did not differ between NE and AT-II. In group E, blood pressure targets were not achieved (mean arterial pressure at study end: NE: 81 mm Hg [76-85 mm Hg]; AT-II: 80 mm Hg [77-84 mm Hg]; E: 53 mm Hg [49-66 mm Hg], p = 0.002, compared to NE), whereas skeletal muscle adenosine triphosphate concentrations were increased. During resuscitation one animal died in groups AT-II and E. CONCLUSIONS: Angiotensin II reversed sepsis-induced hypotension with systemic and regional hemodynamic effects similar to those of norepinephrine. Inhibition of angiotensin-converting enzyme before sepsis worsened the hypotension but enhanced skeletal muscle adenosine triphosphate. Modifying the renin-angiotensin system in sepsis should be further evaluated.

Riding the Escalator: How Dangerous is it Really?

INTRODUCTION: About 10,000 escalator-related injuries per year result in emergency department treatment in the United States. Since the 1990s, a steady increase has been reported, but few statistics on escalator-related injuries have been published worldwide. We have therefore analyzed escalator accident statistics in admissions to our hospital in Switzerland since 2000. METHODS: Using retrospective electronic patient chart analysis, we included in our study patients >16 years treated over an 11-year period. We categorized patients in terms of gender, age and associated risk factors, and classified accidents according to day, time, location and cause. Resulting trauma was categorized according to type and location. We divided post-admission treatment into surgical and conservative, and into treatment as an outpatient, in a short-stay unit, or as a hospital admission. Women and men were compared using Fisher's exact test. RESULTS: We identified 173 patients with 285 discrete injuries. Of these, 87 patients (50%) were women. Fifty-three (61%) of the women and 38 (44%) of the men were >60 years old (P = 0.033). Fifty percent of the men (43/86) of the men, but only 7% (6/87) of the women showed signs of alcohol intoxication (P < 0.0001). Accidents in women occurred predominantly on Tuesdays (19/87; 22%) between 12pm and 6pm (35/87; 40%), and in men on Saturdays (16/86; 19%) between 6pm and 12am (29/86; 34%; P = 0.0097). Sixty-two percent (44/71) of the accidents were in public transport facilities and 30% (21/71) in shopping centers. The majority of injuries in women were to the lower extremities (49/87; 56%), while most accidents in men were to the head and neck (51/86; 59%; P = 0.0052). About half (90; 52%) of the patients were treated conservatively. Almost half of all patients (76, 44%) required hospital admission. Of those, 45% left the hospital within 24 hours of admission (short stay unit) and 55% stayed longer than 24 hours. CONCLUSION: Escalator accidents can result in severe trauma. Significant gender differences in escalator accidents have been observed. Alcohol intoxication and age are significant risk factors in escalator-related accidents and might be possible targets for preventive measures.

Mitochondrial function in sepsis.

BACKGROUND: The relevance of mitochondrial dysfunction as to pathogenesis of multiple organ dysfunction and failure in sepsis is controversial. This focused review evaluates the evidence for impaired mitochondrial function in sepsis. DESIGN: Review of original studies in experimental sepsis animal models and clinical studies on mitochondrial function in sepsis. In vitro studies solely on cells and tissues were excluded. PubMed was searched for articles published between 1964 and July 2012. RESULTS: Data from animal experiments (rodents and pigs) and from clinical studies of septic critically ill patients and human volunteers were included. A clear pattern of sepsis-related changes in mitochondrial function is missing in all species. The wide range of sepsis models, length of experiments, presence or absence of fluid resuscitation and methods to measure mitochondrial function may contribute to the contradictory findings. A consistent finding was the high variability of mitochondrial function also in control conditions and between organs. CONCLUSION: Mitochondrial function in sepsis is highly variable, organ specific and changes over the course of sepsis. Patients who will die from sepsis may be more affected than survivors. Nevertheless, the current data from mostly young and otherwise healthy animals does not support the view that mitochondrial dysfunction is the general denominator for multiple organ failure in severe sepsis and septic shock. Whether this is true if underlying comorbidities are present, especially in older patients, should be addressed in further studies.

782 consecutive construction work accidents: who is at risk? A 10-year analysis from a Swiss university hospital trauma unit.

BACKGROUND: Mortality and morbidity are particularly high in the building industry. The annual rate of non-fatal occupational accidents in Switzerland is 1,133 per 100,000 inhabitants. METHODS: Retrospective analysis of the electronic database of a university emergency centre. Between 2001 and 2011, 782 occupational accidents to construction workers were recorded and analysed using specific demographic and medical keywords. RESULTS: Most patients were aged 30-39 (30.4%). 66.4% of the injured workers were foreigners. This is almost twice as high as the overall proportion of foreigners in Switzerland or in the Swiss labour market. 16% of the Swiss construction workers and 8% of the foreign construction workers suffered a severe injury with ISS >15. There was a trend for workers aged 60 and above to suffer an accident with a high ISS (p = 0.089). CONCLUSIONS: As in other European countries, most patients were in their thirties. Older construction workers suffered fewer injuries, although these tended to be more severe. The injuries were evenly distributed through the working days of the week. A special effort should be made that current health and safety measures are understood and applied by foreign and older construction workers.

The Rapid TEG α-Angle may be a sensitive predictor of transfusion in moderately injured blunt trauma patients.

BACKGROUND: To guide the administration of blood products, coagulation screening of trauma patients should be fast and accurate. The purpose of this study was to identify the correlation between CCT and TEG in trauma, to determine which CCT or TEG parameter is most sensitive in predicting transfusion in trauma, and to define TEG cut-off points for trauma care. METHODS: A six-month, prospective observational study of 76 adult patients with suspected multiple injuries was conducted at a Level 1 trauma centre of a university hospital. Physicians blinded to TEG results made the decision to transfuse based on clinical evaluation. RESULTS: The study results showed that conventional coagulation tests correlate moderately with Rapid TEG parameters (R: 0.44-0.61). Kaolin and Rapid TEG were more sensitive than CCTs, and the Rapid TEG α-Angle was identified as the single parameter with the greatest sensitivity (84%) and validity (77%) at a cut-off of 74.7 degrees. When the Rapid TEG α-Angle was combined with heart rate >75 bpm, or haematocrit < 41%, sensitivity (84%, 88%) and specificity (75%, 73%) were improved. CONCLUSION: Cutoff points for transfusion can be determined with the Rapid TEG α-Angle and can provide better sensitivity than CCTs, but a larger study population is needed to reproduce this finding.

H1N1 outbreak in a Swiss military boot camp--observations and suggestions.

QUESTIONS UNDER STUDY: The A(H1N1)pdm09 influenza virus is a highly contagious pathogen which caused the 2009 influenza pandemic. The virus is known to affect mainly younger people and may be a problem in crowded living conditions. The aim of the study was to describe a major A(H1N1)pdm09 outbreak in a Swiss military boot camp and to develop suggestions for similar future situations. METHODS: Retrospective chart analysis of a A(H1N1)pdm09 outbreak between 14 December and 23 December 2010. Symptoms, signs and lab parameters were documented. RESULTS: 105 of 750 male recruits were affected by the outbreak. All nasopharyngeal swabs of 16 patients with high fever were tested positive. Common clinical symptoms included high fever, myalgia and bronchitis with persistent cough and throat aches. Fever progression typically occurred in two peaks within three days. Median length of stay at the infirmary was 3 days (range: 0.5-9 days). CONCLUSION: A(H1N1)pdm09 has become a ubiquitous seasonal virus in the region. Complications were uncommon and non life threatening. In the event of new influenza outbreaks, hygienic and containment measures must be quickly and correctly implemented, in order to avoid an epidemic. This should also be considered in non-military settings like school camps or in retirement homes.