Microbiological pattern of arterial catheters in the intensive care unit

Background  

Intravascular catheter related infection (CRI) is one of the most serious nosocomial infections. Diagnostic criteria include a positive culture from the catheter tip along with blood, yet in many patients with signs of infection, current culture techniques fail to identify pathogens on catheter segments. We hypothesised that a molecular examination of the bacterial community on short term arterial catheters (ACs) would improve our understanding of the variety of organisms that are present in this niche environment and would help develop new methods for the diagnosis of CRI.     

Hypothermia in a surgical intensive care unit

Background

Inadvertent hypothermia is not uncommon in the immediate postoperative period and it is associated with impairment and abnormalities in various organs and systems that can lead to adverse outcomes. The aim of this study was to estimate the prevalence, the predictive factors and outcome of core hypothermia on admission to a surgical ICU.

Methods

All consecutive 185 adult patients who underwent scheduled or emergency noncardiac surgery admitted to a surgical ICU between April and July 2004 were admitted to the study. Tympanic membrane core temperature (Tc) was measured before surgery, on arrival at ICU and every two hours until 6 hours after admission. The following variables were also recorded: age, sex, body weight and height, ASA physical status, type of surgery, magnitude of surgical procedure, anesthesia technique, amount of intravenous fluids administered during anesthesia, use of temperature monitoring and warming techniques, duration of the anesthesia, ICU length of stay, hospital length of stay and SAPS II score. Patients were classified as either hypothermic (Tc ≤ 35°C) or normothermic (Tc> 35°C). Univariate analysis and multiple regression binary logistic with an odds ratio (OR) and its 95% Confidence Interval (95%CI) were used to compare the two groups of patients and assess the relationship between each clinical predictor and hypothermia. Outcome measured as ICU length of stay and mortality was also assessed.

Results

Prevalence of hypothermia on ICU admission was 57.8%. In univariate analysis temperature monitoring, use of warming techniques and higher previous body temperature were significant protective factors against core hypothermia. In this analysis independent predictors of hypothermia on admission to ICU were: magnitude of surgery, use of general anesthesia or combined epidural and general anesthesia, total intravenous crystalloids administrated and total packed erythrocytes administrated, anesthesia longer than 3 hours and SAPS II scores. In multiple logistic regression analysis significant predictors of hypothermia on admission to the ICU were magnitude of surgery (OR 3.9, 95% CI, 1.4–10.6, p = 0.008 for major surgery; OR 3.6, 95% CI, 1.5–9.0, p = 0.005 for medium surgery), intravenous administration of crystalloids (in litres) (OR 1.4, 95% CI, 1.1–1.7, p = 0.012) and SAPS score (OR 1.0, 95% CI 1.0–1.7, p = 0.014); higher previous temperature in ward was a significant protective factor (OR 0.3, 95% CI 0.1–0.7, p = 0.003). Hypothermia was neither a risk factor for hospital mortality nor a predictive factor for staying longer in ICU.

Conclusion

The prevalence of patient hypothermia on ICU arrival was high. Hypothermia at time of admission to the ICU was not an independent factor for mortality or for staying longer in ICU.     

Prophylaxis for Candida in the intensive care unit patient

Candidemia is one of the most frequent causes of bloodstream infections in intensive care units in the United States and the developed world. It involves a substantial morbidity, crude/attributable mortality, and increased health care costs in excess of an average of $40,000 per episode. Prophylaxis is one of many strategies to control this disease; however, the success of this strategy is directly related to the selection of populations at highest risk and the availability of safe, effective, and economical drugs. Current risk assessment strategies based on clinical prediction rules offer the possibility of targeted prophylaxis, making this approach even more attractive.     

Muscle glutamine depletion in the intensive care unit

Glutamine is primarily synthesized in skeletal muscle and enables transfer of nitrogen to splanchnic tissues, kidneys and immune system. Discrepancy between increasing rates of glutamine utilization at whole body level and relative impairment of de novo synthesis in skeletal muscle leads to systemic glutamine deficiency and characterizes critical illness. Glutamine depletion at whole body level may contribute to gut, liver and immune system disfunctions, whereas its intramuscular deficiency may directly contribute to lean body mass loss. Severe intramuscular glutamine depletion also develops because of outward transport system upregulation, which is not counteracted by increased de novo synthesis. The negative impact of systemic glutamine depletion on critically ill patients is suggested both by the association between a lower plasma glutamine concentration and poor outcome and by a clear clinical benefit after glutamine supplementation. Enteral glutamine administration preferentially increases glutamine disposal in splanchnic tissues, whereas parenteral supplementation provides glutamine to the whole organism. Nonetheless, systemic administration was ineffective in preventing muscle depletion, due to a relative inability of skeletal muscle to seize glutamine from the bloodstream. Intramuscular glutamine depletion could be potentially counteracted by promoting de novo glutamine synthesis with pharmacological or nutritional interventions.     

Nosocomial infections in the pediatric intensive care unit

Nosocomial (hospital-acquired) infections are a major complication of serious illnesses. Severely ill patients have a greater risk of acquiring nosocomial infections, so this problem is greatest in intensive care units. Studies have demonstrated that nosocomial infections are largely preventable. Adherence to recommended techniques for patient care will have the greatest benefit in the intensive care unit. In this paper the background epidemiology of nosocomial infections is reviewed and related to pediatrics and intensive care units. Types of diseases, assistance equipment, and monitoring devices which are associated with a high risk of nosocomial infections are emphasized and specific steps for lowering this risk are listed.     

外科重症治疗病房中侵袭性真菌感染及耐药性分析

近年来,医院内侵袭性真菌感染（invasive fungal infection,IFI）的发生率明显增加,尤多见于免疫功能低下的患者（例如：血液恶性肿瘤、器官移植术后、ICU危重患者等）。不同疾病患者发生的侵袭性真菌感染各有其特点,外科重症治疗病房（surgical intensive care unit,SICU）中,患者多具有高龄、手术史、合并多种基础疾病或免疫功能低下等情况,真菌感染的发生率较普通病房更高^[1],病死率可高达38％-68％^[2],仅次于血液系统肿瘤患者^[3]。     

Sleep in the surgical intensive care unit: continuous polygraphic recording of sleep in nine patients receiving postoperative care.

Sleep was studied in nine patients for two to four days after major non-cardiac surgery by continuous polygraphic recording of electroencephalogram, electrooculogram, and electromyogram. Presumed optimal conditions for sleep were provided by a concerted effort by staff to offer constant pain relief and reduce environmental disturbance to a minimum. All patients were severely deprived of sleep compared with normal. The mean cumulative sleep time (stage 1 excluded) for the first two nights, daytime sleep included, was less than two hours a night. Stages 3 and 4 and rapid eye movement sleep were severely or completely suppressed. The sustained wakefulness could be attributed to pain and environmental disturbance to only minor degree. Sleep time as estimated by nursing staff was often grossly misjudged and consistently overestimated when compared with the parallel polygraphic recording. The grossly abnormal sleep pattern observed in these patients may suggest some fundamental disarrangement of the sleep-wake regulating mechanism.     

Red blood cell T-activation and hemolysis in surgical intensive care patients with severe infections

The exposure of Thomsen-Friedenreich (T) antigens on RBCs, serum neuraminidase, and serum hemoglobin levels were investigated in 53 adult surgical intensive care unit (ICU) patients with septicemia. Unmasked T-antigens were assayed by a hemagglutination test using peanut agglutinin (PNA) (direct anti-T test), and by an indirect anti-T test employing rabbit anti-PNA globulin. RBC T-activation was demonstrated in 17/53 patients (32%); in 2/53 patients (4%) the direct anti-T test was positive, indicating strong T-exposure. No polyagglutination phenomena were observed. Serum neuraminidase was elevated in 12/17 (71%) patients with T-activation and in 7/36 (19%) patients without T-activation. Free serum hemoglobin was elevated in 12/17 (71%) patients with T-activation and in 5/36 (14%) patients without T-activation. Correlations between T-activation and serum neuraminidase and between T-activation and serum hemoglobin were significant (p less than 0.001). Potentially neuraminidase-releasing bacteria were demonstrated in 13/17 (76%) patients with RBC T-exposure. We conclude that neuraminidase-induced RBC T-activation and subsequent hemolysis may be involved in the pathomechanism of hemolytic anemia in patients with severe infections.     

Radiologic assessment in the pediatric intensive care unit.

The severely ill infant or child who requires admission to a pediatric intensive care unit (PICU) often presents with a complex set of problems necessitating multiple and frequent management decisions. Diagnostic imaging plays an important role, not only in the initial assessment of the patient''s condition and establishing a diagnosis, but also in monitoring the patient''s progress and the effects of interventional therapeutic measures. Bedside studies obtained using portable equipment are often limited but can provide much useful information when a careful and detailed approach is utilized in producing the radiograph and interpreting the examination. This article reviews some of the basic principles of radiographic interpretation and details some of the diagnostic points which, when promptly recognized, can lead to a better understanding of the patient''s condition and thus to improved patient care and management. While chest radiography is stressed, studies of other regions including the upper airway, abdomen, skull, and extremities are discussed. A brief consideration of the expanding role of new modality imaging (i.e., ultrasound, CT) is also included. Multiple illustrative examples of common and uncommon problems are shown.     

Respiratory nosocomial infections in the medical intensive care unit

Intensive care unit (ICU)-acquired lower respiratory tract infections include acute tracheobronchitis and hospital-acquired and ventilator-associated pneumonia (VAP). Nosocomial pneumonia is the second most common hospital-acquired infection and the leading cause of death in hospital-acquired infections. The mortality rate in VAP ranges from 24% to 76% in several studies. ICU ventilated patients with VAP have a 2- to 10-fold higher risk of death than patients without it. Early oropharyngeal colonization is pivotal in the etiopathogenesis of VAP. The knowledge of risk factors for VAP is important in developing effective preventive programs. Once the physician decides to treat a suspected episode of ICU-acquired pneumonia, some issues should be kept on mind: first, the adequacy of the initial empiric antibiotic therapy; second, the modification of initial inadequate therapy according to microbiological results; third, the benefit of combination therapy; and finally, the duration of the antimicrobial treatment. Additionally, a protocolized work-up to identify the causes of non-response to treatment is mandatory. All these issues are discussed in depth in this article.