Ionized or Total Magnesium levels, what should we measure in critical ill patients?

Monitoring and measuring magnesium (Mg) values are essential to prevent the development of numerous complications in perioperative medicine and critically ill patients. Although previous studies suggest that measuring free ionized magnesium (iMg) is more useful for estimating Mg status, clinicians currently rely on measurement of total serum magnesium to determine if supplemental magnesium is needed. In this review, we analyzed the recent literature to decide whether it is better to measure ionized serum Mg or total serum Mg when assessing magnesium status, whether iMg predicts clinical outcome, and what are the difficulties in measuring serum iMg levels in intensive care patients and perioperative medicine.

Effect Of α2-Adrenergic Agonists And Antagonists On Cytokine Release From Human Lung Macrophages Cultured In Vitro

The most trusted hypothesis to explain how α2-adrenergic agonists may preserve pulmonary functions in critically ill patients is that they directly act on macrophages by interfering with an autocrine/paracrine adrenergic system that controls cytokine release through locally synthetized noradrenaline and α1- and α2-adrenoreceptors. We tested this hypothesis in primary cultures of resident macrophages from human lung (HLMs). HLMs were isolated by centrifugation on percoll gradients from macroscopically healthy human lung tissue obtained from four different patients at the time of lung resection for cancer. HLMs from these patients showed a significant expression of α2A, α2B and α2C adrenoreceptors both at the mRNA and at the protein level. To evaluate whether α2 adrenoreceptors controlled cytokine release from HMLs, we measured IL-6, IL-8 and TNF-α concentrations in the culture medium in basal conditions and after preincubation with several α2-adrenergic agonists or antagonists. Neither the pretreatment with the α2-adrenergic agonists clonidine, medetomidine or dexdemetomidine or with the α2-adrenergic antagonist yohimbine caused significant changes in the response of any of these cytokines to LPS. These results show that, different from what reported in rodents, clonidine and dexdemetomidine do not directly suppress cytokine release from human pulmonary macrophages. This suggests that alternative mechanisms such as effects on immune cells activation or the modulation of autonomic neurotransmission could be responsible for the beneficial effects of these drugs on lung function in critical patients.

Navigator® and SmartPilot® View are helpful in guiding anesthesia and reducing anesthetic drug dosing

BACKGROUND

The recently introduced Navigator® (GE Healthcare, Helsinki, Finland) and SmartPilot® View (Dräger Medical, Lübeck, Germany) show the concentrations and predicted effects of combined anesthetic drugs, and should facilitate more precisely their titration. Our aim was to evaluate if Navigator® or SmartPilot® View guided anesthesia was associated with a good quality of analgesia, depth of hypnosis and may reduce anesthetic requirements.

METHODS

We performed a prospective non-randomized study. Sixty ASA I-II patients undergoing balanced general anesthesia for abdominal and plastic surgery were enrolled. Patients were divided in 4 groups. Group 1 (N. 15) and group 3 (N. 15) were cases in whom anesthesia was performed with standard monitoring plus the aid of Navigator® (Nav) or SmartPilot® View (SPV) display. Group 2 (N. 15) and group 4 (N. 15) were controls in whom anesthesia was performed with standard monitoring (heart rate, NIBP, SpO2, end-tidal CO2, end-expired sevoflurane concentration, train of four, Bispectral Index [Aspect Medical Systems, Natick, MA, USA] or Entropy [GE Healthcare]). Patients' vital parameters and end-expired sevoflurane concentration were recorded during anesthesia.

RESULTS

All patients recovered uneventfully and showed hemodynamic stability. End-tidal sevoflurane concentrations values [median (min-max)], during maintenance of anesthesia, were significantly (P<0.05) lower in SPV [1.1% (0.8-1.5)] and Nav [1%(0.8-1.8)] groups compared to SPV-control group [1.5%(1-2.5)] and Nav-control group [1.5%(0.8-2)]. BIS and entropy values were respectively higher in the SPV group [53 (46-57)] compared to the control group [43 (37-51)] (P<0.05) and Nav group [53 (43-60)] compared to the control group [41 (35-51)] (P<0.05). No significant differences in Remifentanil dosing were observed in the four groups.

CONCLUSION

Navigator® and SmartPilot® View may be of clinical use in monitoring adequacy of anesthesia. Both displays can optimize the administration and monitoring of anesthetic drugs during general anesthesia and may reduce the consumption of volatile anesthetic agents.

Coagulopathy induced by acidosis, hypothermia and hypocalcaemia in severe bleeding

Acidosis, hypothermia and hypocalcaemia are determinants for morbidity and mortality during massive hemorrhages. However, precise pathological mechanisms of these environmental factors and their potential additive or synergistic anticoagulant and/or antiplatelet effects are not fully elucidated and are at least in part controversial. Best available evidences from experimental trials indicate that acidosis and hypothermia progressively impair platelet aggregability and clot formation. Considering the cell-based model of coagulation physiology, hypothermia predominantly prolongs the initiation phase, while acidosis prolongs the propagation phase of thrombin generation. Acidosis increases fibrinogen breakdown while hypothermia impairs its synthesis. Acidosis and hypothermia have additive effects. The effect of hypocalcaemia on coagulopathy is less investigated but it appears that below the cut-off of 0.9 mmol/L, several enzymatic steps in the plasmatic coagulation system are blocked while above that cut-off effects remain without clinical sequalae. The impact of environmental factor on hemostasis is underestimated in clinical practice due to our current practice of using routine coagulation laboratory tests such as partial thromboplastin time or prothrombin time, which are performed at standardized test temperature, after pH correction, and upon recalcification. Temperature-adjustments are feasible in viscoelastic point-of-care tests such as thrombelastography and thromboelastometry which may permit quantification of hypothermia-induced coagulopathy. Rewarming hypothermic bleeding patients is highly recommended because it improves patient outcome. Despite the absence of high-quality evidence, calcium supplementation is clinical routine in bleeding management. Buffer administration may not reverse acidosis-induced coagulopathy but may be essential for the efficacy of coagulation factor concentrates such as recombinant activated factor VII.

S100B induces the release of pro-inflammatory cytokines in alveolar type I-like cells

S100B, a 21kDa cytosolic calcium-binding protein of the EF-hand type, present in high abundance in the brain, stimulates inflammatory responses in different cellular types inside and outside the central nervous system. Most of extracellular S100B effects are mediated by Receptor for Advanced Glycation End-products (RAGE). RAGE is highly expressed in lung by Alveolar Type-I (AT-I) cells and its activation contributes to ALI/ARDS pathogenesis. In this in-vitro study, we tested the hypothesis that S100B stimulates an ATI-derived cell line (R3/1) to secrete inflammatory mediators involved in lung inflammation. Our main result is that S100B stimulates R3/1 cells to secrete TNF-alpha and IL-6 (well-known pro-inflammatory cytokines in lung inflammation and neurogenic pulmonary edema), but not sICAM-1, CINC-1 or CINC-3. Soluble RAGE (sRAGE) reduced S100B-dependent secretion of TNF-alpha but did not decrease S100B-dependent secretion of IL-6. Moreover, in absence of S100B, sRAGE enhanced IL-6 release. This study demonstrates that in vitro S100B dose-dependently stimulated R3/1 cells, to enhance the secretion of TNF-alpha and IL-6; S100B pro-inflammatory activity might be mediated at least in part by RAGE. Besides acting as decoy receptor, sRAGE could have pro-inflammatory properties.

Biofilm-dependent airway infections: a role for ambroxol?

Biofilms are a key factor in the development of both acute and chronic airway infections. Their relevance is well established in ventilator associated pneumonia, one of the most severe complications in critically ill patients, and in cystic fibrosis, the most common lethal genetic disease in Caucasians. Accumulating evidence suggests that biofilms could have also a role in chronic obstructive pulmonary disease and their involvement in bronchiectasis has been proposed as well. When they grow in biofilms, microorganisms become multidrug-resistant. Therefore the treatment of biofilm-dependent airway infections is problematic. Indeed, it still largely based on measures aiming to prevent the formation of biofilms or remove them once that they are formed. Here we review recent evidence suggesting that the mucokinetic drug ambroxol has specific anti-biofilm properties. We also discuss how additional pharmacological properties of this drug could be beneficial in biofilm-dependent airway infections. Specifically, we review the evidence showing that: 1-ambroxol exerts anti-inflammatory effects by inhibiting at multiple levels the activity of neutrophils, and 2-it improves mucociliary clearance by interfering with the activity of airway epithelium ion channels and transporters including sodium/bicarbonate and sodium/potassium/chloride cotransporters, cystic fibrosis transmembrane conductance regulator and aquaporins. As a whole, the data that we review here suggest that ambroxol could be helpful in biofilm-dependent airway infections. However, considering the limited clinical evidence available up to date, further clinical studies are required to support the use of ambroxol in these diseases.

Perioperative anaphylactic risk score for risk-oriented premedication

Basing on the current knowledge, this paper is aimed to review the core characteristics of the most relevant therapeutic agents (steroids and antihistamines), administered to prevent perioperative anaphylaxis. Moreover, the Authors propose the validation of a Global Anaphylactic Risk Score, built up by recording the individual scores related to the most relevant anaphylaxis parameters (i.e. medical history, symptoms and medication for asthma, rhinitis and urticaria etc) and by adding them on all together; the score could be used in the preoperative phase to evaluate the global anaphylactic risk and to prescribe risk-oriented premedication protocols.

Vasopressin vs Terlipressin in Treatment of Refractory Shock

Arginine vasopressin (AVP) and its synthetic, long-acting analog terlipressin (TP) are potent alternative vasoconstrictors in the treatment of septic patients with catecholamine-refractive vasodilatatory shock. Recent clinical data suggest that early administration of AVP analogues may be advantageous compared to a last resort therapy. However, it is still unknown whether vasopressin and terlipressin are equally effective for hemodynamic support in shock. Despite important pharmacological differences between the two drugs the use of either substance is determined mainly by local availability and institutional inventory. The current literature suggests that neither AVP nor TP should be administered in high doses in shock. Furthermore, increasing evidence indicates that early administration of terlipressin may improve outcome as compared to a last-resort treatment. Low-dose infusion of AVP has been demonstrated to be a safe adjunct in the management of refractory shock. Evidence from experimental studies and initial clinical reports suggests that continuous low-dose infusion of TP may stabilize hemodynamics in shock. In this review we briefly described differences in pharmacokinetics and pharmacodynamics between AVP and Terlipressin (TP) in treatment of refractory shock.

Minimally invasive Swine experimental model for the in vivo study of liver metabolism of drugs

PURPOSE

To develop a clinically relevant porcine model for the study of hepatic metabolism of drugs by means of hepatic vein catheterization.

MATERIALS AND METHODS

review of literature and elaboration of a hypothesis, design of an experimental method.

RESULTS

recent clinical studies were conducted by withdrawing cirrhotic patients' blood from right hepatic vein during hepatic vein pressure gradient measurements. Basing on our personal clinical experience and evaluation of research needs, an experimental model is proposed.

CONCLUSIONS

contemporary measurement of peripheral and hepatic concentration of drugs by peripheral vein and hepatic vein catheterization can be used to create a reliable and reproducible porcine model to study liver metabolism of drugs in vivo.

Toll-like receptor kinetics in septic shock patients: a preliminary study

The aim of this study is to evaluate some inflammatory parameter changes in septic shock patients and their possible correlation with clinical outcome, in particular when continuous veno-venous hemofiltration (CVVH) treatment is required. Considering the objective difficulty in enrolling this kind of patient, a preliminary study was initiated on seventeen septic shock patients admitted to a medical and surgical ICU. The mRNA expression of Toll-like receptor (TLR)-1, TLR-2, TLR-4, TLR-5, TLR-9, TNFα, IL-8 and IL-1β was assessed, the plasmatic concentrations of IL-18, IL-2, IL-10 and TNFα were measured on the day of sepsis diagnosis and after 72 h. In those patients who developed acute renal failure unresponsive to medical treatment and who underwent CVVH treatment the same parameters were measured every 24 h during CVVH and after completion of the treatment. On sepsis diagnosis, gene expression of TLRs was up-regulated compared to the housekeeping gene in all the patients. After 72 h, in 35% of the patients a down-regulation of these genes was found compared to day 1, but it was not associated with a reduction of cytokine serum levels or improved clinical signs, better outcome or reduced mortality. After high volume hemofiltration treatment, cytokine serum levels and TLR expression were not significantly modified. In conclusion, considering the not numerous number of cases, from our preliminary study, we cannot certainly correlate TLR over-expression in septic shock patients with severity or outcome scores.

Neurogenic pulmonary edema in subarachnoid hemorrage

Aneurysmal subarachnoid hemorrhage (SAH), in addition to the direct effects of the initial hemorrhage and secondary neurological complications, predisposes to medical complications. The proportion of deaths caused by non-neurological medical complications (cardiac, pulmonary, gastrointestinal, renal, hematological) equals that from neurological complications. In particular, pulmonary complications are responsible for 50% of all deaths from medical complications. Neurogenic pulmonary edema (NPE) is an increase of interstitial and alveolar fluid occurring as direct consequence of any acute central nervous system injury. Two different pathogenetic mechanisms of NPE have been hypothesized: i) hemodynamic (an increase of pulmonary vascular pressure due to an α-adrenergic response produces hydrostatic edema) and ii) inflammatory mechanism (brain cytokines and chemokines determinates an increase in the permeability of pulmonary capillaries causing exudative edema). Recent studies postulate that both mechanisms may be implicated in the pathogenesis of NPE. Brain injury is known to determine increased levels of S100B, a Ca- binding protein, in cerebrospinal fluid and in blood. Moreover, amine precursor uptake and decarboxylation (APUD) cells located in the respiratory tract produce and release S100B. This protein may contribute to the pathogenesis of NPE binding RAGE receptors in alveolar epithelial type I pneumocytes and amplifying the immune and inflammatory response causing lung injury. S100B can be the link between the brain and the lung and may be among the multiple pathological pathways that determine the development of pulmonary edema after bleeding.

Different patterns of lung recruitment maneuvers in primary acute respiratory distress syndrome: effects on oxygenation and central hemodynamics

BACKGROUND

The aim of this study was to test if different recruitment maneuver (RM) patterns, that achieve the same maximum pressure for the same length of time in humans, have a similar efficacy on alveolar recruitment, intrathoracic vascular pressures and flows, and on cardiac function and ventricular filling.

METHODS

Forty patients were randomly allocated to undergo different RM patterns: sustained inflation (SI) or pressure controlled ventilation (PCV). The RM methods tested are as follows: SI was achieved by raising peak inspiratory pressure to 45 cmH(2)O and sustaining it for 40 seconds. The PCV was set to obtain a 45 cmH(2)O peak inspiratory pressure for 2 minutes, I:E 1:2, PEEP 16 RR 8/min. During the study period, patients were mechanically ventilated to obtain a volume of 6 mL/kg, FiO(2) 0.7, PEEP 14, RR 14, Pplateau < or =30 cmH(2)O according to the ARDSnet trial. All patients were sedated and paralyzed during the study period. All patients were given i.v. norepinephrine. Heart rate, pulse oxymetry, blood pressure, pulmonary artery catheter data (C.I., PVRI, MPAP, PAOP, SvO(2), CVP), and arterial and right heart side venous blood gas analysis data (ph, PaO(2), PaCO(2), SatO(2), HCO(3)(-), SvO(2)) were recorded before and immediately after the lung recruitment maneuver. The static compliance of the respiratory system (CRS) was recorded. Echocardiographic spot evaluations before and after RM were obtained in all cases.

RESULTS

Central venous pressure increased during RM. Mean pulmonary artery pressure, pulmonary capillary wedge pressure and pulmonary vascular resistance index were reduced during PCV RM compared to SI RM (P<0.05). The right ventricle stroke work index decreased to a major extent during PCV RM (P<0.05). The P/F ratio was significantly increased after PCV RM compared to SI RM (P<0.05). PaCO(2) levels were similar in the two groups. Compared to baseline, the Qs/Qt decreased significantly after the PCV recruitment maneuver. Ventricular end-diastolic and end-systolic areas decreased during both RM protocols, but they were decreased to a greater extent after SI RM than after PCV RM (P<0.05). The eccentricity index increased from baseline after the SI RM (P<0.05).

CONCLUSION

Given its comparable, or even superior, performance over the SI RM, we favor the PCV technique over the time-honored SI maneuver.

Do you think my ICU will benefit from an electronic medical record system?

In many Hospitals, Intensive Care Units (ICUs) are the most technologically advanced areas since the Intensive Care physicians deal with a massive quantity of data and information, because of the critical status of their patients each day. An electronic medical record (EMR) is a computer-base patient record optimized to support ambulatory settings and ward activities. An EMR may provide the physician with all the necessary information clearly gathered and stored and satisfy the need for more direct integration of the different information. Even if the installation of an EMR is a positive signal of modernity, it may represent a useless investment with minor effects on the clinical staff improvement and on the risk reduction, because of mayor failures in the installation planning, integration in the hospital system, personnel education. Definitions, advantages and limitation, implementation strategies and objectives of an ICU EMR system are reviewed.

The use of erythtropoietin in cerebral diseases

Global and focal cerebral ischemia is followed by a secondary damage characterized by oxidative stress, excitotoxicity, inflammation and apoptosis. Erythropoietin (EPO) exerts antiapoptotic, anti-inflammatory, antioxidative, angiogenetic and neurotrophic properties. Its potential therapeutic role has been demonstrated in several animal models of cerebral ischemia and also in a clinical trial of ischemic stroke, so it could be considered an ideal compound for neuroprotection in ischemic stroke and in cardiac arrest. Intracerebral hemorrhage (ICH) is the least treatable form of stroke; the mechanisms involved in the secondary brain injury include hematoma mass effect, neuronal apoptosis and necrosis, inflammation. It has been demonstrated in an experimental ICH that EPO intervenes in the inflammatory process, reduces brain water content, hemorrhage volume and hemispheric atrophy, promotes cell survival, preserves cerebral blood flow, has antiapoptotic protective function against oxidative stress and excitotoxic damage. EPO can attenuate acute vasoconstriction and prevent brain ischemic damage in subarachnoid hemorrhage. The neuroprotective function of EPO has been studied also in traumatic brain injury: it reduces the inflammation and improves cognitive and motor deficits. The authors review some of the physiological actions of EPO in the physiopathology of ischemic and hemorrhagic stroke, subarachnoid hemorrhage and brain trauma, and its potential usefulness in the brain injured patient management.

Typing of vancomycin-resistant Enterococcus faecium strains in a cohort of patients in an Italian intensive care Unit

BACKGROUND

Vancomycin-resistant enterococci (VRE) have become a major cause of nosocomial infections. The increase of vancomycin-resistant Enterococcus faecium (VR-Efm) in an intensive care unit (ICU) of an Italian university hospital from 2003 through 2004, led us to evaluate the phenotypic and genetic features of these strains. The prevalence of different bacterial species in this ICU is described. The antibiotic resistance profiles of VR-Efm strains, their van-genotype and pulsed-field gel electrophoresis (PFGE) profiles were also analyzed.

MATERIALS AND METHODS

From January 2003 to December 2004, VR-Efm strains were collected from several biological samples. Bacteria were identified using standard biochemical reactions and automated systems. Antibiotic susceptibility was evaluated by disk diffusion and microdilution methods. Resistance to glycopeptides was confirmed by the E test. Vancomycin-resistant genotypes (vanA, vanB) were identified by PCR. Strains were typed by PFGE.

RESULTS

Fifty E. faecium strains were isolated from a total of 700 patients. Of these, 26 were vancomycin-resistant and were isolated from 26 different patients. We also found one strain with resistance to linezolid. The vanA genotype was identified in 20/26 strains and vanB in the remaining strains. A major pulsed-field cluster ("A") was identified. In this cluster, 14 strains were identified (A1-A14) and 25 out of 26 VR-Efm belonged to it. Only one strain showed a different pattern (strain type "B"). All isolates with the vanA genotype belonged to cluster "A", therefore five out of six isolates with the vanB genotype belonged to cluster A. The only strain with type B pattern was the vanB genotype.

CONCLUSIONS

Isolation of VR-Efm was very frequent (52%) in our cohort of patients and the vanA genotype was the most frequent (77%). We found 25 out of 26 VR-E. faecium strains to be epidemiologically related by PFGE (cluster A). Strains with distinct genotypes shared closely related PFGE profiles. The occurrence of one major cluster among patients of a single unit indicated intra-facility VRE transmission.

Prognosis of isolated acute post-traumatic subdural haematoma

AIM

Acute subdural haematoma (ASDH) is seldom an isolated lesion and it is difficult to understand the mechanisms which determine the poor prognosis associated to this occurrence. Aim of this study was estimating the outcome of patients with ASDH without any companion lesions by analysing the haematoma volume, its thickness and midline shift.

METHODS

Twenty-eight severely head injured patients (Glasgow Coma Scale, GCS =/<8) with isolated unilateral ASDH admitted in intensive care unit (ICU) were retrospectively studied. The haematoma thickness, the midline shift, the ASDH volume were obtained from the first emergency computerized tomography (CT) scan and analysed by a computer assisted programme (Osiris). Patients' outcome was scored according to the Glasgow Outcome Scale (GOS) 6 months after the event. According to their GOS the patients were further divided in 2 groups (favourable outcome: GOS 4-5, poor outcome: GOS 1-2-3).

RESULTS

Midline shift ranged from 0 to 19.2 mm; we found a larger midline shift in those patients who died and in patients with severe disability or vegetative state 6 months after the trauma.

CONCLUSION

The presence and size of midline shift was a more important determinant of outcome than ASDH volume or its thickness.

Intra-abdominal hypertension is not reliable as an early predictor of mortality in the intensive care unit

AIM

The aim of this study was to assess the prevalence of intra-abdominal hypertension and its prognostic value in critical patients.

METHODS

In an observational study, 56 patients of a multidisciplinary intensive care unit (ICU) of a university hospital, with either surgical (44.6%) or medical (55.4%) diagnoses, were studied. Intra-abdominal pressure was quantified daily by bladder pressure method from the first to the eighth day of hospitalization.

RESULTS

The mean intra-abdominal pressure at admission was 9.97+/-5.26 mmHg; 41% of patients suffered moderate intra-abdominal hypertension (defined as intra-abdominal pressure greater than 11 mmHg) at admission. On day 1 mean intra-abdominal pressure was not significantly different between the patients who died and those who survived (9.69+/-5.06 mmHg vs 10.12+/-5.57 mmHg respectively), but by measuring IAP until day 8 it was possible to distinguish a subgroup of patients who showed a persistently elevated intra-abdominal pressure, developed further complications, later died (12.5+/-4.37 mmHg vs 7.17+/-2.02 mmHg, P=0.022).

CONCLUSION

Intra-abdominal pressure does not have prognostic value at ICU admission, but may predict bad outcomes later during the ICU stay. Intra-abdominal hypertension is a frequent and rarely recognized event in the ICU which can be monitored by the bladder pressure method throughout the period of hospitalization.

Elevated S100B levels do not correlate with the severity of encephalopathy during sepsis

BACKGROUND

Sepsis-associated encephalopathy (SAE) is defined as a diffuse cerebral dysfunction induced by the systemic response to infection without any clinical or laboratory evidence of direct infectious involvement of the central nervous system. The astroglial protein S100B has been used as a marker of severity of brain injury and as a prognostic index in trauma patients and cardiac arrest survivors. We measured S100B serum levels in patients with severe sepsis to investigate if the severity of SAE correlated with an increase in S100B levels.

METHODS

Twenty-one patients, with a diagnosis of severe sepsis, were included in this study. S100B levels were measured at intensive care unit (ICU) admission, 72 h and 7 days after admission. Their association with markers of brain dysfunction such as Glasgow coma scale (GCS), and EEG, and with sepsis-related organ failure assessment score (SOFA) and ICU mortality was investigated.

RESULTS

Fourteen patients had elevated S100B levels. The levels did not correlate with GCS at admission, EEG pattern, or SOFA scores. Also, S100B levels did not differ between patients who recovered neurologically and those who did not (P = 0.62).

CONCLUSIONS

In severe sepsis, an increase in S100B does not allow the physicians to distinguish patients with severe impairment of consciousness from those with milder derangements or to prognosticate neurological recovery.

S100B is not a reliable prognostic index in paediatric TBI

BACKGROUND

As far as paediatric traumatic brain injury is concerned, it is difficult to quantify the extent of the primary insult, to monitor secondary changes and to predict neurological outcomes by means of the currently used diagnostic tools: physical examination, Glasgow Coma Scale (GCS) score and computed tomography. For this reason, several papers focused on the use of biochemical markers (S100B, neuron-specific enolase) to detect and define the severity of brain damage and predict outcome after traumatic head injury or cardiac arrest.

OBJECTIVE

The aim of this paper is measuring the range of S100B serum concentrations in children affected by traumatic brain injury and describing the possible roles of this protein in the reaction to trauma.

METHODS

Fifteen children aged 1-15 years were included in the study. Traumatic brain injury severity was defined by paediatric GCS score as mild (9 patients), moderate (2 patients) or severe (4 patients). Blood samples for S100B serum measurement were taken at emergency department admission and after 48 h.

RESULTS

The serum S100B concentration was higher in the group of severe trauma patients, who scored the lowest on the GCS at admission, and among them, the highest values were reported by the children with concomitant peripheral lesions.

CONCLUSIONS

The role of S100B in paediatric traumatic brain injury has not been clarified yet, and the interpretation of its increase when the head trauma is associated with other injuries needs the understanding of the physiopathological mechanisms that rule its release in the systemic circulation. The levels of S100B in serum after a brain injury could be related to the mechanical discharge from a destroyed blood-brain barrier, or they could be due to the active expression by the brain, as a part of its involvement in the systemic inflammatory reaction. Early increase of this protein is not a reliable prognostic index of neurological outcome after pediatric traumatic brain injury, since even very elevated values are compatible with a complete neurological recovery.

The effects of hydroxyethyl starch solution in critically ill patients

AIM

In the treatment of the critically ill patients an adequate fluid therapy appears to be essential to optimize hemodynamics and to get a suitable tissue perfusion. In this study we have evaluated the effects of volume replacement, carried out with 2 different solutions: hydroxyethyl starch 6% (HAES) and albumin 20% (HA).

METHODS

Twenty patients suffering from sepsis were recruited and randomized into 2 groups. The first group was treated with hydroxyethyl starch 6% ( HAES treated group), and the second with albumin 20% (HA treated group). The volume of colloids was given to maintain pulmonary capillary wedge pressure (PCWP) between 15 and 18 mmHg. Daily, both hemodynamic parameters and blood gas analyses were monitored.

RESULTS

Groups were homogeneous for age, sex and pathology. During the treatment we observed that cardiac index (CI), right ventricular ejection fraction (RVEF), oxygen consumption index (VO(2)I), oxygen delivery index (DO(2)I), and rate between arterial oxygen pressure and fraction of inspired oxygen (PaO(2)/FiO(2)) were increased significantly only in HAES treated group (P<0.05). APACHE II score decreased significantly only in HAES treated group (P<0.05), contrarily to the HA treated group, in which we observed a non significant increase.

CONCLUSIONS

Since hydroxyethyl starch induced a hemodynamic and clinical improvement, these effects translated into an improvement of sensorium and a reduction of APACHE II score, without causing pulmonary edema, we can conclude that hydroxyethyl starch 6% ws 130,000 dalton ms 0.4 (Voluven) is an effective fluid for resuscitation of hypovolemic patients and represent an attractive alternative to albumin.

Conscious analgosedation for radiofrequency ablation of lung neoplasm

AIM

Radiofrequency ablation (RFA) is a minimally invasive therapy for pulmonary malignant cancers in patients with medical co-morbidities or refusal of surgery. The aim of this study was to evaluate a conscious analgosedation protocol for RFA of lung neoplasm.

METHODS

Ten RFAs were performed. Following analgesic premedication patients underwent local anesthesia (lidocaine 2%) and propofol infusion.

RESULTS

The procedures were always uneventful. Postoperative severe pain was not reported; a deep sedation was required to allow the quick and safe management of RFA.

CONCLUSIONS

Spontaneous breathing sedation is safe in monitored and well-oxygenated patients and may limit the incidence of tension pneumothorax. Postoperative period needs a proper pain control for the first 24 h. Data on the long-term efficacy of lung tumor RFA are not yet available.

S100B is a sensitive but not specific prognostic index in comatose patients after cardiac arrest

AIM

The aim of this study was to compare serum S100B levels and EEG findings as prognostic indexes in comatose (GCS<8) patients after cardiac arrest.

METHODS

S100B serum levels were assessed 12 h after the event and EEG findings were recorded within 24 h in comatose cardiac arrest survivors. At hospital discharge, patients were divided into groups according the Glasgow-outcome scale (GOS): group 1 with bad neurological outcome and group 2 with good neurological outcome (GOS 4-5). S100B levels and EEG findings were retrospectively tested about their predictive value.

RESULTS

S100B has a very low specificity (37.5%) while S100B sensitivity is 100%. EEG findings specificity is 75% and sensitivity 50%. S100B was not significantly lower in patients who recovered consciousness (10 patients) and there was no significant difference in EEGs findings between group 1 and 2.

CONCLUSIONS

The association of serum S100B levels with EEG might be helpful when used together to formulate outcome in comatose patients within 24 h after cardiac arrest. However, increased levels of S100B 12 h after a cardiac arrest might be expression of a still amendable brain damage.

Incidence of antimicrobial-resistant ventilator associated pneumonia: an eighteen-month survey

AIM

Microbes commonly involved in ventilator associated pneumonia (VAP) are difficult to eradicate: Pseudomonas aeruginosa and Acinetobacter baumannii are often resistant to piperacillin, aztreonam and ceftazidim while Klebsiella pneumoniae and other Enterobacteriaceae are resistant to third generation cephalosporins. Physicians need to tailor their therapeutic approach depending on individual patients and clinical setting, firmly based on local epidemiology. The aim of this study was to assess the incidence of VAP caused by multidrug-resistant bacteria in our ICU.

METHODS

We conducted a retrospective review of all patients mechanically ventilated for longer than 72 h, who developed pneumonia over an eighteen-month period for whom final culture data were available. One-hundred and forty-three patients admitted to a University Hospital medical surgical ICU were included in this survey. VAP was diagnosed by Centers for Disease Control and Prevention criteria and confirmed by mini- bronchoalveolar lavage.

RESULTS

In this study, the incidence of VAP in the period January 1, 2002-June 31, 2003 was very high, accounting for about 20% of all at-risk cases. Multiresistant agents were involved in about 57% of VAP occurring within 7 days of mechanical ventilation, and in 80% of late VAP.

CONCLUSIONS

This study revealed differences in VAP incidence and features among our ICU and literature data, indicating a need for caution when using hospital infection surveillance data for comparisons and choice of therapy. In our setting, with high levels of antibiotic resistance, combined approaches of non-antibiotic using strategies and education programs might be beneficial.

Use of quinupristin/dalfopristin in a critical patient with a methicillin-resistant Staphilococcus aureus infection

The growing incidence of infections due to Gram-positive multiresistant germs has stimulated research into new drugs endowed with broader activity, that are useful in case of infections unresponsive to common antibiotics. The case of a 28-year-old man infected with a methicillin resistant Staphylococcus aureus non responder to therapy with glycopeptide antibiotics is reported. At admission the patient presented a septic condition and required mechanical ventilation. Antibiotic therapy was immediately started with teicoplanin+meropenem. Blood culture and bronchial aspirate evidenced a methicillin resistant Staphylococcus aureus with high sensibility to glycopeptide antibiotics. Although this therapy produced a slight improvement in clinical condition and the patient was extubated, fever and leucocytosis associated with a BAL positive to methicillin resistant Staphylococcus aureus, in vitro susceptible to glycopeptides, persisted. Considering the possibility of a non-responder condition of the patient to glycopeptide antibiotics, quinupristin/dalfopristin was added. The streptogramin produced a quick improvement in clinical condition with resolution of sepsis and culture sterilization. The patient improved progressively and was discharged. In conclusion, in our experience the association quinupristin/dalfopristin was effective in the resolution of a critical methicillin resistant Staphylococcus aureus infection non responder to classical treatment with glycopeptide antibiotics that showed a high sensibility in vitro.

Candidemia in Intensive Care patients. Risk factors and mortality

AIM

Aim of this study was to evaluate if the risk factors for candidemia could be used to identify patients who have a greater possibility of death after Candida spp blood infection.

METHODS

A retrospective observational comparative study.

SETTING

the Intensive Care Unit of an University Hospital.

PATIENTS

478 critical patients were included in this study. Neutropenic and immuno-suppressed patients were excluded.

INTERVENTIONS

routine care for acutely ill patients, with regard to their pathology.

MEASUREMENTS

age, APACHE II at the admission, length of stay in the ICU before the diagnosis of candidemia and whole length of stay, outcome, risk factors for candidemia (Candida colonisation, previous antibiotic therapy, central vein, mechanical ventilation, abdominal surgery, hemodialysis, adult respiratory distress syndrome, chronic obstructive pulmonary disease, diabetes, malignancy, splenectomy, immunosuppression, total parenteral nutrition, malnutrition) and clinical signs of multiorgan failure, systemic inflammatory response syndrome, sepsis or shock, concomitant presence of other infections.

RESULTS

Twelve Candida spp blood infections were diagnosed. All the risk factors were homogenously distributed between patients who survived and those who died with the exception of the malnutrition state, associated with a higher mortality rate.

CONCLUSION

If the candidemia is present, none of the risk factors for the onset of fungemia considered in this study, but the malnutrition state, are mortality predictors.

Luxatio cordis due to right pericardium tear, a difficult diagnosis: report of a case

BACKGROUND

Dislocation of the heart is a rare complication of thoracic blunt trauma. A high index of suspicion of pericardium rupture is necessary to formulate an early diagnosis to reduce morbidity and mortality.

PATIENTS

A 23-year-old man suffered a blunt thoracoabdominal trauma and was admitted 3 days later to a university hospital ICU for right heart luxation due to right pericardial tear. Mechanical ventilation delayed radiological findings.

METHODS AND RESULTS

Surgery by repositioning the heart and repairing the pericardial tear allowed restoration of hemodynamic equilibrium.

Cerebral blood flow and metabolic changes produced by repetitive magnetic brain stimulation

We evaluated cerebral variation in oxyhemoglobin, deoxyhemoglobin, and cytochrome oxidase before and after transcranial magnetic and electrical stimulation in ten healthy volunteers using near-infrared spectroscopy. Immediately after magnetic but not after electric stimulation a significant increase in oxyhemoglobin and a decrease in cytochrome oxidase were observed (P < 0.05). Our data suggest that repetitive transcranial magnetic stimulation induces metabolic activation of the cerebral cortex together with an increase in cerebral blood flow.

Injury of the vertebral artery after closed head trauma

Two case reports characterized by the complete occlusion of the basilar artery, secondary to dissection of the vertebral artery after closed head trauma are described. These lesions, often clinically silent in the beginning, were able to cause severe neurologic impairment, even after minor head trauma in healthy individuals without predisposing structural disorders. Early detection, based upon the knowledge of the modality of the trauma and upon a correct diagnostic approach, is mandatory to reduce secondary injury. The authors suggest an extensive use of cerebral angiography or angio-magnetic resonance in all cases where clinical conditions are more severe than the computed tomography scan, particularly if the trauma produced a cervical injury with a movement of flexo-extension of the neck. Therapeutic management is discussed. Anti-coagulants, thrombolytic agents or surgical ligation of the vessel has been proposed to prevent the extension of the lesion and to improve the outcome.

What is the best test to predict outcome after prolonged cardiac arrest?

Multimodality evoked potentials (EPs), linear electroencephalograms and Glasgow Coma Scale (GCS) scores were recorded within 24 h of cardiac arrest in 62 patients who were comatose following cardiopulmonary resuscitation. The cardiac arrest had a cardiac cause in 35 patients and a non-cardiac cause in 27 patients. The Glasgow Outcome Scale (GOS) scores were established 6 months after resuscitation. The prognostic value of all the recorded variables was calculated in terms of sensitivity, specificity and accuracy. Spearman's rank test was also used for the determination of the correlation coefficients with GOS. EP recordings furnished no falsely pessimistic predictions, with a specificity of 100%. In other words, when EPs were altered, the prognosis was always poor. However, while all patients who regained consciousness had normal EPs, not all patients in whom EPs were recordable survived. The GCS score showed a higher sensitivity and correlation with GOS score than EPs, but it was associated with a high percentage of false positive results, and its specificity was only 67%. The combination of the GCS score with EPs may be a promising strategy to counterbalance the respective limits of these methods and to reduce the loss of information due to sedation and myorelaxation, which impede clinical examination but not EP results.