Antithrombin reduces ischemic volume, ameliorates neurologic deficits, and prolongs animal survival in both transient and permanent focal ischemia

BACKGROUND AND PURPOSE

Antithrombin (AT), a glycoprotein belonging to the serpin family, blocks thrombin formation and activity at several steps. Thrombin, beside its relevant role in the coagulation cascade, exerts neurodetrimental effects through the activation of a family of protease-activated receptors, which can be implicated in stroke pathophysiology. The aims of the present study were to evaluate whether AT could reduce brain damage, ameliorate neurologic deficits, and prolong animal survival.

METHODS

Two different doses of AT (10 and 30 IU/kg IP) were administered 3 hours, 6 hours, or 3 and 6 hours after an ischemic insult to mice and rats subjected to either transient or permanent focal ischemia. Ischemic volume was evaluated 24 hours or 7 days after the ischemic insult. Neurologic deficits were also scored.

RESULTS

In mice, 10 or 30 IU/kg AT administered twice, at 3 and 6 hours after transient ischemia, and 30 IU/kg AT administered 3 hours only after transient ischemia substantially reduced total ischemic volume, significantly improved neurologic deficits evaluated 24 hours after the insult, and prolonged animal survival. In rats, the same doses given at the same time intervals significantly reduced ischemic volume, evaluated 24 hours after permanent ischemia.

CONCLUSIONS

These results indicate that AT remarkably reduces infarct volume, ameliorates neurologic deficit scores, and prolongs animal survival in 2 rodent models of brain ischemia. Taken together, our data suggest that AT, delivered via systemic administration, an easily achievable route of administration and in a clinically useful time window, could represent a new therapeutic strategy to be validated for the clinical treatment of human stroke.

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.

Posterior reversible encephalopathy syndrome in intensive care medicine

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is a well-recognized clinico-neuroradiological transient condition. Early recognition is of paramount importance for prompt control of blood pressure or removal of precipitating factors and treatment of epileptic seizures or status epilepticus. Delay in the diagnosis and treatment may in fact results in death or in irreversible neurological sequelae.

DISCUSSION

PRES is characterized by headache, altered mental status, seizures, and visual disturbances and is associated with a number of different causes, most commonly acute hypertension, preeclampsia/eclampsia, and immunosuppressive agents. Clinical symptoms and neuroradiological findings are typically indistinguishable among the cases of PRES, regardless of underlying cause. Magnetic resonance studies typically show edema involving the white matter of cerebral posterior regions, especially parieto-occipital lobes but frontal and temporal lobes, and other encephalic structures may be involved.

CONCLUSIONS

Intensivists and other physicians involved in the evaluation of patients with presumed PRES must be aware of the clinical spectrum of the associated conditions, the diagnostic modalities, and the correct treatment.

Monitoring cerebral oxygen saturation in elderly patients undergoing general abdominal surgery: a prospective cohort study

BACKGROUND AND OBJECTIVES

The aim of this prospective, observational study was to evaluate changes in regional cerebral oxygen saturation (rSO2) and incidence of intraoperative cerebral desaturation in a cohort of elderly patients undergoing major abdominal surgery.

METHODS

rSO2 was continuously monitored on the left and right sides of the forehead in 60 patients older than 65 yr (35 males and 25 females; ASA II-III; age: 72 +/- 5 yr; without pre-existing cerebral pathology, and baseline Mini Mental State Examination (MMSE) score >23) undergoing sevoflurane anaesthesia for major abdominal, non-vascular surgery >2 h.

RESULTS

Baseline rSO2 was 63 +/- 8%; cerebral desaturation (rSO2 decrease <75% of baseline or <80% in case of baseline rSO2 <50%) occurred in 16 patients (26%). The MMSE decreased from 28 +/- 1 before surgery to 27 +/- 2 on 7th postoperative day (P = 0.05). A decline in cognitive function (decrease in MMSE score > or = 2 points one week after surgery as compared to baseline value) was observed in six patients without intraoperative cerebral desaturation (13.6%) and six patients who had intraoperative cerebral desaturation (40%) (P = 0.057) (odds ratio: 4.22; CI95%: 1.1-16). Median (range) hospital stay was 14 (5-41) days in patients with an area under the curve of rSO2 <50% (AUCrSO2<50%) >10 min%, and 10 (4-30) days in those with an AUCrSO2<50% <10 min% (P = 0.0005).

CONCLUSIONS

In a population of healthy elderly patients, undergoing non-vascular abdominal surgery cerebral desaturation can occur in up to one in every four patients, and the occurrence of cerebral desaturation is associated with a higher incidence of early postoperative cognitive decline and longer hospital stay.

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.

Effects of dopamine infusion on forearm blood flow in critical patients

BACKGROUND

In critical care, dopamine is administered by infusion at low doses (<or=3 microg/kg/min) or at high doses (>or=5 microg/kg/min) for assessment of hemodynamics. The present study was conducted to explore the effects of dopamine infusion on the vast microvascular network of skeletal muscle in the early phases of sepsis.

MATERIAL/METHODS

An observational study was performed which included twelve critically ill patients. Patients' response to dopamine infusion (3 microg/kg/min) was studied within 24 hours from admission to the ICU. The forearm blood flow (FBF) and vascular resistance (FVR) were measured by near-infrared spectroscopy (NIRS).

RESULTS

Dopamine did not ameliorate forearm regional oxygenation. The infusion of dopamine caused an increase in MAP, while FBF decreased with the resistance increase (p>0.05).

CONCLUSIONS

NIRS was suitable to measure bedside the vascular resistance and to test the effects of low doses of dopamine on forearm blood flow. A dopamine infusion of 3.0 microg/kg/min caused a reduction in forearm blood flow and an increase in vascular resistance in our patients.

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.

Sepsis and organ dysfunction: an ongoing challenge

In recent years the problem of infection has become increasingly significant, especially in intensive care hospital wards such as Intensive Care Units (ICU), emergency medicine, surgery and critically ill patient care departments. Sepsis is a complex, multifactorial syndrome that can develop into conditions of different severity, described as severe sepsis or septic shock. In these conditions the triggering event may coincide with the functional impairment of one or more vital organs or systems, thus leading to poorer prognosis in patients with overt signs of sepsis or systemic inflammation syndromes. The available data are quite alarming, as most prevention and treatment is performed empirically and requires considerable human and technological resources. Clinical signs are often misleading and, in some circumstances, it may be difficult or even impossible to identify the source of the infection which might otherwise be removed relatively simply, using proper antimicrobial treatment or a less invasive surgical removal of the area from which the infection originates based on needle-guided radiology. In addition, the complex pathophysiological mechanisms involved can be an obstacle to gaining a full understanding of the various biohumoral interactions or mediators action mechanisms. It may not be easy to enroll patients belonging to homogeneous groups in terms of age, underlining disease, immune profile or genetic predisposition, although the use of specific severity indexes has proved helpful also to establish the prognosis. Although the interpretation of generalised inflammation as a warning sign also in the absence of clear signs of infection or a state of overt inflammation has to rely largely on simple intuition, it has helped to drive experimental and clinical research work towards the investigation of interaction between different factors such as infection and sepsis, or inflammation and coagulation. An additional useful tool is the possibility of modulating the endothelial response which may support the process of disseminated thrombosis typical of sepsis evolution. In this context the improvement of standards of care can shed light on the efficacy of different treatments.

Continuous Monitoring of Cerebral Oxygen Saturation in Elderly Patients Undergoing Major Abdominal Surgery Minimizes Brain Exposure to Potential Hypoxia

Elderly patients are more prone than younger patients to develop cerebral desaturation because of the reduced physiologic reserve that accompanies aging. To evaluate whether monitoring cerebral oxygen saturation (rSO(2)) minimizes intraoperative cerebral desaturation, we prospectively monitored rSO(2) in 122 elderly patients undergoing major abdominal surgery with general anesthesia. Patients were randomly allocated to an intervention group (the monitor was visible and rSO(2) was maintained at > or =75% of preinduction values; n = 56) or a control group (the monitor was blinded and anesthesia was managed routinely; n = 66). Cerebral desaturation (rSO(2) reduction <75% of baseline) was observed in 11 patients of the treatment group (20%) and 15 patients of the control group (23%) (P = 0.82). Mean (95% confidence intervals) values of mean rSO(2) were higher (66% [64%-68%]) and the area under the curve below 75% of baseline (AUCrSO2(2)< 75% of baseline) was lower (0.4 min% [0.1-0.8 min%]) in patients of the treatment group than in patients of the control group (61% [59%-63%] and 80 min% [2-144 min%], respectively; P = 0.002 and P = 0.017). When considering only patients developing intraoperative cerebral desaturation, a lower Mini Mental State Elimination (MMSE) score was observed at the seventh postoperative day in the control group (26 [25-30]) than in the treatment group (28 [26-30]) (P = 0.02), with a significant correlation between the AUCrSO(2) < 75% of baseline and postoperative decrease in MMSE score from preoperative values (r(2)= 0.25, P = 0.01). Patients of the control group with intraoperative cerebral desaturation also experienced a longer time to postanesthesia care unit (PACU) discharge (47 min [13-56 min]) and longer hospital stay (24 days [7-53] days) compared with patients of the treatment group (25 min [15-35 min] and 10 days [7-23 days], respectively; P = 0.01 and P = 0.007). Using rSO(2) monitoring to manage anesthesia in elderly patients undergoing major abdominal surgery reduces the potential exposure of the brain to hypoxia; this might be associated with decreased effects on cognitive function and shorter PACU and hospital stay.