Marino Viviani

Effect of positive expiratory pressure and type of tracheal cuff on the incidence of aspiration in mechanically ventilated patients in an intensive care unit.

Objective: To test the effects of positive expiratory pressure on the leakage of fluid around cuffs of different tracheal tubes, in mechanically ventilated patients and in a benchtop model. Design: Randomized clinical trial and experimental in vitro study. Setting: Intensive care unit of a university hospital. Patients: Forty patients recovering in the intensive care unit were ventilated in volume-controlled mode. Twenty patients were randomly intubated with Hi-Lo tubes (HL group), whereas the remaining 20 subjects were intubated with SealGuard tubes (SG group). Interventions: Immediately after intubation and cuff inflation with 30 cm H2O, Evans blue was applied onto the cephalic surface of the tracheal tube cuff. A 5-cm H2O positive expiratory pressure was used during the first 5 hrs of stay, and thereafter it was removed. Bronchoscopy verified whether the dye leaked around the cuff. The experiment lasted 12 hrs. Leakage was also tested in vitro with the same tracheal tubes with incremental level of positive expiratory pressure. Measurements and Main Results: At 1 hr, 5 hrs, and thereafter hourly until 12 hrs, bronchoscopy was used to test the presence of dye on the trachea caudal to the cuff. At the fifth hour, two patients of the HL group failed the test. One hour after positive expiratory pressure removal, all subjects in group HL exhibited a dyed lower trachea. On the other hand, one patient in group SG presented a leak at the eighth hour, and at the 12th hour three of them were still sealed. In vitro, the same level of positive expiratory pressure delayed the passage of dye around the cuff; after 30 mins positive expiratory pressure was removed, and in 10 mins all dye leaked only in the Hi-Lo tube. Conclusions: We found that 5 cm H2O positive expiratory pressure was effective in delaying the passage of fluid around the cuffs of tracheal tubes both in vivo and in vitro. The SealGuard tube proved to be more resistant to leakage than Hi-Lo.

Simple thoracostomy in prehospital trauma management is safe and effective: a 2-year experience by helicopter emergency medical crews.

Objective To evaluate the effectiveness and potential complications of simple thoracostomy, as first described by Deakin, as a method for prehospital treatment of traumatic pneumothorax. Methods Prospective observational study of all severe trauma patients rescued by our Regional Helicopter Emergency Medical Service and treated with on-scene simple thoracostomy, over a period of 25 months, from June 1, 2002 to June 30, 2004. Results Fifty-five consecutive severely injured patients with suspected pneumothorax and an average Revised Trauma Score of 9.6±2.7 underwent field simple thoracostomy. Oxygen saturation significantly improved after the procedure (from 86.4±10.2% to 98.5%±4.7%, P<0.05). No difference exists in the severity of thoracic lesions between patients with systolic arterial pressure and oxygen saturation below and above or equal to 90. A pneumothorax or a haemopneumothorax was found in 91.5% of the cases and a haemothorax in 5.1%. No cases of major bleeding, lung laceration or pleural infection were recorded. No cases of recurrent tension pneumothorax were observed. Forty (72.7%) patients survived to hospital discharge. Conclusions Prehospital treatment of traumatic pneumothorax by simple thoracostomy without chest tube insertion is a safe and effective technique.

Influence of prehospital treatment on the outcome of patients with severe blunt traumatic brain injury: a single-centre study

Aim, patients, and methods To compare retrospectively the outcomes of patients with severe traumatic brain injury (Injury Severity Score, ISS total ≥15; the Abbreviated ISS-head, aISShead ≥9) admitted to our Intensive Care Unit by helicopter (helicopter emergency medical service, HEMS group = 89) with those transported by ambulance (GROUND group = 105) from January 2002 to December 2007. Results The groups were comparable for age, Glasgow Coma Scale, ISS total, and aISShead. The preadmission time of the HEMS group was significantly longer as compared with the GROUND group, but the interval from admission to definitive care was significantly shorter. In the prehospital phase, HEMS patients were more aggressively treated, as indicated by a significantly greater number of procedures performed (i.e. tracheal intubation and positioning of intravenous lines) and larger volumes of fluids infused. The overall mortality was lower in the HEMS than in the GROUND patients (21 vs. 25% respectively, P<0.05). The survival with or without only minor neurological disabilities was higher in the HEMS than in the GROUND group (54 vs. 44% respectively, P<0.05); among the survivors, the rate of severe neurological disabilities was lower in the HEMS than in the GROUND group (25 vs. 31%, P<0.05). Conclusion In our experience, aggressive early treatment of patients with severe traumatic brain injury was associated with a better outcome likely because of the prevention of secondary brain injury and a shorter interval elapsing from the trauma to definitive care despite more time spent on the scene by the intervening team.

Relationship between the timing of administration of IgM and IgA enriched immunoglobulins in patients with severe sepsis and septic shock and the outcome: a retrospective analysis.

PURPOSE Because the use of IgM and IgA enriched polyclonal intravenous immunoglobulins (eIg) is a standard of care in critically ill patients admitted to our intensive care unit (ICU) with the diagnosis of severe sepsis or septic shock, we investigated if the delay from the onset of severe sepsis and septic shock and their administration could influence the outcome. MATERIALS AND METHODS The medical records of all patients with severe sepsis or septic shock admitted to our ICU from July 2004 through October 2009 and treated with eIg (Pentaglobin®; Biotest, Dreieich, Germany) were retrospectively examined. RESULTS A total of 129 adult patients with severe sepsis or septic shock were considered eligible. Thirty-two percent of patients died during the ICU stay. Survivors were given eIg significantly earlier than nonsurvivors (23 vs 63 hours, P < .05). The delay in the administration of eIg and the Simplified Acute Physiology Score II were the only variables that entered stepwise a propensity score-adjusted logistic model. The delay in the administration of eIg was a significant predictor of the odds of dying during the ICU stay (odds ratio for 1 hour of delay, 1.007; P < .01; 99% confidence interval from 1.001 to 1.010) and proved to be independent from the Simplified Acute Physiology Score II and other variables. CONCLUSIONS The efficacy of eIg, being maximal in early phases of severe sepsis and/or septic shock, is probably time dependent.

Pulmonary embolism in critically ill patients receiving antithrombotic prophylaxis: A clinical-pathologic study

PURPOSE The true incidence of pulmonary embolism (PE) in critically ill adult patients receiving antithrombotic prophylaxis is unknown, as well as the impact on the outcome. The aim of this study was to assess the incidence of PE in a surgical and medical intensive care unit and to evaluate the presence of risk factors that could be helpful in identifying patients at higher risk of missed diagnosis. MATERIALS AND METHODS We retrospectively reviewed the autopsies and clinical data of all patients who died in our intensive care unit from 1996 to 2007. All patients received prophylaxis with subcutaneous low-molecular weight heparin. RESULTS Among the 600 autopsies, the clinical diagnosis of PE was confirmed in 13 patients (true positives) and not confirmed in 20 patients; in 73 patients, the PE was discovered only at the autopsy (false negatives [FNs]). The overall incidence of PE in our patients was 14.3%. Pulmonary embolism was considered the cause of death in 45% of FNs and 77% of true positives. Among all comorbidities, only a recent abdominal surgery and the presence of acute renal failure were associated with a higher risk of missed diagnosis. In the FN group, there was a significantly higher frequency of cases of septic shock. CONCLUSIONS Despite thromboprophylaxis, critically ill patients remain at risk for PE; and because of the difficulty in diagnosing it clinically, the death certificate diagnosis of PE underestimates the problem.

SDD, SOD, or oropharyngeal chlorhexidine to prevent pneumonia and to reduce mortality in ventilated patients: which manoeuvre is evidence-based?

Dear editor: We read with interest the editorial by Segers and de Mol on the prevention of ventilator-associated pneumonia (VAP) after cardiac surgery [1]. We would like to comment on the authors’ statements on the use of selective digestive decontamination (SDD), selective oropharyngeal decontamination (SOD), and oropharyngeal chlorhexidine, as they are based on inaccurate interpretation of the evidence. The authors refer to a large SDD/ SOD study [2] which showed a significant reduction in the odds for mortality of SDD and SOD compared to standard care of 16% (odds ratio [OR] 0.835, 95% confidence interval [CI] 0.72–0.968, P = 0.016) and 14% (OR 0.858, 95% CI 0.739–0.996, P = 0.045), respectively. The reduction in mortality was higher in the SDD group than in the SOD group, albeit not significantly. There are nine randomized controlled trials (RCTs) evaluating the impact of SOD on lower respiratory tract infection and mortality. We performed a metaanalysis of those RCTs showing that SOD significantly reduces lower respiratory tract infections, but not mortality (Table 1). Contrastingly, there is robust evidence from the literature which indicates that the full SDD regimen of parenteral and enteral antimicrobials significantly reduces morbidity, i.e. pneumonia [3] and bloodstream infection [4], and mortality [3, 5]. The authors advocate the use of SOD instead of SDD ‘‘because it does not include widespread systemic prophylaxis with cephalosporins and involves a lower volume of topical antibiotics, thus minimizing the risk of development of antibiotic resistance’’. However, the Dutch study [2] clearly shows that patients with Gram-negative bacteria in rectal swabs resistant to the marker antibiotics are lower with SDD than with SOD. These results confirm that the resistance problem is not a function of intestinally applied volume of antimicrobials, but of systemically administered antibiotics. Remarkably, the use of all systemic antibiotics was higher in the SOD group than in the SDD group. Finally, the Dutch study confirms the findings that SDD does not increase the resistance problem, but actually reduces it [3]. The authors recommend the use of oropharyngeal chlorhexidine in cardiac surgery. Of the five metaanalyses of oropharyngeal chlorhexidine, three demonstrated a significant reduction in pneumonia, but none showed a significant reduction in mortality (see S1 in the Electronic Supplementary Material). The metaanalysis of the only three RCTs of chlorhexidine in cardiac surgery shows that chlorhexidine significantly reduces lower respiratory tract infections (Table 1). However, this result should be cautiously interpreted, as the duration of mechanical ventilation was short, and those studies reported the incidence of nosocomial pneumonia, not that of VAP, e.g. most patients received only few doses of the oral rinsing agent because extubation occurred within 4–12 h after surgery. Again, mortality is not significantly reduced by chlorhexidine. Therefore, although we welcome the authors’ claim of ‘‘prepare and defend’’, we advocate prevention of pneumonia using evidence based medicine (EBM) manoeuvres. SDD is the only EBM manoeuvre which has been shown to significantly reduce severe infections, i.e. pneumonia and bloodstream infection, and mortality, whilst SOD and oropharyngeal chlorhexidine still require further investigation.

Surviving Sepsis Campaign needed consensus to exclude selective decontamination of the digestive tract.

To the Editor: We thank Dr. MacIntyre for his editorial (1) on our article (2). We have four questions for him. One, we identified more than 15 methodologic errors in the metaanalysis performed by the EvidenceBased-Medicine Task Force on weaning (3). Our article holds no importance if we are wrong about the methodologic errors we identified (2). Dr. MacIntyre does not contend a single one of these errors. He writes “I’m not going to address the methodologic criticisms” (1). Yet, this is the very core of our article. The primary means for correcting scientific error is the dialectic process (4). Avoiding engagement in argument and counter-argument is the antithesis of science (4). We ask Dr. MacIntyre: “If we mistakenly identified some methodologic errors, which ones are they?” (Dr. MacIntyre writes “the methodologic criticisms [are] addressed in accompanying editorial”. But Dr. Marini did not write that we made methodologic errors). Two, Dr. MacIntyre continues, “Rather I will clarify how the McMaster findings were used by the task force to create operational guidelines for clinicians at the bedside.” (1) In this sentence, Dr. MacIntyre implies that the Task Force created clinical guidelines without analyzing the primary data (5). Our questions to Dr. MacIntyre: “Did Task-Force members check for errors in the analyses undertaken by the McMaster group?” (If the Task Force’s primary role was to imprint a seal-of-approval on a metaanalysis conducted by another group, readers should be so informed). Three, Dr. MacIntyre notes their meta-analysis revealed “consistently significant likelihood ratios” (1). But consistency is no guard against systematic error. If a spirometer contains a positive bias, the recorded volumes will overestimate true volume in a “consistent” manner (2). Dr. MacIntyre writes “the task force concluded that the individual likelihood ratios were not sufficiently high enough to drive clinical decision making at the bedside.” (1) We ask Dr. MacIntyre: “Is it wise to drive clinical decisions based on likelihood ratios that involve a series of compounded methodologic errors?” Four, Dr. MacIntyre writes “The guidelines seem to be standing the ‘test of time’ and are continuing to serve as an important tool to reduce iatrogenic delays in mechanical ventilation withdrawal.” (1) We ask Dr. MacIntyre: “If these are not mere assertions, please present the data that warrant your conclusion: that the guidelines are (a) standing the test of time and (b) reducing iatrogenic weaning delays?” We listed more than 15 methodologic errors in the Task Force’s meta-analysis (2). If we are wrong about these, we welcome correction from any member of the Task Force (3, 5). If the methodologic errors cannot be refuted, then what is the validity of the evidence on which the Evidence-Based-Medicine Task Force base their conclusions? The authors have not disclosed any potential conflicts of interest.

Traumatic blunt carotid injury: clinical experience and review of the literature.

To evaluate the symptoms, the associated lesions, the treatment and the outcome of patients with blunt carotid injury (BCD, we reviewed the records of all patients admitted to our intensive care unit with head trauma between May 1991 and May 1995. A patients assessment included the commonly used severity scores and cranial computed tomography (CT). Other diagnostic investigations were performed according to the clinical setting. Four patients (2 males, 2 females, age 29±13 years) out of 145 were diagnosed to have BCI. At admission, the Glasgow Coma Scale (GCS) was s 12 in all patients, and was associated with hemiparesis in three of them; the fourth became paretic 48 hours later. No pathological elements were demonstrated at the initial CT scan, whilst subsequent examinations showed signs of ischaemia after a variable interval from admission. In every patient the radiologic investigations demonstrated a thrombotic obstruction of the internal carotid artery (ICA), associated with an intimal dissection in two cases. Three patients were discharged with only minor neurologic symptoms. The fourth patient was referred to our ICU after the development of a massive hemispheric infarction, and died 3 days after admission.

Effects of the Volume of Processed Plasma on the Outcome, Arterial Pressure and Blood Procalcitonin Levels in Patients with Severe Sepsis and Septic Shock Treated with Coupled Plasma Filtration and Adsorption

Aims: To understand how coupled plasma filtration and adsorption (CPFA) could influence the time course of the advanced stages of sepsis, mean arterial pressure (MAP) and norepinephrine dosage. Methods: Patients with severe sepsis and septic shock with ≥2 organ failures not responding to volume resuscitation and vasopressor infusion were treated with CPFA within 8 h of admission to the intensive care unit. Results: Thirty-nine patients were treated (median age: 63 years, median SAPS II score: 45) and 28 survived advanced sepsis. In the latter, the median MAP increased and the norepinephrine dosage decreased significantly after CPFA, whereas in the nonsurvivors these values did not change significantly. The volume of treated plasma was significantly higher in survivors than nonsurvivors. Conclusion: These results suggest a possible existence of a dose-response effect for CPFA. Future studies are therefore recommended to evaluate the efficacy of this treatment and to determine its best timing and intensity.

An uncommon cause of lower limb weakness

Abstract We describe a case of a severely mentally disabled patient diagnosed as suffering from Guillain-Barré syndrome and treated with repeated plasma exchange. However, the abrupt onset of a cardiovascular collapse prompted a more in-depth diagnostic workup which demonstrated that the neurologic symptoms were likely to be ascribed to poisoning with heavy metals from a large number of ingested coins and other metallic items.