Luigi Camporota

Chest electrical impedance tomography examination, data analysis, terminology, clinical use and recommendations: consensus statement of the TRanslational EIT developmeNt stuDy group

Electrical impedance tomography (EIT) has undergone 30 years of development. Functional chest examinations with this technology are considered clinically relevant, especially for monitoring regional lung ventilation in mechanically ventilated patients and for regional pulmonary function testing in patients with chronic lung diseases. As EIT becomes an established medical technology, it requires consensus examination, nomenclature, data analysis and interpretation schemes. Such consensus is needed to compare, understand and reproduce study findings from and among different research groups, to enable large clinical trials and, ultimately, routine clinical use. Recommendations of how EIT findings can be applied to generate diagnoses and impact clinical decision-making and therapy planning are required. This consensus paper was prepared by an international working group, collaborating on the clinical promotion of EIT called TRanslational EIT developmeNt stuDy group. It addresses the stated needs by providing (1) a new classification of core processes involved in chest EIT examinations and data analysis, (2) focus on clinical applications with structured reviews and outlooks (separately for adult and neonatal/paediatric patients), (3) a structured framework to categorise and understand the relationships among analysis approaches and their clinical roles, (4) consensus, unified terminology with clinical user-friendly definitions and explanations, (5) a review of all major work in thoracic EIT and (6) recommendations for future development (193 pages of online supplements systematically linked with the chief sections of the main document). We expect this information to be useful for clinicians and researchers working with EIT, as well as for industry producers of this technology.

Advantages of ProSeal and SLIPA airways over tracheal tubes for gynecological laparoscopies

PurposeTo compare the efficacy of the ProSeal LMA™ and SLIPA™ supralaryngeal airways (SLA) with the standard tracheal tube (TT) in 150 consecutive day-case laparoscopic gynecological surgery procedures requiring general anesthesia.MethodsOne hundred and fifty patients were randomized into three groups. An identical general anesthesia technique was used in all patients apart from the addition of muscle relaxants and reversal drugs in the TT group. Patients were excluded if there were risk factors for gastroesophageal reflux. Ease of use, quality of seal, ventilation, systolic pressure, response to intubation, side effects and operating room time were assessed.ResultsBoth ProSeal LMA™ and SLIPA™ were easy to insert (100% success) and ventilate with respective mean (standard deviation) maximum sealing pressures of 31 (4.6) and 30 (5.2) cmH2O (P = 0.4) with no muscle relaxants. The seal quality in both ProSeal LMA™ and SLIPA™ permitted the use of low flows, 485 (291) and 539 (344) mL·min-1 (P = 0.2) respectively, although in the TT group significantly lower flows [377 (124) mL·min-1], (P < 0.01) were achieved. Systolic pressure in the SLA groups was more stable in response to insertion than in the TT. With ProSeal™ there was a lower incidence of sore throats than with TT (30% vs 57%), (P < 0.05), but there was a lesser difference as compared with SLIPA™ (30% vs 49%), (P > 0.05). With both SLAs, there was a significant reduction in operating room time (> three minutes), (P < 0.001).ConclusionsThese results suggest that the ProSeal LMA™ (reusable) and SLIPA™ (single-use) SLAs were easy to use without requiring muscle relaxants, and reduce operating room time compared to the TT technique in day case laparoscopies.RésuméObjectifComparer ľefficacité des canules supralaryngées (CSL) ProSeal LMA™et SLIPA™avec celle du tube endotrachéal (TET) régulier dans 150 interventions gynécologiques laparoscopiques consécutives nécessitant une anesthésie générale.MéthodeNous avons réparti 150 patientes au hasard en trois groupes. La même technique ďanesthésie générale a été appliquée chez toutes, sauf ľaddition de myorelaxants et de contre-myorelaxants avec le TET. Certaines ont été exclues s’il y avait des risques de reflux gastro-œsophagien. La facilité ďutilisation, ľétanchéité, la ventilation, la tension artérielle systolique, la réaction à ľintubation, les effets secondaires et le temps en salle ďopération ont été évalués.RésultatsĽinsertion des ProSeal LMA™ et SLIPA™ (100 % de succès) et la ventilation ont été faciles avec une moyenne respective (écart type) maximale de pression ďétanchéité de 31 (4,6) et 30 (5,2) cmH2O (P = 0,4) sans myorelaxants. La bonne étanchéité des ProSeal LMA™ et SLIPA™ a permis ďutiliser de faibles débits, respectivement de 485 (291) et 539 (344) mL·min-1 (P = 0,2), et significativement plus bas [377 (124) mL·min-1], (P < 0,01) avec le TET. La tension systolique chez les patients des groupes CSL, comparés au groupe TET, a été plus stable en réaction à ľinsertion de la canule. Avec le ProSeal™, comparé au TET, il y a eu une incidence plus faible de mal de gorge (30 % vs 57 %), (P < 0,05), et une plus petite différence avec le SLIPA™ (30 % vs 49 %), (P > 0,05). Avec les CSL, le temps en salle ďopération a été significativement réduit (> trois minutes), (P < 0,001).ConclusionCes résultats montrent que, pour des laparoscopies, les CSL ProSeal LMA™ (réutilisable) et SLIPA™ (jetable) ont été faciles à utiliser sans nécessiter de myorelaxants et qu’ils réduisent le temps de salle ďopération comparativement au TET.Objectif Comparer ľefficacite des canules supralaryngees (CSL) ProSeal LMA™et SLIPA™avec celle du tube endotracheal (TET) regulier dans 150 interventions gynecologiques laparoscopiques consecutives necessitant une anesthesie generale.

Pitfalls in haemodynamic monitoring based on the arterial pressure waveform

The accuracy of the arterial pressure-based cardiac output FloTrac-Vigileo system remains unacceptably low during haemodynamic instability. Data show that the measurement of cardiac output (CO) is strongly influenced by changes in factors that affect arterial blood pressure (ABP) - for example, vascular tone and compliance and the arterial site - independently of true changes in CO. Although in theory the autocalibration algorithm of FloTrac-Vigileo should adjust for those changes, the model undercompensates (or overcompensates) for prominent increases (or decreases) in vascular tone and compliance, making the system largely dependent on changes in ABP. These limitations make FloTrac-Vigileo accurate in stable haemodynamic conditions only, and until more robust algorithms and further validation studies become available, we should be aware that during haemodynamic instability or in extreme conditions of vasodilation or vasoconstriction, the measured CO may diverge from an independent bolus indicator dilution measurement, particularly if a peripheral artery is used. In these conditions, we advocate the use of transpulmonary indicator dilution via a femoral artery.

Les avantages des canules ProSeal™ et SLIPA™ sur les tubes endotrachéaux pour les laparoscopies gynécologiques

PurposeTo compare the efficacy of the ProSeal LMA™ and SLIPA™ supralaryngeal airways (SLA) with the standard tracheal tube (TT) in 150 consecutive day-case laparoscopic gynecological surgery procedures requiring general anesthesia.MethodsOne hundred and fifty patients were randomized into three groups. An identical general anesthesia technique was used in all patients apart from the addition of muscle relaxants and reversal drugs in the TT group. Patients were excluded if there were risk factors for gastroesophageal reflux. Ease of use, quality of seal, ventilation, systolic pressure, response to intubation, side effects and operating room time were assessed.ResultsBoth ProSeal LMA™ and SLIPA™ were easy to insert (100% success) and ventilate with respective mean (standard deviation) maximum sealing pressures of 31 (4.6) and 30 (5.2) cmH2O (P = 0.4) with no muscle relaxants. The seal quality in both ProSeal LMA™ and SLIPA™ permitted the use of low flows, 485 (291) and 539 (344) mL·min-1 (P = 0.2) respectively, although in the TT group significantly lower flows [377 (124) mL·min-1], (P < 0.01) were achieved. Systolic pressure in the SLA groups was more stable in response to insertion than in the TT. With ProSeal™ there was a lower incidence of sore throats than with TT (30% vs 57%), (P < 0.05), but there was a lesser difference as compared with SLIPA™ (30% vs 49%), (P > 0.05). With both SLAs, there was a significant reduction in operating room time (> three minutes), (P < 0.001).ConclusionsThese results suggest that the ProSeal LMA™ (reusable) and SLIPA™ (single-use) SLAs were easy to use without requiring muscle relaxants, and reduce operating room time compared to the TT technique in day case laparoscopies.RésuméObjectifComparer ľefficacité des canules supralaryngées (CSL) ProSeal LMA™et SLIPA™avec celle du tube endotrachéal (TET) régulier dans 150 interventions gynécologiques laparoscopiques consécutives nécessitant une anesthésie générale.MéthodeNous avons réparti 150 patientes au hasard en trois groupes. La même technique ďanesthésie générale a été appliquée chez toutes, sauf ľaddition de myorelaxants et de contre-myorelaxants avec le TET. Certaines ont été exclues s’il y avait des risques de reflux gastro-œsophagien. La facilité ďutilisation, ľétanchéité, la ventilation, la tension artérielle systolique, la réaction à ľintubation, les effets secondaires et le temps en salle ďopération ont été évalués.RésultatsĽinsertion des ProSeal LMA™ et SLIPA™ (100 % de succès) et la ventilation ont été faciles avec une moyenne respective (écart type) maximale de pression ďétanchéité de 31 (4,6) et 30 (5,2) cmH2O (P = 0,4) sans myorelaxants. La bonne étanchéité des ProSeal LMA™ et SLIPA™ a permis ďutiliser de faibles débits, respectivement de 485 (291) et 539 (344) mL·min-1 (P = 0,2), et significativement plus bas [377 (124) mL·min-1], (P < 0,01) avec le TET. La tension systolique chez les patients des groupes CSL, comparés au groupe TET, a été plus stable en réaction à ľinsertion de la canule. Avec le ProSeal™, comparé au TET, il y a eu une incidence plus faible de mal de gorge (30 % vs 57 %), (P < 0,05), et une plus petite différence avec le SLIPA™ (30 % vs 49 %), (P > 0,05). Avec les CSL, le temps en salle ďopération a été significativement réduit (> trois minutes), (P < 0,001).ConclusionCes résultats montrent que, pour des laparoscopies, les CSL ProSeal LMA™ (réutilisable) et SLIPA™ (jetable) ont été faciles à utiliser sans nécessiter de myorelaxants et qu’ils réduisent le temps de salle ďopération comparativement au TET.Objectif Comparer ľefficacite des canules supralaryngees (CSL) ProSeal LMA™et SLIPA™avec celle du tube endotracheal (TET) regulier dans 150 interventions gynecologiques laparoscopiques consecutives necessitant une anesthesie generale.

An international survey

BACKGROUND The last decade has seen an increase in the number of centres able to provide venovenous extracorporeal membrane oxygenation (VV-ECMO) internationally across different health care systems. To support this growth, a variety of staffing arrangements have been adopted depending on local need and availability of resources, both in terms of manpower and finances to safely meet the complex needs of the patient and circuit management. AIM The aim of the survey was to describe current staffing arrangements of care provision for adult patients on VV-ECMO, with a focus on understanding the professional roles and responsibilities of staff managing the circuit in order to inform further discussion around different approaches to staffing. METHODS We conducted a cross-sectional international survey using an electronic questionnaire emailed to 177 worldwide ECMO centres treating adult patients with acute respiratory failure. The survey questions were generated through an internal and external iterative process and assessed for clarity, content and face validity. RESULTS The response rate was 82%. Respondents managed extracorporeal oxygenation for adult respiratory alone (75%) or in combination with adult cardiac (67%), paediatric respiratory (62%) and paediatric cardiac (58%). The specialist nurse to patient ratio was 1:1 in 59% of centres, with 24-h/day presence in 74%. Overall, the specialist nurse provided the 24-h/day management of the circuit, including interventions. Perfusionists were responsible for the technical aspects of circuit management. CONCLUSIONS A specialist nurse with perfusion backup is the staffing arrangement implemented by most centres and likely reflects the most efficient use of the professional competences available. RELEVANCE TO CLINICAL PRACTICE Staffing for adult respiratory extracorporeal support has important implications for the planning of workforce, training and education, quality of service and the number of ECMO beds available.

Prevalence of Venous Thrombosis Following Venovenous Extracorporeal Membrane Oxygenation in Patients With Severe Respiratory Failure.

Objectives:Venovenous extracorporeal membrane oxygenation for patients with severe respiratory failure is increasingly common. There has been a significant change in the population, technology, and approach used for venovenous extracorporeal membrane oxygenation over the last 10 years. The objective of this study is to describe the prevalence of postdecannulation deep vein thrombosis in the cannulated vessel in adults who have received venovenous extracorporeal membrane oxygenation for severe respiratory failure. Design:A single-center, retrospective, observational cohort, electronic note review study. Setting:Tertiary referral university teaching hospital. Patients:Patients commenced on venovenous extracorporeal membrane oxygenation for severe respiratory failure. Interventions:None. Measurements and Main Results:We identified 103 patients commenced on extracorporeal membrane oxygenation with 81 survivors from December 2011 to February 2014. We performed postdecannulation venous Doppler ultrasound in 88.9% of extracorporeal membrane oxygenation survivors. The prevalence of deep vein thrombosis in the cannulated vessel following extracorporeal membrane oxygenation is 8.1/1,000 cannula days in patients who were screened. Conclusions:The prevalence of deep vein thrombosis following decannulation from extracorporeal membrane oxygenation for severe respiratory failure is clinically significant, and routine venous Doppler ultrasound following decannulation is warranted in this population.

Physiological predictors of survival during high-frequency oscillatory ventilation in adults with acute respiratory distress syndrome

IntroductionData that provide clinical criteria for the identification of patients likely torespond to high-frequency oscillatory ventilation (HFOV) are scarce. Our aim wasto describe physiological predictors of survival during HFOV in adults with severeacute respiratory distress syndrome (ARDS) admitted to a respiratory failurecenter in the United Kingdom.MethodsElectronic records of 102 adults treated with HFOV were reviewed retrospectively.We used logistic regression and receiving-operator characteristics curve to testassociations with oxygenation and mortality.ResultsPatients had severe ARDS with a mean (SD) Murrays score of 2.98 (0.7). Partialpressure of oxygen in arterial blood to fraction of inspired oxygen(PaO2/FiO2) ratio and oxygenation index improved only insurvivors. The earliest time point at which the two groups differed was at threehours after commencing HFOV. An improvement of >38% inPaO2/FiO2 occurring at any time within the first 72hours, was the best predictor of survival at 30 days (area under the curve (AUC)of 0.83, sensitivity 93%, specificity 78% and a positive likelihood ratio (LR) of4.3). These patients also had a 3.5 fold greater reduction in partial pressure ofcarbon dioxide in arterial blood (PaCO2). Multivariate analysis showedthat HFOV was more effective in younger patients, when instituted early, and inpatients with milder respiratory acidosis.ConclusionsHFOV is effective in improving oxygenation in adults with ARDS, particularly wheninstituted early. Changes in PaO2/FiO2 during the firstthree hours of HFOV can identify those patients more likely to survive.

Practical aspects of treatment with drotrecogin alfa (activated)

In November 2001, drotrecogin alfa (activated) was approved by the US Food and Drug Administration; in August 2002 it was approved by the European Medicines Agency. Since the approval of drotrecogin alfa (activated), however, critical care physicians have been faced with several challenges, namely its costs, selection of patients who are more likely to benefit from it, and the decision regarding when to start drotrecogin alfa (activated) treatment. There are also operational issues such as how to manage the infusion to deliver an effective treatment while minimizing the risk for bleeding, particularly in patients with deranged clotting, at around the time of surgery or during renal replacement therapy. While addressing these issues, this review remains practical but evidence based as much as possible.

Use of an Electromagnetic Device Compared With Chest X-ray to Confirm Nasogastric Feeding Tube Position in Critical Care.

BACKGROUND Insertion of nasogastric feeding tubes (NGTs) is common in critical care. However, misplacement is frequent and can carry a significant morbidity. Current methods to confirm position of NGTs are not reliable in this setting. We retrospectively compared the position of NGTs using an electromagnetically guided nasogastric tube (e-NGT) with that demonstrated by chest x-ray (CXR), the proportion of lung placements avoided, and the time taken to establish enteral feeding. METHODS This was a retrospective, observational study undertaken in a tertiary referral, adult intensive care unit between February 2006 and November 2013. Patients were included if they had a radiologically confirmed NGT. All CXRs were independently reviewed by an intensivist to determine position, and a subset of patients had their e-NGT image independently reviewed for quality control. Statistical analysis was in the form of sensitivity and specificity and descriptive where indicated. RESULTS In total, 121 NGT placements in 113 patients were analyzed. We found a sensitivity of 98% (95% confidence interval [CI], 93.9%-99.7%) and a specificity of 100% (95% CI, 48.0%-100.0%) when using the e-NGT compared with CXR. In the subset of 51 independently reviewed e-NGT images, 9 lung placements were avoided. The mean (SD) time from e-NGT placement to CXR was 185 (264.4) minutes and to feeding was 404 (77.8) minutes. CONCLUSION When placed by a dedicated team, e-NGT allowed immediate detection of tube misplacement. As such, if used as the sole method for determining NGT position, e-NGTs minimize feeding delay and the need for multiple CXRs with subsequent cost savings.

Short-term and medium-term survival of critically ill patients with solid tumours admitted to the intensive care unit: a retrospective analysis

Objectives Patients with cancer frequently require unplanned admission to the intensive care unit (ICU). Our objectives were to assess hospital and 180-day mortality in patients with a non-haematological malignancy and unplanned ICU admission and to identify which factors present on admission were the best predictors of mortality. Design Retrospective review of all patients with a diagnosis of solid tumours following unplanned admission to the ICU between 1 August 2008 and 31 July 2012. Setting Single centre tertiary care hospital in London (UK). Participants 300 adult patients with non-haematological solid tumours requiring unplanned admission to the ICU. Interventions None. Primary and secondary outcomes Hospital and 180-day survival. Results 300 patients were admitted to the ICU (median age 66.5 years; 61.7% men). Survival to hospital discharge and 180 days were 69% and 47.8%, respectively. Greater number of failed organ systems on admission was associated with significantly worse hospital survival (p<0.001) but not with 180-day survival (p=0.24). In multivariate analysis, predictors of hospital mortality were the presence of metastases (OR 1.97, 95% CI 1.08 to 3.59), Acute Physiology and Chronic Health Evaluation II (APACHE II) Score (OR 1.07, 95% CI 1.01 to 1.13) and a Glasgow Coma Scale Score <7 on admission to ICU (OR 5.21, 95% CI 1.65 to 16.43). Predictors of worse 180-day survival were the presence of metastases (OR 2.82, 95% CI 1.57 to 5.06), APACHE II Score (OR 1.07, 95% CI 1.01 to 1.13) and sepsis (OR 1.92, 95% CI 1.09 to 3.38). Conclusions Short-term and medium-term survival in patients with solid tumours admitted to ICU is better than previously reported, suggesting that the presence of cancer alone should not be a barrier to ICU admission.