MINERVA ANESTESIOLOGICA ITALIAN JOURNAL OF ANESTHESIOLOGY AND ANALGESIA MONTHLY JOURNAL FOUNDED IN 1935 BY A. M. DOGLIOTTI OFFICIAL JOURNAL OF ITALIAN SOCIETY OF ANESTHESIOLOGY, ANALGESIA, RESUSCITATION AND INTENSIVE CARE (S.I.A.A.R.T.I.) Vol. 81 August 2015 No. 8 OFFICIAL JOURNAL OF ITALIAN SOCIETY OF ANESTHESIOLOGY, ANALGESIA, RESUSCITATION AND INTENSIVE CARE (SIAARTI) CONTENTS 825 837 EDITORIALS ORIGINAL ARTICLES Videolaryngoscopy: may the force be with you! Surgical Pleth Index guided analgesia blunts the intra- Kleine-Brueggeney M., Theiler L. G. operative sympathetic response to laparoscopic chol- ecystectomy Colombo R., Raimondi F., Rech R., Castelli A., Fossali T., 827 Marchi A., Borghi B., Corona A., Guzzetti S. Measuring (and interpreting) the esophageal pressure: a challenge for the intensivist Grasso S., Cassano S. 846 830 Indirect videolaryngoscopy using Macintosh blades in patients with non-anticipated difficult airways results Is esophageal pressure monitoring essential for the in significantly lower forces exerted on teeth relative most critically ill? to classic direct laryngoscopy: a randomized crossover Berra L., Kacmarek R. M. trial Pieters B., Maassen R., Van Eig E., Maathuis B., Van Den Dobbelsteen J., Van Zundert A. 832 How should I structure my Post-ICU Clinic? From early goal rehabilitation to outpatient visits Ranzani O. T., Jones C. 855 Esophageal pressure measurements under different 835 conditions of intrathoracic pressure. An in vitro study Near-infrared spectroscopy for monitoring brain oxy- of second generation balloon catheters genation: to trust or not to trust? Mojoli F., Chiumello D., Pozzi M., Algieri I., Bianzina S., Bruder N., Velly L. Luoni S., Volta C. A., Braschi A., Brochard L. Vol. 81 - No. 8 MINERVA ANESTESIOLOGICA I CONTENTS 865 910 Feasibility of Post-Intensive Care Unit Clinics: REVIEWS an observational cohort study of two different Preoxygenation and general anesthesia: a review approaches Bouroche G., Bourgain J. L. Dettling-Ihnenfeldt D. S., De Graaff A. E., Nollet F., Van Der Schaaf M. 921 876 Statin therapy in critically-ill patients with severe sep- Assessment of cerebral oxygenation in neurocriti- sis: a review and meta-analysis of randomized clinical cal care patients: comparison of a new four wave- trials lengths forehead regional saturation in oxygen sensor Thomas G., Hraiech S., Loundou A., Truwit J., Kruger P., (EQUANOX®) with brain tissue oxygenation. A pro- Mcauley D. F., Papazian L., Roch A. spective observational study Esnault P., Boret H., Montcriol A., Carre E., Prunet B., Bordes J., Simon P., Joubert C., Dagain A., Kaiser E., 931 Meaudre E. LETTERS TO THE EDITOR Association between steroid particle sizes and serious 885 complications during epidural injections Ghobadifar M. A. Moderate-degree acidosis is an independent determi- nant of postoperative bleeding in cardiac surgery Ranucci M., Baryshnikova E., Simeone F., Ranucci M., 932 Scolletta S. Missed citations Caldiroli D., Orena E. F. 894 EXPERT OPINION OPRM1 receptor as new biomarker to help the predic- 933 tion of post mastectomy pain and recurrence in breast Videolaryngoscopy offers us more than classic direct cancer laryngoscopy De Gregori M., Diatchenko L., Belfer I., Allegri M. Van Zundert A. A. J., Pieters B. M. A. 901 935 Epidural steroid injections: update on efficacy, safety, and newer medications for injection TOP 50 MINERVA ANESTESIOLOGICA Kozlov N., Benzon H. T., Malik K. REVIEWERS VOLUME 81 · No. 8 · AUGUST 2015 About the cover: the cover shows the trends of rSO and PbtO for patient n. 4 in the prospective, 2 2 observational, unblinded study about the assessment of cerebral oxygenation in neurocritical care patients. Data show the inability of rSO to detect ongoing brain death. For more information, see 2 the article by Esnault P. et al. beginning on page 876. II MINERVA ANESTESIOLOGICA August 2015 Anno: 2015 Lavoro: Mese: August titolo breve: VIDEOLARYNGOSCOPY Volume: 81 primo autore: KLEINE-BRUEGGENEY No: 8 pagine: 825-6 Rivista: MINERVA ANESTESIOLOGICA Cod Rivista: Minerva Anestesiol EDITORIAL Videolaryngoscopy: may the force be with you! M. KLEINE-BRUEGGENEY, L. G. THEILER Department of Anaesthesiology and Pain Medicine, Inselspital, University of Bern and Bern University Hospital, Bern, Switzerland Since John Pacey, a surgeon, introduced the incidence of dental lesions is reduced by using GlideScope® into clinical practice in 2001, VLS, but it is difficult to study the incidence of videolaryngoscopes (VLS) have become increas- dental lesions because they occur in only about ingly successful. Similar to the use of ultrasound 1/2000 (0.05%) of anesthesia cases.6 The force guided techniques for vascular puncture and exerted on the teeth appears to be an acceptable nerve blocks, VLS have very quickly gained surrogate parameter. Importantly, those findings popularity among anesthesiologists. They are apply to the non-difficult airway, not the non- becoming more and more indispensable tools anticipated difficult airway: the title of the study for teaching purposes, for the management of might be misleading. difficult airways and as documentation tools for VLS can be divided into devices without a everyday cases. Many different VLS are available guiding channel for the tracheal tube (such as and their number keeps steadily increasing. Prior the three devices evaluated by Pieters et al.) and to marketing, all these devices lack evidence of devices with a guiding channel. Additionally, efficacy or safety. Hence, without academic guid- VLS blades may resemble the standard Macin- ance, the choice to use and to buy one particular tosh blade (e.g. the C-MAC® blades evaluated VLS will depend on marketing strategies of the in the study) or may feature a more pronounced companies. The British Difficult Airway Society curve (e.g. the MacGrath® series 5 and the Gli- has addressed this problem in an article that de- deScope® 7 evaluated by Pieters et al., or the C- fines “a minimum level of evidence needed to make MAC “D-blade”). Curved blades are primarily a pragmatic decision about the purchase or selection designed for the difficult airway and direct com- of an airway device”.1 In this issue of Minerva parisons with Macintosh blades are difficult. The more curved the blade, the more essential it is Anestesiologica, Pieters et al. provide some of the to introduce a stylet into the tracheal tube for necessary evidence about efficacy and safety of guidance. If a stylet is not used, tracheal intuba- three VLS.2 From everyday clinical practice we tion will be more difficult, as shown by Pieters et know that the force necessary to obtain a good al. who did not use stylets in their study.2 Most view of laryngeal structures is markedly de- likely, this is why the GlideScope® seemed to creased with VLS. This has also been shown by perform inferiorly. Goto et al.3 Pieters and the study group led by Facing the emerging importance of VLS, a André van Zundert present more data enforcing crucial question becomes whether we should this knowledge. They confirm their previously abandon the 80-year old standard Macintosh published finding that the force exerted on the blade in favor of VLS. While superiority has maxillary incisors is lower with the use of VLS been claimed for VLS in the ICU setting 8 and compared to the use of the Macintosh laryngo- evidence shows that in normal airways, laryn- scope.2, 4, 5 We cannot directly deduct that the goscopy becomes even easier when using vide- Comment on p. 846. olaryngoscopes, there are important advantages Vol. 81 - No. 8 MINERVA ANESTESIOLOGICA 825 KLEINE-BRUEGGENEY VIDEOLARYNGOSCOPY of direct laryngoscopy using the Macintosh Pieters et al. More evidence will have to follow blades. The most obvious one is the fact that in the future, especially about the role of VLS in one drop of blood or mucus may be sufficient to the setting of difficult airway management. completely obstruct the view obtained by vide- olaryngoscopes. Also, equipment failure remains References a problem.9 The Macintosh laryngoscope is a simple, reliable tool that is difficult to break. It 1. Pandit JJ, Popat MT, Cook TM, Wilkes AR, Groom P, Cooke H et al. The Difficult Airway Society ‘ADEPT’ guid- is cheap, transportable, available in all sizes and ance on selecting airway devices: the basis of a strategy for usable in all settings, even in the pre-hospital equipment evaluation. Anaesthesia 2011;66:726-37. 2. Pieters B, Maassen R, van Eig E, Maathuis B, van Den setting in bright sunlight. Of note, VLS have so Dobbelsteen J, van Zundert A. Indirect videolaryngoscopy far not been incorporated into difficult airway using Macintosh blades in patients with non-anticipated difficult airways results in significantly lower forces exerted algorithms, although this may change in the on teeth relative to classic direct laryngoscopy; a random- near future.10 While VLS seem to be very valu- ized crossover trial. Minerva Anestesiol 2015;81:846-54. 3. Goto T, Koyama Y, Kondo T, Tsugawa Y, Hasegawa K. A able assets to the airway tool library, we risk los- comparison of the force applied on oral structures during ing our skills with two important techniques by intubation attempts between the Pentax-AWS airwayscope more and more using VLS: intubation with the and the Macintosh laryngoscope: a high-fidelity simulator- based study. BMJ Open 2014;4:e006416. ubiquitously available Macintosh laryngoscope 4. Lee RA, van Zundert AA, Maassen RL, Willems RJ, Beeke and fibreoptic intubation. Several studies on LP, Schaaper JN et al. Forces applied to the maxillary in- cisors during video-assisted intubation. Anesth Analg VLS in the simulated difficult airway situation 2009;108:187-91. using manual inline stabilization have been con- 5. Lee RA, van Zundert AA, Maassen RL, Wieringa PA. Forc- es applied to the maxillary incisors by video laryngoscopes ducted, mostly demonstrating a better visibility and the Macintosh laryngoscope. Acta Anaesthesiol Scand of the vocal cords and some showing a higher in- 2012;56:224-9. 6. Newland MC, Ellis SJ, Peters KR, Simonson JA, Durham tubation success rate with VLS compared to the TM, Ullrich FA et al. Dental injury associated with anes- Macintosh laryngoscope.9, 11 Despite that, it is thesia: a report of 161,687 anesthetics given over 14 years. J Clin Anesth 2007;19:339-45. also known that even with a good view obtained 7. Agro’ F, Doyle D, Vennari M. Use of Glidescope in adults: by the VLS, there still might be problems to ac- an overview. Minerva Anestesiol 2015;81:342-51. tually intubate the trachea (“you see that you 8. De Jong A, Molinari N, Conseil M, Coisel Y, Pouzeratte Y, Belafia F et al. Video laryngoscopy versus direct laryngos- fail”).11 Therefore, alternative techniques like the copy for orotracheal intubation in the intensive care unit: flexible fibreoptic intubation must continue to a systematic review and meta-analysis. Intensive Care Med 2014;40:629-39. be taught and used on a regular basis. To secure 9. Ilyas S, Symons J, Bradley W, Segal R, Taylor H, Lee K the airway in the spontaneously breathing pa- et al. A prospective randomised controlled trial compar- ing tracheal intubation plus manual in-line stabilisation tient (awake intubation) remains the gold-stand- of the cervical spine using the Macintosh laryngoscope ard in the management of the anticipated dif- vs the McGrath Series 5 videolaryngoscope. Anaesthesia 2014;69:1345-50. ficult airway, especially when difficult face-mask 10. Frova G. Do videolaryngoscopes have a new role in the ventilation is suspected, and should not be aban- SIAARTI difficult airway management algorithm? Minerva Anestesiol 2010;76:637-40. doned. Videolaryngoscopes are additions, not 11. Byhahn C, Iber T, Zacharowski K, Weber CF, Ruesseler replacements to our airway tool library. Their M, Schalk R et al. Tracheal intubation using the mobile role in securing patients’ airways is increasingly C-MAC video laryngoscope or direct laryngoscopy for pa- tients with a simulated difficult airway. Minerva Anestesiol being supported by evidence like the study by 2010;76:577-83. Conflicts of interest.—The authors are investigators on several randomized controlled trials of videolaryngoscopes and received grants from the “Gottfried und Julia Bangerter-Rhyner Foundation”, from the “Fondation Latine des Voies Aériennes (FLAVA)” and the “Swiss Society of Anaesthesiology and Resuscitation” for an ongoing study comparing videolaryngoscopes. Received on November 15, 2014. - Accepted for publication on November 20, 2014. -Epub ahead of print on November 26, 2014. Corresponding author: L. G. Theiler, Department of Anaesthesiology and Pain Medicine, University Hospital Bern, Inselspital CH-3010 Bern, Switzerland. E-mail: [email protected] 826 MINERVA ANESTESIOLOGICA August 2015 Anno: 2015 Lavoro: Mese: August titolo breve: MEASURING (AND INTERPRETING) THE ESOPHAGEAL PRESSURE Volume: 81 primo autore: GRASSO No: 8 pagine: 1-2 Rivista: MINERVA ANESTESIOLOGICA Cod Rivista: Minerva Anestesiol EDITORIAL Measuring (and interpreting) the esophageal pressure: a challenge for the intensivist S. GRASSO, S. CASSANO Dipartimento dell’Emergenza e Trapianti d’Organo (DETO), Sezione di Anestesiologia eRianimazione, Università degli Studi Aldo Moro, Bari, Italy In a mechanically ventilated passive patient fusions and increased abdominal pressure may a portion of the positive pressure applied at impair chest wall compliance. If the chest wall the airway opening (P ) does not distend the is stiff, a relevant portion of P is dissipated to AO AO lung but works to “move” the chest wall. As a move it, generating higher P and lower P . PL L consequence, the pleural pressure (P ) increases When this happens, the P -based lung protec- PL AO above its end-expiratory level, proportionally to tive and/or lung-recruiting strategies often fail, chest wall stiffness. What actually distends the regardless the potential for alveolar recruitment.9 lung is the increase in trans-pulmonary pressure Studies have shown that titrating mechanical (P ) above its end-expiratory level, i.e. P mi- ventilation on P rather than on P significant- L AO L AO nus P .1 The straightforward implication is that ly improves gas exchange and lung mechanics 10 PL P is always lower than the applied P .2 In pa- and may reverse refractory hypoxemia.11 L AO tients with acute respiratory distress syndrome In the assisted ventilation modes, the patient (ARDS), in the attempt to minimize alveolar actively contracts his or her inspiratory muscles hyperinflation, we limit the end-inspiratory air- and P results by the interplay between the venti- L way opening plateau pressure (P ) to 30 lator that pushes (positive P ) and the patients AO,PLAT AO cmH2O.3 In the most severe ARDS forms, in the that pulls (negative PPL). Think to a patient with attempt to increase lung aeration, we use lung- mild ARDS non-invasively ventilated with a recruiting maneuvers (LRM) followed by high pressure support of 15 cmH2O. If this patient positive end-expiratory pressure (PEEP).4-6 In- generates a substantial inspiratory effort (PPL deed, alveolar recruitment may change the clini- minus 20 cmH2O), the end-inspiratory PL will cal course of severe ARDS: a non “recruiting” be 35 cmH2O, a figure compatible with venti- patient is candidate to “rescue” strategies, for lator induced lung injury (VILI).12 Indeed, PL is of paramount importance to estimate work example extracorporeal membrane oxygenation of breathing and patient-ventilator interactions (ECMO).7 For P , LRM and PEEP we AO,PLAT during assisted ventilation.13 reason in terms of pressure applied at the airway Despite its importance, we rarely measure opening, assuming that the chest wall stiffness is P in clinical practice or, even worst, take the P normal. Unfortunately, this is not the case in a L L “concept” into account in our clinical reason- relevant portion of patients.8 Several pathologic ing. There are at least four reasons to explain this conditions, for example deformities, pleural ef- paradox: Comment on p. 865. A) Measuring P is virtually impossible in the PL Vol. 81 - No. 8 MINERVA ANESTESIOLOGICA 827 GRASSO MEASURING (AND INTERPRETING) THE ESOPHAGEAL PRESSURE clinical setting. We have a surrogate, the esopha- rigorous in vitro study testing six second-gen- geal pressure (P ), measured through a catheter eration P catheters at different balloon filling ES ES positioned in the lower esophageal third. Since volumes and surrounding pressures to define the the esophageal lumen is a virtual space, to sense catheter-specific range of “appropriate” balloon the pressure acting on the esophageal wall, the filling volumes. Rather surprisingly, it shows catheter tip must be inserted in an air filled bal- that this range may be different from the one loon. The air volume put in the balloon needs recommended by catheters manufacturers. Most careful titration: if the balloon collapses on the importantly, the study establishes a “gold stand- catheter tip, P is underestimated. On the other ard” in vitro approach to test P catheters. We ES ES hand, if the balloon is overinflated, the stretch urgently need preclinical and clinical studies like on the balloon wall generates positive pressure this one.13 Our challenge is to quickly go from by itself, and P is overestimated. In adjunct, theory to practice. Measuring and interpreting ES the P reading is influenced by patient posture P is complex, requires considerable expertise ES L and the esophageal muscular tone and contrac- and technological improvements. Nevertheless, tions.1 we should wonder if it is challenging like meas- B) The correct catheter positioning in the low- uring and interpreting the electrocardiogram. er esophageal third requires expertise. There are Cardiologists won this challenge several years several methods to check the catheter position:14 ago. Will the intensivists do the same in the near some of them require active patients inspiration future? against the occluded airway.15 Unfortunately few ventilators are equipped with airway opening oc- References clusion devices. C) We lack of devices to measure P . For a ES 1. Hedenstierna G. Esophageal pressure: benefit and limita- correct reading P should be showed together tions. Minerva Anestesiol 2012;78:959-66. ES with P , Flow and Volume, in real time. Few 2. Gattinoni L, Chiumello D, Carlesso E, Valenza F. Bench- AO to-bedside review: chest wall elastance in acute lung injury/ ventilators and multi-parametric monitors are acute respiratory distress syndrome patients. Crit Care equipped with an auxiliary port to measure P . 2004;8:350-5. ES 3. Network TA. Ventilation with lower tidal volumes as com- D) After years of debates, we yet don’t know pared with traditional tidal volumes for acute lung injury how to interpret P .16, 17 Some authors main- and the acute respiratory distress syndrome. The Acute ES Respiratory Distress Syndrome Network. N Engl J Med tain that the absolute P value is just the “right” ES 2000;342:1301-08. P value.10, 14, 18 Others do not trust on abso- 4. de Matos GF, Stanzani F, Passos RH, Fontana MF, Albalade- PL lute P and just trust on the P and P swings jo R, Caserta RE et al. How large is the lung recruitability in ES AO ES early acute respiratory distress syndrome: a prospective case for partitioning the respiratory system elastance series of patients monitored by computed tomography. Crit (E ) into its lung and chest wall components Care 2012;16:R4. RS 5. Fan E, Wilcox ME, Brower RG, Stewart TE, Mehta S, (EL and EC, w).2 This is reasonable since: a) the Lapinsky SE et al. Recruitment maneuvers for acute lung E /E ratio defines the partitioning of P in injury: a systematic review. Am J Respir Crit Care Med L CW AO 2008;178:1156-63. P and P during positive pressure lung infla- PL L 6. Gattinoni L, Caironi P, Cressoni M, Chiumello D, Ranieri tion; and b) a single “real” absolute P virtually VM, Quintel M et al. Lung recruitment in patients with PL the acute respiratory distress syndrome. N Engl J Med does not exist. In healthy subjects P is slightly PL 2006;354:1775-86. negative at functional residual capacity (FRC), 7. Esan A, Hess DR, Raoof S, George L, Sessler CN: Severe varies with gravity and body posture 1 and is oc- hypoxemic respiratory failure: part 1--ventilatory strategies. Chest 2010;137:1203-16. casionally frankly positive in the dependent lung 8. Malbrain ML, Cheatham ML, Kirkpatrick A, Sugrue M, regions, for example in patients with abdominal Parr M, De Waele J et al. Results from the International Conference of Experts on Intra-abdominal Hypertension hypertension.14 and Abdominal Compartment Syndrome. I. Definitions. In summary, while the experts recommend Intensive Care Med 2006;32:1722-32. 9. Staffieri F, Stripoli T, De Monte V, Crovace A, Sacchi M, measuring P , several problems wait a solu- L De Michele M, Trerotoli P, Terragni P, Ranieri VM, Grasso tion. The paper by Mojoli et al. published in S: Physiological effects of an open lung ventilatory strat- the present issue of Minerva Anestesiologica is egy titrated on elastance-derived end-inspiratory transpul- monary pressure: study in a pig model. Crit Care Med a step in this direction.19 It is an elegant and 2012;40:2124-31. 828 MINERVA ANESTESIOLOGICA August 2015 MEASURING (AND INTERPRETING) THE ESOPHAGEAL PRESSURE GRASSO 10. Talmor D, Sarge T, Malhotra A, O’Donnell CR, Ritz R, Lis- 15. Baydur A, Behrakis PK, Zin WA, Jaeger M, Milic-Emili J. bon A et al. Mechanical ventilation guided by esophageal pres- A simple method for assessing the validity of the esophageal sure in acute lung injury. N Engl J Med 2008;359:2095-104. balloon technique. Am Rev Respir Dis 1982;126:788-91. 11. Grasso S, Terragni P, Birocco A, Urbino R, Del Sorbo L, 16. Hubmayr RD. Is there a place for esophageal manometry Filippini C et al. ECMO criteria for influenza A (H1N1)- in the care of patients with injured lungs? J Appl Physiol associated ARDS: role of transpulmonary pressure. Inten- 2010;108:481-2. sive Care Med 2012;38:395-403. 17. Chiumello D, Cressoni M, Colombo A, Babini G, Brioni 12. Slutsky AS, Ranieri VM: Ventilator-induced lung injury. N M, Crimella F et al. The assessment of transpulmonary Engl J Med 2014;370:980. pressure in mechanically ventilated ARDS patients. Inten- 13. Akoumianaki E, Maggiore SM, Valenza F, Bellani G, Ju- sive Care Med 2014;40:1670-8. bran A, Loring SH et al. The application of esophageal pres- 18. Talmor D, Sarge T, O’Donnell CR, Ritz R, Malhotra A, sure measurement in patients with respiratory failure. Am J Lisbon A et al. Esophageal and transpulmonary pressures in Respir Crit Care Med 2014;189:520-31. acute respiratory failure. Crit Care Med 2006;34:1389-94. 14. Loring SH, O’Donnell CR, Behazin N, Malhotra A, Sarge 19. Mojoli F, Chiumello D, Pozzi M, Algieri I, Bianzina S, Luo- T, Ritz R et al. Esophageal pressures in acute lung injury: ni S et al. Esophageal pressure measurements under differ- do they represent artifact or useful information about trans- ent conditions of intrathoracic pressure. An in vitro study pulmonary pressure, chest wall mechanics, and lung stress? of second generation balloon catheters. Minerva Anestesiol J Appl Physiol 2010;108:515-22. 2015;81:855-64. Conflicts of interest.—The authors certify that there is no conflict of interest with any financial organization regarding the material discussed in the manuscript. Received on April 24, 2015. - Accepted for publication on April 25, 2015. - Epub ahead of print on April 30, 2015. Corresponding author: S. Grasso,Università degli Studi di Bari “Aldo Moro”. Dipartimento dell’Emergenza e Trapianti d’Organo (DETO),Sezione di Anestesiologia e Rianimazione, Azienda Ospedaliero-Universitaria, PoliclinicoPiazza Giulio Cesare 11, Bari, Italy. E-mail: [email protected] Vol. 81 - No. 8 MINERVA ANESTESIOLOGICA 829 Anno: 2015 Lavoro: Mese: August titolo breve: ESOPHAGEAL PRESSURE MONITORING IN CRITICAL ILLNESS Volume: 81 primo autore: BERRA No: 8 pagine: 1-2 Rivista: MINERVA ANESTESIOLOGICA Cod Rivista: Minerva Anestesiol EDITORIAL Is esophageal pressure monitoring essential for the most critically ill? L. BERRA 1, R. M. KACMAREK 1, 2, 1Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA; 2Department of Respiratory Care, Massachusetts General Hospital, Boston, MA, USA The use of esophageal manometry has become characterized by increased pleural pressure and/ increasingly important for the management or chest wall elastic abnormalities, including but of the most critically ill mechanically ventilated not limited to ARDS, obesity or surgical pneu- patients.1 When performed properly, esopha- moperitoneum. This differentiation allows the geal pressure measurement provides an estimate clinician to better understand whether it is rea- of pleural pressure and its measurement has ad- sonably safe and feasible to increase airway pres- vanced our understanding of the pathophysiol- sures to better customize mechanical ventilation ogy of critically ill patients and has increasingly in different pathophysiological settings.3 Specifi- assisted in the management of the most complex cally, to be able to identify those situations where patients. Esophageal pressure measurement is plateau pressure can exceed 28 cmH O without 2 useful in guiding the setting of positive end-expir- increased risk of lung injury. End expiratory atory pressure (PEEP) in severe adult respiratory transpulmonary pressure has been proposed as distress syndrome (ARDS),2 the determination the ideal method of determining optimal PEEP.2 of maximum plateau pressure without undue risk The goal, is to insure end expiratory transpulmo- of induced lung injury in patients with altered nary pressure in positive and thus to avoid end expiratory collapse. Additionally, the measure- chest wall mechanics or marked obesity,3 and ment of esophageal pressure has proven useful for the determination of autoPEEP and work of in hemodynamic interpretation (as it allows the breathing in spontaneously breathing patients calculation of transmural filling pressures). Mon- receiving assisted ventilation. Scientific interest itoring of patient-ventilator synchrony, measure- in the exploration of possible applications of es- ment of auto-PEEP during spontaneous breath- ophageal pressure guided ventilation has been re- ing and estimation of work-of-breathing through cently highlighted by the PLUG working group.1 measurement of the pressure-time product has The use of esophageal manometry to describe been shown to be particularly useful in patients intrathoracic pressure changes during spontane- difficult to wean from ventilator support.1 ous breathing dates back to 1878.5 The estimation Since the introduction of esophageal manom- of pleural pressure through esophageal manom- etry, there has been debate whether esophageal etry allows the determination of transpulmonary pressure faithfully reflected pleural pressure. The pressures (end inspiratory plateau pressure minus main issue with esophageal pressure measure- pleural pressure), i.e. the distending pressure of ments is its geometrically limited validity. As the lungs.6 The assessment of how much pressure pleural pressure is characterized by different val- is spent for the passive inflation of the thorax ues, following a gravity-vectored gradient, the is particularly helpful in any clinical condition pleural pressure estimated through esophageal Comment on p. 855. manometry is valid only for structures in close 830 MINERVA ANESTESIOLOGICA August 2015 ESOPHAGEAL PRESSURE MONITORING IN CRITICAL ILLNESS BERRA proximity of the balloon itself. For the same rea- son, balloon positioning at different depths yields recommended (0.5 to 1.0 mL).4 However, these different pleural pressure estimates. As a result po- studies were performed exclusively in vitro and sitioning and functioning of the balloon is criti- on a single catheter per brand; adoption of the cal. Proper positioning is at the mid-esophageal suggested filling volumes is still debated. Further- level identified by the presence of cardiac artifact more, the findings of these two studies have yet to and a matching of esophageal pressure change be validated in an in vivo setting. with airway pressure change during active inspi- Esophageal manometry is an increasingly ration determined by an occlusion test.6 There- important tool in the management of com- fore, the esophageal pressure and airway pressure plex, refractory respiratory failure, allowing the change during inspiration and expiration should evaluation of the true amount of airway pressure be equivalent. Similarly during controlled ven- used for lung inflation and the minimum level tilation, airway and esophageal pressure should of PEEP required to avoid cyclic inflation and change equivalently. Additionally, the volume of deflation. It is also useful for the assessment of air used for balloon inflation influences the relia- autoPEEP, and work of breathing in the spon- bility of esophageal manometry. Balloon pressure taneously breathing patient failing ventilator increases with balloon volume, as a result of dis- discontinuation trials. However, esophageal bal- tension of the balloon itself and the surrounding loon manometry is still flawed by methodologi- structures, as shown in 1964 by Milic-Emili J et cal issued. Mojoli et al. have filled one of the gaps al.4 These authors concluded that esophageal pres- that afflict measurement.8 Future clinical studies sure best estimates pleural pressure at near-zero however are needed to validate their results. balloon volume. More recently Walterspacher et al.7 and Mojoli et al.8 published interesting papers that address the issue of esophageal balloon fill- References ing volumes. Specifically, in this issue of Minerva 1. Akoumianaki E, Maggiore SM, Valenza F, Bellani G, Ju- Anestesiologica, Mojoli et al. 8 studied in vitro the bran A, Loring SH et al. The application of esophageal pres- minimum and maximum volume at which differ- sure measurement in patients with respiratory failure. Am J Respir Crit Care Med 2014;189:520-31. ent catheters accurately measure the surrounding 2. Talmor D, Sarge T, Malhotra A, O’Donnell CR, Ritz R, Lis- pressure. It is interesting to note that the mini- bon A et al. Mechanical ventilation guided by esophageal pres- sure in acute lung injury. N Engl J Med 2008;359:2095-104. mum volume to be injected for proper pressure 3. Chiumello D, Carlesso E, Cadringher P, Caironi P, Valenza measurement was greater than recommended by F, Polli F et al. Lung stress and strain during mechanical ventilation for acute respiratory distress syndrome. Am J each of the four manufacturers of the catheters Respir Crit Care Med 2008;178:346-55. tested, and the best balloon working volume did 4. Milic-Emili J, Mead J, Turner Jm, Glauser Em. Improved technique for estimating pleural pressure from esophageal vary considerably among catheters. Clinicians, in balloons. J Appl Physiol 1964;19:207-11. addition, should be aware that the pressure-vol- 5. Luciani L. Archivio delle scienze mediche. Vol II. Torino: ume curve of the balloon changes after the first Tipografo Vincenzo Bona; 1878. p. 186. 6. Sarge T, Talmor D. Transpulmonary pressure: its role in pre- inflation, suggesting that some inflation/deflation venting ventilator-induced lung injury. Minerva Anestesiol cycles should be performed before placement. 2008;74:335-9. 7. Walterspacher S, Isaak L, Guttmann J, Kabitz HJ, Schu- The authors emphasize that in the case of an un- mann S. Assessing respiratory function depends on me- successful occlusion test evaluation of balloon chanical characteristics of balloon catheters. Respir Care 2014;59:1345-52. filling volume should occur before repositioning 8. Mojoli F, Chiumello D, Pozzi M, Algieri I, Bianzina S, of the balloon. According to their data, some bal- Luoni S et al. Esophageal pressure measurements under different conditions of intrathoracic pressure. An in vitro loons require working filling volumes of up to 7.5 study of second generation balloon catheters Minerva Anes- mL considerably more that has been traditionally tesiol 2015;81:855-64. Conflicts of interest.—The authors certify that there is no conflict of interest with any financial organization regarding the material discussed in the manuscript. Received on Febrary 27, 2015. - Accepted for publication on April 28, 2015. - Epub ahead of print on April 30, 2015. Corresponding author: R. M. Kacmarek, Department of Respiratory and Department of Anesthesia, Massachusetts General Hospital and Harvard Medical School, Warren Building 1225, 55 Fruit Street, Boston, MA 02114, USA. E-mail: [email protected] Vol. 81 - No. 8 MINERVA ANESTESIOLOGICA 831 Anno: 2015 Lavoro: Mese: August titolo breve: HOW SHOULD I STRUCTURE MY POST-ICU CLINIC? Volume: 81 primo autore: RANZANI No: 8 pagine: 1-2 Rivista: MINERVA ANESTESIOLOGICA Cod Rivista: Minerva Anestesiol EDITORIAL How should I structure my Post-ICU Clinic? From early goal rehabilitation to outpatient visits O. T. RANZANI 1, C. JONES 2, 3 1Respiratory Intensive Care Unit, Pulmonary Division, Heart Institute, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil; 2Critical Care Rehabilitation, Whiston Hospital, Prescot, UK; 3Institute of Ageing and Chronic Disease, Faculty of Health and Life Sciences, University of Liverpool, Liverpool, UK Passing through a critically illness and facing ever, there are questions around their implemen- the Intensive Care Unit (ICU) scenario are tation.6, 8, 9 experiences that frequently brings uncomfort- able physical, cognitive and psychological se- What are the aims of the Post-ICU Clinic? quelae for patients and family members.1-3 In contrast, a smaller proportion of patients deal This is a crucial point in the topic and has with surviving ICU as a victory in their life and, changed over time. Post-ICU Clinics can be so, a source of energy and a life changing op- facilities for screening ICU survivors and their portunity. families sometime after hospital discharge. The Concurrently, the multidisciplinary staff in- rational is to identify patients who are not re- volved in the care of critically ill patients also covering or presented with new problems.6 Post- receive many inputs during the workday apart ICU Clinics can also be focused on physical and of technical issues: from happiness of recovering psychological rehabilitation, manned by staff patients and gratefulness of family members to specializing in the care of ICU survivors, who stressful situations, dealing with life threatening have different demands from routine patients, conditions, death, and impotence feelings.4 such as hallucinations related to their ICU stay. Nowadays, the proportion of ICU survivors However, the ideal goal of Post-ICU Clinics is increasing and new challenges caused to the should be an advanced facility that allows con- health care system, health care workers and tinuity of care. Indeed, initiatives beginning as population. Indeed, the suffering of recovering early as possible (sometimes inside the ICU) patients and relatives can be high and negatively could decrease the incidence of problems after affects their quality of life.1 hospital discharge.10, 11 The context of each cen- Furthermore, the burden of ICU survivors is tre should be understood, since the cost-effec- enormous and needs special attention.5 In this tiveness of these models must be discussed. In a issue of Minerva Anestesiologica, Dettling-Ihnen- national survey in the UK, financial constraints feldt et al.6 reported a pilot experience in con- was the main reason for not having a Post-ICU ducting two Post-ICU Clinics in Netherlands. Clinic.12 Other point raised by Dettling-Ih- Post-ICU clinics are specialized units with the nenfeldt et al.6 is the existence of other services main aim to help ICU survivors and was first de- within the health system, which already provide scribed in UK in 19857. Several centres around rehabilitation and support, sometimes close to the world have implemented these clinics; how- the patients’ home or familiar to them because of previous attendance. The ICU-rehabilitation Comment on p. 865. 832 MINERVA ANESTESIOLOGICA August 2015