Anesthetic+Management+of+VATS

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=** Introduction **=
 * Although there are cosmetic and economical advantages to the VATS approach, large randomized controlled trials are still lacking documenting the benefit of VATS versus conventional ‘thoracotomy’.


 * Patient expectations are different as a minimal invasive approach is often falsely associated with minimal risk. This leads to an additional stress factor on the anesthesiologist.


 * ’VATS’ approach shows benefits in regards to post-op pain and economics, reduced pain scores, improved pulmonary function, length of chest tube placement and length of hospital stay.


 * The first utilization of thoracoscopy to treat illnesses within the chest cavity was reported in 1910 by the Swedish physician Jacobaeus.

=** Indications **=
 * Although initially used only for simple procedures of the mediastinum, pleura and lungs, thoracic surgeons are now performing very complex surgical procedures, such as lobectomies, through a VATS approach.

=** Choice of anesthetic technique depends upon **=
 * 1) Wishes of the patient
 * 2) Experience level of the clinician
 * 3) Type and duration of the procedure (diagnostic, tissue sampling etc.)


 * Most VATS procedures today are performed under general anesthesia utilizing one-lung ventilation (OLV) techniques, which provide better exposure and guarantee a secure airway in the lateral decubitus position.

=** Indications for one-lung ventilation (OLV) **=
 * Absolute vs. Relative (true for most circumstances in pre VATS era).


 * A recent paper proposed a different approach that includes the terms lung separation and isolation. Where isolation would include all absolute indications for OLV In which protection from contamination of the contralateral lung is the goal, such as:
 * 1) massive bleeding
 * 2) pus
 * 3) alveolar proteinosis or
 * 4) bronchopleural fistula


 * VATS for diagnostic and therapeutic procedures, which require a well collapsed lung, should fall under indications for lung separation where there is no risk of contamination to the dependent lung and is performed primarily to improve surgical exposure.
 * Inability to completely deflate the nondependent lung during VATS leads to poor surgical exposure, which, in turn, can jeopardize the success of the procedure, potentially requiring conversion to an open technique.
 * Prior algorithms used to improve oxygenation during OLV cannot be used during VATS. Unfortunately, the application of CPAP which represented an attractive maneuver to treat hypoxemia during OLV in the open thoracotomy patient, is poorly tolerated during VATS because of the obstruction of the surgical field by the partially inflated lung.
 * Alternative methods should be employed in VATS such as:
 * 1) positive end-expiratory pressure (PEEP) to the dependent lung,
 * 2) recruitment maneuvers or
 * 3) intermittent inflation of the nondependent lung

=** Double-Lumen Tubes (DLTs) or Bronchial Blockers **= =** Ventilation **=
 * (DLTs) classically considered the ‘gold standard’ for achieving OLV.
 * Naraya naswamy et al. showed that in 100 patients undergoing left-sided lung surgery, in regards to quality of surgical exposure, there was no difference found between the use of bronchial blockers (Arndt wire- guided, Cohen Flexi-tip, Fuji Uni-blocker; Cook Critical Care, Bloomington, Indiana, USA) and a left-sided DLT (Mallinckrodt Medical). Authors concluded that DLT and Bronchial Blockers provided equivalent surgical exposure during left-sided open or VATS procedures
 * Consequently, as most VATS procedures require lung separation and not isolation, the insertion of a bronchial blocker to obtain OLV is an attractive alternative to a DLT, especially as multiple intubations of the trachea will not be necessary when using a bronchial blocker. Additionally, the incidence of difficult intubation is much higher when using a DLT
 * It is well established in the critical care population that large tidal volumes (12 – 15 ml/kg) and excessive airway pressures can lead to lung damage.
 * Esteban et al. [18] found in a large observational study that patients who were ventilated with plateau airway pressures greater 35cmH2O had increased 28-day mortality rates when compared with those who did not.
 * A study by Garutti et al. showed that the mode of OLV (pressure controlled versus volume controlled) did not affect arterial oxygenation during OLV or during the early postoperative period as long as a tidal volume of 8ml/kg was applied.
 * The question, however, as to what tidal volume should be used during OLV is still open and requires further investigation.

=** Inhalational or Intravenous Anesthetics **= =** Monitoring **= =** Postoperative Analgesia **= =** Increased level of stress for the anesthesiologist **= =** Complications **= In a large series published by Shaw et al. [9], in 180 patients after VATS =** Conclusion **= The field of thoracic surgery is dynamic and constantly evolving. A shift to video-assisted surgery is clearly taking place. Although certain procedures have gone out of favor due to unexpected disappointing results (e.g. lung volume reduction surgery) [28], other areas are rapidly embracing this technology. Electrophysiolo- gists are using VATS to isolate the pulmonary veins in the hope of achieving improved results in the treatment of chronic atrial fibrillation [29]. As anesthesiologists, we must stay in tune with developments occurring within the field. = References and recommended reading = 1 Walker WS, Codispoti M, Soon SY, et al. Long-term outcomes following VATS lobectomy for nonsmall cell bronchogenic carcinoma. Eur J Cardiothor- ac Surg 2003; 23:97–402. 2 Kaseda S, Aoki T, Hangai N, Shimizu K. Better pulmonary function and prognosis with videoassisted thoracic surgery than with thoracotomy. Ann Thorac Surg 2000; 70:1644–1646. 3 McKenna RJ Jr, Houck W, Fuller CB. Video-assisted thoracic surgery lobectomy: experience with 1,100 cases. Ann Thorac Surg 2006; 81:421– 425. 4 Demmy TL, Curtis JJ. Minimally invasive lobectomy directed toward frail and high-risk patients: a case-control study. Ann Thorac Surg 1999; 68:194– 200. 5 Braimbridge MV. The history of thoracoscopic surgery. Ann Thorac Surg 1993; 56:610–614. 6 Lewis RJ, Caccavale RJ, Sisler GE, Mackenzie JW. Video-assisted thoracic surgical resection of malignant lung tumors. J Thorac Cardiovasc Surg 1992; 104:1679 – 1685. 7 Hazelrigg SR, Nunchuck SK, LoCicero J 3rd. Video assisted thoracic surgery study group data. Ann Thorac Surg 1993; 56:1039–1043. 8 Onaitis MW, Petersen RP, Balderson SS, et al. Thoracoscopic lobectomy is a safe and versatile procedure: experience with 500 consecutive patients. Ann Surg 2006; 244:420–425. 9 Shaw JP, Dembitzer FR, Wisnivesky JP, et al. Video assisted thoracoscopic 􏰀 lobectomy: state of the art and future directions. Ann Thorac Surg 2008; 85:S705 – S709. VATS for lung resection can safely be performed even in the elderly and patients with impaired pulmonary function. 10 Whitson BA, Andrade RS, Boettcher A, et al. Video-assisted thoraco- 􏰀􏰀 scopic surgery is more favorable than thoracotomy for resection of clinical stage I nonsmall cell lung cancer. Ann Thorac Surg 2007; 83:1965– 1970. Patients undergoing VATS lobectomy for stage I nonsmall cell lung cancer had fewer postoperative complications than the open thoracotomy group. 11 Shiraishi T, Shirakusa T, Hiratsuka M, et al. Video-assisted thoracoscopic surgery lobectomy for c-T1N0M0 primary lung cancer: its impact on locor- egional control. Ann Thorac Surg 2006; 82:1021–1026. 12 Sugi K, Kaneda Y, Esato K. Video-assisted thoracoscopic lobectomy achieves a satisfactory long-term prognosis in patients with clinical stage IA lung cancer. World J Surg 2000; 24:27–31. 13 Kirby TJ, Mack MJ, Landreneau RJ, Rice TW. Lobectomy – video-assisted thoracic surgery versus muscle-sparing thoracotomy. A randomized trial. J Thorac Cardiovasc Surg 1995; 109:997–1002. 14 Narayanaswamy M, McRae K, Slinger P, et al. Choosing a lung isolation device for thoracic surgery: a randomized trial of three bronchial blockersversus double-lumen tubes. Anesth Analg 2009; 108:1097–1101. Bronchial blockers provide equivalent surgical exposure when compared with left- sided DLTs during left-sided open or VATS thoracic procedures. 15 Dreyfuss D, Soler P, Basset G, Saumon G. High inflation pressure pulmonary edema. Respective effects of high airway pressure, high tidal volume, and positive end-expiratory pressure. Am Rev Respir Dis 1988; 137:1159– 1164. 16 Ricard JD, Dreyfuss D, Saumon G. Production of inflammatory cytokines in ventilator-induced lung injury: a reappraisal. Am J Respir Crit Care Med 2001; 163:1176 – 1180. 17 Amato MB, Barbas CS, Medeiros DM, et al. Effect of a protective-ventilation strategy on mortality in the acute respiratory distress syndrome. N Engl J Med 1998; 338:347–354. 18 Esteban A, Anzueto A, Frutos F, et al. Characteristics and outcomes in adult patients receiving mechanical ventilation: a 28-day international study. JAMA 2002; 287:345–355. 19 Garutti I, Martinez G, Cruz P, et al. Effects of ventilatory mode during one-lung ventilation on intraoperative and postoperative arterial oxygenation in thoracic surgery. J Cardiothorac Vasc Anesth 2009. [Epub ahead ofprint] In patients undergoing thoracic surgery, the mode of mechanical [pressure- controlled ventilation (PCV) versus volume-controlled ventilation (VCV)] ventilation during OLV does not affect arterial oxygenation. 20 Marshall C, Lindgren L, Marshall BE. Effects of halothane, enflurane, and isoflurane on hypoxic pulmonary vasoconstriction in rat lungs in vitro. Anesthesiology 1984; 60:304–308. 21 Bassi A, Milani WR, El Dib R, Matos D. Intravenous versus inhalation anaesthesia for one-lung ventilation. Cochrane Database Syst Rev 2008:CD006313. There is no evidence from randomized controlled trials of differences in patient outcomes for anesthesia maintained by intravenous versus inhalational anesthesia during OLV. 22 De Conno E, Steurer MP, Wittlinger M, et al. Anesthetic-induced improvement 􏰀 of the inflammatory response to one-lung ventilation. Anesthesiology 2009;110:1316 – 1326. A significant reduction of inflammatory mediators is found after OLV when sevoflurane is administered as opposed to propofol with a significantly better clinical outcome. 23 Kaya FN, Turker G, Basagan-Mogol E, et al. Preoperative multiple-injection thoracic paravertebral blocks reduce postoperative pain and analgesic re- quirements after video-assisted thoracic surgery. J Cardiothorac Vasc Anesth 2006; 20:639–643. 24 Vogt A, Stieger DS, Theurillat C, Curatolo M. Single-injection thoracic paravertebral block for postoperative pain treatment after thoracoscopic surgery. Br J Anaesth 2005; 95:816–821. 25 Della Rocca G, Coccia C, Pompei L, et al. Postthoracotomy analgesia: epidural vs intravenous morphine continuous infusion. Minerva Anestesiol 2002; 68:681–693. 26 Block BM, Liu SS, Rowlingson AJ, et al. Efficacy of postoperative epidural analgesia: a meta-analysis. JAMA 2003; 290:2455–2463. 27 Joshi GP, Bonnet F, Shah R, et al. A systematic review of randomized trials 􏰀􏰀 evaluating regional techniques for postthoracotomy analgesia. Anesth Analg 2008; 107:1026–1040. Thoracic epidural analgesia or continuous paravertebral block is equivalent for treatment of postoperative pain after thoracotomy. 28 Fishman A, Martinez F, Naunheim K, et al. A randomized trial comparing lung- volume-reduction surgery with medical therapy for severe emphysema. N Engl J Med 2003; 348:2059–2073. 29 Edgerton JR, McClelland JH, Duke D, et al. Minimally invasive surgical ablation of atrial fibrillation: six-month results. J Thorac Cardiovasc Surg 2009; 138:109–113.
 * Although work published in the 1980s was able to make a clear association between the blunting of hypoxic pulmonary vasoconstriction (HPV) and inhalational anesthetics in rat lungs, a recent meta-analysis by Bassi et al. was unable to demonstrate a benefit of one technique over the other in humans.
 * A study published by De Conno et al. showed that patients receiving Sevoflurane during OLV expressed lower levels of inflammatory mediators than patients receiving a target controlled infusion of propofol. This study also showed an improvement in clinical outcome in the sevoflurane group.
 * False readings, especially in the setting of poor peripheral perfusion, can limit the utility of noninvasive pulse oximetry.
 * Intermittent ABG sampling to confirm noninvasive pulse oximetry readings provides an additional layer of safety for the patient which makes arterial line placement highly advised.
 * During VATS if massive hemorrhage occurs, the surgeon is often unable to easily gain control of large vessel bleeding without converting to an open thoracotomy. Maintaining stable hemodynamics, while the surgeon performs a thoracotomy, is extremely challenging and mandates the placement of large bore intravenous catheters prior to the start of the procedure.
 * In patients in whom peripheral venous access is difficult or cardiovascular comorbidities are present, central venous access is recommended for rapid volume resuscitation and for the central administration of vasoactive medications.
 * Although VATS showed reduction in postoperative pain when compared with thoracotomy, VATS procedures are still associated with a significant amount of postoperative pain, that is, not only disturbing to patients but may also be associated with pain-related morbidities and prolonged hospital stays [23,24].
 * Thoracic epidural analgesia is considered the gold standard in pain relief by many anesthesiologists during the post- operative period for the thoracic patient [25,26].
 * Although other forms of postoperative analgesia are possible, many are associated with unwanted side effects such as:
 * 1) Systemic opioids are respiratory depressive and inhibit the cough reflex.
 * 2) Nonsteroidal anti-inflammatory medication can inhibit coagulation and does not control the immediate postoperative pain experienced by this patient population.
 * 3) The utilization of paravertebral blocks has shown promise as an alternative to epidural analgesia [27].
 * A false assumption that is made by patients coming for minimal invasive surgery is that the perioperative risk will also be ‘minimal’.
 * VATS is frequently described to the patient and their family as a ‘simple three-hole’ entry into the chest. Although, VATS is associated with improved healing, lung function and shorter hospital length of stay, by no means should one be lured into thinking that the procedure is any less invasive than an open thoracotomy.
 * Diagnostic VATS procedures are being increasingly performed on ASA III – IV patients, who historically would have been classified as inoperable using an open approach. A typical example would be a patient on the cardiac transplant list who needs a pretransplant tissue diagnosis of a lung lesion seen on a preoperative chest radiograph.
 * Consequently, very ill patients requiring flawless lung separation techniques, who expect an uneventful perioperative course, pose a tremendous burden of psycho- logical stress upon the anesthesiologist.
 * 1) atrial fibrillation (10%)
 * 2) Air leak (7.2%)
 * 3) pneumonia (2.0%)
 * 4) respiratory failure (2.0%)
 * 5) empyema (1.3%) and
 * 6) deep venous thrombosis (0.7%)

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