NON-CARDIAC SURGERY IN PATIENTS WITH VENTRICULAR ASSIST DEVICES:
OUR EXPERIENCE IN PUERTA DE HIERRO UNIVERSITY HOSPITAL, MADRID. 
Albajar, A; González, A; Álvarez J.M; Forteza, A; Gómez-Bueno, M; García, J. 
Anaesthesiology and Reanimation.
Puerta de Hierro University Hospital, Madrid; Spain. 

BACKGROUND: 
Heart failure  constitutes a high incident and prevalent syndrome. Its prevalence in devoloped countries is 10000 cases per million habitants. The calculated risk of developing a heart failure is around 20% in the American population above 40 years old. It affects at 1-2% of the global population and above 75 years old its prevalence raises up to 10-20% (1), representing around 2% of the total health expenditure. It takes around 10% of the hospital beds and the surviving expectations of the patients with an advance disease is less than the surviving expectations of some kinds of cancer. Eventhough the surviving rates are being modified , currently is about 50% to five years  from the diagnose date. At present, we can realize the higher use of ventricular assist devices (VAD) for patients with congestive heart failure refractory to medical treatment (divided in four groups: shock after myocardial acute infraction, myocardial disfunction after cardiac surgery, heart failure after myocarditis and chronic descompesated heart failure (2))  and for patients as a bridge to cardiac trasplant due to the low number of appropiate heart donations (3). We present two cases of patients with ventricular assist devices (berlin heart R) undergoing urgent surgery. 

CASE REPORT: 
CASE 1: 
Male, with a left ventricle assist device (Berlin heart) implanted in early december 2009 because of a dilated cardiomyopathy (FEVI 30%;  tricuspid and mitral insufficiency and severe pulmonary hypertension). No allergies. No other personal background.  Regular medication: alopurinol, dipiridamol 100mg c/8h, acetylsalicylic acid 300mg c/24h., carvedilol, captopril, sildenafil, enoxaparine 80mg c/12. 
Hospitalized requiring emergency laparotomy for an open appendicectomy and drainage of an appendicular abscess. 3L of ascitis are aspirated during the surgery and a left pleural drainage is placed with a debit of 1L of serohematic pleural liquid. Haemodynamically stable during introperatory not requiring vasoactive support. Not important intraoperatory bleeding, Transfusion of 1 platelet pool. Enoxaparin suspended during hospitalization befote surgery. Fluids: 500mL colloids and 1000mL crystalloids
After the surgery is transfer to the ICU intubated. Blood test after admission in ICU: lactate: 1.1; troponin: 0,13; GOT: 26; GGT 122;  platelets: 783.000; INR 2,34; APTT: 47,7 sec; Hb: 10,2 g/dL; Htco: 32%; Urea: 60; Creatinine: 0,9. Leucocytes: 24,920. Extubated after 4 hours in ICU (Sat above 97% pO2: 163 pCo2: 37,5 with nasal prongs at 2lpm. Antibiotherapy with Vancomycin and Meropenem is continuated (iniciated before surgery because of febricula and leukocytosis). 
The day after surgery the patient remains hemodynamically stable and starts oral tolerance without problems, the acetylsalicylic acid (100mg/d), dipiridamol (100mg c/8h) and Infussion of 1000Ui of sodic heparin are initiated. Not  active bleeding nor anemization not required transfusion during the postoperatory.  Discharge from ICU 3 days after surgery. 

CASE2:  
Male, 50 years old with a biventricular assist device (berlin heart) implanted in April 2015 because of a hipertrofic cardiomyopathy in dilated phase (FEVI 25%). Regular medication: Acenocumarol (removed 3 days before surgery), clopidogrel (changed to acetylsalycilic acid 100mg a week before surgery), bisoprolol, furosemide, omeprazol.
 In July 2015 is hospitalized for an elective laparoscopic cholecystectomy. Tendency to hypotension during the surgery requiring vasoactive support i(norepinephrine in a low dose (0,022 mcg/kg/min) and volumen. Altough the patient was not taking the acenocumarol 3 days before surgery we could observe a coagulopathy with INR of 2 so we proceded to the administration of 1200Ui of prothrombinic complex. Not important intraoperatory bleeding, Not transfussion. Profilactic antibiotherapy with cefazoline 2gr. Intraoperative fluids administration: 2000mL crystalloids. 
Admission in ICU after surgery: haemodinamically stable and extubated. O2 saturation around 99% pO2: 100 pCo2: 34,1 pH: 7,4 HCO3-: 22 with nasal prongs at 4lpm. Blood test at arriving: Lactate 0,7; platelets:262,000; INR 1,4; APTT:48,60 sec; Hb:7,60  g/dL; Htco:23,70 ; Urea: 46,00 Creatinine: 0,85. Leucocytes: 12,000. Hb of 7,6 after surgery with no acute bleeding, requiring transfusion of red cells during the postoperatory.  The day after the surgery,  the Infussion of 400Ui/h of sodic heparin is initiated. Good subsequent oral tolerance.
Discharge from ICU 24hs after surgery. No signs of infection. Good appearance of the surgical wound. Reinsertion of Sintrom with INR control between 2,5-3,5 48h after surgical procedure. Control of surgical pain with paracetamol and metamizol avoiding other NSAIDs for risk of cardiac descompensation. 


DISCUSSION: 
Nowadays, is becoming more common to deal with patients carriying an assist device serving as a brigde  to a cardiac transplant as we have seen in these two patients.  Eventhough every day we know more about the performance of these devices and its indications (4), there is not a lot of information published about the intraoperatory management of the patients carriers of VAD that require urgent or scheduled surgery . The presence of these sets,added to the usual comorbidities of these patients, enhance the posibillity of intraoperatory and postoperatory complications. Altough we only have the experience with a low number of patients , we can see the importance of understanding several aspects: the safe and proper operation of each device, underlying the importance of the correct placement of the VAD cannulas during the intervention avoiding this way their kincking so the cardiac output is the adecuate for the patient during the whole procedure; In second place, the accurate managment of the medication, including anticoagulants and antiplatelet, for their correct suspension or the correct reversion of their action to prevent a profuse intraoperatory bleeding (1); In addition qe should know the physiological cardiaopulmonary changes due to the implation of VAD knowing thet large volumen infussions during the surgery are necessary due to its dependance of high preload to its correct function. To sum up, we have to be able to determine the correct implementation of antibiotherapy ,profilact or therapeutic, in this patients because of their higher risk of infections. 

REFERENCES: 
1. Kristensen, S; Knutti, J; Saraste A; Anker,S; Botker, H E; DeHert, S; Ford, I; Gonzáles-Juanatey, JR; Gorenek, B; Roberts, G; Hoeft, A; Huber, K; Lung, B; Kjeldsen, K; Longrois, D; Luscher, TF; Pierard, L; Pocock, S; Price, S; Roffi, M; Sirnes, PA; Sousa-Uva, M; Voudris, V; Funck-Brentano, C.. 2014 ESC/ESA  guidelines on non cardiac surgery: cardiovascular assessment and Management. European Heart Journal (2014) 35; 2383-2431. 
2. Delgado M; Bernabeo, G; Hernán Delgado, D;  Avances en asistencias circulatorias mecánicas. Division of cardiology and trasplantation. University Health Network. Toronto. Ontario. Canada.
3. Gómez Bueno, M; Segovia Cuber, J; Alonso-Pulpón Rivera, L. Asistencia mecánica circulatoria y trasplante cardiaco. Indicaciones y situación en España. Unidad de insuficiencia cardiaca y trasplantre. Servicio cardiología. Hospital universitario Puerta de Hierro. Madrid. España. 
4. Feldman, D; Pamboukinan, SV; Teuteberg JJ, et al. The 2013 International society for heart and lung transplantation guidelines for mechanical circulatory support: executive summary. J Heart Lung Transplant 2013; 32: 157.

LEARNING POINT: 
In brief, we should create protocols for the corecct anaesthetic management of patients with VAD. There are not a lot of cases per year in our hospital or others with the same characteristics so it is important to be prepared in advance and study the managment of this patients in other centres. There are not a lot of intraoperatory modifications but we have to understand perfectly the managment of these devices so if a complication shows up we know how to deal with it inmediatly. The two most relevant points during the intraoperatory are the manteinance of a good preload and the correct colocation of the cannulas, in order to avoid their kinking, so we can ensure the correct cardiac flow corresponding to the CMI (coporal mass index) of the patient. We also have to know the antibiotic and the anticoagulation management before and after the surgery and have a close perioperatively monitoring.

Non-cardiac surgery in patients with ventricular assist devices: our experience in Puerta de Hierro University Hospital, Madrid