[Perioperative morbidity and mortality in surgery for dissecting aneurysm of the ascending aorta]. / Morbimortalidad perioperatoria de la cirugía de la disección de aorta ascendente.

OBJECTIVE: To describe complications and mortality in patients diagnosed of Stanford's type A (Daily) dissection of the ascending aorta requiring circulatory arrest for emergency placement of an aortic graft. PATIENTS AND METHODS: Retrospective study of 21 patients treated between December 1992 and November 1997. RESULTS: Hypertension was the disease most often associated with the diagnosis (in 8 of the 21 patients). Preoperative mortality was 9.5% (2 of the 21 patients), no deaths occurred in the operating room and postoperative mortality was 15.8% (3 of the 19 patients who underwent surgery). Durations in mean time (SD) in minutes were as follows: anesthesia-surgery 437.9 (92), extracorporeal circulation 192.5 (47), aortic clamping 82.6 (20), circulatory arrest 30.5 (8). Retrograde cerebral circulation was carried out during circulatory arrest in all cases. Mean temperature during this period was 14.9 degrees C. During the postoperative period we recorded three permanent neurological complications, six cases of acute renal failure and seven respiratory complications, specifically one instance of adult respiratory distress syndrome and six of pneumonia, the most common. Consumption of blood products was high, with great interindividual variation. CONCLUSION: Anesthesia for and recovery from surgery for acute aortic dissection is complex and associated with a high rate of postoperative complication and high consumption of blood products.

[Oxygen consumption during anaphylactic shock]. / Consumo de oxígeno durante un shock anafiláctico.

We report the case of a 49-year-old man who suffered anaphylactic/anaphylactoid shock within the first few minutes of reaching the recovery room after unremarkable coronary surgery and revascularization. Adequate monitoring permitted differential diagnosis and establishment of specific treatment Monitoring also allowed us to document hemodynamic changes and oxygen consumption during this instance of anaphylactic/anaphylactoid shock. Anaphylactic/anaphylactoid shock caused significant vasoparalysis with decreases in arterial pressures, reduction of oxygen consumption and discrete changes in oxygen exchange. The reposition of volume and administration of adrenaline were insufficient. Appropriate management of noradrenaline perfusion, which was made possible by complete monitoring, was essential for reestablishing normal hemodynamic and oximetric readings and preventing myocardial ischemia.

[Depression of the mononuclear phagocyte system caused by high doses of narcotics]. / Depresión del sistema mononuclear-fagocítico provocada por altas dosis de morfínicos.

We evaluated in human monocytes the effect of high doses of alfentanyl on the expression of vimentin filaments, the phagocytic activity and the membrane display of HLA-DR molecules in the subjects undergoing surgery. The study was performed on 30 patients, ASAI-II. The patients received 100 mcg/kg i.v. of Alfentanil and the maintenance of anaesthesia was made with Alfentanil (2-3 mcg/kg/min.). The patients were randomized in two groups. The patients were ventilated with N2O:O2 (1:1) (Group I) or air: O2 (1:1) (Group II). After surgery, all patients of the Group II received Naloxone (0.2-0.4 mg). Central venous blood samples were obtained before induction, one and two hours after induction of anaesthesia and at the end of surgery. Separation of monocytes was performed according to Boyum technique. CD35 and HLA-DR molecules and vimentin filaments were studied by indirect immunofluorescence method using monoclonal antibodies. Percentage of positive cells were read with a cytofluorometer. The phagocytic function of monocytes was determined by ingestion of latex particles. Cortisol and ACTH plasma levels were determined by RIA. High doses of Alfentanyl depress phagocytic function and membrane display of CD35 and HLA-DR molecules in monocyte and induce marked changes in the organization of vimentin filaments in these cells in patients undergoing surgery. This monocytic depression was more marked in the patients ventilated with N2O. In our results there was uninhibition of ACTH and cortisol plasma levels responses to surgical stress by Alfentanil administration. Since the effects of Alfentanil were reversed by Naloxone, an opioid receptor mechanism seems to mediate these events.