Traqueostomía percutánea con asistencia fibrobroncoscópica: evaluación prospectiva de 100 casos consecutivos y revisión de la literatura / Fiberoptic bronchoscopy assisted percutaneous tracheostomy: report of 100 patients

Background: Development of percutaneous techniques for tracheostomy have facilitated its implementation in the intensive care unit (ICU). Aim: To evaluate the safety of performing percutaneous tracheostomy (PT) using the Ciaglia Blue Rhino thechnique with fiberoptic bronchoscopy assistance in patients with prolonged mechanical ventilation. Patients and methods: Prospective evaluation of 100 consecutive patients aged 62±16 years (38 women) subjected to percutaneous tracheostomy. AU the procedures were performed in the ICU. Demographic variables, APACHE II, days of mechanical ventilation before PT, operative and post operative complications were recorded. Results: Mean APACHE II score was 20±3. Patients required on average 16±7 days of mechanical ventilation before PT. Eight patients (8 percent) had operative complications. One had an episode of transitory desaturation, one had a transitory hypotension related to sedation and six had mild bleeding not requiríng transfusión. No patient required conversión to surgical tracheostomy. Four patients (4 percent) presentedpost operative complications. Two had a mild and transitory bleeding ofthe ostomy and two had a displacement ofthe cannula. No other complications were observed. Conclusions: PT using the Ciaglia Blue Rhino technique with fiberoptic bronchoscopy assistance is a safe procedure that can be performed in the ICU by trained intensivists.

Sedación guiada por protocolo versus manejo convencional en pacientes críticos en ventilación mecánica / Protocol based sedation versus conventional treatment in critically ill patients on mechanical ventilation

Background: Sedatives and analgesic drugs give comfort and allow adequate respiratory support to critically ill patients in mechanical ventilation (MV). Its improper use may increase the duration of MV. Clinical guidelines suggest implementation of protocols, however this is seldom done in clinical practice. Aun: To compare in MV patients, nurse-applied guided by protocol administration of sedatives and analgesic drugs (protocol: group P) with the habitual practice using physicians criteria (control: group C). Material and methods: Inclusión criteria was the need of MV more than 48 h. The exclusión criteria were acute neurological diseases, hepatic cirrhosis, chronic renal failure and limitation of therapeutic efforts. Midazolam and fentanyl were used in both groups. The level of sedation was monitored with the Sedation Agitation Scale (SAS). In the P group, trained nurses applied algorithms to adjust the sedative doses according to a predefined SAS goal. Results: Forty patients were included, 22 aged 65±19 years in group P and 18 aged 54±21 years in group C. Apache II scores were 16±8 and 19±8 in each group. SAS score was more frequently evaluated within goal boundaries in group P than in group C (44 percent and 32 percent, respectively p =0.001). No differences in the proportion of patients with inadequate sedation were observed between treatment groups. Midazolam doses were lower in P than in C group (0.04 (0.02-0.07) and 0.06 (0.03-0.08) mg/kg/h respectively, p =0.005). Conclusions: The implementation of sedation protocol applied by nurses improved the quality of sedation and reduced the doses of Midazolam in mechanically ventilated patients.

Acidosis láctica severa asociada a infusión de propofol: Caso clínico / Severe lactic acidosis caused by propofol infusion: Report of one case

Propofol infusion syndrome (PRIS) is a rare but potentially lethal complications. This disorder is triggered under unknown circumstances by a propofol infusion of more than 5 mg/kg/h for more than 48 h. PRIS is characterized by a multiorgan failure and rhabdomyolysis and is induced by a disturbance in mitochondrial long chain fatty acid oxidation. We report a 43 year-old woman who underwent brain surgery due to a vascular malformation. In the immediate postoperative period, she had an unexplained and severe lactic acidosis. During anaesthesia, she received a propofol infusion of 7 mg/kg/h that continued in the UCI at a rate of 3.5 mg/kg/h, for 8 hours more. The suspicion of PRIS motivated immediate discontinuation of propofol with rapid correction of lactic acidosis and full recovery of the patient.

Reanimación protocolizada del shcok séptico / Protocolized reanimation of septic shock

Severe sepsis and septic shock are pathologies with an increasing incidence in the world. Annually, in the USA 200.000 people die because of severe sepsis, the same number that die because of a myocardial infarction, being this last disease much more common. In Chile, a multicentric study found a 40 percent of prevalence of severe sepsis in critically ill patients, with amortality of 27 percent. In this scenario, it becomes of great importance the appropriate and integral management of this condition, by means of an early diagnosis and the implementation of anaggressive protocolized resuscitation, guided by clear goals. During the first stage of the resuscitation cristalloids and/ or colloids can be used, in order to expand the intravascular space, searching for CVP around 8 to 12 mmHg. In case of hypotension refractory to the administration of fluids, it is recommended to start with increasing doses of norepinephrin untila MAP of 65 - 75 mmHg is achieved. The intensity of the septic shock can be stratified according to the requirements of norepinephrine. It is of great importance to obtain blood cultures of the patients and to start with empiric antibiotic therapy as soon as possible. The initial metabolic goal must be the normalization of the central venous oxygen saturation. The implementation of the resuscitation bundle during the first six hours, since the diagnose of severe sepsis is done, increases the chances of surviving. Protocols of sedation and analgesia, and the use of protective mechanical ventilation is highly recommended. The use of hydrocortisone and human recombinant protein C in selected patients, may have a beneficial result in the outcome.Vasopressin, terlipressin and high-volume hemofiltration can be used as rescue measures for the most severe patients.

Estrés oxidativo y sepsis / Oxidative stress and sepsis

El Shock Séptico es una importante causa de morbi-mortalidad en pacientes críticos que podría ser explicado, al menos en parte, por una desregulación de la respuesta inmuno-inflamatoria. La liberación de componentes microbianos produciría un desbalance con predominio de agentes prooxidantes como las especies reactivas de oxigeno (EROS), sobre las defensas antioxidantes. Las EROS dañan directamente los tejidos al atacar las biomoléculas e indirectamente actuando como mediadores pro inflamatorios. Estudios efectuados en pacientes críticos que cursan con sepsis, han demostrado disminución de lasdefensas antioxidantes. Esto compete a mecanismos enzimáticos y no enzimáticos entre los que han sido estudiados: actividad de enzimas antioxidantes, niveles plasmáticos de vitaminas antioxidantes y capacidad antioxidante del plasma, parámetros que también han sido correlacionados con elpronóstico de sobrevida de estos pacientes. Además, se ha evidenciado un incremento de los niveles plasmáticos de productos de lipoperoxidación, lo que representa aumento del daño oxidativo en las membranas celulares. Los parámetros relacionados con el estrés oxidativo podrían ser, potencialmente, marcadores útiles, y los agentes antioxidantes podrían ser considerados como una nueva oportunidad terapéutica en el manejo médico de estos pacientes.

Septic Shock is an important cause of morbility and mortality in critically ill patients that might be explained, at least partly, by a dysregulation of immune/inflammatory response. The liberation of microbial components could lead to the development of animbalance between pro-oxidant agents as reactive oxygen species (ROS) and the antioxidants systems, with a prevalence of the first. ROS are known to exert tissue damage by direct attack to biomolecules as well as to act as proinflammatory mediators. Studies performed in critical patients that presented sepsis, have demonstrated a decrease in antioxidants defences in these patients. This effect is characterized by an alteration in the activity of the antioxidant enzymes, as well as a drop in plasma levels ofantioxidant vitamins associated with a decrease of antioxidant capacity of plasma, parameters that have also been related to the prognosis of these patients. In addition, increased plasma levels of lipid peroxidation products have been found, which represents anincrease of the tissue damage caused by oxidative stress, mainly in biological membranes. The oxidative stress related parameters could be potentially used as markers and antioxidant agents couldbe considered as new therapeutic opportunities in the medicalmanagement of these patients.

Criterios de ingreso y egreso de una unidad de pacientes críticos / Admission and discharge criteria at an intensive care unit

Admission and discharge criteria for patients in an intensive care unt are controversial, especially in view of the fact that some patients derive no benefit from intensive care therapy while depriving others from a potential benefit. The general characteristics of patients in need of intensive care are discussed. Irreversibility of the underlyng condition, the quality of "terminal patient" and other factors that may contraindicate admission to an intensive care unit are analyzed. Discharge criteria for patients not expected to derive further benefit from a prolonged stay in unit are outlined