[Ultrasound-guided puncture of the jugular vein using a posterior approach]. / Punción ecodirigida de la vena yugular interna por abordaje posterior.

BACKGROUND: Ultrasound-guided central venous catheterization provides a direct view of anatomical structures, making it easier to determine the exact puncture site, thereby reducing the associated mechanical complications. PATIENTS AND METHODS: This study included patients scheduled for central venous catheterization. An ultrasound examination was performed on the necks of all patients before the right internal jugular vein was catheterized by a single operator using ultrasound monitoring. RESULTS: We studied 21 men and 14 women; the mean (SD) age of the patients was 53 (17) years. Forty percent were kidney transplant recipients and 57% had had the right internal jugular vein catheterized on other occasions. The carotid artery had accidentally been punctured using the standard catheterization technique in 4 of the patients; the internal jugular vein was then catheterized successfully using ultrasound-guidance, which clearly showed the hematoma caused by the carotid puncture. The right internal jugular vein was successfully catheterized in 34 patients; it was necessary to catheterize the left jugular vein in 1 patient as the ultrasound examination revealed thrombosis of the right vein. A single puncture was performed in all cases and none of the complications associated with venous puncture were observed. CONCLUSION: Ultrasound images allowed us to effectively examine the jugular vein prior to puncture for central venous catheterization. Ultrasound-guided puncture of the vein was satisfactory and free from complications in all cases.

[Anesthetic and physiologic implications of neurophysiologic monitoring with evoked potentials during spinal surgery]. / Implicaciones anestésicas y fisiológicas de la monitorización neurofisiológica intraoperatoria con potenciales evocados en la cirugía vertebral y medular.

Neurophysiologic monitoring with somatosensory and motor evoked potentials in spinal surgery is now widely applied in order to reduce the risk of neural injury and facilitate intraoperative decision making. Most anesthetics affect such monitoring by altering both somatosensory and motor evoked responses and these effects may place constraints on the choice of anesthetic. Intraoperative management includes maintaining stable physiologic conditions, which involves adjusting hemodynamic parameters, maintaining normal blood flow to promote proper oxygen exchange, ensuring proper ventilation, and avoiding variations in temperature. Close collaboration between the anesthetist, the surgeon, and the neurophysiologist will ensure the success of intraoperative monitoring and make it possible to avoid neural injury by making timely changes in the surgical approach.

[Routine preoperative screening of asymptomatic patients: beliefs and attitudes of anesthesiologists in the Canary Islands, Spain]. / Pruebas preoperatorias rutinarias en población asintomática: opiniones y actitudes de los profesionales en Canarias.

OBJECTIVES: To identify factors that explain anesthesiologists' inappropriate use of preoperative tests in asymptomatic patients scheduled for elective surgery. MATERIAL AND METHODS: A validated questionnaire was sent to anesthesiologists at university hospitals in the Canary Islands. Information about preoperative testing patterns and reasons for selecting tests was gathered. RESULTS: The questionnaire was self-administered by 66 anesthesiologists (68% of the total). Scientific knowledge was not the reason why most respondents ordered preoperative tests in asymptomatic individuals. That was the opinion of 95% of anesthesiologists for chest x-rays, 82% for electrocardiograms, and 68% for laboratory tests. Clinical history and a medical examination gave sufficient information for selecting patients in need of specific tests in the opinion of 77.19% of the respondents. Half did not agree that routine electrocardiograms and laboratory tests should be abandoned. The justification for these tests was coverage of medical malpractice liability for 68.42%. Most considered that the need to order preoperative tests in asymptomatic patients increased after age 40. CONCLUSIONS: Although anesthesiologists admit that their request for preoperative tests in asymptomatic individuals is not supported by scientific evidence, the quest for safety and legal protection from the consequences of potential adverse consequences of providing anesthesia affects the selection of preoperative tests for asymptomatic patients.

Submammary median sternotomy.

A vertical skin incision is used as routine approach for sternotomy. The resulting scar is often disappointing and the top is visible and unpleasant, especially for young women. In 35 women ranging from 10 to 48 years (mean 29.2 years), median sternotomy was performed via a submammary skin incision. In all cases an open heart surgical procedure was performed. Adequate exposure of the heart was achieved in every case and there were no technical problems related to this approach, no hospital mortality or major complications. The cosmetic result is excellent and this approach is certainly justified in open heart surgery for young women.

[Ketamine]. / Ketamina.

Ketamine is an intravenous drug with special properties that make it the only agent that presently serves as anesthetic, sedative, amnesiac and analgesic. Although it is sometimes forgotten, ketamine is still considered a viable drug. Water soluble, stable and non-irritant when administered intravenously, ketamine has rapid onset after intravenous injection and provides acceptable anesthesia when administered in continuous infusion. There properties make ketamine useful for total intravenous anesthesia. Both propofol and midazolam are effective in reducing ketamine's adverse side effects. Administered in children by oral, nasal, rectal and intramuscular routes, ketamine allows for gentle anesthetic induction. It can also serve as an adjuvant in regional anesthesia to supplement analgesia. In adults ketamine is most often used for major surgery, particularly in the elderly or in high risk patients who are in shock, severely dehydrated or hemodynamically unstable, or in obstetric patients with hypovolemia or hemorrhage. It is probably the anesthetic of choice for patients with hyperreactive airways. Ketamine's strong analgesic effect at subanesthetic doses allows it to be used as an analgesic during postoperative intensive care or as an analgesic-plus-sedative for patients receiving mechanical ventilation. Interest in using ketamine at low doses for cancer and non-cancer patients with chronic pain has grown recently.

[Prolonged neuromuscular block with mivacurium]. / Bloqueo neuromuscular prolongado con mivacurio.

We describe a case of prolonged neuromuscular block (longer than 8 hours) after administration of mivacurium. The patient was shown to be homozygous for the atypical butyrylcholinesterase gene. We discuss our treatment of the patient as well as other cases described in the literature, emphasizing the need for neuromuscular monitoring.

[Intrapulmonary short-circuit during coronary or aortic valve heart surgery]. / Cortocircuito intrapulmonar en cirugía cardíaca coronaria o de válvula aórtica.

BACKGROUND: The alterations in gas exchange during cardiac surgery was studied by the measurement of the perioperative intrapulmonary shunt. PATIENTS AND METHODS: Forty patients divided into two groups were studied. Group 1 consisted of 20 patients undergoing myocardial vascularization and group 2 consisted of 20 patients undergoing aortic valve replacement. The anesthetic technique was similar in both groups but the patients in group 1 received a continuous perfusion of nitroglycerin from the beginning of surgery plus a bolus of intranasal nifedipine 30 minutes prior to the exit of extracorporeal circulation. The measurement of the shunt was performed 5 times: following the induction of anesthesia, prior to and after extracorporeal circulation, upon termination of surgery and one hour following admission to the ICU. RESULTS: In both groups an increase of the shunt was produced at the end of extracorporeal circulation which later returned to basal levels. The increase was greater in patients of group 1 during the different phases of surgery although significant differences only existed at the beginning and end of extracorporeal circulation. The variations of the shunt were not related with the state of preoperative pulmonary function or with the duration of extracorporeal circulation. CONCLUSIONS: Although intrapulmonary shunt increases during cardiac surgery, especially coronary, its clinical transcendence is nul and no special measures are required.

[Preoperative testing routines for healthy, asymptomatic patients in the Canary Islands (Spain)]. / Patrón de utilización de pruebas preoperatorias en una población sana y asintomática en Canarias.

OBJECTIVES: To analyze patterns of routine testing before elective/scheduled surgery in healthy/asymptomatic patients classified as ASA I or II according to the American Society of Anesthesiologists. MATERIAL AND METHOD: A questionnaire on the organization of preoperative testing was completed by anesthesiologists at five public hospitals in the Canary Islands. The questionnaire emphasized the most commonly ordered screening procedures, such as chest X-rays, electrocardiograms, laboratory tests and spirometry. RESULTS: Red cell counts were most frequently requested (for 86% of the patients), followed by platelet counts (80%) and blood chemistry (75%) and coagulation studies (72%). Least requested were urine tests and spirometry. The frequencies of electrocardiogram and chest X-ray requests fell between the two extremes, with patient age and the presence of certain indications seeming to affect whether those tests would be ordered or not. The need for such screening was perceived to increase for patients over 40 years of age. The ordering of preoperative tests varied from hospital to hospital and among anesthesiologists at a single site in spite of established protocols. CONCLUSIONS: Hospitals and individual anesthesiologists differ considerably in how they request preoperative tests. The variations can not be explained solely by differing patient needs given that respondents were contemplating only healthy/asymptomatic individuals undergoing relatively simple procedures.

[General anesthesia with remifentanil in two cases of emergency cesarean section]. / Anestesia general con remifentanilo en dos casos de cesárea urgente.

Remifentanil is a synthetic opiate with evident advantages for various anesthetic techniques, enhancing quality of anesthesia. Indications are increasingly well-defined. Remifentanil may be used in obstetric analgesia-anesthesia thanks to advantages demonstrated in patients with heart disease (cardiac and non-cardiac anesthesia) and in those requiring neuroanesthesia. Remifentanil is known to cross the placenta rapidly and to be rapidly metabolized and redistributed to both mother and fetus. Based on this, and on pharmacokinetic and pharmacodynamic studies in children, we judged remifentanil to be indicated for use in two patients undergoing emergency cesarean section, for whom hemodynamic stability and immediate postoperative assessment were basic requirements. The first case involved a woman 40 weeks pregnant with a history of mitral valve prolapse and an episode of acute pulmonary edema in the 28th week, who presented with ruptured membrane and the fetus in sacroposterior breech presentation without subsequent progression of labor. The second involved a woman 40-weeks pregnant with a diagnosis of Hunt-Hess grade II subarachnoid hemorrhage who had gone into labor. Outcome was satisfactory in both cases, with no complications potentially affecting the status of either mother or child. No infant respiratory insufficiency occurred and Apgar scores were favorable. We consider remifentanil to be safe and effective for general anesthesia for emergency cesarean delivery in patients with cardiac and/or neurological risk factors.

[Patient with tricuspid atresia undergoing orthopedic surgery: anesthetic considerations]. / Paciente con atresia tricúspide para cirugía ortopédica: cuidados anestésicos.

We describe a 52-year-old patient with rheumatoid arthritis, interventricular communication and pulmonary stenosis. After an accidental fall she was scheduled for total hip replacement. The main objective of anesthetic management was to preserve pulmonary blood circulation at arterial pressures that would assure adequate tissue perfusion. Other objectives were to maintain hydration to prevent decreases in hematocrit levels, avoid systemic embolization and allow for antibiotic prophylaxis.