Intraoperative high flow oxygen therapy for tubeless anaesthesia in thoracoscopic surgery.

Tubeless anaesthesia has become widespread in videothoracoscopic surgery, even in major procedures such as lobectomies. There are several advantages in avoiding general anaesthesia and one-lung mechanical ventilation, such as faster recovery and shorter hospital stays. However, hypoxaemia and hypercapnia are the most reported causes of conversion to general anaesthesia. High Flow Oxygen Therapy (HFOT) generates flow-dependent positive end-expiratory pressure, improves oxygenation and also carbon dioxide washout by flow-dependent dead space flushing. For this reason, intraoperative HFOT may reduce the rate of conversion to general anaesthesia. We report our experience with intraoperative HFOT in a 71-year-old female with lung adenocarcinoma undergoing VATS upper left lobectomy.

Non intubated video-assisted thoracoscopic lung resections (NI-VATS) in COVID times.

The emergence of epidemic Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in December 2019 in Wuhan, China causing Coronavirus Disease 2019 (COVID-19) and its rapid expansion around the world, leading to a global pandemic of dimensions not observed at least since the "Spanish influenza" pandemic in 1917-18, has had great consequences at all levels, including social, health and economic spheres. This pandemic situation forces us, as health care workers, to redefine our medical and surgical actions to adapt them to this new reality. It is important, when the rules of the game change, to rethink and to reevaluate if the balance between risk and benefit have moved to a different point of equilibrium, and if our indications of certain surgical interventions need to be redefined. In this article we try to answer the doubts that arise about the suitability of the NI-VATS technique and assess whether its use in these new pandemic circumstances might add advantages, especially in relation to minimize the risks of virus contagion between patients and all healthcare personnel during the surgical procedure, as well as the known advantages described in many articles the last ten years.

[Remifentanil in heart surgery]. / Remifentanilo en cirugía cardíaca.

The contributions of remifentanil to anesthesia for heart surgery is described. The pharmacokinetic properties are described along with our clinical experience with the various modes and doses of perfusion for induction as well as during and after surgery.

[The use of high-frequency jet ventilation for ventilatory support in an extreme case]. / Utilidad de la ventilación con jet a alta frecuencia como soporte ventilatorio alternativo en un caso extremo.

We report the case of a 27-year old man given a left lateral thoracotomy for emergency repair of the aortic isthmus, which had partially ruptured as a consequence of chest trauma. The patient also suffered serious trauma to the right lung, such that selective ventilation of that lung had to be applied with the left lung collapsed to allow the surgeon access to the descending aorta. Rapid decrease in SpO2 occurred, with excessively high airway pressures, requiring reinstatement of conventional ventilation of both lungs and interruption of surgery. Conventional ventilation was then replaced by high frequency jet ventilation to both lungs. That technique, combined with intermittent inflation of the left lung (inclined), provided sufficient oxygen as well as a wide and sufficiently immobile surgical field.

[Quantification of dehydration of soda lime in clinical circumstances]. / Cuantificación de la desecación de la cal sodada en circunstancias clínicas.

HYPOTHESIS AND OBJECTIVES: When the CO2 absorbents, soda lime and baralime, have lost their normal level of hydration, they may react with certain halogenated anesthetics to produce appreciable levels of carbon monoxide. The degree of absorbent desiccation has been considered the limiting factor for this phenomenon. This study quantifies the level of dehydration of lime produced under clinical conditions and the influence of several factors. MATERIAL AND METHOD: Desiccation was determined: 1) at set periods of time (3, 7 and 14 days) after clinical use of fresh soda lime in general anesthesia using a fresh gas flow (FGF) of 6 l/min, and 2) after gas had been crossing the continuous flow (CF) oxygen reservoir at 7 l/min for 17 and 65 hours. Two anesthetic systems were used: a) the Ohmeda Excel-210, in which the continuous FGF did not cross the reservoir and b) the Siemens Ventilator 710, in which the FGF did cross the reservoir. The experiments were repeated with three types of lime. RESULTS: The clinical use of lime for 3, 7 and 14 days caused different levels of desiccation, with decreases in hydration of up to 50% and 14 days. Nevertheless, water content was always over 5%, a level at which no reaction with halogenated agents takes place. After 17 and 65 hours of CF in the circuit where continuous FGF did not pass through the canister, the water content did not change. With the Siemens 710 circuit, in which the continuous FGF crossed the canister, the dehydration level was 1.2 +/- 0.3% after 17 hours and 0.7 +/- 0.3% after 65 hours, a level that can produce CO upon reaction between lime and halogenated gases. The type of lime used had little effect. CONCLUSIONS: Lime does not desiccate to levels able to produce CO in daily use, regardless of the FGF system used. The phenomenon of desiccation depends on two factors: 1) use of anesthetic equipment in which continuous FGF conditions require gas to pass through the canister, and 2) the maintenance of CF for a sufficient period of time.

[Epidural abscess secondary to the implantation of a thoracic catheter]. / Absceso epidural secundario a la implantación de un catéter torácico.

Spinal compression related to the formation of an epidural abscess after epidural blockade is a rare but serious complication. We report the case of a male patient in whom a thoracic epidural catheter was implanted to provide analgesia after trauma involving fracture ribs. The patient developed an epidural abscess within one week of implantation. Delay in diagnosis led to persistent neurogenic bladder symptoms in spite of aggressive treatment. We review causal factors, mechanisms of formation, pathogenesis, diagnosis and management, as well as possible relation between injury and abscess formation. We also emphasize the importance of adequate vigilance as well as rapid diagnosis and adoption of therapeutic measures in order to avoid permanent sequelae such as paresis, sensory deficits or mechanical sphincter dysfunction.

Low-flow anesthesia and reduced animal size increase carboxyhemoglobin levels in swine during desflurane and isoflurane breakdown in dried soda lime.

UNLABELLED: After institutional approval, we studied the effect of animal size, anesthetic concentration, and fresh gas flow (FGF) rate on inspired carbon monoxide (CO) and carboxyhemoglobin (COHb) during anesthesia in swine, using soda lime previously dried to 1 +/- 0.1% water content. To ascertain the effect of anesthesia, eight adult pigs were anesthetized with either 1 minimum alveolar anesthetic concentration (MAC) desflurane or isoflurane and, to characterize the effect of the FGF rate, it was doubled in four pigs. To determine the effect of animal size, four small and four large pigs received 1 MAC desflurane or isoflurane, and to determine the effect of the anesthetic concentration, a group of four swine was exposed to 0.5 MAC. CO and COHb concentrations were larger with desflurane (5500 +/- 980 ppm and 57.90% +/- 0.50%, respectively) than with isoflurane (800 ppm and 17.8% +/- 2.14%, respectively), especially in the small animals. Increasing the FGF rate significantly reduced peak CO and COHb concentrations resulting from both anesthetics; however, when each anesthetic was reduced to 0.5 MAC, the concentrations obtained were similar. We conclude that CO intoxication is more severe with desflurane than with isoflurane, that small animals are at higher risk for CO poisoning, and that low FGF can increase COHb concentrations. IMPLICATIONS: The present study shows that the use of desflurane with desiccated carbon dioxide absorbents in pediatric anesthesia can produce a dangerous carbon dioxide intoxication, especially with low-flow anesthesia.