Pneumomediastinum and pneumothorax during emergency tracheotomy under spontaneous ventilation: Macklin meets Müeller?

Potentially serious complications associated to emergency tracheotomy continue being a matter of concern. We review the pathogenesis of gas leakage in this setting and discuss about the possible mechanisms involved in its cause. We present two cases of pneumomediastinum, subcutaneous emphysema and pneumothorax in the context of emergency tracheotomy under spontaneous ventilation, finally resolved by chest drainage. The combination of overly negative pleural pressures due to extreme inspiratory efforts in the context of an almost completely obstructed airway together with over-pressurized alveoli because of gaseous entrapment secondary to serious expiratory obstruction appears to be the most plausible primary cause of air leaks in our patients. Understanding the underlying mechanisms evolved in its production will help clinicians to suspect and diagnose this phenomenon.

Anesthesia for bariatric surgery: 8-year retrospective study: are our patients now easier to manage?

OBJECTIVES: To review the perioperative management of patients who had undergone bariatric surgery in our institution during an 8-year period, with the aim of identifying variables that correlated with improved clinical outcomes and changes in perioperative practice. METHODS: This was a retrospective observational study of 437 patients who had undergone bariatric surgery from January 2005 to June 2013. Of these patients, 163 had undergone open or laparoscopic biliopancreatic diversion (Group 1), and 274 had been managed according to a Tailored Laparoscopic Approach Program (TLAP) (Group 2). We analyzed major cardiocirculatory, pulmonary, and surgery-related complications, mortality rate, intensive care unit (ICU) admissions, post-anesthetic care unit (PACU) length of stay, and perioperative management standards, throughout the study period. RESULTS: Changes were observed in anesthetic patterns and perioperative care standards during the study period: 25% of patients had combined epidural anesthesia in 2005, compared with none at present; ICU admissions decreased from 28.6% in 2005 to 3.1% at present; and time in PACU declined from a median of 23 h in 2005 to 5.12h at present. Duration of postoperative opioid therapy was also significantly reduced (from 48 h to 6h). Group 2 had a significantly lower mortality rate than Group 1 (0.37% versus 4.3%, respectively, P=0.004). CONCLUSIONS: In our institution, adoption of a TLAP for bariatric surgery has led to changes in perioperative care standards that have been followed by clear improvements according to morbidity, mortality and management indicators.

Effects of inhalational anaesthesia with low tidal volume ventilation on end-tidal sevoflurane and carbon dioxide concentrations: prospective randomized study.

OBJECTIVE: We investigated how ventilation with low tidal volumes affects the pharmacokinetics of sevoflurane uptake during the first minutes of inhaled anaesthesia. METHODS: Forty-eight patients scheduled for lung resection were randomly assigned to three groups. Patients in group 1, 2 and 3 received 3% sevoflurane for 3 min via face mask and controlled ventilation with a tidal volume of 2.2, 8 and 12 ml kg(-1), respectively (Phase 1). After tracheal intubation (Phase 2), 3% sevoflurane was supplied for 2 min using a tidal volume of 8 ml kg(-1) (Phase 3). RESULTS: End-tidal sevoflurane concentrations were significantly higher in group 1 at the end of phase 1 and lower at the end of phase 2 than in the other groups as follows: median of 2.5%, 2.2% and 2.3% in phase 1 for groups 1, 2 and 3, respectively (P<0.001); and 1.7%, 2.1% and 2.0% in phase 2, respectively (P<0.001). End-tidal carbon dioxide values in group 1 were significantly lower at the end of phase 1 and higher at the end of phase 2 than in the other groups as follows: median of 16.5, 31 and 29.5 mm Hg in phase 1 for groups 1, 2 and 3, respectively (P<0.001); and 46.2, 36 and 33.5 mm Hg in phase 2, respectively (P<0.001). CONCLUSION: When sevoflurane is administered with tidal volume approximating the airway dead space volume, end-tidal sevoflurane and end-tidal carbon dioxide may not correctly reflect the concentration of these gases in the alveoli, leading to misinterpretation of expired gas data.

[Evaluation of a new computerized recording system for preoperative assessment data]. / Evaluación de la puesta en marcha de un sistema de registro electrónico en la valoración preoperatoria de los pacientes.

BACKGROUND AND OBJECTIVES: Little information is available on the use of computerized systems in preanesthetic assessment. Our aim was to evaluate staff acceptance of a computerized system for the structured recording of preoperative assessment data in our hospital. The time taken to complete the assessment was compared to the time usually taken to record the information on paper. MATERIAL AND METHODS: Observational, descriptive cross-sectional survey of user satisfaction 3 months after the system had been launched. We later carried out a prospective observational study of 796 preanesthetic assessment visits, comparing the mean time the users took to record information on paper to the time required to enter the data into the computer, analyzing differences between anesthesiologists and according to American Society of Anesthesiologists (ASA) classification and patient age. RESULTS: A total of 401 paper records and 395 electronic files were included. The users believed that the computerized system improved quality and accessibility of recorded data and clinical decision-making. The time required to enter data into the computer was believed to be the main drawback; the users took a mean (SD) 15.21 (5.41) minutes to enter the electronic data and 13.37 (5.08) minutes to record the information on paper (P < .001). There were also significant differences in the time taken to record data according to ASA classification and between anesthesiologists (P < .001). CONCLUSIONS: In spite of drawbacks such as extra time taken to record electronic data, the users perceived benefits, such as improved quality and accessibility of records. For this reason, the computerized system was well accepted.

[Utility of preoperative chest radiography in smokers undergoing transurethral resection of urinary bladder tumors]. / Utilidad de la radiografía de tórax preoperatoria en pacientes fumadores sometidos a resección transuretral de cáncer vesical.

OBJECTIVES: To assess the utility of preoperative chest radiographic findings for predicting cardiopulmonary complications in smokers undergoing transurethral resection of urinary bladder tumors under spinal anesthesia. To analyze perioperative changes in attitude in this setting. MATERIAL AND METHODS: Prospective study of 309 smokers with > or = 20 pack-years of cumulative smoking who were candidates for transurethral resection of urinary bladder tumors. The patients were classified in 2 groups according to radiographic findings. Between groups we compared the incidence of cardiopulmonary complications, perioperative changes in attitude to anesthesia and surgery, delays in completing the preanesthesia workup, and differences in the duration of surgery and hospital stay. RESULTS: Patients older than 65 years were 1.92 times more likely to have significant findings on the chest radiograph. Radiographic findings were associated with a higher incidence of perioperative complications (P=.02), need for further preoperative consultations (P<.01), longer delay in completing the preanesthesia study (P<.01), longer mean (SD) hospital stay (3.43 [3.17] days vs 2.50 [1.77] days, P<.001), and longer duration of surgery (P<.001). Attitudes did not change in relation to radiographic findings during or after surgery. Chest radiography correctly classified 3.54% of the patients with complications (predictive value). CONCLUSIONS: The predictive value of chest radiography for cardiopulmonary complications is low and findings do not influence intra- or postoperative attitudes. We therefore find no justification for performing chest x-rays in the population studied.