Karl Schebesta

Tissue oxygenation in obese and non-obese patients during laparoscopy

Background: Wound infection risk is inversely related to subcutaneous tissue oxygenation, which is reduced in obese patients and may be reduced even more during laparoscopic procedures. Methods: We evaluated subcutaneous tissue oxygenation (PsqO2) in 20 patients with a body mass index (BMI) ≥40 kg/m2 (obese group) and 15 patients with BMI <30 kg/m2 (non-obese group) undergoing laparoscopic surgery with standardized anaesthesia technique and fluid administration. Arterial oxygen tension was maintained near 150 mmHg. PsqO2 was measured from a surrogate wound on the upper arm. Results: A mean FIO2 of 51% (13%) was required in obese patients to reach an arterial oxygen tension of 150 mmHg; however, a mean FIO2 of only 40% (7%) was required to reach the same oxygen tension in non-obese patients (P=0.007). PsqO2 was significantly less in obese patients: 41 (10) vs 57 (15) mmHg (P<0.001). Conclusion: Obese patients having laparoscopic surgery require a significantly greater FIO2 to reach an arterial oxygen tension of about 150 mmHg than non-obese patients; they also have significantly lower subcutaneous oxygen tensions. Both factors probably contribute to an increased infection risk in obese patients.

Comparison of economical aspects of interscalene brachial plexus blockade and general anaesthesia for arthroscopic shoulder surgery

BACKGROUND This study investigated the cost-effectiveness of ultrasonographic-guided interscalene brachial plexus blockade (ISB) in comparison with general anaesthesia (GA) for arthroscopic shoulder surgery. METHODS Forty patients undergoing arthroscopic shoulder surgery received either an ultrasonographic-guided ISB or GA. ISB was performed outside the operation room (OR) and patients were transferred in the OR at the earliest 20 min after block performance. All drugs and disposables were recorded to evaluate the costs for both techniques. The following anaesthesia-related times were defined: ready for surgical preparation (from arrival in the OR until end of anaesthesia induction), OR emergence time (from end of dressing until leaving the OR), anaesthesia control time (from patients arrival in the OR until readiness for positioning plus time from the end of surgery to patients discharge from the OR), and post-anaesthesia care unit (PACU) time (from patients arrival in the PACU to the eligibility for discharge to normal ward). Personnel costs were excluded from statistical analysis. RESULTS The total costs were [mean (sd)] 33 (9)euro for patients with ISB and 41 (7)euro for those who received GA (P<0.01). The anaesthesia-related workflow was improved in the ISB group when compared with the GA group [ready for surgical preparation 8 (3) vs 13 (5) min, P<0.001; OR emergence time 4 (3) vs 10 (5), P<0.001; anaesthesia control time 12 (4) vs 23 (6), P<0.001; and PACU time 45 (17) vs 70 (20), P<0.001]. CONCLUSIONS Ultrasonographic-guided ISB is a cost-effective method for arthroscopic shoulder surgery.

Effects of supplemental oxygen and dexamethasone on surgical site infection: a factorial randomized trial

BACKGROUND Tissue oxygenation is a strong predictor of surgical site infection. Improving tissue oxygenation should thus reduce wound infection risk. Supplemental inspired oxygen can improve tissue oxygenation, but whether it reduces infection risk remains controversial. Low-dose dexamethasone is often given to reduce the risk of postoperative nausea and vomiting, but steroid-induced immunosuppression can increase infection risk. We therefore tested the hypotheses that supplemental perioperative oxygen reduces infection risk and that dexamethasone increases it. METHODS Using a factorial design, patients having colorectal resections expected to last ≥2 h were randomly assigned to 30% (n=270) or 80% (n=285) inspired oxygen during and for 1 h after surgery, and to 4 mg intraoperative dexamethasone (n=283) or placebo (n=272). Physicians blinded to group assignments evaluated wounds postoperatively, using US Centers for Disease Control criteria. RESULTS Subject and surgical characteristics were similar among study groups. Surgical site infection incidence was similar among groups: 30% oxygen 15.6%, 80% oxygen 15.8% (P=1.00); dexamethasone 15.9%, placebo 15.4%, (P=0.91). CONCLUSIONS Supplemental oxygen did not reduce surgical site infection risk. The preponderance of clinical evidence suggests that administration of 80% supplemental inspired oxygen does not reduce infection risk. We did not observe an increased risk of surgical site infection with the use of a single low dose of dexamethasone, indicating that it can be used for nausea and vomiting prophylaxis without promoting wound infections. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov number: NCT00273377.

Alternative management techniques for the difficult airway: esophageal-tracheal Combitube.

Purpose of review To summarize knowledge about the esophageal-tracheal Combitube in emergency medicine and anesthesia, with special emphasis on uncommon indications. Papers published between August 2003 and July 2004 are reviewed. Recent findings Tracheal intubation in the field is difficult and success rates are dependent upon training level (90-98%). Therefore, the esophageal-tracheal Combitube has been recommended for emergency ventilation after failed tracheal intubation with success rates of about 90%, even when performed by emergency medical technicians. Combitube insertion is easy to learn, but practice is necessary to retain skills. Use of this device has also been recommended for ventilatory support during routine anesthesia. Combitube ventilation is successful in over 96% of patients, with minimal trauma. Since only a small percentage of American anesthesiologists are familiar with the Combitube (<50%), using the device in anesthesia care may improve the skills required during emergency airway management. Blood gases are in the range of those obtained during endotracheal tube ventilation and aspiration prophylaxis is at least as good as that of the laryngeal mask airway. Successful uncommon uses of the device have also been recommended, for example, Combitube ventilation in craniomaxillomandibular surgery via the submental route and insertion of the device in a burns patient with minimal mouth opening and significant tracheal stenosis after long-term ventilation. Summary The esophageal-tracheal Combitube is a useful and efficient alternative airway characterized by high success rates in emergency situations. We recommend the use of a laryngoscope for insertion and strict adherence to the manufacturers guidelines in order to maximize success and minimize potential injury.

Exposure to anaesthetic trace gases during general anaesthesia: CobraPLA vs. LMA classic

Background: To prospectively investigate the performance, sealing capacity and operating room (OR) staff exposure to waste anaesthetic gases during the use of the Cobra perilaryngeal airway (CobraPLA) compared with the laryngeal mask airway classic (LMA).

Comparison of the EasyTube® and endotracheal tube during general anesthesia in fasted adult patients ☆

STUDY OBJECTIVE To evaluate the effectiveness, safety, ease of placement, and ventilatory parameters of a new alternate airway device, the EasyTube (EzT; Teleflex Ruesch, Research Triangle Park, NC), in comparison to the endotracheal tube (ETT). DESIGN Prospective, randomized controlled trial. SETTING University Hospital. SUBJECTS 200 adult ASA physical status I and II patients scheduled for surgery. INTERVENTIONS Patients were randomized to two groups, one to receive ventilation via the EzT (n = 100) or the ETT (n = 100). After preoxygenation and induction with fentanyl and propofol, patients received muscle relaxation. The respective airway device was then inserted and mechanical ventilation was instituted. MEASUREMENTS Ease of insertion, number of insertion maneuvers, time until airtight seal of the airway was achieved, duration of surgery, leak pressure as well as arterial oxygen saturation (SpO(2)), and end-tidal carbon dioxide (ETCO(2)) data, were recorded. MAIN RESULTS Mallampati airway class was higher in the EzT group (P < 0.029), while thyromental distance showed no difference between the two groups. Ease of insertion was noted in the EzT group (P < 0.043). Number of insertions was equal in both groups; insertion time was shorter with the EzT (15.5 +/- 3.6 sec vs. 19.3 +/- 4.6 sec; P < 0.0001). Leak pressure and SpO(2) were not significantly different, while ETCO(2) was lower with the ETT (P < 0.024). Adjustments had to be made for two EzT group patients. No difference in frequency of laryngo-pharyngeal discomfort was observed in either group. CONCLUSION Insertion of an EzT appears to reduce time and facilitate placement of an airway device when compared with direct laryngoscopy and tracheal intubation.

Distance from the glottis to the grille: the LMA Unique, Air-Q and CobraPLA as intubation conduits: a randomised trial.

BACKGROUND Supraglottic airway devices are often used in airway management to facilitate tracheal intubation. Knowledge of the distance from the grille of the device to the patients vocal cords is essential for the safe passage of the tracheal tube below the vocal cords. OBJECTIVES To assess the distance from the glottis to the grille of three supraglottic airway devices [LMA (LMA Unique), Air-Q (Air-Q Intubating Laryngeal Airway Reusable) and CobraPLA (Cobra Perilaryngeal Airway)] and their safe usage as intubation conduits. DESIGN Randomised controlled trial. SETTING Tertiary, university hospital. PATIENTS Thirty women undergoing elective gynaecological surgery with planned supraglottic airway management. INTERVENTIONS In-vivo fibreoptic assessment and in-vitro measurement. MAIN OUTCOME MEASURES The distance from the grille to the glottis was defined as primary outcome. The distance from the beginning of the cuff of a tracheal tube passed through the device to the grille was assessed as secondary outcome. RESULTS The three devices exhibited significant differences in the mean ± SD distance from the glottis to the grille (LMA 4.6 ± 1.5 cm, Air-Q 5.7 ± 1.4 cm, CobraPLA 3.4 ± 1.4 cm; P = 0.009). The Air-Q was predicted to allow the safe passage of a tracheal tube into the trachea, whereas the cuff was predicted to rest on the vocal cords in 57% of the LMA patients and 14% of the CobraPLA patients. CONCLUSION Using the LMA Unique as a conduit for tracheal intubation may pose a safety risk, whereas the use of the Air-Q would position the tracheal tube at a safe depth in the trachea.

Preparedness of anesthesiologists working in humanitarian disasters

OBJECTIVE Many skills needed to provide patients with safe, timely, and adequate anesthesia care during humanitarian crisis and disaster relief operations are not part of the daily routine before deployment. An exploratory study was conducted to identify preparedness, knowledge, and skills needed for deployment to complex emergencies. METHODS Anesthesiologists who had been deployed during humanitarian crisis and disaster relief operations completed an online questionnaire assessing their preparedness, skills, and knowledge needed during deployment. Qualitative data were sorted by frequencies and similarities and clustered accordingly. RESULTS Of 121 invitations sent out, 55 (46%) were completed and returned. Of these respondents, 24% did not feel sufficiently prepared for the deployment, and 69% did not undertake additional education for their missions. Insufficient preparedness involved equipment, drugs, regional anesthesia, and related management. CONCLUSIONS As the lack of preparation and relevant training can create precarious situations, anesthesiologists and deploying agencies should improve preparedness for anesthesia personnel. (Disaster Med Public Health Preparedness. 2013;0;1-5).

The effect of the molecular adsorbent recirculating system on moxifloxacin and meropenem plasma levels.

Adequate plasma antibiotic concentrations are necessary for effective elimination of invading microorganism; however, extracorporeal organ support systems are well known to alter plasma concentrations of antibiotics, requiring dose adjustments to achieve effective minimal inhibitory concentrations in the patients blood.

Influence of wikipedia and other web resources on acute and critical care decisions. a web-based survey

Physicians use the Internet to gather medical information. However, little is known about the use and influence of Wikipedia, Google and other non-scientific web resources in acute and critical care medicine.