Ultrasound guided vascular access: efficacy and safety

In the United Kingdom and United States, US guidance for internal jugular central venous catheterisation is recommended. Despite reluctance to adopt these guidelines, there is sufficient evidence to support routine use, as even proceduralists skilled in landmark techniques commonly encounter complications. Serious morbidity and mortality may result, which arguably is avoidable, if ultrasonography was used. Real-time 2D US demonstrates patient anatomy and anatomical variability in a manner not previously possible for anaesthetists. Unencumbered by reliance on surface landmarks, the needle path and tip can be visually directed into the target vessel lumen. This potent ability improves successful cannulation and first-attempt success, reduces the number of needle attempts and decreases mechanical complications associated with vascular access procedures.

Conflict of interest

AC has received honoraria from SonoSite and AstraZeneca as a workshop tutor for teaching ultrasound-guided procedures.     

Towards pain free cardiac surgery - high thoracic epidural analgesia

Epidural analgesia is a well-established analgesic technique, providing complete or near complete perioperative analgesia for major surgery. Epidural analgesia may also confer additional benefits during the perioperative period, including attenuation of the stress response, reduction in procoagulation tendency, and reduction in myocardial ischaemia and infective complications. These additional benefits are an advantage in patients with ischaemic heart disease. We discuss the use of high thoracic epidural anaesthesia in cardiac surgery, outlining potential benefits and risks. Our experience with epidural analgesia in over 300 patients undergoing cardiac surgery is briefly described.     

Risk factors for citation errors in peer-reviewed nursing journals

BACKGROUND: Citation errors are common among nursing journals. But, there are no data regarding the factors that predispose to these errors. OBJECTIVE: To determine the risk factors that predispose to citation error in peer-reviewed nursing journals. METHODS: Five hundred and fifty references were selected randomly from articles published in eleven nursing journals for the year 1998. The incidences of major and minor citation errors were determined by comparing with the original articles. The relative odds of citation errors for the number of authors, collaborating institutions and the length of the reference list were calculated. The correlation between the scientific quality of the journal (by means of journal impact factor and immediacy index) and the incidence of citation error were also determined. RESULTS: The incidence of citation errors is comparable to those reported previously. Long reference lists in articles written by a single author predicted strongly the occurrence of minor citation errors. Journals with a high impact factor and immediacy index tend to contain fewer minor mistakes. None of these factors affect the incidence of major errors. CONCLUSION: Contributors to journals should be aware of the various risk factors for citation errors. Citation accuracy may be improved by modifying these factors.     

Induction, Recovery, and Safety Characteristics of Sevoflurane in Children Undergoing Ambulatory Surgery: A Comparison with Halothane

Background: Sevoflurane is an inhalational anesthetic with characteristics suited for use in children. To determine whether the induction, recovery, and safety characteristics of sevoflurane differ from those of halothane, the following open-labeled, multicenter, randomized, controlled, phase III study in children undergoing ambulatory surgery was designed.

Methods: Three hundred seventy-five children, ASA physical status 1 or 2, were randomly assigned in a 2:1 ratio to receive either sevoflurane or halothane, both in 60% N2 O and 40% O2. Anesthesia was induced using a mask with an Ayre's t piece or Bain circuit in four of the centers and a mask with a circle circuit in the fifth center. Maximum inspired concentrations during induction of anesthesia were 7% sevoflurane and 4.3% halothane. Anesthesia was maintained by spontaneous ventilation, without tracheal intubation. End-tidal concentrations of both inhalational anesthetics were adjusted to 1.0 MAC for at least 10 min before the end of surgery. Induction and recovery characteristics and all side effects were recorded. The plasma concentration of inorganic fluoride was measured at induction of and 1 h after anesthesia.

Results: During induction of anesthesia, the time to loss of the eyelash reflex with sevoflurane was 0.3 min faster than with halothane (P < 0.001). The incidence of airway reflex responses was similar, albeit infrequent with both anesthetics. The total MAC *symbol* h exposure to sevoflurane was 11% less than the exposure to halothane (P < 0.013), although the end-tidal MAC multiple during the final 10 min of anesthesia was similar for both groups. Early recovery as evidenced by the time to response to commands after sevoflurane was 33% more rapid than it was after halothane (P < 0.001), although the time to discharge from hospital was similar for both anesthetics. The mean (+/-SD) plasma concentration of inorganic fluoride 1 h after discontinuation of sevoflurane was 10.3+/-3.5 micro Meter. The overall incidence of adverse events attributable to sevoflurane was similar to that of halothane, although the incidence of agitation attributable to sevoflurane was almost threefold greater than that attributable to halothane (P < 0.004).     

Use of the Cuffed Oropharyngeal Airway as an Alternative to the Laryngeal Mask Airway with Positive-pressure Ventilation

Background: The cuffed oropharyngeal airway is a modified Guedel-type oral airway with a cuff at its distal end. The objectives of this study were to compare the ability of the cuffed oropharyngeal airway and the laryngeal mask airway to provide positive-pressure ventilation during general anesthesia, and to assess their relative ease of use and ability to reduce total fresh gas flow rates.

Methods: In this prospective, randomized study, a cuffed oropharyngeal airway (n = 25) or a laryngeal mask airway (n = 25) device was inserted after induction of anesthesia intravenously using 2 mg/kg propofol. While anesthesia was maintained with sevoflurane and nitrous oxide, the leak pressure, leak fraction (the fractional difference between the inspired and expired tidal volume), minimum fresh gas flow rate, and need for airway manipulations were determined. The anesthesia provider who inserted the device completed an evaluation form at the end of the 15-min study period.

Results: Positive-pressure ventilation was established successfully on the first attempt in 92% of the patients when the cuffed oropharyngeal airway was used and in 88% of the patients when the laryngeal mask airway device was used. However, manipulations of the airway device were necessary more frequently (8 vs. 1 patients; P < 0.05) and the leak pressure was less (22 +/- 6 cm water vs. 26 +/- 5 cm water; P < 0.05) with the cuffed oropharyngeal airway than with the laryngeal mask airway. In addition, the leak fraction (0.19 +/- 0.18 vs. 0.31 +/- 0.22; P < 0.05) and the minimum fresh gas flow rate (1.3 +/- 1.5 vs. 2.4 +/- 2.5; P = 0.12) were less in the laryngeal mask airway group.