Journal of Clinical Anesthesia - Articles in Press

Factors influencing unexpected disposition after orthopedic ambulatory surgery - Corrected Proof

2012-02-06

Abstract: Study Objective: To analyze whether patient characteristics, ambulatory facility type, anesthesia provider and technique, procedure type, and temporal factors impact the outcome of unexpected disposition after ambulatory knee and shoulder surgery.Design: Retrospective analysis of a national database.Setting: Freestanding and hospital-based ambulatory surgery facilities.Measurements: Ambulatory knee and shoulder surgery cases from 1996 and 2006 were identified through the National Survey of Ambulatory Surgery. The incidence of unexpected disposition status was determined and risk factors for such outcome were analyzed.Main Results: Factors independently increasing the risk for unexpected disposition included procedures performed in hospital-based versus freestanding facilities [odds ratio (OR) 6.83 (95% confidence interval [CI] 4.34; 10.75)], shoulder versus knee procedures [OR 3.84 (CI 2.55; 5.77)], anesthesia provided by nonanesthesiology professionals and certified registered nurse-anesthetists versus anesthesiologists [OR 7.33 (CI 4.18; 12.84) and OR 1.80 (CI 1.09; 2.99), respectively]. Decreased risk for unexpected disposition was for procedures performed in 2006 versus 1996 [OR 0.15 (CI 0.10; 0.24)] and the use of anesthesia other than regional or general [OR 0.34 (CI 0.18; 0.68)].Conclusions: The decreased risk for unexpected disposition associated with more recent data and with freestanding versus hospital-based facilities may represent improvements in efficiency, while the decreased odds for such disposition status associated with the use of other than general or regional anesthesia may be related to a lower invasiveness of cases. We found an increased risk of adverse disposition in cases where the anesthesia provider was a nonanesthesiology professional. No difference in this outcome was noted when an anesthesia care team provided care.

The teaching of anesthesia history in US residency programs: results of a nationwide survey - Corrected Proof

Manisha S. Desai, Shirish R. Chennaiahgari, Sukumar P. Desai — 2012-02-02

Abstract: Study Objective: To determine the extent to which history of anesthesia-related topics are included in the didactic curriculum of United States residency programs in anesthesiology.Design: Survey instrument.Setting: University-affiliated hospital.Measurements: In addition to information related to the identity of the respondent and institution, we inquired about the presence of faculty members with an interest in the history of anesthesia (HOA), the inclusion of HOA-related lectures in the didactic curriculum, whether the program would consider inviting an outside lecturer for a session devoted to HOA, the inclusion of HOA-related tours, and whether the program would allow residents an elective rotation of one to three months devoted to a research project related to HOA.Main Results: On the basis of responses from 46 of 132 residency programs (35%), 54% of programs had at least one faculty member with an interest in HOA, and 45% of programs included lectures related to HOA in their didactic curriculum. An encouraging finding was that 83% of programs (without such didactic sessions) were willing to invite visiting professors to deliver lectures on HOA. The vast majority (91%) did not conduct tours related to HOA, while 74% indicated a willingness to allow residents interested in HOA to devote one to three months to undertake such projects.Conclusions: The low rate of interest in HOA among faculty members, and the lower rate of inclusion of lectures related to HOA during residency training, suggests that substantial barriers exist within the academic community towards a wider acceptance of the importance of HOA. Two positive indicators were the willingness to invite outside speakers and the receptivity to allowing residents to devote one to three months to projects related to HOA.

Unanticipated dispositions after ambulatory surgery: an important topic with multiple factors - Corrected Proof

Kelly L. Wiltse Nicely, Russell R. Lynn — 2012-02-02

As health care costs continue to come under increasing scrutiny, health care providers must evaluate their practices to ensure high-quality care while being mindful of resources and expenditures. Ambulatory surgical units are venues that, when fully utilized, allow for high-quality, cost-effective care . However, if these venues are not utilized appropriately, the results may actually increase health care costs and warrant investigations into methods to optimize these centers. In this issue of the Journal of Clinical Anesthesia, Memtsoudis et al's analysis of unexpected disposition after orthopedic ambulatory surgery attempts to address factors that have a negative impact on ambulatory centers . But the article falls short in several areas. The methodology, data sets, and comparisons employed in this study, along with a lack of generalizability of the findings, suggest significant flaws that call into question the conclusions drawn from this study.

Shoulder and head elevation improves laryngoscopic view for tracheal intubation in nonobese as well as obese individuals - Corrected Proof

Philip W. Lebowitz, Hamilton Shay, Tracey Straker, Daniel Rubin, Scott Bodner — 2012-02-02

Abstract: Study Objective: To determine whether shoulder and head elevation, such that the patient's ear lies at or higher than the sternum (“ramp”), improves laryngoscopic grade in adult patients of various body mass index (BMI) values.Design: Prospective, unblinded study, with patients and laryngoscopists acting as their own controls.Setting: Operating room of a university-affiliated hospital.Patients: 189 adult ASA physical status 1, 2, and 3 patients.Interventions: After performing a standard preoperative airway evaluation and inducing general anesthesia, the anesthetist performed and graded two laryngoscopies: one in the “ramp” position and one in the “sniff” position.Measurements: Patient BMI, Mallampati airway class, thyromental distance, neck circumference, cervical extension ability, Cormack and Lehane laryngoscopic grade for each laryngoscopy, subjective lifting force required, and need for external laryngeal pressure were recorded.Main Results: Use of the “ramp” provided significantly better or equal laryngoscopic views, relative to those with the “sniff” position, in the entire study population.Conclusions: Shoulder and head elevation by any means that brings the patient's sternum onto the horizontal plane of the external auditory meatus maintains or improves laryngoscopic view significantly.

Hemodynamic effects of laparoscopic radiofrequency ablation of liver tumors versus laparoscopic hepatic ultrasound examination - Corrected Proof

2012-02-02

Abstract: Study Objective: To compare the hemodynamic changes that occur during laparoscopic radiofrequency ablation of liver metastases with those occurring during laparoscopic ultrasound hepatic examination alone.Design: Prospective, observational study.Setting: Operating rooms of a university-affiliated hospital.Patients: 40 ASA physical status 2 and 3 patients with liver metastases.Interventions: 20 patients underwent laparoscopic radiofrequency ablation of liver tumors following laparoscopic ultrasound examination, and 20 had laparoscopic ultrasound examination alone. The anesthetic technique was standardized.Measurements: The primary endpoint of the study was the number of episodes of mean arterial pressure (MAP) < 70 mmHg. Secondary endpoints were significant differences between the groups in MAP, heart rate, cardiac index, ejection fraction (EF; both measured with thoracic bioimpedance), calculated systemic vascular resistance index (SVRI), and central venous pressure.Main Results: The number of episodes of MAP < 70 mmHg did not differ between groups: there were 9 episodes in the ultrasound alone group and 7 in the radiofrequency group (P = 0.668). Cardiac index, EF, and SVRI were similar between groups. Central venous pressure was slightly higher in the radiofrequency group [11.99 (10.8-13.2) mmHg vs. 10.3 (9.2-11.4) mmHg, P = 0.04].Conclusions: Hemodynamic profiles were similar when comparing laparoscopic radiofrequency ablation of liver metastases with laparoscopic ultrasound hepatic examination alone.

Does the covering of children during induction of anesthesia have an effect on body temperature at the end of surgery? - Corrected Proof

2012-02-02

Abstract: Study Objectives: To determine whether the covering of healthy children during anesthetic induction reduces hypothermia at the end of minor surgeries.Design: Randomized, single-blinded, prospective study.Setting: Operating room and postoperative recovery area of a university-affiliated hospital.Patients: 50 ASA physical status 1 patients, aged 6 months to 3.5 years, scheduled for simple urological surgeries.Interventions: Subjects were randomly assigned to one of two groups: covered or uncovered. Children in the covered group (Group C) were actively warmed on arrival in the operating room (OR) using cotton blankets and a warm forced-air blanket set at 43°C. Children in the uncovered group (Group U) remained uncovered during the induction of general anesthesia. Children in both groups were actively warmed following placement of surgical drapes.Measurements: Temperature (in Celsius) during the study procedure was recorded for each patient.Main Results: Mean core body temperature at the end of induction did not differ in the two groups, 36.4°C in Group C and 36.6°C in Group U. Mean core body temperature at the end of surgery did not differ between the two groups: 36.9°C in Group C and 37.0°C in Group U.Conclusion: Leaving healthy children uncovered during induction of general anesthesia does not have a clinically significant effect on core temperature at the end of induction or of surgery.

Systemic lidocaine decreases the Bispectral Index in the presence of midazolam, but not its absence - Corrected Proof

2012-02-02

Abstract: Study Objective: To evaluate the effects of intravenous (IV) lidocaine on the Bispectral Index (BIS) in the presence or absence of midazolam.Design: Prospective, randomized, double-blinded, placebo-controlled clinical study.Setting: Operating room of a university hospital.Patients: 96 ASA physical status 1, 2, and 3 patients undergoing general anesthesia.Interventions: Patients were assigned to one of 6 treatment groups to receive IV midazolam (0.03 mg/kg) or placebo, followed 5 minutes later by one of three IV preinduction doses of lidocaine: 0.5, 1.0, or 1.5 mg/kg.Measurements: BIS values were recorded before administration of lidocaine and at 30-second intervals afterwards for three minutes. The primary endpoint was the average BIS level recorded.Main Results: Baseline BIS values were lower in the midazolam group (94 ± 4 vs. 90 ± 7, P < 0.001). There was no significant decrease in BIS values in the placebo group for any of the three lidocaine doses. However, in the midazolam groups, significant decreases in BIS levels versus baseline values were measured.Conclusion: IV lidocaine decreases BIS in the presence of midazolam, suggesting that the effect of lidocaine on BIS is not direct, but rather results from modulation by midazolam.

Optimal shoulder roll height for internal jugular venous cannulation: a study of awake adult volunteers - Corrected Proof

2012-02-02

Abstract: Study Objective: To explore the influence of shoulder roll height on internal jugular vein (IJV) diameter and IJV/common carotid artery (CCA) overlap.Design: Cross-sectional study.Setting: University-affiliated hospital.Patients: 40 healthy participants.Measurements: Ultrasonography to measure the effects of using shoulder rolls ranging between 0 and 5 cm high on IJV diameter, CCA diameter, and percentage overlap of the CCA.Main Results: The percentage overlap of CCA decreased for both left (LIJV) and right IJV (RIJV) with the use of higher shoulder rolls. Greater values were seen in depth from skin surface to anterior wall of left IJV in almost all stages, with the exception of Stages 0 and 1 (P < 0.016); and the use of a 5 cm shoulder roll resulted in a significantly decreased anteroposterior (AP) diameter of both RIJVs and LIJVs (both P < 0.008).Conclusions: Shoulder rolls can reduce the overlap between the IJV and CCA, and may be useful in positioning patients for IJV puncture.

Low social support is associated with an increased risk of postoperative delirium - Corrected Proof

Thuy-Dung Do, Cédric Lemogne, Didier Journois, Denis Safran, Silla M. Consoli — 2012-02-02

Abstract: Study Objective: To examine the predictive value of social support in postoperative delirium.Design: Prospective observational study.Setting: Postoperative recovery room and orthopedic surgery department.Patients: 106 consecutive patients undergoing a planned orthopedic surgery with general anesthesia.Measurements: All patients completed questionnaires to assess depressive mood (the Beck Depression Inventory) and social support (Sarason's Social Support Questionnaire) during the preanesthesia visit. Postoperative delirium symptoms were assessed daily using the Memorial Delirium Assessment Scale. Demographic, clinical, and biological data, including anesthesia procedure, were recorded.Main Results: Controlling for various potential confounders through multivariate binary logistic regression, postoperative delirium was independently predicted by satisfaction with social support, but neither by depressive mood nor the number of supportive persons. Other significant predictors were the preoperative use of benzodiazepines, age, and type of surgery.Conclusion: Patients who report low satisfaction with social support may present with a particular vulnerability to postoperative delirium, even after controlling for physical confounding variables and depressive mood.

The effect of low versus high tidal volume ventilation on inflammatory markers in healthy individuals undergoing posterior spine fusion in the prone position: a randomized controlled trial - Corrected Proof

Stavros G. Memtsoudis, Anna Maria Bombardieri, Yan Ma, Federico P. Girardi — 2011-10-17

Abstract: Study Objective: To evaluate the effect of ventilation strategy on markers of inflammation in patients undergoing spine surgery in the prone position.Design: Randomized controlled trial.Setting: University-affiliated teaching hospital.Patients: 26 ASA physical status 1 and 2 patients scheduled for elective primary lumbar decompression and fusion in the prone position.Interventions: Patients were randomized to receive mechanical ventilation with either a tidal volume (VT) of 12 mL/kg ideal body weight with zero positive end-expiratory pressure (PEEP) or VT of 6 mL/kg ideal body weight with PEEP of 8 cm H2O.Measurements: Plasma levels of interleukin (IL)-6 and IL-8 were determined at the beginning of ventilation and at 6 and 12 hours later. Urinary levels of desmosine were determined at the beginning of ventilation and on postoperative days 1 and 3.Main Results: A significant increase in IL-6, IL-8, and urine desmosine levels was noted over time compared with baseline (P < 0.01). However, no significant difference in the levels of markers was seen between the groups at any time point when controlling for demographics, ASA physical status, body mass index, duration of ventilation, or estimated blood loss.Conclusions: Although markers of inflammation are increased after posterior spine fusion surgery, ventilation strategy has minimal impact on markers of systemic inflammation.