Complications of Different Ventilation Strategies in Endoscopic Laryngeal Surgery: A 10-year Review.
Jaquet, Yves M.D.; Monnier, Philippe M.D. ; Van Melle, Guy M.D., Ph.D.; Ravussin, Patrick M.D; Spahn, Donat R. M.D., F.R.C.A; Chollet-Rivier, Madeleine M.D.
Anesthesiology. 104(1):52-59, January 2006.

Background: Spontaneous ventilation, mechanical controlled ventilation, apneic intermittent ventilation, and jet ventilation are commonly used during interventional suspension microlaryngoscopy. The aim of this study was to investigate specific complications of each technique, with special emphasis on transtracheal and transglottal jet ventilation.
Methods: The authors performed a retrospective single-institution analysis of a case series of 1,093 microlaryngoscopies performed in 661 patients between January 1994 and January 2004. Data were collected from two separate prospective databases. Feasibility and complications encountered with each technique of ventilation were analyzed as main outcome measures.
Results: During 1,093 suspension microlaryngoscopies, ventilation was supplied by mechanical controlled ventilation via small endotracheal tubes (n = 200), intermittent apneic ventilation (n = 159), transtracheal jet ventilation (n = 265), or transglottal jet ventilation (n = 469). Twenty-nine minor and 4 major complications occurred. Seventy-five percent of the patients with major events had an American Society of Anesthesiologists physical status classification of III. Five laryngospasms were observed with apneic intermittent ventilation. All other 24 complications (including 7 barotrauma) occurred during jet ventilation. Transtracheal jet ventilation was associated with a significantly higher complication rate than transglottal jet ventilation (P < 0.0001; odds ratio, 4.3 [95% confidence interval, 1.9-10.0]). All severe complications were related to barotraumas resulting from airway outflow obstruction during jet ventilation, most often laryngospasms.
Conclusions: The use of a transtracheal cannula was the major independent risk factor for complications during jet ventilation for interventional microlaryngoscopy. The anesthetist's vigilance in clinically detecting and preventing outflow airway obstruction remains the best prevention of barotrauma during subglottic jet ventilation.

Comparison of Plastic Single-use and Metal Reusable Laryngoscope Blades for Orotracheal Intubation during Rapid Sequence Induction of Anesthesia.
Amour, Julien M.D. ; Marmion, Frederic M.D. ; Birenbaum, Aurelie M.D. ; Nicolas-Robin, Armelle M.D. ; Coriat, Pierre M.D. ; Riou, Bruno M.D., Ph.D. ; Langeron, Olivier M.D., Ph.D. 
Anesthesiology. 104(1):60-64, January 2006.

Background: Plastic single-use laryngoscope blades are inexpensive and carry a lower risk of infection compared with metal reusable blades, but their efficiency during rapid sequence induction remains a matter of debate. The authors therefore compared plastic and metal blades during rapid sequence induction in a prospective randomized trial.
Methods: Two hundred eighty-four adult patients undergoing general anesthesia requiring rapid sequence induction were randomly assigned on a weekly basis to either plastic single-use or reusable metal blades (cluster randomization). After induction, a 60-s period was allowed to complete intubation. In the case of failed intubation, a second attempt was performed using metal blade. The primary endpoint of the study was the rate of failed intubations, and the secondary endpoint was the incidence of complications (oxygen desaturation, lung aspiration, and oropharynx trauma).
Results: Both groups were similar in their main characteristics, including risk factors for difficult intubation. On the first attempt, the rate of failed intubation was significantly increased in plastic blade group (17 vs. 3%; P < 0.01). In metal blade group, 50% of failed intubations were still difficult after the second attempt. In plastic blade group, all initial failed intubations were successfully intubated using metal blade, with an improvement in Cormack and Lehane grade. There was a significant increase in the complication rate in plastic group (15 vs. 6%; P < 0.05).
Conclusions: In rapid sequence induction of anesthesia, the plastic laryngoscope blade is less efficient than a metal blade and thus should not be recommended for use in this clinical setting.

ACTA ANAESTHESIOLOGICA SCANDINAVICA - VOLVER ARRIBA

Acta Anaesthesiologica Scandinavica
Volume 50 Page 135  - February 2006, Volume 50 Issue 2

Clonidine in paediatric anaesthesia: review of the literature and comparison with benzodiazepines for premedication
H. Bergendahl, P-A. Lönnqvist and S. Eksborg

Background: Children undergoing anaesthesia and surgery can experience significant anxiety and distress during the peri-operative period, but whether routine premedication is necessary is currently debated.
Benzodiazepines are the most frequently used drugs as premedication in paediatric anaesthesia. In the US, 50% of young children undergoing surgery receive premedication and midazolam is the most frequently used drug in this context. Nishina and coworkers  concluded in a review article in 1999 that clonidine, administered via an oral, rectal, or caudal route, is a promising adjunct to anaesthetics and analgesics to enhance quality of peri-operative management in infants and children. Later publications also support the use of clonidine for premedication.
The aim of this communication is to review the use of clonidine in paediatric anaesthesia and to propose clonidine as a promising alternative to midazolam.
Clonidine is associated with a number of beneficial effects in the context ofanaesthesia both in adults and children. Why clonidine is not routinely use in clinical practice despite the massive publication list is to a large extent due to the lack of marketing efforts from the pharmaceutical industry since multiplegeneric preparations are now readily available on most markets.
Midazolam is also associated with a number of beneficial effects, but is far from an ideal premedicant in children, especially with regards to the amnesia, confusion and long term behavioural disturbances. Clonidine has contrary to midazolam no effect on respiration. We believe that clonidine is a good alternative to midazolam as premedication in infants and children.

BRITISH JOURNAL OF ANAESTHESIA - TOP

Bougie-guided insertion of the ProSeal^TM laryngeal mask airway has higher first attempt success rate than the digital technique in children
M. Lopez-Gil, J. Brimacombe, L. Barragan and C. Keller
British Journal of Anaesthesia 2006 96(2):238-241

Background. We tested the hypothesis that bougie-guided insertion of the ProSeal^TM laryngeal mask airway (ProSeal^TM LMA) has higher success rate than the digital technique in children.
Methods. One hundred and twenty children (ASA I–II, aged 1–16 yr) were randomly allocated for ProSeal^TM LMA insertion using the digital or bougie-guided technique. The digital technique was performed according to the manufacturer's instructions. The bougie-guided technique involved priming the drain tube with a bougie, placing the bougie in the oesophagus under direct vision and railroading the ProSeal^TM LMA into position. Unblinded data were collected about ease of insertion (number of attempts and time taken to provide an effective airway), efficacy of seal, ease of gastric tube placement, haemodynamic responses and blood staining. Blinded data were collected about postoperative airway morbidity.
Results. The first attempt success rate was higher for the bougie-guided technique (59/60 vs 52/60, P=0.015), but effective airway time was longer (37 vs 32 s, P<0.001). There were no differences in efficacy of seal, ease of gastric tube placement, haemodynamic responses, blood staining or postoperative airway morbidity.
Conclusion. We conclude that bougie-guided insertion of the ProSeal^TM LMA has a higher first attempt success rate than the digital technique in children.


Intra-articular injection of warmed lidocaine improves intraoperative anaesthetic and postoperative analgesic conditions
Y.-C. P. Arai, M. Ikeuchi, K. Fukunaga, W. Ueda, T. Kimura and T. Komatsu
British Journal of Anaesthesia 2006 96(2):259-261

Background. Although local anaesthesia for knee arthroscopy is a well-documented procedure, arthroscopy under local anaesthesia is often interrupted because of intolerable discomfort and pain. Warming local anaesthetic solutions may increase its anaesthetic effect. We tested whether intra-articular injection of warmed lidocaine solution could improve intraoperative anaesthetic and postoperative analgesic conditions.
Methods. Patients in the warmed group received 20 ml warmed (40°C) lidocaine 1% intra-articularly 20 min before surgery. The patients in the control group received 20 ml room-temperature (25°C) lidocaine 1% intra-articularly 20 min before surgery. During surgery, the patients reported pain on a visual analogue scale (VAS).
Results. The median VAS pain score was 1.5 (range, 0.0–3.0) in the warmed lidocaine group and 5.0 (4.0–8.0) in the control group (P<0.001). The median intra- and postoperative analgesic requirements in the control group were significantly greater than that in the warmed group.
Conclusion. Warmed lidocaine injected intra-articularly provides improved intraoperative anaesthetic and postoperative analgesic conditions for patients undergoing knee arthroscopy.

CANADIAN JOURNAL OF ANESTHESIA - TOP

Bispectral index monitoring does not improve early recovery of geriatric outpatients undergoing brief surgical procedures
Edna Zohar, MD, Ilia Luban, MD, Paul F. White, PhD MD, Erez Ramati, MD, Shay Shabat, MD and Brian Fredman, MB BCH
Canadian Journal of Anesthesia 53:20-25 (2006)

Purpose: To assess if titration of sevoflurane using the bispectral index (BIS) monitor improves the early and intermediate recovery in geriatric outpatients undergoing brief urologic procedures under general anesthesia without muscle relaxants.
Methods: After a standardized induction with propofol and fentanyl, a laryngeal mask airway was inserted and sevoflurane was administered in combination with 60% nitrous oxide in oxygen for maintenance of anesthesia in spontaneously breathing outpatients. In the Control group (n = 25), sevoflurane and fentanyl were titrated according to standard clinical practice. In the BIS-directed group (n = 25), sevoflurane was titrated to maintain a BIS value between 50 and 60, and supplemental fentanyl, 25 µg iv boluses were administered to treat tachypnea. The intraoperative anesthetic and analgesic requirements, as well as the times to eye opening, removal of the laryngeal mask airway device, response to simple commands, orientation to person and place, and postanesthesia care unit discharge eligibility (fast-track score of 14) were assessed at specific time intervals.
Results: The minimum alveolar concentration-hour of sevoflurane (0.25 ± 0.15 and 0.31 ± 0.2) and end-tidal concentrations of sevoflurane at the end of surgery (0.3 ± 0.3 and 0.4 ± 0.20%) did not differ significantly between the Control and BIS-directed groups, respectively. Although the percentage of patients requiring supplemental boluses of fentanyl was reduced in the BIS-directed group (16 vs 48%, P <0.05), the intraoperative BIS values and recovery times were similar in the two groups.
Conclusion: In this non-paralyzed elderly outpatient surgery population, the use of BIS monitoring for titrating the maintenance anesthetic (sevoflurane) failed to improve the early recovery process.

 
High levels of impulsivity may contraindicate midazolam premedication in children
G. Allen Finley, MD FRCPC FAAP, Sherry H. Stewart, PhD, Susan Buffett-Jerrott, PhD, Kristi D. Wright, MA and Donna Millington, BSc
Canadian Journal of Anesthesia 53:73-78 (2006)

Purpose: To investigate the effects of midazolam on emotional reactivity during induction of anesthesia in a pediatric day surgery setting. A secondary purpose was to determine if these effects were influenced by child temperament factors.
Methods: Forty children (age four to six years) scheduled for myringotomy were randomly assigned, in a double blind fashion, to receive either oral midazolam 0.5 mg·kg–1 mixed with acetaminophen suspension or acetaminophen alone. The Emotionality, Activity, Sociability, and Impulsivity (EASI) scale was used as a measure of child temperament. The modified Yale Preoperative Anxiety Scale (m-YPAS), an observer-rated measure of state anxiety, was employed to assess anxiety pre- and post-drug, and also at induction of anesthesia.
Results: Children who received midazolam reacted significantly less to induction of anesthesia than did children in the placebo control group, F (1, 38) = 7.46, P = 0.01. A significant positive association was observed between baseline levels of anxiety and observer-rated anxiety at anesthetic induction, but only in the placebo group, r = 0.58, P < 0.01. A significant positive association was observed between levels of impulsivity at baseline and observer-rated anxiety at anesthetic induction, but only in the midazolam group, r = 0.42, P < 0.05.
Conclusions: Midazolam dampened adverse reactivity during anesthetic induction, particularly among children with high baseline levels of anxiety. Baseline level of impulsivity was positively associated with adverse reactions to anesthesia induction in the drug group, but not in the placebo group, suggesting that high levels of trait impulsivity may contraindicate the use of midazolam as a preoperative medication.


PUB MED - TOP

Increasing Operating Room Efficiency Through Parallel Processing
David M. Friedman, MD, Suzanne M. Sokal, MSPH, Yuchiao Chang, PhD, and David L. Berger, MD
Ann Surg 2006;243: 10–14

Objective: Because of rising costs and shrinking reimbursements, hospitals must continually find ways to improve efficiency and productivity. This study attempts to increase caseloads in ambulatory surgery operating rooms while maintaining patient satisfaction and safety.
Summary Background Data: In most hospitals, patients move through their operative day in a linear fashion, starting at registrationand finishing in the recovery room. Given this pattern, only 1 patient may occupy the efforts of the operating room team at a time. Byprocessing patients in a parallel fashion, operating room efficiencyand patient throughput are increased while costs remain stable.
Methods: Patients undergoing hernia repairs under local anesthesia with intravenous sedation were divided into a control group and an experimental group. Patients in the control group received their local anesthesia in the operating room at the start of the surgery. The experimental group patients received their local anesthesia in the induction room by the surgeon while the operating room was being cleaned and set up.
Results: While operative time for the control group and the experimental group were nearly identical, the turnover time and the induction time were significantly shorter for the experimental group. The cumulative reduction in time during the operative day was sufficient to allow the addition of new operative cases.
Conclusions: This study demonstrates a system of increasing operating room efficiency by changing patient flow rather than simply working to streamline existing steps. This increase in efficiency is not associated with the expansion of hospital budgets or a decrease in patient safety or satisfaction.

Hypertension: Classification, Pathophysiology, and Management During Outpatient Sedation and Local Anesthesia
Stephen Wilford Holm, DMD, Larry L. Cunningham, Jr, DDS, MD, Eric Bensadoun, MD,
and Matthew J. Madsen, BS
J Oral Maxillofac Surg. 2006 Jan;64(1):111-21.

Hypertension is defined as a systolic blood pressure (SBP) higher than 140 mHg or a diastolic blood pressure (DBP) higher than 90 mmHg; the diagnosis is based on the average of 2 or more readings taken at each of 2 or more visits after an initial screening. When determined by these criteria, hypertension affects 20% to 30% of the adult population in most developed countries, and its prevalence appears to increase with the age of the patient. Recent publications have shown that the lifetime risk of hypertension for patients who are normotensive at age 55 is 90%. African Americans are affected by hypertension nearly twice as often as whites and seem to be more vulnerable to its complications. Hypertension is an important risk factor for cardiovascular accidents, coronary heart disease, cardiac hypertrophy with heart failure (hypertensive heart disease), aortic dissection, and renal failure. Hypertension can also accelerate atherogenesis and can induce changes favorable for aortic dissection and cerebrovascular hemorrhage. Despite the prevalence of hypertension and its associated complications, only 29% of patients with hypertension are treated, and only 45% of those treated with antihypertensive medications have controlled disease.
This paper reviews and summarizes the new classification system based on the Seventh Report of the Joint National Committee on the Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JNC-7). In addition, it reviews the guidelines, pathophysiology, clinical symptoms, and diagnosis of hypertension. Finally, it reviews treatment recommendations for common local anesthetics, conscious sedative agents, and general anesthetics as they pertain to hypertensive patients undergoing oral and
maxillofacial surgery.
Oral and maxillofacial surgeons will frequently encounter patients with undiagnosed or poorly
controlled hypertension. The recent JNC-7 report addressed the following issues: 1) the publication of many new hypertension observational studies and clinical trials; 2) the need for a new, clear, and concise guideline that would be useful for clinicians; 3) the need to simplify the classification of blood pressure; and 4) the clear recognition that previous JNC reports were not being used to their full potential.

To continue reading, please click here (PDF format).

The role of oral fluid intake following adeno-tonsillectomy
Abtin Tabaee, Jerry W. Lin, Vanessa Dupiton, Jacqueline E. Jones
Int J Pediatr Otorhinolaryngol. 2006 Jan 5;

Objective: To compare the incidence of complications following pediatric adenotonsillectomy (T&A) in patients who are encouraged to drink oral liquid versus
patients who drink on a voluntary basis.
Methods: This is a prospective, randomized, non-blinded study performed in a
tertiary care medical center. Ninety-three otherwise healthy pediatric patients aged
2—12 years undergoing ambulatory T&A by a single surgeon were included in the study.
Forty four patients were encouraged to drink 240 ml of clear liquid prior to discharge
while 49 patients drank on a voluntary basis. Patients were followed prospectively for
the incidence of emesis, dehydration and other complications.
Results: Overall, emesis was experienced by 18% of patients in the post anesthesia
care unit (PACU) and by 20% at home. Fifty percent of patients in the encouraged
group versus 31% in the voluntary group reached the goal volume of oral liquids
( p < 0.05). The incidence of emesis was higher in both the encouraged (41% versus
14%) and voluntary group (40% versus 26%) when the goal volume of 240 ml was
reached. There was no statistically significant difference between the two groups in
terms of duration of PACU stay, incidence of emesis, number of episodes of emesis or
volume of emesis. Further, there was no difference between the two groups in terms
of post-operative complications including dehydration.
Conclusions: The current practice of a mandatory trial of oral fluid intake in the postoperative period may not be a necessary requirement for discharge. Further, mandatory
oral fluids may result in a higher incidence of emesis.

TOP

PAGE 2     PAGE 4