General Anesthesia For Elective Surgery Research Articles

Cricoid Pressure Does Not Increase the Rate of Failed Intubation by Direct Laryngoscopy in Adults

Cricoid pressure (CP) is applied during induction of anesthesia to prevent regurgitation of gastric content and pulmonary aspiration. However, it has been suggested that CP makes tracheal intubation more difficult. This double-blind randomized study evaluated the effect of CP on orotracheal intubation by direct laryngoscopy in adults. Seven hundred adult patients undergoing general anesthesia for elective surgery were randomly assigned to have a standardized CP (n = 344) or a sham CP (n = 356) during laryngoscopy and intubation. After anesthesia induction and complete muscle relaxation, a 30-s period was allowed to complete intubation with a Macintosh No. 3 laryngoscope blade. The primary endpoint was the rate of failed intubation at 30 s. The secondary endpoints included the intubation time, the Cormack and Lehane grade of laryngoscopic view, and the Intubation Difficulty Scale score. Groups were similar for demographic data and risk factors for difficult intubation. The rates of failed intubation at 30 s were comparable for the two groups: 15 of 344 (4.4%) and 13 of 356 (3.7%) in the CP and sham CP groups, respectively (P = 0.70). The grades of laryngoscopic view and the Intubation Difficulty Scale score were also comparable. Median intubation time was slightly longer in the CP group than in the sham CP group (11.3 and 10.4 s, respectively, P = 0.001). CP applied by trained personnel does not increase the rate of failed intubation. Hence CP should not be avoided for fear of increasing the difficulty of intubation when its use is indicated.

Response of Preoperative Anesthetic Explanation to Parents or Guardians for Elective Surgery Planned Children

Background: Pre-anesthesia information of pediatric patients is usually conducted to their parents and sometimes inadequate information makes the parents very anxious about anesthesia. We designed this study to evaluate the response of pediatric patients´ parents to pre-anesthesia information. Methods: The data was collected based on the answers of 432 parents of pediatric patients to receive general anesthesia for elective surgery. The age of patient is under 17. At the day of admission they were received an explanatory pamphlet. Before the day of surgery, an anesthesiologist visited them and explained about conduct of general anesthesia and its possible complication. After the surgery, we asked the to answer the questionnaire. Results: Eighty-five percent of the parents had informed about anesthesia and fifity-three percent of them were satisfied about the explanation. Eighty percent of the parents answered their anxiety about general anesthesia wasn't increased after the information and fifty percent of parents answered that it is necessary to tell the plain explanation about general anesthesia to pediatric patients. Conclusions: We concluded that pre-anesthetic information is useful to reduce the anxiety of pediatric patients' parents also we got information about what the parents wanted to know about the anesthesia and changes after anesthesia.

The Efficacy of Dexmedetomidine in Suppressing Cardiovascular and Sympathoadrenal Response to Endotracheal Intubation in Hypertensive Patients Undergoing Elective Surgery

The Present study was conducted on 20 controlled hypertensive adult patients. They all received general anesthesia for elective surgery and dexedetomidine infusion for 5 minutes before endotracheal intubation and for 10 minutes thereafter. It was found out that there was a significant mild reduction in systolic blood pressure, mean heart rate, and rate pressure product after start of infusion, P = 0.01, 0.05, and 0.01, respectively. After intubation, there were insignificant changes in systolic blood pressure [P=0.05] and heart rate showed mild significant increase at 1, 2, and 4 minutes with back to normal values at 6, 8, and 10 minutes. Rate pressure products also showed insignificant increase at 2, 4, and 6 minutes and back to normal at 6, 8 and 10 minutes. Epinephrine plasma level showed insignificant change after 10 minutes of intubation from baseline value 79.5±21 Vs. 76.8±18 pg/ml [P=0.01], while norepinephrine level was 419±48 pg/ml as baseline Vs. 428±51 pg/ml at 10 minutes after intubation with also mild insignificant change. The total dose of propfol used for induction of anesthesia was less than calculated as evidenced by loss of eyelash reflex and apnea with a mean value of 159 mg [1.54 mg/kg Bwt.] indicating that dexmedetomidine infusion before induction significantly reduced the dose of propofol needed for induction of anesthesia.

The Influence of Explaining Risk on Parents' Decision to Participate Their Child in Clinical Studies

Background: The participation of children in clinical research requires parental permission. We designed this study to evaluate the extent to which the risk associated with a clinical study affects the parents' decision to provide permission. Simultaneously, we evaluated factors which led parents to allow or decline their child's participation in such clinical studies. Methods: We interviewed 82 parents of children of ASA class I-II scheduled to receive general anesthesia for elective surgery. Parents were presented with either of two sham protocols: no risk (Control, n = 44), or pain (Pain, n = 38) and asked to complete a questionnaire detailing the reasons for their decision. Results: There were no differences in the demographics of the two groups. Whereas comprehension of the doctor's explanation was similar in both groups, consenting rates were higher in the control group (54.5% versus 28.7%; P

The Effects of Lidocaine on Pain Due to Rocuronium

Background: Rocuronium is a non depolarizing muscle relaxant of rapid onset and of intermediate action duration. It is particularly suitable for short operation and rapid control airway. But, intravenous rocuronium cause pain and a withdrawal movement. The purpose of this study was to evaluate the effect of intravenous lidocaine on pain and withdrawal movement in patients receiving rocuronium. Methods: The study was approved by our institutional review board, and informed consent was obtained from all patients. One hundred and twenty patients, ASA physical status 1-2 undergoing general anesthesia for elective surgery were randomly enrolled. Allergy history to trial drug, chronic pain, pregnancy, patient on analgesics, difficult vein access and deeply sedated patients were excluded. Patients were not premedicated, and had a 20-18 G intravenous catheter inserted into a hand dorsum before operation. On arrival in the operation room, routine non-invasive monitors were placed and the free flow of intravenous fluid without edema, redness or hardness was confirmed. A subparalyzing dose of rocuronium 0.06 mg/kg (RS group) or vecuronium 0.01 mg/kg (VS group) was administered after 2 ml of 0.9% NaCl in one group, and a subparalyzing dose of rocuronium 0.06 mg/kg (RL group) or vecuronium 0.01 mg/kg (VL group) was administered after 2 ml of 2% lidocaine injection in a second group. All patients then received 5 mg/kg of 2.5% thiopental sodium and 0.6 mg/kg rocuronium (RS and RL group) or 0.1 mg/kg of vecuronium (VS and VL group). Muscle relaxant-induced pain and withdrawal movements were assessed using 4-grade scales (0-3). Vein redness was measured just after administration and vein hardness five minutes after intubation using 4-grade scales (0-3). Results: Incidence of pain (8.2 times) and withdrawal movement (6.2 times) was more frequent in the rocuronium group than in the vecuronium group (P

The Effect of Lidocaine on Withdrawal Movement Due to Rocuronium Injection in Pediatric Patients

Background: Rocuronium is a non depolarizing muscle relaxant of rapid onset and of intermediate duration. It is useful for short operations and for rapid control of the airway in pediatric patients. However the intravenous injection of rocuronium cause pain and a withdrawal movement. The purpose of this study was to evaluate the effect of lidocaine pretreatment in pediatric patients receiving rocuronium (10 mg/ml) and diluted rocuronium (1 mg/ml) on withdrawal movement Methods: The study was approved by our institutional review board, and informed consent was obtained from all parents. One hundred and twenty five patients, aged from 4 months to 10 years, ASA physical status 1-2 undergoing general anesthesia for elective surgery were randomly enrolled in the study. Allergy history to a trial drug, pediatric patients on analgesics, difficult vein access and severely crying pediatric patients on arrival were excluded. All patients were non-premedicated and had a 22 G i.v. catheter inserted into the dorsum of hand before operation. On arrival in the operation room, routine non invasive monitors were placed and a free flow of i.v. fluid without edema, redness, hardness or pain was confirmed. After the administration of glycopyrrolate 0.004 mg/kg, inhalational induction was performed with 4-8 vol% sevoflurane by face mask fitting. One group received rocuronium 0.3 mg/kg (RS group) or vecuronium 0.05 mg/kg (VS group) was administered after 0.5 ml of 0.9% NaCl. A second group received rocuronium 0.3 mg/kg (RL group) or vecuronium 0.5 mg/kg (VL group) after lidocaine 1 mg/kg. A third group received rocuronium 1 mg/ml diluted with 0.9% NaCl (1：9) (RD group). Muscle relaxant-induced withdrawal movements were assessed by using a 4-grade scales (0-3). We also observed pulse rate alterations. Vein redness was evaluated just after administration and vein hardness five minutes after intubation by using a 4-grade scale (0-3). Results: Withdrawal movements were more intense in the rocuronium group (R group, 3.8 times, P

The effects of concurrent atorvastatin therapy on the pharmacokinetics of intravenous midazolam.

Midazolam is a commonly used anaesthetic agent and is metabolised by the 3A4 isoform of the cytochrome P450 enzyme system. Atorvastatin is also metabolised by cytochrome P450 3A4 and, in vitro, atorvastatin inhibits the cytochrome P450 3A4-mediated metabolism of mexazolam. We hypothesised that concurrent administration of atorvastatin and midazolam would result in altered midazolam pharmacokinetics. Fourteen patients scheduled to undergo general anaesthesia for elective surgery were recruited in a matched pair design to receive intravenous midazolam (0.15 mg.kg-1). Of these patients, seven were taking long-term atorvastatin. Atorvastatin patients demonstrated a greater area under the curve (889.4 (standard deviation 388.6) ng-h.ml-1) vs. control patients (629.1 (standard deviation 197.2) ng-h.ml-1) (p < 0.05). Patients taking atorvastatin also demonstrated a decreased clearance (0.18 (standard deviation 0.08) l-kg. h-1) vs. control patients (0.27 (standard deviation 0.08) l-kg.h-1) (p < 0.05). This study suggests that chronically administered atorvastatin decreases the clearance of intravenously administered midazolam.

In children, nitrous oxide decreases pain on injection of propofol mixed with lidocaine

To investigate if 50% nitrous oxide reduces the pain during injection of propofol mixed with lidocaine in children. Healthy children undergoing iv induction of general anesthesia for elective surgery were recruited into this prospective, randomized, double-blind study. None of the patients received any premedication except for eutectic mixture of local anesthetics cream. Before induction of anesthesia with propofol 1% mixed with lidocaine 0.05% (propofol dose 3 mg x kg(-1)), the treatment group received 50% N(2)O in O(2) and the control group received 100% oxygen. Pain due to propofol administration was rated with a four-point behavioural scale: none, mild, moderate or severe. There were 28 subjects in the control group and 26 subjects in the treatment group. Demographic data were similar in both groups. The incidence of pain at induction was 4% after N(2)O and 36% in the control group, P < 0.01. No patients had severe pain. Most patients had mild pain. Three of the ten patients with pain in the control group had moderate pain. The number needed to treat was 3:1. Nitrous oxide reduces pain during induction with propofol mixed with lidocaine in healthy children.

Pre‐audit survey of documentation of invasive procedures in paediatric anaesthesia

Introduction Consent of patients for any medical procedure is an essential part of good practice (1). Verbal consent is increasingly sought for invasive anaesthetic procedures and documentation of this is an important feature of risk management. Paediatric consent is a complex issue and although it is common practice to explain things to the child, written consent is generally still sought from the parent (2). Recent guidelines from the Royal College (3) are quite specific about having a ‘child centred approach’. They clearly state that ‘where special techniques (e.g. epidurals, other regional blocks including caudal, and invasive monitoring or blood transfusion) are used there should generally be written evidence that these have been discussed with the child (when appropriate) and the parents’.Our aim was to discover the current amount of documentation on invasive procedures in our paediatric anaesthetic notes and to subsequently agree on a local standard.Method We looked retrospectively at anaesthetic records of children aged 10, 11 and 12 years undergoing general anaesthesia for elective surgery over a 2‐month period. We specifically looked for documentation of who was present at the pre‐operative discussion and where an invasive anaesthetic technique was planned. written evidence that it had been discussed.Results 73 anaesthetic records were examined. The case mix was as follows: 37% ENT, 28% Plastic Surgery, 24% General Surgery, 11 % Orthopaedic and Oral Surgery. A Consultant was present for 98% of the anaesthetics and was accompanied by a trainee in half of those cases. In 82% (60 patients) there was no documentation of who was present at the pre‐operative discussion. In 2 cases (3%) the child was seen alone, in 8 cases (11 %) both a parent and child were documented to have been involved in the discussion and in 3 cases (4%) only the parents appeared to have been involved. Of the 73 anaesthetic records, 11 did not have invasive procedures planned or performed and the following data is from the remaining 62 anaesthetic records 83.5% of invasive procedures were documented pre‐operatively 12 patients (19%) had more than one procedure. Only 7 notes (11 %) had a record of the procedure being specifically discussed with the child. 2 out of the 4 caudal (50%) were done without documentatior, of discussion about the procedure 7 out of 48 suppositories (14%) were given without record of verbal consent 5 out of 16 (31 %) of the local anaesthetic techniques were performed without documentation of discussion. Discussion This pre‐audit survey demonstrates that in 82% of cases there was no record of exactly who was present at the preoperative discussion and that some invasive procedures were carried out without any record of a discussion having taken place. We feel that this level of documentation is insufficient. We looked at the age range 10–12 years as this might be regarded as approximately the age at which agreement should be sought for relatively simple procedures such as those chosen in this survey. This is not to imply that children below this age should not be involved in a plan of management or that all children of this age will be fully competent to participate in decisions. We deliberately chose to look at elective surgery, as there should be better documentation in these cases. One reason for such poor results may be that most anaesthetists do not realise the importance of documentation. Our current chart provides no means of prompting the anaesthetist to record who was present at pre‐operative discussions. There is also a lack of a clear standard as to an age when invasive procedures should generally be discussed. We feel that this is probably a common problem and hope this surveys increases awareness on this important topic.Conclusions The results of this survey are to be brought to the attention of the local department. Having identified the problem we hope to agree on a local standard and audit against these standards.

Mémorisation peropératoire.Évaluation de l’incidence chez 326 patients au décours d’une anesthésie générale

Objectives: Measuring the incidence of intraoperative recall in our hospital. Study design: Prospective study. Patients and methods: Three hundred and twenty-six patients who underwent a general anaesthesia for elective surgery on selected sites (general, urology, ORL, gynaecology and obstetrical, vascular and cardiac, thoracic) were interviewed on the first or the second postoperative day using a standard questionnary. When recall was suspected, the anaesthetist was consulted and the anaesthetic record was looked at in order to evaluate the authenticity of any recollections. Results: Four patients mentioned an anomaly evoking intra-operative recall. The reduction in the anaesthetic level would explain authentic recollection for one patient. The recollection of another patient could not be truly verified. The site was the same for these two cases and the anaesthetic protocol for digestive surgery comprised curare and droperidol. The recollections for the two other patients did not correspond to the intraoperative period. The incidence of this phenomenon on the totality of sites was 0.6 per cent. Conclusion: This result conforms to other studies. This phenomenon is a quality indicator, but probably under estimated. Although retrospective, this evaluation is quick and easy. This research in post-operative period should be systematic in order to find the reason and to propose an early course of action for these patients. An analysis of the anaesthetic protocol is necessary when the frequency of intra-operative recall is too high.

Impedance cardiographic waveforms in children: Involvement in left ventricular ejection time determination during anesthesia.

OBJECTIVE: The physiologic basis of the impedance cardiographic (ICG) signal is still a matter of debate. An accurate determination of left ventricular ejection time (LVET) is needed to calculate stroke volume. In children, several shapes of the ICG signal are observed during anesthesia or in critical care. The aim of this study was to determine the relationship between the shape of the ICG signal and various morphologic and hemodynamic determinants obtained with Doppler echocardiography to highlight the effect of the various shapes in the accuracy of LVET determination. DESIGN: Prospective study. SETTING: Pediatric surgery in a university hospital. PATIENTS: 103 children, ASA physical status I or II. INTERVENTIONS: General anesthesia for elective surgery. Measurements: Electrocardiography, ICG, and Doppler echocardiography were recorded simultaneously. Classic hemodynamic variables, such as heart rate, LVET, stroke volume, or systemic vascular resistance, were measured or calculated. A mathematical model of the ICG signal was used to determine the shape of the ICG signal and its potential relationship to various morphologic and hemodynamic determinants. The ICG signal shape was then modeled with the normalized amplitudes (NHA) and phase (NHP) of the three harmonics of the fundamental signal. Analysis was performed with a multiple correspondence analysis. RESULTS: ICG method LVET did not significantly correlate with LVET determined with Doppler or with heart rate. NHA and NHP of the ICG signal were not significantly related to LVET determined with Doppler or to stroke volume. NHA were linked to heart rate and the relative length of the cardiac diastolic period. CONCLUSION: The absence of relationship between LVET determined with Doppler and the main variables defining the shape of the ICG signal highlight the relative limit of stroke volume determination with ICG method. The involvement of the arterial compliance in the ICG signal shape can be discussed in regard to the links between NHA and both heart rate and the relative length of the cardiac diastolic period, respectively.

Persistent wheezing in very young children is associated with lower respiratory inflammation.

Despite advances in understanding the pathophysiology of asthma, morbidity and mortality in pediatrics continue to rise. Little is known about the initiation and chronicity of inflammation resulting in asthma in this young population. We evaluated 20 "wheezing" children (WC) (median age 14.9 mo) with a minimum of two episodes of wheezing or prolonged wheezing > or = 2 mo in a 6-mo period with bronchoscopy and bronchoalveolar lavage (BAL). Comparisons were made with six normal controls (NC) (median age 23.3 mo) undergoing general anesthesia for elective surgery. BAL fluid cell counts and differentials were determined. The eicosanoids, leukotriene (LT) B(4), LTE(4), prostaglandin (PG)E(2), and 15-hydroxyeicosatetraenoic acid (HETE) and the mast cell mediators, beta-tryptase and PGD(2), were evaluated by enzyme immunoassay (EIA). WC had significant elevations in total BAL cells/ml (p = 0.01), as well as, lymphocytes (LYMPH, p = 0.007), macrophages/monocytes (M&M, p = 0.02), polymorphonuclear cells (PMN, p = 0.02), epithelial cells (EPI, p = 0.03), and eosinophils (EOS, p = 0.04) compared with NC. Levels of PGE(2) (p = 0.0005), 15-HETE (p = 0.002), LTE(4) (p = 0.04), and LTB(4) (p = 0.05) were also increased in WC compared with NC, whereas PGD(2) and beta-tryptase were not. This study confirms that inflammation is present in the airways of very young WC and may differ from patterns seen in adults with asthma.

Surgical approaches to membranous tracheal wall lacerations

Background: Smaller postintubation tracheal tears are often misdiagnosed and, when recognized, they are effectively managed in a conservative fashion. Large membranous lacerations, especially if associated with important manifestations, require immediate surgical repair. We report our experience over the past 7 years. Methods: From 1993 to 1999, 11 patients with a postintubation posterior tracheal wall laceration were treated in our institution. One patient was male and 10 were female, with a mean age of 68 years. Ten patients underwent orotracheal intubation under general anesthesia for elective surgery, 4 of whom were treated with a double-lumen selective tube. One patient underwent emergency intubation because of anaphylactic shock. In 9 cases the tracheal tear was promptly repaired, by way of a thoracotomy in 4 and by way of a cervicotomy and longitudinal tracheotomy in 5. In 2 cases the tear was small and was consequently managed conservatively. Results: All surgical procedures proved effective in repairing the laceration, and there was no mortality or morbidity in the perioperative period. Early and late endoscopic follow-up showed no signs of tracheobronchial stenosis. Conclusions: When repair of membranous tracheal laceration is required, the surgical approach should be through a thoracotomy if the tear involves the distal trachea, a main stem, or both, and through a cervicotomy when the laceration is located in the proximal two thirds of the trachea. Performing a longitudinal tracheotomy to reach and suture the posterior tracheal wall is a reliable, quick, and safe procedure, and it avoids lateral and posterior dissection of the trachea. (J Thorac Cardiovasc Surg 2000;120:115-8)

Patients’ perception of sound levels in the surgical suite

Study Objectives: To measure sound levels that our patients are exposed to in the surgical suite and their perception of these sound levels. Design: Sound levels experienced by 100 patients undergoing general anesthesia for elective surgery during three phases: induction and maintenance of anesthesia in the operating room (OR), and recovery from anesthesia in the recovery room, were measured using a Type 4436 Noise Dose Meter. The equivalent continuous sound levels (Leq), maximum sound levels (Lmax), and the sources of sounds were noted. Patients were interviewed 24 hours after anesthesia about their perception of the sound levels they had experienced in the OR and recovery rooms. Measurements and Main Results: The Leq during the induction, maintenance, and recovery phases were 70.3 ± 16.8 dB(A), 66.2 ± 4.1 dB(A) and 71.8 ± 6.1 dB(A), respectively. These sound levels are much higher than international recommendations for hospital acute care areas and exceed the thresholds to produce noise-induced cardiovascular and endocrine effects. Sound levels were significantly higher during the induction and recovery phases compared to the maintenance phase. Thirty-two patients found the induction phase noisy and 33 patients found the recovery phase noisy. The sound levels distressed 16 patients and 52 patients would have preferred a quieter environment. There was no difference in the sound levels experienced by those who expressed dissatisfaction with the sound levels and those who did not. Much of the noise, particularly staff conversations, unnecessary alarms, and preparation of equipment, could have been prevented by simple measures. Conclusion: Noise prevention in the OR and recovery room needs more attention and should be a routine part of patient care.

Use of an illuminated flexible catheter for light-guided tracheal intubation through the intubating laryngeal mask by nurses.

We evaluated the ability of inexperienced personnel in using a prototype illuminated flexible catheter to assist tracheal intubation through the intubating laryngeal mask in anaesthetised, paralysed patients. The device consists of a completely flexible thin plastic catheter, a bulb attached to its distal end and a 15-mm concentric adapter at its proximal end. The illuminated catheter is placed into a straight silicone tracheal tube in such a way that the bulb is placed at the distal end of the tracheal tube. Six nurses inexperienced in tracheal intubation followed a 2-hr training program by using the device through the intubating laryngeal mask in a mannequin and then intubated 10 patients each, with instruction from an anaesthetist. All patients (n=60) were ASA 1-2, scheduled to undergo general anaesthesia for elective surgery. After fentanyl/propofol induction the intubating laryngeal mask was inserted. When an adequate airway was established, patients received atracurium and the endotracheal tube preloaded with the device was inserted through the intubating laryngeal mask and by observing the glow in the neck was advanced into the trachea. The final outcome and the duration of the procedure were recorded. The intubating laryngeal mask was inserted successfully in all patients. The success rate of intubation was 57/60 (95%); 38 patients at first attempt and 19 after two or three attempts. The mean (+/-SD) duration of the procedure in the first five patients in the series of each nurse was 74+/-40 s while in the last five patients it was diminished to 52+/-23 s (P=0.01). We conclude that the described methodology has the potential for more widespread use of tracheal intubation through the intubating laryngeal mask even by inexperienced personnel.

Use of an illuminated flexible catheter for light-guided tracheal intubation through the intubating laryngeal mask by nurses

We evaluated the ability of inexperienced personnel in using a prototype illuminated flexible catheter to assist tracheal intubation through the intubating laryngeal mask in anaesthetised, paralysed patients. The device consists of a completely flexible thin plastic catheter, a bulb attached to its distal end and a 15-mm concentric adapter at its proximal end. The illuminated catheter is placed into a straight silicone tracheal tube in such a way that the bulb is placed at the distal end of the tracheal tube. Six nurses inexperienced in tracheal intubation followed a 2-hr training program by using the device through the intubating laryngeal mask in a mannequin and then intubated 10 patients each, with instruction from an anaesthetist. All patients (n = 60) were ASA 1-2, scheduled to undergo general anaesthesia for elective surgery. After fentanyl/propofol induction the intubating laryngeal mask was inserted. When an adequate airway was established, patients received atracurium and the endotracheal tube preloaded with the device was inserted through the intubating laryngeal mask and by observing the glow in the neck was advanced into the trachea. The final outcome and the duration of the procedure were recorded. The intubating laryngeal mask was inserted successfully in all patients. The success rate of intubation was 57/60 (95%); 38 patients at first attempt and 19 after two or three attempts. The mean (±SD) duration of the procedure in the first five patients in the series of each nurse was 74±40 s while in the last five patients it was diminished to 52±23 s (P=0.01). We conclude that the described methodology has the potential for more widespread use of tracheal intubation through the intubating laryngeal mask even by inexperienced personnel.

Propofol or sevoflurane for laryngeal mask airway insertion

Sevoflurane is a volatile anesthetic agent, which combines rapid, smooth inhalational induction of anesthesia with rapid recovery, making it particularly suitable for day case anesthesia. The laryngeal mask airway is often also used in ambulatory anesthesia, with intravenous propofol being the agent of choice for its insertion. Our objective was to compare the conditions for laryngeal mask airway (LMA) insertion obtained by modified vital capacity breath sevoflurane inhalational induction of anesthesia with propofol intravenous induction. Eighty-eight patients, aged 18-65 yr, ASA I-II, undergoing general anesthesia for elective surgery were randomized into two groups in a prospective, single-blind study. Patients in Group P (n=44) received 2.5 mg x kg(-1) propofol i.v. and in Group S (n=44) received sevoflurane 8% in nitrous oxide 50% and oxygen. Ventilation was not assisted. Laryngeal mask airway insertion was attempted at one minute intervals from loss of both verbal response and eyelash reflex, by an anesthesiologist unaware of the induction technique. Complications, such as coughing and head movement, were also noted at each attempt. Mean time to successful LMA insertion was 1.3 (1-3) min in P and 2.2 (1-3) min in S, P < 0.05. Eleven patients in Group P, (25%) required additional propofol compared with four (9%) in S, P < 0.05. Incidence of complications was similar in both groups and by 3 min, LMA was successfully inserted in all patients. Modified vital capacity breath inhalational induction with sevoflurane 8% is efficient for LMA insertion in most cases, but takes slightly longer than propofol.

-The clinical use of the cuffed oropharyngeal airway (COPA)-.

To assess the performance of the COPA device during general anaesthesia. Prospective, clinical, open study. Eighty patients scheduled for short elective surgical procedures under general anaesthesia not requiring tracheal intubation. After premedication (midazolam, atropine), anaesthesia was induced with propofol (154 +/- 40 mg = 2.47 +/- 0.8 mg.kg-1) and alfentanil (1.14 +/- 0.43 mg). The COPA device was inserted in a fashion similar to a Guedel airway device. The device was evaluated on the following criteria: correct choice of COPA size, ease of insertion, ability to obtain or maintain patent airway. Adverse reactions were noted, such as coughing, nausea, regurgitation, inhalation, and sore throat. The overall rating of the COPA as a "hand free device" was evaluated on the basis of excellent, good, fair, and poor. Insertion of the device was easy and in 70 cases successful on the first attempt. Jaw thrust on head tilt was necessary in half the cases. No patient necessitated intubation because of hypoxaemia or airway obstruction. Adverse reactions occurred in few cases and consisted of sore throat (always moderate) in 10% of the cases. COPA was evaluated as excellent or good in 80% of the cases. COPA is a convenient device for airway management in fasting patients undergoing general anaesthesia for elective surgery in the supine position, in whom tracheal intubation is not indicated.

Reduction of propofol injection pain with a double lumen IV set

Study Objective: To investigate if the use of a new double lumen IV set (DLIS) decreases the incidence of propofol injection pain compared with single lumen IV set (SLIS) administration. Design: Prospective, randomized, double-blinded study. Setting: Operating rooms in a university hospital. Patients: 50 adult ASA physical status I and II patients of both genders undergoing general anesthesia for elective surgery. Interventions: Patients were injected with propofol either through a DLIS or a SLIS. Measurements and Main Results: Three different pain indices were recorded to be present or absent: (1) verbal report of pain during propofol injection, (2) grimacing during propofol injection, and (3) recall of injection pain in the recovery room. When the DLIS was used, the incidence of verbal pain, grimacing during propofol injection, and recall of pain during recovery were lowered significantly by 53%, 46%, and 52 %, respectively (chi square analysis of contingency table with Yates correction, p < 0.05). Conclusions: The DLIS significantly reduced the incidence of propofol injection pain compared with SLIS. Further studies are indicated to evaluate the cost-effectiveness of this device.

Rocuronium versus succinylcholine for rapid-sequence induction using a variation of the timing principle

Study Objective: To determine if, using a variation of the “timing” principle, 0.6 mg/kg of rocuronium can achieve an onset time and intubating conditions similar to those achieved with succinylcholine. Study Design: Prospective, randomized, double-blind clinical comparison. Setting: Operating room in a university medical center. Patients: 42 ASA physical status I and II patients undergoing general anesthesia for elective surgery. Interventions: All patients were fitted with a Grass FT-10 force transducer attached to the thumb. Supramaximal stimulation was applied to the ulnar nerve with a variable current peripheral nerve stimulator. 22 patients (succinylcholine group) received a placebo bolus injection followed 20 seconds later by thiopental 4 to 5 mg/kg and succinylcholine 1 mg/kg; 20 additional patients (rocuronium group) received a bolus dose of rocuronium 0.6 mg/kg followed 20 seconds later by thiopental 4 to 5 mg/kg and a placebo bolus injection. Measurements and Main Results: We measured the onset time from administration of the muscle relaxant to 95 % twitch reduction and assessed the quality of intubating conditions 60 seconds after the induction of anesthesia. There was a significant difference in the mean onset time of rocuronium (72 sec) versus succinylcholine (42 sec, p < 0.0001). However, there was no significant difference in intubating conditions 60 seconds after administration of thiopental. Conclusion: Rocuronium given 20 seconds prior to thiopental provides intubating conditions equivalent to thiopental-succinylcholine for rapid-sequence inductions, circumventing rocuronium's longer onset time to 95% neuromuscular blockade.