Impact of fellowship training level on colonoscopy quality and efficiency metrics.

BACKGROUND AND AIMS: Previous studies have described variable effects of fellow involvement on the adenoma detection rate (ADR), but few have stratified this effect by level of training. We aimed to evaluate the "fellow effect" on multiple procedural metrics including a newly defined adenoma management efficiency index, which may have a role in documenting colonoscopy proficiency for trainees. We also describe the impact of level of training on moderate sedation use. METHODS: We performed a retrospective review of 2024 patients (mean age, 60.9 ± 10 years; 94% men) who underwent outpatient colonoscopy between June 2012 and December 2014 at our Veterans Affairs Medical Center. Colonoscopies were divided into 5 groups. The first 2 groups were first-year fellows in the first 6 months and last 6 months of the training year. Second- and third-year fellows and attending-only procedures accounted for 1 group each. We collected data on doses of sedatives used, frequency of adjunctive agent use, procedural times, and location, size, and histology of polyps. We defined the adenoma management efficiency index as average time required per adenoma resected during withdrawal. RESULTS: Of the colonoscopies performed, 1675 involved a fellow and 349 were performed by the attending alone. There was no difference in ADR between fellows according to level of training (P = .8) or between fellows compared with attending-only procedures (P = .67). Procedural times decreased consistently during training and declined further for attending-only procedures. This translated into improvement in the adenoma management efficiency index (fellow groups by ascending level of training: 23.5 minutes vs 18.3 minutes vs 13.7 minutes vs 13.4 minutes vs attending group 11.7 minutes; P < .001). There was no difference in the average doses of midazolam and fentanyl used among fellow groups (P = .16 and P = .1, respectively). Compared with attending-only procedures, fellow involvement was associated with higher doses of fentanyl and midazolam and more frequent use of diphenhydramine and glucagon (P < .0001, P = .0002, P < .0001, and P = .01, respectively). CONCLUSIONS: ADR was similar at different stages of fellowship training and comparable with the attending group. Efficiency of detecting and resecting polyps improved throughout training without reaching the attending level. Fellow involvement led to a greater use of moderate sedation, which may relate to a longer procedure duration and an evolving experience in endoscopic technique.

Ready-to-use pre-filled syringes of atropine for anaesthesia care in French hospitals - a budget impact analysis.

BACKGROUND: Patient safety is improved by the use of labelled, ready-to-use, pre-filled syringes (PFS) when compared to conventional methods of syringe preparation (CMP) of the same product from an ampoule. However, the PFS presentation costs more than the CMP presentation. OBJECTIVE: To estimate the budget impact for French hospitals of switching from atropine in ampoules to atropine PFS for anaesthesia care. METHODS: A model was constructed to simulate the financial consequences of the use of atropine PFS in operating theatres, taking into account wastage and medication errors. The model tested different scenarios and a sensitivity analysis was performed. RESULTS: In a reference scenario, the systematic use of atropine PFS rather than atropine CMP yielded a net one-year budget saving of €5,255,304. Medication errors outweighed other cost factors relating to the use of atropine CMP (€9,425,448). Avoidance of wastage in the case of atropine CMP (prepared and unused) was a major source of savings (€1,167,323). Significant savings were made by means of other scenarios examined. The sensitivity analysis suggests that the results obtained are robust and stable for a range of parameter estimates and assumptions. STUDY LIMITATIONS: The financial model was based on data obtained from the literature and expert opinions. CONCLUSION: The budget impact analysis shows that even though atropine PFS is more expensive than atropine CMP, its use would lead to significant cost savings. Savings would mainly be due to fewer medication errors and their associated consequences and the absence of wastage when atropine syringes are prepared in advance.

Assessment of Carbon Dioxide, Carbon Dioxide/Oxygen, Isoflurane and Pentobarbital Killing Methods in Adult Female Sprague-Dawley Rats.

BACKGROUND: Exposure to carbon dioxide (CO2) gas as a killing method is aversive and exposure to high concentrations is likely to be painful. Bradycardia during exposure to CO2 is associated with nociception and pain. However, it is unclear if bradycardia occurs before loss of consciousness as definitions of loss of consciousness vary in the literature. The objectives of this study were to explore the relationship between recumbency, loss of righting reflex (LORR) and a quiescent electromyograph as measures of loss of consciousness, and identify the onset of bradycardia in relation to these measures. Our primary hypothesis was that CO2 exposure would result in bradycardia, which would precede LORR. METHODS: Thirty-two adult, female Sprague-Dawley rats were instrumented with a telemetry device and randomly assigned to one of four killing methods (concentrations of 100% CO2, CO2 (70%)/O2 (30%), isoflurane (5%) and intraperitoneal pentobarbital (200 mg/kg). Time to achieve recumbency, LORR, quiescent electromyograph, isoelectric electrocorticograph, heart rate and apnea were recorded. RESULTS: The general order of progression was recumbency, LORR, quiescent electromyograph, isoelectric electrocorticograph and apnea. Recumbency preceded LORR in the majority of animals (CO2; 7/8, CO2/O2; 8/8, isoflurane; 5/8, pentobarbital; 4/8). Bradycardia occurred before recumbency in the CO2 (p = 0.0002) and CO2/O2 (p = 0.005) groups, with a 50% reduction in heart rate compared to baseline. The slowest (time to apnea) and least consistent killing methods were CO2/O2 (1180 ± 658.1s) and pentobarbital (875 [239 to 4680]s). CONCLUSION: Bradycardia, and consequently nociception and pain, occurs before loss of consciousness during CO2 exposure. Pentobarbital displayed an unexpected lack of consistency, questioning its classification as an acceptable euthanasia method in rats.

A Rapid, Cost-Effective Method to Prepare Recombinant Adeno-Associated Virus for Efficient Gene Transfer to the Developing Mouse Inner Ear.

There is keen interest to define gene therapies aimed at restoration of auditory and vestibular function in the diseased or damaged mammalian inner ear. A persistent limitation of regenerative medical strategies that seek to correct or modify gene expression in the sensory epithelia of the inner ear involves efficacious delivery of a therapeutic genetic construct. Our approach is to define methodologies that enable fetal gene transfer to the developing mammalian inner ear in an effort to correct defective gene expression during formation of the sensory epithelia or during early postnatal life. Conceptually, the goal is to atraumatically introduce the genetic construct into the otocyst-staged mouse inner ear and transfect otic progenitors that give rise to sensory hair cells and supporting cells. Our long-term goal is to define therapeutic interventions for congenital deafness and balance disorders with the expectation that the approach may also be exploited for therapeutic intervention postnatally.In the inaugural volume of this series, we introduced electroporation-mediated gene transfer to the developing mouse inner ear that encompassed our mouse survival surgery and transuterine microinjection protocols (Brigande et al., Methods Mol Biol 493:125-139, 2009). In this chapter, we first briefly update our use of sodium pentobarbital anesthesia, our preferred anesthetic for mouse ventral laparotomy, in light of its rapidly escalating cost. Next, we define a rapid, cost-effective method to produce recombinant adeno-associated virus (rAAV) for efficient gene transfer to the developing mouse inner ear. Our immediate goal is to provide a genetic toolkit that will permit the definition and validation of gene therapies in mouse models of human deafness and balance disorders.

Quantitative assessment of pupillary light reflex in normal and anesthetized dogs: a preliminary study.

The purpose of this study was to quantitatively assess the pupillary light reflex (PLR) in normal and anesthetized dogs using a pupillometer. Eleven dogs (20 eyes) of various breeds were included. PLRs were measured with a handheld pupillometer in dim light before and during anesthesia. Anesthesia was conducted with atropine, xylazine and ketamine. Parameters of pupillometry included neurological pupil index (NPi), pupil size, percent of change (%CH), latency (LAT), constriction velocity (CV), maximum constriction velocity (MCV) and dilation velocity (DV). NPi,%CH, CV and MCV were significantly decreased during anesthesia compared with the pre-anesthesia data. The results suggest that atropine-xylazine-ketamine combination anesthesia depresses the PLR. Additionally, this study demonstrates the feasibility of the use of a pupillometer in dogs.

Procedural sedation in children for magnetic resonance imaging--comparison between ketamine diazepam combination with midazolam fentanyl combination.

A deeper level of sedation by an anaesthesiologist is requirement for magnetic resonance imaging (MRI) in paediatric populations and sedation of children is different from sedation of adults. The purpose of the study was to compare the efficacy, safety, tolerability and cost effectiveness of ketamine, diazepam combination to midazolam, fentanyl combination for sedation of children during MRI. One hundred twenty children of both sex, age between 1-10 years, American Society of Anesthesiologist (ASA) physical status I and II were distributed into two groups. Group A (n=60) were sedated with 1.5 mg/kg body weight ketamine and 0.1 mg/kg body weight diazepam intravenously. Group B (n=60) were sedated with midazolam 0.05 mg/kg bodyweight and fentanyl 1 microg/kg body weight intravenously. Both groups showed satisfactory sedating condition for MRI. Incidences of side effects of drug regimens during sedation and recovery were recorded in both groups; those were transient and minor inconveniences. Pulse, blood pressure and respiration were within normal range in both groups. Mean procedure time was almost same in both groups and mean recovery time was more in group A than group B and the difference was statistically significant (p<0.05). Every child of both groups was discharged to home. Sedation regimen of group B found 5 times more costly than group A. Both the regimens were found safe and effective for paediatric sedation during MRI but ketamine, diazepam combination found more cost effective which, is a considerable matter in Bangladesh.

Assessment of brachial plexus blockade in chickens by an axillary approach.

OBJECTIVE: To assess the brachial plexus block in chickens by an axillary approach and using a peripheral nerve stimulator. STUDY DESIGN: Prospective, randomized, double-blinded study. ANIMALS: Six, 84-week old, female chickens. METHODS: Midazolam (1 mg kg(-1)) and butorphanol (1 mg kg(-1)) were administered into the pectoralis muscle. Fifteen minutes later, the birds were positioned in lateral recumbency and following palpation of the anatomic landmarks, a catheter was inserted using an axillary approach to the brachial plexus. Lidocaine or bupivacaine (1 mL kg(-1)) was injected after plexus localization by the nerve stimulator. Sensory function was tested before and after blockade (carpus, radius/ulna, humerus and pectoralis muscle) in the blocked and unblocked wings. The latency to onset of motor and sensory block and the duration of sensory block were recorded. A Friedman nonparametric one-way repeated-measures ANOVA was used to compare scores from baseline values over time and to compare the differences between wings at each time point. RESULTS: A total of 18 blocks were performed with a success rate of 66.6% (12/18). The latency for motor block was 2.8 +/- 1.1 and 3.2 +/- 0.4 minutes for lidocaine and bupivacaine, respectively. The latencies for and durations of the sensory block were 6.0 +/- 2.5 and 64.0 +/- 18.0 and 7.8 +/- 5.8 and 91.6 +/- 61.7 minutes for lidocaine and bupivacaine, respectively. There was no statistical difference between these times for lidocaine or bupivacaine. Sensory function was not abolished in nonblocked wings. CONCLUSIONS AND CLINICAL RELEVANCE: The brachial plexus block was an easy technique to perform but had a high failure rate. It might be useful for providing anesthesia or postoperative analgesia of the wing in chickens and exotic avian species that have similar wing anatomy.

[Assessment of the effects of sodium oxybutyrate and normal pressure hyperoxia on human blood plasma and erythrocyte membrane lipids during antiorthostatic hypokinesia].

Benefits from an antihypoxic agent (sodium oxibutyrate) and normal pressure hyperoxia to the lipid composition of erythrocyte membranes and blood plasma were assessed in 9 subjects on the thirtieth day of head-down tilting at -8(0). The greatest variations in HDT occurred in polyunsaturated fatty acids in erythrocyte membranes. After infusion of sodium oxibutyrate a marked reduction in polyunsaturated fatty acids was mainly in consequence of expressed decreases in linoleic and, particularly, arachidonic acids. However, ensuing hyperoxic treatment led to their steady rise. Sequential sodium oxibutyrate infusion to the tilted subjects breathing air and then exposed to normal pressure hyperoxia seemed to have compensated, as judged by the fatty acids in erythrocyte membranes, for the activity of free radical oxidation in hypoperfusated regional tissues.

The effect of Pencan needle orientation on spinal anesthesia outcomes.

Slow resolution of block and incidence of side effects deter many practitioners from choosing spinal anesthesia for out-patient surgical procedures. Some studies suggest that controlling bevel or side port orientation of a spinal needle during anesthetic injection can affect occurrence of side effects and time to block resolution. The objective of this study was to determine the effects of varying Pencan spinal needle (B-Braun, Bethlehem, Pa) side port orientations on duration of block and incidence of side effects in groups of patients receiving spinal anesthesia. We randomized 87 subjects scheduled for spinal anesthesia to receive a spinal anesthesia injection using a cephalad, lateral, or caudad side port orientation. Onset, duration, block height, incidence of side effects, and analgesic requirements were among the variables measured. No difference in onset, duration, or analgesic requirements was noted among groups. Differences were noted in time to discharge from the hospital (P = .027) and time to first voiding (P = .023) in the lateral compared with the cephalad and caudad orientation groups. Patients in whom the lateral needle side port orientation was used for injection were discharged earlier and had fewer side effects. This could translate into significant savings, financially and in terms of staff requirements.

Under "real world" conditions, desflurane increases drug cost without speeding discharge after short ambulatory anesthesia compared to isoflurane.

PURPOSE: To compare the measured "real world" perioperative drug cost and recovery associated with desflurane- and isoflurane-based anesthesia in short (less than one hour) ambulatory surgery. METHODS: We conducted a prospective, randomized, blinded trial with patients undergoing arthroscopic meniscectomy under general anesthesia. Following iv induction, patients received either isoflurane (group I; n = 25) or desflurane (group D; n = 20) for maintenance. The primary outcome variable was total perioperative drug cost per patient in Canadian dollars. Secondary outcome variables included volatile agent consumption and cost, adjuvant anesthetic and postanesthesia care unit (PACU) drug cost, readiness for PACU discharge, and incidence of adverse events. RESULTS: Total perioperative drug cost per patient was 14.58 +/- 6.83 Canadian dollars (mean +/- standard deviation) for group I, and 21.47 +/- 5.18 Canadian dollars for group D (P < 0.001). Isoflurane consumption per patient was 6.0 +/- 3.0 mL compared to 18.6 +/- 7.7 mL for desflurane (P < 0.0001); corresponding costs were 0.83 +/- 0.42 Canadian dollars vs 7.61 +/- 3.15 Canadian dollars (P < 0.0001). There were no differences in adjuvant anesthetic or PACU drug cost. All but one patient from each group were deemed ready for PACU discharge at 15 min postoperatively (Aldrete score >or= 9). One patient in group D experienced postoperative nausea. No other adverse events were noted. CONCLUSIONS: Measured total perioperative drug cost for a short ambulatory procedure (less than one hour) under general anesthesia was higher when desflurane rather than isoflurane was used for maintenance, essentially due to volatile agent cost. Desflurane use did not translate into faster PACU discharge under "real world" conditions.

Comparative assessment of the effects of alfentanil, esmolol or clonidine when used as adjuvants during induction of general anaesthesia.

BACKGROUND AND OBJECTIVE: This randomized, double-blinded, prospective study compared the effects of clonidine, esmolol or alfentanil on the level of hypnosis and haemodynamic responses to intravenous induction of anaesthesia and endotracheal intubation. METHODS: Forty-five patients scheduled for elective surgery were allotted to one of three groups. They were given either alfentanil 3 microg kg(-1) min(-1) (n = 15); esmolol 1 mg kg(-1) min(-1) (n = 16) or clonidine 3 microg kg(-1) (n = 14) as a 10 min infusion. The infusions of alfentanil and esmolol, but not of clonidine, were maintained during endotracheal intubation. Anaesthesia was induced with midazolam (2 mg) and thiopental as required to suppress the eyelash reflex. Atracurium (0.5 mg kg(-1)) was given to produce neuromuscular block. Mean arterial pressure, heart rate, and bispectral index were recorded on arrival (baseline), after study drug infusion, after injecting midazolam and thiopental, as well as after endotracheal intubation. ANOVA and chi2-test were used for analysis. RESULTS: Blood pressure, heart rate and the bispectral index were unaltered by the study drugs, but thiopental requirements were reduced by alfentanil and clonidine (P < 0.014). Mean arterial pressure values (mean +/- standard error of mean) in the alfentanil, esmolol and clonidine groups were: baseline: 107.8 +/- 3.8; 106.6 +/- 3.9; 103.4 +/- 3.7 mmHg; after thiopental: 74.0 +/- 4.2; 85.6 +/- 4.3; 94.2 +/- 4.1 mmHg and after endotracheal intubation: 91.7 +/- 5.3; 114.1 +/- 6.9; 123.6 +/- 5.6 mmHg, respectively (two-way ANOVA, P < 0.001). Mean arterial pressure changed significantly after intubation from baseline (P < 0.001) after alfentanil (-15%) and clonidine (+20%) but not after esmolol (+7%), while the changes between pre- and postintubation values were similar in all groups (24-33% increase). The bispectral index indicated that all patients had an adequate level of hypnosis, but the variability was higher in the esmolol group (P < 0.002). CONCLUSIONS: None of the study drugs blocked the increase in mean arterial pressure induced by endotracheal intubation, but esmolol provided better overall haemodynamic stability. All groups had an adequate level of hypnosis.

Anesthesia for ambulatory anorectal surgery.

The prevalence of minor anorectal diseases is 4-5% of adult Western population. Operations are performed on ambulatory or 24-hour stay basis. Requirements for ambulatory anesthesia are: rapid onset and recovery, ability to provide quick adjustments during maintenance, lack of intraoperative and postoperative side effects, and cost-effectiveness. Anorectal surgery requires deep levels of anesthesia. The aim is achieved with 1) regional blocks alone or in combination with monitored anesthesia care or 2) deep general anesthesia, usually with muscle relaxants and tracheal intubation. Modern general anesthetics provide smooth, quickly adjustable anesthesia and are a good choice for ambulatory surgery. Popular regional methods are: spinal anesthesia, caudal blockade, posterior perineal blockade and local anesthesia. The trend in regional anesthesia is lowering the dose of local anesthetic, providing selective segmental block. Adjuvants potentiating analgesia are recommended. Postoperative period may be complicated by: 1) severe pain, 2) urinary retention due to common nerve supply, and 3) surgical bleeding. Complications may lead to hospital admission. In conclusion, novel general anesthetics are recommended for ambulatory anorectal surgery. Further studies to determine an optimal dose and method are needed in the group of regional anesthesia.

Development of a behavioral assessment of craniofacial muscle pain in lightly anesthetized rats.

In this study, a new behavioral assessment of craniofacial muscle pain in the lightly anesthetized rat is described. Intramuscular injections with algesic agents in lightly anesthetized rats evoked a characteristic ipsilateral hindpaw shaking behavior for several minutes similar to previously described orofacial pain-induced grooming behavior in awake rats (Neurosci Lett 103 (1989) 349, Pain 62 (1995) 295). Eighty-two male Sprague-Dawley rats were used in a series of experiments to study whether this behavior could serve as a valid measure of craniofacial muscle pain. First, we demonstrated that different algesic chemicals, mustard oil (20%), formalin (3%) or hypertonic saline (5%) injected in the mid-region of the masseter muscle effectively elicited the hindpaw shaking behavior. The behavior was only minimally evoked with vehicle injection. Repeated administrations of hypertonic saline, a short duration non-sensitizing algogen, demonstrated reproducibility of the assay. Second, we showed that the peak and overall magnitude of the shaking behavior evoked by injections with different concentrations of mustard oil (1 and 5%) changed in a concentration dependent manner. Finally, we showed that systemic administration of morphine sulfate (3 and 0.3 mg/kg, i.p.) dose dependently attenuated mustard oil induced hindpaw-shaking behavior. Lidocaine injected locally 5 min prior to mustard oil injection also significantly decreased the hindpaw shaking behavior. Based on these results we concluded that ipsilateral hindpaw shaking in lightly anesthetized rats is a stereotypical behavior evoked by noxious muscle stimulation and can be used as a reliable behavioral measure to assess craniofacial muscle pain.

A comparison of oral diazepam versus midazolam, administered with intravenous meperidine, as premedication to sedation for pediatric endoscopy.

OBJECTIVES: This study was performed to compare the effects of oral midazolam and oral diazepam, administered with intravenous (IV) meperidine, on pre-procedural, procedural, and post-procedural sedation and recovery in children undergoing diagnostic upper endoscopy. The costs of pre-procedure sedation were compared for the two benzodiazepines. METHODS: A randomized, double-blind study was conducted in 154 children (mean age 96.73 +/- 59.34 months, 53% male) undergoing endoscopy. Oral midazolam (0.5 mg/kg, maximum dose of 20 mg) or oral diazepam (0.3 mg/kg, maximum dose of 10 mg) was given before IV insertion, and with IV meperidine (2 mg/kg, maximum dose of 100 mg) given to all patients just before upper endoscopy. Further "rescue" midazolam doses (to a maximum cumulative dose of 5 mg) were given as needed to achieve a pre-procedure sedation score of > or =2. All patients received intravenous propofol for procedural sedation. Patients were evaluated for the efficacy and safety of pre-procedural sedation, sedation during upper endoscopy, and recovery following completion of the procedure. RESULTS: There were no significant differences between study groups for level of pre-procedural sedation, need for midazolam rescue in endoscopy, effectiveness of procedural sedation, occurrence of adverse events, and recovery parameters. CONCLUSIONS: Oral midazolam and diazepam, in conjunction with IV administration of meperidine, provide comparable, effective, and safe premedication for children undergoing upper endoscopy. The cost of midazolam was substantially higher than diazepam.

[Epidural vs. intradural anesthesia in ambulatory surgery]. / Anestesia epidural frente a anestesia intradural en cirugía ambulatoria.

Spinal anesthesia is the technique of choice for many outpatient procedures. With appropriate screening and preparation, it can provide excellent surgical conditions and highly satisfactory anesthesia for the patient, while remaining cost-effective. Intradural anesthesia has advantages over epidural anesthesia: technical simplicity, rapid onset, efficacy and depth of blockade. Its use has been controversial, however, for many years due to the potential risk of headache after puncture of the dura mater. Epidural anesthesia causes fewer hemodynamic changes and provides greater dose flexibility and local anesthetic concentration, with less risk of headache after accidental puncture of the dura mater. The drawbacks are that it takes longer to perform and onset of blockade comes later. Both techniques are valid alternatives to general anesthesia in outpatient surgery. The choice of one over the other will depend on patient characteristics, availability of a presurgical area, and the anesthesiologist's skill.

A randomized double-blind placebo-controlled trial evaluating the cost-effectiveness of droperidol as a sedative premedication for EUS.

BACKGROUND: Droperidol is a neuroleptic agent with anti-emetic properties that produces mild sedation, reduced anxiety, and a state of mental detachment and indifference to one's surroundings. Routine premedication with droperidol has been shown to improve sedation during esophagogastroduodenoscopy and endoscopic retrograde cholangiopancreatography. The purpose of this randomized double-blind placebo-controlled study was to determine whether premedication with droperidol improves sedation during routine upper endoscopic ultrasound (EUS) in a cost-effective manner. METHODS: One hundred consecutive patients referred for EUS were randomly assigned to receive either 2.5 mg or 5 mg of droperidol or placebo before the procedure. After EUS, the physician, nurse, and recovered patient scored various parameters of procedural sedation. RESULTS: In the group receiving 5 mg of droperidol there was significantly less gagging at intubation, less retching during the procedure, better patient cooperation, less need for physical restraint, and improved nurses' and physician's impression of sedation. Significantly less meperidine and less midazolam were required for sedation, making medication costs significantly lower in the group receiving 5 mg droperidol. CONCLUSIONS: A 5 mg dose of droperidol given as premedication for routine upper EUS improves sedation during the procedure while significantly decreasing the overall cost of sedation.

A coronary artery bypass "fast-track" protocol is practical and realistic in a rural environment.

BACKGROUND: In this study we determine retrospectively whether assignment of all patients undergoing coronary artery bypass grafting to a "fast-track" protocol (FT) is practical and realistic in our rural institution. METHODS: We compared the outcome of 266 consecutive patients undergoing coronary artery bypass grafting who were fast-tracked in 1996 with that of 266 consecutive patients who were managed conventionally (NFT) in 1994. The surgical techniques were comparable in both groups; however, FT anesthesia used inhalational agents and short-acting narcotics. All comparisons were performed using the Student's t test or the chi 2 test. RESULTS: Postoperatively 95% of the FT group were extubated by 24 hours compared with 0% in the NFT group (p < 0.0001). The mean intensive care unit length of stay in the FT group was 1.7 +/- 0.8 days, whereas it was 2.6 +/- 0.6 days in the NFT group (p < 0.001). The mean postoperative length of stay was 6.4 +/- 1.2 days in the FT group compared with 7.5 +/- 0.9 days in the NFT group (p < 0.001). There were no significant differences in 30-day morbidity/mortality. There was a substantial cost savings in the FT group. CONCLUSIONS: The fast-track protocol can be successful without any compromise of patient care. Early discharge from the hospital, however, is not always feasible.

Evaluation of the safety and efficacy of deep sedation for electrophysiology procedures administered in the absence of an anesthetist.

UNLABELLED: Several procedures performed in the electrophysiology laboratory (EP lab) require surgical manipulation and are lengthy. Patients undergoing such procedures usually receive general anesthesia or deep sedation administered by an anesthesiologist. In 536 consecutive procedures performed in the EP lab, we assessed the safety and efficacy of deep sedation administered under the direction of an electrophysiologist and in the absence of an anesthetist. Patients were monitored with pulse oximetry, noninvasive blood pressure recordings, and continuous ECGs. The level of consciousness and vital signs were evaluated at 5-minute intervals. Deep sedation was induced in 260 patients using midazolam, phenergan, and meperidine, then maintained with intermittent dosing of meperidine at the following mean doses: midazolam 0.031 +/- 0.024 mg/kg; phenergan 0.314 +/- 0.179 mg/kg; and meperidine 0.391 +/- 0.167 mg/kg per hour. In the remaining 276 patients, deep sedation was induced with midazolam and fentanyl and maintained with a continuous infusion of fentanyl at a mean dose of 2.054 +/- 1.43 micrograms/kg per hour. Fourteen patients experienced a transient reduction in oxygen saturation that was readily reversed following administration of naloxone. An additional 11 patients desaturated secondary to partial airway obstruction, which resolved after repositioning the head and neck. Fourteen patients experienced hypotension with fentanyl. All but one returned to baseline blood pressures following an infusion of normal saline. No patient required intubation and no death occurred. Only three patients had recollection of periprocedure events. No patient remembered experiencing pain with the procedure. Hospital stays were not prolonged as a result of the sedation used. IN CONCLUSION: (1) deep sedation during EP procedures can be administered safely under the guidance of the electrophysiologist without an anesthetist present; (2) the drugs used should be readily reversible in case of respiratory depression; and (3) this approach may reduce the overall cost of the procedures in the EP lab, maintaining adequate patient comfort.

Respiratory sinus arrhythmia during anaesthesia: assessment of respiration related beat-to-beat heart rate variability analysis methods.

Beat-to-beat heart rate variability analysis is a powerful tool for the diagnosis of neuropathy. Respiration-related heart rate variability (respiratory sinus arrhythmia, RSA) reflects the function of parasympathetic nervous system during spontaneous ventilation while awake. RSA is also claimed to monitor the depth of anaesthesia. Power spectrum analysis or various averaging techniques of the heart rate variability are usually applied. The current literature, however, does not usually interpret the ground rules and limitations of the method used, and this may sometimes lead to erroneous conclusions on the data. The aim of our study was to compare and analyse critically the performance of different methods of evaluating RSA during anaesthesia and positive pressure ventilation. Power spectrum analysis, the root mean square of the successive RR-interval difference (RMSSD), and two respiration related methods, RSA index and average phase RSA, were included in the comparison. To test these methods, 11 patients were anaesthetised with isoflurane and their lungs were ventilated mechanically with a frequency of 6 cycles min-1. Each patient received a bolus dose of atropine (20 micrograms kg-1) during the trial. Electrocardiogram, electroencephalogram and tracheal pressure signal from respirator were recorded and analyses were performed off-line. We demonstrated that general indices, such as RMSSD, may be strongly affected by heart rate level and other non-respiration related variations in heart rate. We also showed that the effect of unwanted fluctuations on RSA can be reduced with respiration dependent beat-to-beat methods. Furthermore we confirmed that in addition to the amplitude, also the pattern of respiratory sinus arrhythmia is of interest: the pattern is reversed in phase compared to spontaneous breathing while awake, as we have shown earlier. To analyse RSA during anaesthesia, we recommend the use of an average phase RSA method based on beat-to-beat variability that shows both the amplitude and pattern of RSA. Finally, no measure of RSA should be used without a presentation of the actual beat-to-beat heart rate curve.