PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Anesthesia, Inhalation”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 523 records · Page 29Linked to original sources

A new method of multisegment motor pathway monitoring using muscle potentials after train spinal stimulation.

STUDY DESIGN: Evoked muscle and nerve action potentials after spinal stimulation for intraoperative monitoring were investigated using a modified stimulation technique. Animal experiments and clinical application were performed. OBJECTIVES: To contrive a useful method of intraoperative motor pathway monitoring under inhalation anesthesia. SUMMARY OF BACKGROUND DATA: Many different kinds of procedures have been reported. No reliable method that reflects pure motor tract function has been established. METHODS: Characteristic of our stimulating technique was the use of numbered consecutive pulses ("train stimulation"). In 16 cats, optimum condition of train stimulation, effects of anesthetic agents, and conductive pathway were examined. In 35 patients, muscle potentials evoked by train stimulation were recorded, and clinical usefulness was evaluated. RESULTS: In the experimental study, the optimum stimulus condition was determined 1 ms interstimulous interval train of five pulses. Conductive pathway of this method was identified as a lateral column by selective spinal cord transection. In the clinical application, by using train stimulation, multisegmental muscle potentials were obtainable even using inhalation anesthetics. CONCLUSIONS: The facilitative effects of train stimulation, attributed to temporal summation, are considered to overcome the suppression of inhalation anesthesia. The evoked muscle potentials by train spinal stimulation reflect the functions of pure motor tract and is the only, extremely efficient method for intraoperative motor pathway monitoring.

Action Potentials↗

[Diagnostic value of heart rate variability in general anesthesia].

Modifications of heart rate variability were investigated during intravenous-inhalation anesthesia in 80 cancer patients. Heart rate was recorded during active orthostatic test before surgical intervention as well as during: (1) before operation; (2) after atropine (0.01 mg/kg); (3) after intubation; (4) at the beginning of operation; (5) after 30 min from the beginning of operation; (6) after extubation. Heart rate power spectrum analysis with distribution to the three major oscillatory components was performed. Two groups of patients were investigated: (1) with normal baseline autonomic heart rate control and (2) with reduced one. During different stages of surgical intervention and anesthesia heart rate modifications in both groups were seen, although more expressed in patients with normal autonomic control. Concluding, heart rate variability changes throughout operation were related to different stages of anesthesia. Heart rate monitoring might be used for assessment of reflex and humoral heart rate control during anesthesia as well as for evaluation of operational stress.

Anesthesia, General↗

The effect of midazolam premedication on discharge time in pediatric patients undergoing general anesthesia for dental restorations.

PURPOSE: The purpose of this study was to evaluate the effect of oral premedication with midazolam on recovery times of children undergoing dental restorations under general anesthesia. METHODS: The records of 106 children (1.2-11.3 years, ASA I or II) undergoing ambulatory dental restorations were randomly selected and retrospectively reviewed: 50 subjects received midazolam (M) 0.5 mg/kg orally approximately 30 minutes prior to their procedure and 56 control subjects received no premedication (C). General anesthesia consisted primarily of inhalational anesthesia. Time in the operating room (OR), post-anesthesia care unit (PACU) and same day surgery (SDS) were determined and compared between groups. RESULTS: Both groups were similar with respect to age and weight. There were no significant differences between groups in time spent in the OR, PACU or SDS (p>0.05). In a subset of children having shorter dental procedures (OR time < or =75 minutes, n=29), there remained no significant difference in discharge times between groups. CONCLUSIONS: Preoperative administration of oral midazolam does not delay discharge of children undergoing general anesthesia for dental rehabilitation.

Ambulatory Care↗

[Comparison of sevoflurane and halothane in pediatric anesthesia].

In the present study we compared sevoflurane (group S) and halothane (group F) as used in pediatric endotracheal anesthesia. The subjects consisted of 100 pediatric patients, each 50 in group S and F, most of whom underwent otorhinolaryngological surgery. Anesthesia was induced with nitrous oxide-oxygen-sevoflurane (GOS) (S 3-5%) or nitrous oxide-oxygen-halothane (GOF) (F 1.5-2.5%), and maintained with GOS (S 2-3%) or GOF (F 1.0-1.5%). In comparing the groups with respect to anesthetic induction, group S required 2.1 min for the loss of consciousness, 6.1 min for ocular fixation and 9.7 min for completion of intubation, while in group F the time intervals for the above items were 2.4, 4.9 and 10.2 min, respectively. No significant differences were found between the two groups except in the loss of consciousness and ocular fixation. Comparison of the groups during maintenance of anesthesia revealed no significant differences, although pulse rate and diastolic blood pressure increased in both groups. When the groups were compared for awakening from anesthesia, group S required 10.1 min for awakening and 11.9 min for extubation, while in group F the time was 13.0 min and 15.4 min, respectively. These values were significantly different. The present study demonstrated that sevoflurane anesthesia is rapid in both induction and awakening as compared with halothane anesthesia, and that GOS inhalation anesthesia with single use of sevoflurane can be usefully applied to pediatric endotracheal anesthesia.

Anesthesia, Inhalation↗

Anesthesia and blood sampling of wild big brown bats (eptesicus fuscus) with an assessment of impacts on survival.

We anesthetized and blood sampled wild big brown bats (Eptesicus fuscus) in Fort Collins, Colorado (USA) in 2001 and 2002 and assessed effects on survival. Inhalant anesthesia was delivered into a specially designed restraint and inhalation capsule that minimized handling and bite exposures. Bats were immobilized an average of 9.1+/-5.1 (SD) min (range 1-71, n=876); blood sample volumes averaged 58+/-12 microl (range 13-126, n=718). We randomly selected control (subject to multiple procedures before release) and treatment (control procedures plus inhalant anesthesia and 1% of body weight blood sampling) groups in 2002 to assess treatment effects on daily survival over a 14-day period for adult female and volant juvenile bats captured at maternity roosts in buildings. We monitored survival after release using passive integrated transponder tag detection hoops placed at openings to selected roosts. Annual return rates of bats sampled in 2001 were used to assess long-term outcomes. Comparison of 14-day maximum-likelihood daily survival estimates from control (86 adult females, 92 volant juveniles) and treated bats (187 adult females, 87 volant juveniles) indicated no adverse effect from anesthesia and blood sampling (juveniles: chi2=22.22, df=27, P>0.05; adults: chi2=9.72, df=18, P>0.05). One-year return rates were similar among adult female controls (81%, n=72, 95% confidence interval [CI]=70-91%), females treated once (82%, n=276, 95% CI=81-84%), and females treated twice (84%, n=50, 95% CI=74-94%). Lack of an effect was also noted in 1-yr return rates of juvenile female controls (55%, n=29, 95% CI=37-73%), juveniles treated once (66%, n=113, 95% CI=58-75%), and juveniles treated twice (71%, n=17, 95% CI=49-92%). These data suggest that anesthesia and blood sampling for health monitoring did not measurably affect survival of adult female and volant juvenile big brown bats.

Anesthesia, Inhalation↗

Intermittent apnea and total intravenous anesthesia for microscopic laryngeal surgery.

Intermittent apnea with inhalational anesthesia has been reported to improve the visualization of the larynx but it has some disadvantages from inhalational anesthetics. The authors evaluated the use of total intravenous anesthesia instead of inhalation anesthesia in 30 patients undergoing microscopic laryngeal surgery. Anesthesia was started with propofol, fentanyl and cisatracurium. The patients were ventilated with 100% oxygen and the period of intermittent apnea, guided by pulse oximetry and end tidal carbon dioxide monitoring, was started by removal of the endotracheal tube. This technique provided a good visualization and immobile field for the operation. The average duration of apnea was 258 +/- 107 sec. The number of periods of apnea ranged from 1 to 4. A few patients showed some sympathetic responses to surgical stimuli. In conclusion, intermittent apnea with total intravenous anesthesia, with appropriate precaution, could be used without any serious adverse outcome for microscopic laryngeal surgery.

Adolescent↗

[Anesthesia with sevoflurane for tonsillectomy in a boy with Duchenne muscular dystrophy].

A 6-year-old boy with Duchenne muscular dystrophy (DMD) and foreseen difficult tracheal intubation underwent tonsillectomy under general inhaled anesthesia with sevoflurane. No neuromuscular blockers were administered and no perioperative complications emerged. In spite of advances in genetic diagnosis there continue to be patients with DMD because of spontaneous mutation of the dystrophin gene. Late detection leaves them vulnerable to administration of drugs like succinylcholine that can trigger fatal reactions involving hyperpotassemia, rhabdomyolysis, and malignant hyperthermia. Total intravenous anesthesia seems the best way to provide general anesthesia for a patient with DMD. Inhaled anesthesia is an alternative. Although halogenated agents can lead to rhabdomyolysis and malignant hyperthermia, the frequency seems low if we bear in mind that the use of sevoflurane is widespread in pediatrics. In this case sevoflurane induction facilitated safe tracheal intubation.

Anesthesia↗

Total intravenous anesthesia with propofol and remifentanil is associated with a nearly twofold higher incidence in postanesthetic shivering than desflurane-fentanyl anesthesia.

BACKGROUND: Postanesthetic shivering (PAS) is a frequent side effect of general anesthesia. Previous reports on the incidence of PAS of propofol for the induction or maintenance of anesthesia have been controversial, but have not been studied in detail. The aim of the present study was to evaluate the incidence and severity of PAS in total intravenous anesthesia (TIVA) with propofol and remifentanil compared with an inhalative anesthesia. MATERIAL/METHODS: After ethics committee approval and written informed consent from the patients, 53 patients scheduled for urologic, gynecologic, or surgical operations were studied for shivering postoperatively using a five-point rating scale. They received desflurane-fentanyl based anesthesia (n=27) or TIVA with propofol and remifentanil (n=26). Hemodynamics and temperature were measured after induction of anesthesia (T0), and 5 min (T1), 15 min (T2), 30 min (T3), and 60 min (T4) after reaching the postanesthetic care unit (PACU). RESULTS: In the TIVA group, 18/26 (69.2%) patients suffered from PAS compared with 10/27 (37%) in the desflurane-fentanyl group (P<0.02). The severity of shivering was significantly higher with TIVA than with desflurane (P<0.02), whereas temperature showed no significant difference between the study groups. CONCLUSIONS: Postanesthetic shivering appears significantly more frequently and intensively after TIVA with propofol and remifentanil compared with an inhalative anesthesia with fentanyl and desflurane.

Aged↗

Propofol anesthesia.

Although questions may still remain regarding the use of this unique sedative-hypnotic drug with anesthetic properties in high-risk patients, our studies have provided cardiopulmonary and neurological evidence of the efficacy and safety of propofol when used as an anesthetic under normal and selected impaired conditions in the dog. 1. Propofol can be safely and effectively used for the induction and maintenance of anesthesia in normal healthy dogs. Propofol is also a reliable and safe anesthetic agent when used during induced cardiovascular and pulmonary-impaired conditions without surgery. The propofol requirements to induce the safe and prompt induction of anesthesia prior to inhalant anesthesia with and without surgery have been determined. 2. The favorable recovery profile associated with propofol offers advantages over traditional anesthetics in clinical situations in which rapid recovery is important. Also, propofol compatibility with a large variety of preanesthetics may increase its use as a safe and reliable i.v. anesthetic for the induction and maintenance of general anesthesia and sedation in small animal veterinary practice. Although propofol has proven to be a valuable adjuvant during short ambulatory procedures, its use for the maintenance of general anesthesia has been questioned for surgery lasting more than 1 hour because of increased cost and marginal differences in recovery times compared with those of standard inhalant or balanced anesthetic techniques. When propofol is used for the maintenance of anesthesia in combination with a sedative/analgesic, the quality of anesthesia is improved as well as the ease with which the practitioner can titrate propofol; therefore, practitioners are able to use i.v. anesthetic techniques more effectively in their clinical practices. 3. Propofol can induce significant depression of respiratory function, characterized by a reduction in the rate of respiration. Potent alpha 2 sedative/analgesics (e.g., xylazine, medetomidine) or opioids (e.g., oxymorphone, butorphanol) increase the probability of respiratory depression during anesthesia. Appropriate consideration of dose reduction and speed of administration of propofol reduces the degree of depression. Cardiovascular changes induced by propofol administration consist of a slight decrease in arterial blood pressures (systolic, mean, diastolic) without a compensatory increase in heart rate. Selective premedicants markedly modify this characteristic response. 4. When coupled with subjective responses to painful stimuli, EEG responses during propofol anesthesia provide clear evidence that satisfactory anesthesia has been achieved in experimental dogs. When propofol is used as the only anesthetic agent, a higher dose is required to induce an equipotent level of CNS depression compared with the situation when dogs are premedicated. 5. The propofol induction dose requirement should be appropriately decreased by 20% to 80% when propofol is administered in combination with sedative or analgesic agents as part of a balanced technique as well as in elderly and debilitated patients. As a general recommendation, the dose of propofol should always be carefully titrated against the needs and responses of the individual patient, as there is considerable variability in anesthetic requirements among patients. Because propofol does not have marked analgesic effects and its metabolism is rapid, the use of local anesthetics, nonsteroidal anti-inflammatory agents, and opioids to provide postoperative analgesia improves the quality of recovery after propofol anesthesia. 6. The cardiovascular depressant effects of propofol are well tolerated in healthy animals, but these effects may be more problematic in high-risk patients with intrinsic cardiac disease as well as in those with systemic disease. In hypovolemic patients and those with limited cardiac reserve, even small induction doses of propofol (0.75-1.5 mg/kg i.v.) can produce profound hypotens

Anesthesia, General↗

Comparison of 3 different anesthetic techniques on 24-hour recovery after otologic surgical procedures.

Intravenous propofol anesthesia is better than inhalational anesthesia for otologic surgery, but cost and intraoperative movement make this technique prohibitive. This study compares a propofol sandwich anesthetic with a total propofol or inhalational anesthetic for otologic surgery to determine which produces the best perioperative conditions and least expense. One hundred twenty patients undergoing ear surgery were randomly chosen to receive an anesthetic with either isoflurane (INHAL), total propofol (TPROP), or propofol used in conjunction with isoflurane (PSAND). Postoperative wakeup and the incidence and severity of nausea, vomiting, and pain were compared among groups. Antiemetic administration and discharge times from recovery and the hospital were also compared. The groups were similar, but anesthesia times were longer in the INHAL group. Emergence from anesthesia after PSAND or TPROP was more rapid than after INHAL. Recovery during the next 24 hours was associated with less nausea and vomiting with PSAND than with INHAL. The cost of the PSAND anesthetic was similar to that of INHAL, and both were less than TPROP. PSAND anesthesia may be similar to TPROP and better than INHAL for otologic procedures. PSAND was less expensive than TPROP and produced a similar recovery profile and antiemetic effect in the 24-hour period after surgery.

Adult↗

[Intravenous anesthesia using propofol during lengthy neurosurgical interventions].

OBJECTIVE: To compare the hemodynamic stability and time to recovery of consciousness after long-duration (> 3 h) neurosurgery with 2 anesthetic protocols: total intravenous anesthesia with propofol as the single hypnotic agent and inhalational anesthesia with isoflurane. PATIENTS AND METHOD: We studied 58 middle-aged patients (range 40-50 years) scheduled for intracranial surgery. The patients, who all scored over 13 on the Glasgow coma scale before surgery, were randomly divided into two groups: 27 in group I received isoflurane and 31 in group II received propofol. Anesthetic induction was with sodium thiopental 4 mg/kg i.v. in group I and with propofol 2.5 mg/kg i.v. in group II. Both groups then received fentanyl 2 micrograms/kg i.v., lidocaine 1.5 mg/kg i.v. and vecuronium 0.2 mg/kg i.v. Before placement of the Mayfield head grip, with clamps, or before start of surgery in those cases in which the head grip was not used, all patients were given a 3 micrograms/kg i.v. dose of fentanyl. Hypnosis was maintained in group I with concentrations of isoflurane that were adequate for keeping minimum alveolar concentration (MAC) between 0.6 and 1. In group II maintenance was by continuous i.v. perfusion of propofol 10 mg/kg/h for 30 min., followed by 8 mg/kg/h for 30 min. and 6 mg/kg/h until the end of surgery. N2O was never used. RESULTS: After induction systolic and mean arterial pressures (SAP and MAP) decreased significantly in both groups in comparison with baseline values (SAP: 113.1 +/- 30.0 vs. 140.9 +/- 27.08 mmHg in group I and 109.6 +/- 22.1 vs. 135.0 +/- 19.7 mmHg in group II; MAP: 76.8 +/- 18.7 vs. 95.6 +/- 17.0 mmHg in group I and 74.9 +/- 13.2 vs. 93.4 +/- 13.7 mmHg in group II). The patients in group II showed less tendency to develop arterial hypertension in response to orotracheal intubation (SAP and MAP at the moment of intubation: 156.4 +/- 33.7 and 104.6 +/- 18.1 mmHg, respectively, in group I as compared to 135.1 +/- 31.2 and 93.5 +/- 22.4 mmHg in group II; p < 0.05 between the 2 groups and p < 0.05 for the baseline and intubation pressures in group I). Time to recovery of effective, spontaneous breathing was shorter in group I (5.9 +/- 4.9 and 8.9 +/- 5.7 min.) than in group II (10.9 +/- 9.6 and 13.0 +/- 7.4 min.) and tubes could be extracted earlier from patients in the isoflurane group (10.4 +/- 6.1 min. vs. 17.6 +/- 12.8 min.; p < 0.01). We found no differences between the 2 groups for time until eye opening, response to verbal orders or time until start of spontaneous movement. CONCLUSIONS: Propofol can be considered an alternative to the traditional thiopental-isoflurane sequence in neurosurgery lasting more than 3 h. In our study the hypertensive response to the stimulus of orotracheal intubation was lower in the propofol group than in the thiopental-isoflurane group.

Adult↗

[Is propofol (Diprivan) indicated in emergency surgery?].

Propofol is an anesthetic characterized by specific pharmacologic qualities, conditioning compliance of the clinical picture with the drug infusional rate, high-degree safety and facilitated anesthesia conduction--qualities by which it bears resemblance to inhalation anesthesia. This is an assessment of the qualities of TIVA with Propofol in poor-risk patients according to ASA, operated on an emergency basis. Proceeding from the obtained results, the inference is reached that continuous Propofol infusion provides for adequate anesthesia control and safety of the patients with heightened anesthesiologic and operative risk.

Adolescent↗

Ventilatory response during CO2 inhalation after airway anesthesia with lidocaine.

Airway anesthesia with inhaled aerosolized lidocaine has been associated with increases in minute ventilation (VE) and mean inspiratory flow rate (VT/TI) during CO2 inhalation. However, it is unclear whether these increases are local effects of the anesthesia or systemic effects of absorbed and circulating lidocaine. To evaluate this 20 normal subjects were treated on separate days with aerosolized lidocaine, intravenous lidocaine, aerosolized control solution, or intravenous control solution, and the effects of each treatment on VE and VT/TI were determined and compared during room-air breathing and inhalation of 5% CO2-95% O2. None of the treatments altered VE or VT/TI during room-air breathing. Aerosolized lidocaine produced small (5.9-6.0%) increases in VE and VT/TI during CO2 inhalation, but these effects were not present after intravenous lidocaine despite equivalent lidocaine blood levels. We concluded that the increases in VE and VT/TI after aerosolized lidocaine were local effects of airway anesthesia rather than systemic effects of absorbed and circulating lidocaine.

Adult↗

[Monitoring of gases and vapors in the anesthesia system].

By now inhalation anesthesia makes anesthetic gaz and vapours analysis compulsory. This paper give an account of numerous gaz analyzers which are available today. Different kinds of oximeters (galvanic, polarographic, paramagnetic) carbon dioxide analysers, halothane, enflurane or isoflurane-meters are reviewed. Advantage/cost ratio of mass spectrometer is discussed too. Practical advices on use and site of slow and fast analysers are recalled.

Anesthesiology↗

The effect of rectal temperature on perianesthetic serum concentrations of transdermally administered fentanyl in cats anesthetized with isoflurane.

OBJECTIVES: To determine whether moderate hypothermia during 4 hours of anesthesia with isoflurane substantially affects serum concentrations of transdermally administered fentanyl in the perianesthetic period in cats. ANIMALS: 7 healthy mature cats. PROCEDURE: A fentanyl patch (25 microg/h) was applied to the shaved thorax 24 hours before induction of anesthesia. Anesthesia was induced at time 0. Each cat received 2 treatments in a random order. Treatments were isoflurane anesthesia with normothermia and isoflurane anesthesia with hypothermia. Cats were intubated, connected to a nonrebreathing circuit, and maintained at 1.3X minimum alveolar concentration for 4 hours. Cats in the hypothermia treatment groups were actively cooled to 35 degrees C following the induction of anesthesia. Serum fentanyl analysis was performed at -24, -12, 0, 1, 2, 3, 4, 4.5, 5, 6, 7, 8, 9, 10, 12, and 24 hours. RESULTS: Mean +/- SEM serum fentanyl concentration (SFC) for the hypothermia treatment group (0.598 +/- 0.3048 ng/mL) was significantly lower than the baseline concentration (1.834 +/- 0.6393 ng/mL) at 1 hour. This significant reduction persisted for the duration of anesthesia for the hypothermia treatment group. Serum fentanyl concentrations returned to baseline values within 1 hour of the end of anesthesia, regardless of body temperature. CONCLUSIONS AND CLINICAL RELEVANCE: Hypothermia during inhalant anesthesia induced a significant reduction in SFC obtained with transdermal administration. The impact of this reduction in SFC on the contribution of transdermally administered fentanyl to any reduction in the need for inhalant anesthesia remains to be determined.

Administration, Cutaneous↗