A sevoflurane induction of anesthesia with gradual reduction of concentration is well tolerated in elderly patients

Sevoflurane Induction With Snorkel Technique in an Adult With Mask and Needle Phobia

Snorkel breathing involves mouth breathing into a snorkel tube and is necessary for underwater activities. Anesthesiologists may have difficulty when dealing with adults who have a concomitant face mask and needle fear because both inhalation and intravenous induction cannot be performed. This case report describes a novel use of the snorkel breathing technique for anesthetic gas induction in an adult with face mask fear. A 24-year-old female with mask and needle fear underwent a craniotomy and biopsy of a frontal lesion while under general endotracheal anesthesia. During anesthesia induction, the patient was directed to hold the breathing tube tightly between her lips and breathe via her mouth into it with sevoflurane at 8% dial setting and 6 L/min of fresh gas flow. The snorkel approach was effectively used to induce anesthesia with better patient cooperation, and an intravenous cannula was inserted.

Schizophrenia and anaesthesia

Administering anaesthesia for elderly patients with chronic schizophrenia has always been a great challenge to anaesthetists. These patients will usually be on multiple antipsychotic drugs for many years and may lead to delayed awakening, cardiovascular instability, arrhythmias and sudden cardiac death during general anaesthesia. This case report is about the perioperative anaesthetic management of an elderly schizophrenic patient undergoing removal of femur implant. This article will explore important drug interactions and available options for a successful anaesthesia.

A clinical review of inhalation anesthesia with sevoflurane: from early research to emerging topics

A large number of studies during the past two decades have demonstrated the efficacy and safety of sevoflurane across patient populations. Clinical researchers have also investigated the effects of sevoflurane, its hemodynamic characteristics, its potential protective effects on several organ systems, and the incidence of delirium and cognitive deficiency. This review examines the clinical profiles of sevoflurane and other anesthetic agents, and focuses upon emerging topics such as organ protection, postoperative cognitive deficiency and delirium, and novel ways to improve postanesthesia outcomes.

Hemodynamic profile of target-controlled spinal anesthesia compared with 2 target-controlled general anesthesia techniques in elderly patients with cardiac comorbidities

BACKGROUND AND OBJECTIVES

The impact of anesthesia techniques in patients experiencing hip fracture is controversial. This study compares the effects on blood pressure of 3 anesthesia techniques that are considered safe for the elderly.

METHODS

Forty-five patients older than 75 years, with American Society of Anesthesiologists physical status III or IV, with cardiac comorbidities, and undergoing surgery for hip fracture, were randomized to receive continuous spinal anesthesia (CSA), propofol target-controlled infusion (TCI), or sevoflurane (SEVO). In CSA patients, a T10 metameric level target was achieved by titration of 2.5 mg of bupivacaine boluses. In patients on TCI and SEVO, a bispectral value target of around 50 guided the concentration of propofol or sevoflurane. Analgesia in the TCI and SEVO groups was provided with remifentanil. Hypotension was defined as a 30% decrease in mean arterial pressure and was treated with an intravenous bolus of ephedrine.

RESULTS

The number of hypotension episodes was lower in the CSA group: 0 (range, 0-6) versus 11.5 (range, 1-25) in the TCI group and 10 (range, 1-23) in the SEVO group (P < 0.001). Both TCI and SEVO patients needed more ephedrine compared with CSA patients (30.5 [15.5], 26 [23], and 1.5 [2.5] mg, respectively, P < 0.001). The maximal decrease in mean arterial pressure was lower in the CSA group (26% [17%]) compared with that in the TCI group (47% [8%]) and the SEVO group (46% [12%]; P < 0.001).

CONCLUSIONS

In elderly patients, spinal anesthesia using titrated doses of bupivacaine provided better blood pressure stability than propofol or sevoflurane anesthesia.

General anaesthesia in elderly patients with cardiovascular disorders: choice of anaesthetic agent

Our population is aging; currently 15% of the Western population are aged >65 years, and represent 25% of those undergoing surgery. The proportion of the population aged >or=65 years is rapidly growing, and an increasing number are affected with cardiovascular disease. The older person is a high-risk patient. This is because of their altered physiology and associated co-morbidities, as well as the pharmacokinetic and pharmacodynamic changes that may alter drug responses. There is considerable variability seen in the physical and physiological states of individual patients within the older population. This has an important impact on choosing a safe anaesthetic technique for each individual, which in turn can influence the morbidity and mortality in this population. The physiological changes in the aging cardiovascular system affect the arterial and venous vasculature, myocardium and autonomic nervous system, making the older person more prone to cardiovascular instability. In addition to the physiological changes, the cardiovascular status of the older person tends to be compromised by associated pathological conditions that are more common with increasing age. Pharmacokinetic and pharmacodynamic changes must be taken into account when deciding about drug dosing in this age group. Aspects of dose reduction, titration of drugs, dosing intervals and the pharmacodynamic effects of each class of drug are explained in detail in the text. The major challenge in anaesthesia for the older person with cardiovascular disease is maintenance of haemodynamic stability, particularly in the face of reduced physiological reserve and capability to respond to periods of instability. An appropriate anaesthetic technique must be selected to minimize haemodynamic changes and maintain near normal physiological status. The other key objective is to minimize the incidence of adverse outcomes, such as perioperative myocardial ischaemia/infarction, arrhythmias, heart failure, postoperative cognitive dysfunction and stroke. No single anaesthetic regimen or agent can be advocated. Knowledge of the pharmacokinetic and pharmacodynamic principles of anaesthetic agents and their altered response in elderly patients is essential when selecting an anaesthetic agent. This article provides a practical guide to the selection and use of general anaesthetic agents in older patients with cardiovascular disorders, highlighting the differences among various agents.

Desflurane and Sevoflurane in Cardiac Surgery: A Meta-Analysis of Randomized Clinical Trials

OBJECTIVES

The authors performed a meta-analysis to investigate whether the cardioprotective effects of volatile anesthetics translate into decreased morbidity and mortality in patients undergoing cardiac surgery.

BACKGROUND

It is commonly believed that the choice of the primary anesthetic agent does not result in different outcomes after cardiac surgery. Recent evidence, however, has indicated that volatile anesthetics improve postischemic recovery at a cellular level, in isolated hearts, in animals, and in humans.

METHODS

Four investigators independently searched BioMedCentral and PubMed. Inclusion criteria were random allocation to treatment and comparison of a total intravenous anesthesia regimen versus an anesthesia plan including desflurane or sevoflurane performed on cardiosurgical patients. Exclusion criteria were duplicate publications, nonhuman experimental studies, and no outcome data. The endpoints were the rate of perioperative myocardial infarction and hospital mortality.

RESULTS

The search yielded 22 studies, involving 1,922 patients. Volatile anesthetics were associated with significant reductions of myocardial infarctions (24/979 [2.4%] in the volatile anesthetics group v 45/874 [5.1%] in the control arm, odds ratio [OR] = 0.51 [0.32-0.84], p for effect = 0.008, and p for heterogeneity = 0.77) and mortality (4/977 [0.4%] v 14/872 [1.6%], OR = 0.31 [0.12-0.80], p for effect = 0.02, and p for heterogeneity = 0.88).

CONCLUSIONS

Desflurane and sevoflurane have cardioprotective effects that result in decreased morbidity and mortality. The present data show for the first time that the choice of an anesthetic regimen based on administration of halogenated anesthetics is associated with a better outcome after cardiac surgery.

Implication of aging on anesthetic drugs

PURPOSE OF REVIEW

The elderly population is increasing in number each year, and more patients are presenting for anesthesia and surgery. One of the key areas for improving the care of the elderly is a better understanding of the influence of aging on drug pharmacokinetics and dynamics.

RECENT FINDINGS

We now know more about the effects of risk factors on the occurrence of postoperative complications, and strategies to improve outcome after anesthesia and surgery. Two such strategies include the role of perioperative beta-adrenoceptor blockade in obtunding cardiovascular responses and myocardial ischaemia, and the provision of effective perioperative analgesia. Both topics have featured in key publications during the past year. Cognitive dysfunction following surgery occurs in about 10% of elderly patients; possible etiologies include a decline in central nervous system cholinergic function. One major disease of the elderly is Parkinson's disease, which offers challenges to the anesthesiologist both with regard to alterations of physiology and in choice of anesthetic drugs and techniques.

SUMMARY

The effects of comorbidity and intercurrent medications may alter the normal anesthetic practice of the clinician's care of the elderly patient. Further studies in these key areas may lead to improved outcomes.

Comparison of Propofol and Sevoflurane for Laryngeal Mask Airway Insertion in Elderly Patients

BACKGROUND

Sevoflurane and propofol have been widely used for anesthesia induction. This study compared the efficacies of sevoflurane and propofol inductions for laryngeal mask airway (LMA) insertion in elderly patients.

METHODS

Ninety patients, aged 60 or more, received anesthesia induction with propofol and with sevoflurane 8% using the vital capacity breath (VCB) or tidal volume breath (TVB) techniques. Hemodynamic changes, induction time, complications, and the quality and ease of LMA insertion were observed.

RESULTS

LMA was inserted most, less or least rapidly with propofol (89 +/- 28 s), sevoflurane 8% using the VCB (163 +/- 34 s) or TVB (205 +/- 44 s) techniques, respectively. Anesthesia induction with propofol or sevoflurane 8% using the VCB technique produced either more frequent apnea or greater reduction in mean blood pressure than with sevoflurane 8% using the TVB technique.

CONCLUSIONS

Sevoflurane 8% using the TVB technique provides a smoother induction with a stable hemodynamic profile, less apnea and technical demand, but requiring longer time for LMA insertion in unpremedicated elderly patients.

Comparison of a propofol target-controlled infusion and inhalational sevoflurane for fibreoptic intubation under spontaneous ventilation

BACKGROUND

A propofol target-controlled infusion (TCI) is often proposed for the management of difficult airway intubation and fibreoptic intubation under anaesthesia and spontaneous ventilation. No data are available about sevoflurane. The aim of the present study was to compare propofol and sevoflurane as hypnotics during fibreoptic intubation under spontaneous ventilation.

METHODS

After regional ethical committee approval, 52 ASA I-II patients without any predictors for difficult intubation gave their informed consent. They were randomly assigned to one of two groups. After 3 min of pre-oxygenation, patients received either propofol with a plasmatic target concentration of 4 mg/l (group P; n= 26) or sevoflurane 4% with tidal volume ventilation (group S; n= 26). After 2 min, propofol was increased by 1 mg/l and sevoflurane was increased by 1% every 2 min until there was no reaction during mandible translation. This concentration was maintained for 4 min before starting nasotracheal fibrescopy for intubation. During both induction and fibrescopy, pulse oximetry, bispectral index (BIS), heart rate, and arterial blood pressure were monitored. Quality of intubation and operator satisfaction were evaluated. Data were compared using Student's t-test, Mann-Withney U-test or chi-square test. A P-value < 0.05% was considered to be significant.

RESULTS

During induction, no difference in pulse oximetry, BIS values at the end of induction, or duration of induction were noticed. Five episodes of desaturation under 90% occurred during fibreoptic intubation in group P compared with none in group S.

CONCLUSION

Sevoflurane provides good fibreoptic intubation conditions to spontaneously breathing patients without any hypoxemic episodes such as those observed with propofol.

Pressure support ventilation during inhalational induction with sevoflurane and remifentanil in adults

BACKGROUND AND OBJECTIVE

The purpose of this prospective randomized study was to assess the value of pressure support ventilation during inhalational induction with sevoflurane in adult patients.

METHODS

Thirty-five adult patients, ASA I-II and scheduled for ear nose throat surgery were studied. Vital capacity induction with 8% sevoflurane in 8 L min-1 oxygen was performed. Pressure support ventilation was used in Group 1 with pressure set at 15 cmH2O. In Group 2, patients breathed spontaneously. After 2 min, sevoflurane was set to 3% and remifentanil 1 microg kg(-1) was injected over 2 min followed by an infusion of 0.1 microg kg(-1) min(-1). Two minutes after the end of the bolus, intubation was performed. Bispectral index, oxygen saturation, respiratory rate, end-tidal carbon dioxide, expired tidal volume and expired sevoflurane concentration were recorded every minute.

RESULTS

Eighteen patients were included in Group 1 and 17 in Group 2. Saturation, respiratory rate and end-tidal carbon dioxide were similar in the two groups. Expired tidal volume was significantly higher and bispectral index values significantly lower in Group 1. Intubating conditions were better in Group 1.

CONCLUSIONS

Pressure support ventilation provides both better ventilation and deeper level of anaesthesia during inhalation induction with sevoflurane.

Induction par inhalation de sévoflurane à objectif de concentration chez l'adulte avec le respirateur ZEUS®

OBJECTIVES

To evaluate if the new anaesthesia platform ZEUS (Dräger Medical) allows the induction of anaesthesia with target-controlled inhalation of sevoflurane.

STUDY DESIGN

Prospective clinical study.

PATIENTS

Adult ASA I or II patients scheduled for elective surgery under general anaesthesia.

METHODS

After preoxygenation during 3 min at 100% oxygen, patients were asked to breathe normally; the target end-tidal concentration of sevoflurane was fixed at 4% without priming of the circuit. Sufentanil (target concentration 0.5 ng/ml) was administered 40 s after.

RESULTS

Ten patients (48+/-22 yrs) were included. Sevoflurane was detected in the circuit after 36+/-5 s; the target end-tidal concentration of sevoflurane was obtained at 130+/-19 s. Loss of consciousness was observed after 119+/-7 s. The induction was achieved in all patients without any incident.

CONCLUSION

This new anaesthesia system make available the induction of anaesthesia with sevoflurane without priming of the circuit.