Co-induction of anaesthesia with 0.75 mg kg propofol followed by sevoflurane: a randomized trial in the elderly with cardiovascular risk factors

[Inhalational anesthetics]

Inhalational anesthetics have been used for induction and maintenance of general anesthesia for more than 150 years. All of the currently used inhalational anesthetics are chlorinated and fluorinated derivatives of ether. Dosing is carried out using the minimal alveolar concentration (MAC) concept. The pharmacokinetic properties of the various inhalational anesthetics are governed by the specific distribution coefficients. Mechanisms of action include specific modulations of various receptors of the central nervous system as well as an unspecific interaction with the cell membrane. Organ toxicity of modern inhalational anesthetics is considered to be minimal. The role of inhalational anesthetics in the context of postoperative nausea and vomiting (PONV) has been reassessed in recent years. The superiority of inhalational anesthetics over intravenous hypnotics with respect to intraoperative awareness is undisputed. The organ protective mechanism of preconditioning is an exclusive property of inhalational anesthetics among all the currently available hypnotics.

A Co-Induction Technique Utilizing 4% Sevoflurane Followed by 0.75 mg/kg Propofol in Elderly Patients Undergoing Minimally Invasive Procedures: A Prospective Randomized Control Study

Background and Objectives: Elderly patients constitute a large segment of healthcare receivers. Considering the functional deterioration of multiple organ systems with aging, achieving a safe perioperative approach is challenging. Our aim is to study the safety and effectiveness of a genuinely regimented co-induction technique in order to minimize anesthesia-related complications. Materials and Methods: One hundred and five patients were assigned to three groups according to the induction technique: propofol, sevoflurane and co-induction group. Inclusion criteria: patients with age ≥65 and American Society of Anesthesiologists physical status classification (ASA) II-III who underwent endoscopic urological procedures. The propofol group received a dose of 1.5 mg kg⁻¹ of propofol over two minutes for induction. The sevoflurane group received 8% of sevoflurane and 100% oxygen through a plastic facemask with the fresh gas flow set at 8 L min⁻¹. The co-induction group received 4% sevoflurane through plastic facemask for two minutes, followed by a 0.75 mg kg⁻¹ dose of propofol. After ensuring full range jaw relaxation, the laryngeal mask airway (LMA) was inserted. Results: Overall, the co-induction technique had a favorable profile in terms of respiratory adverse events, while the sevoflurane group had a favorable profile in terms of hemodynamic stability. Furthermore, 24 (68.6%) patients receiving inhalational sevoflurane had episodes of transient apnea, which constitutes 77.4% of the 31 episodes of transient apnea in the studied sample (p < 0.001). Moreover, six (17.1%) patients in the sevoflurane group had an episode of partial laryngospasm (p = 0.034). Compared with the co-induction group, we found that the propofol group had significantly less systolic and diastolic blood pressures in the second minute, with p values of (0.018) and (0.015), respectively. Conclusions: The co-induction technique utilizing 4% sevoflurane at 8 L min⁻¹ flow of oxygen inhaled over two minutes followed by 0.75 mg kg⁻¹ of propofol achieved less respiratory adverse events compared with the sevoflurane group, and less hemodynamic instability compared with the propofol group.

Current world literature

This bibliography is compiled by clinicians from the journals listed at the end of this publication. It is based on literature entered into our database between 1 February 2008 and 31 January 2009 (articles are generally added to the database about two and a half months after publication). In addition, the bibliography contains every paper annotated by reviewers; these references were obtained from a variety of bibliographic databases and published between the beginning of the review period and the time of going to press. The bibliography has been grouped into topics that relate to the reviews in this issue.