Ketamine, revival of a versatile intravenous anaesthetic

Effects of anesthetics, sedatives, and opioids on ventilatory control

This article provides a comprehensive, up to date summary of the effects of volatile, gaseous, and intravenous anesthetics and opioid agonists on ventilatory control. Emphasis is placed on data from human studies. Further mechanistic insights are provided by in vivo and in vitro data from other mammalian species. The focus is on the effects of clinically relevant agonist concentrations and studies using pharmacological, that is, supraclinical agonist concentrations are de-emphasized or excluded.

Cortico-cardio-respiratory network interactions during anesthesia

General anesthetics are used during medical and surgical procedures to reversibly induce a state of total unconsciousness in patients. Here, we investigate, from a dynamic network perspective, how the cortical and cardiovascular systems behave during anesthesia by applying nonparametric spectral techniques to cortical electroencephalography, electrocardiogram and respiratory signals recorded from anesthetized rats under two drugs, ketamine-xylazine (KX) and pentobarbital (PB). We find that the patterns of low-frequency cortico-cardio-respiratory network interactions may undergo significant changes in network activity strengths and in number of network links at different depths of anesthesia dependent upon anesthetics used.

[Anesthesia in drug addiction]

The growing social problem of drug abuse has increased the likelihood that anesthesiologists will find acute or chronic drug users among patients requiring anesthesia for elective or emergency surgery. We must therefore be aware of the effects drugs have on the organism and their possible pharmacokinetic and pharmacodynamic interactions with anesthetic agents in order to prevent complications during surgery and postoperative recovery. Such knowledge is required for the management of abstinence syndrome or overdose, which pose the greatest potential dangers for the hospitalized drug addict.

[Choice of anaesthetic approach and anaesthetic drugs]

BACKGROUND

All types of anaesthesia should ensure absence of pain, inhibit autonomic responses and provide optimal conditions for surgery. Choice of anaesthetic approach (local, regional or general anaesthesia or a combination of methods) depends on type of surgery and the patients' health and preferences.

MATERIAL AND METHODS

The review is based on literature identified through non-systematic searches in PubMed and own research and experience.

RESULTS

When selecting anaesthetic approach and anaesthetic drugs one has to consider not only the perioperative period, but also postoperative aspects such as pain relief, awakeness, functional ability and absence of nausea. After major surgery, regional anaesthesia (especially epidural anaesthesia) and postoperative analgesia have been shown to reduce pulmonary complications and chronic pain. General anaesthesia can be administered either by volatile agents for inhalation, intravenous hypnotics, potent opioids or a combination (often used). Volatile agents, shown to be cardioprotective during cardiac surgery, are recommended for major non-cardiac surgery in patients with heart disease (even though clinical documentation is limited).

INTERPRETATION

An appropriate anaesthetic approach, taking into account patient characteristics and type of surgery, is important for safety and potential complications. In some situations, the anaesthetic approach and anaesthetic drugs may have an impact on outcome.