Mount Sinai Expert Guides. Группа авторов

       Analgesia and sedation are primarily indicated to prevent self‐harm and ensure the comfort of a patient. Examples include intubated patients who are dyssynchronous with a ventilator, those with open wounds postoperatively, and patients who are unable to have their pain controlled by less intensive measures.

       Post‐traumatic stress disorder (PTSD) has been found in 20% of patients after discharge from an ICU. Appropriately targeted sedation therapy has been associated with decreased rates of PTSD.

       ‘Sedation vacations’ are associated with shorter length of ICU stay, fewer days on a ventilator, improved return to independent function at discharge, and trend toward lower ICU mortality.

       Pain is experienced at greater rates among the critically ill than among the wider population. Up to 70% of patients will experience moderate to severe pain during their ICU stay. Rates have been measured up to 30% while at rest and the majority will experience pain during routine cleaning and nursing interventions.

       Experiencing pain in the ICU has been associated with greater levels of chronic pain in the post ICU setting and of PTSD.

       Analgosedation, or the practice of first treating with analgesics before actively sedating the patient with hypnotics, has been linked to shorter ICU length of stay and decreased duration of mechanical ventilation.

       Context‐sensitive half‐time (CSHT) is defined as the duration of time required for plasma concentrations of a drug to decrease by 50% after discontinuing administration of the drug. ‘Context’ is meant to refer to the duration of time that an infusion has been running.

       The CSHT is often different from the elimination half‐time and explains differences in duration of effect that exist based on how long an infusion is running versus the effect we see with a single bolus dose of a medication. As an example, if we were to believe that elimination half‐time determined the duration of effect of propofol, then a single bolus should leave our patient obtunded for several hours. Instead we know that a single bolus will wear off in a few minutes due to redistribution of the medication out of the central compartment into the periphery.

       Likewise, the CSHT also explains why medications take longer for their effects to wear off after longer infusions. A simplified, if not perfectly scientific, explanation is that anesthetic drug effects wear off as medications redistribute from the central to the peripheral compartments. However, over time, the peripheral compartments can approach saturation, causing the central compartment to refill or maintain a steady state as its concentration decreases. Each drug has a different volume of periphery that it can fill at a different rate. Accordingly, we see that a medication like remifentanil which has virtually no CSHT will wear off in a few minutes regardless of the administration duration, while midazolam may take days after a sufficiently long infusion.

       Two methods have been well validated for monitoring sedation levels with equivalent results:The Richmond Agitation‐Sedation Scale (Table 2.1) extends from –5 (unarousable) to +4 (combative) with zero representing a calm and alert patient. A typical goal is a light sedation of –1 to –2.The Riker Sedation‐Agitation Scale (Table 2.2), extends from 1 (unarousable) to 7 (dangerous agitation), with 4 representing the calm and alert patient. A typical goal is a light sedation of 3.

       Objective monitoring modalities such as EEG, bispectral index, or patient state index are not recommended by the Society of Critical Care Medicine guidelines as a regular monitoring tool. However, if the patient is paralyzed (through neuromuscular blockers or clinical condition), then use of an objective monitoring device is suggested.