# Isoflurane anesthesia and sleep deprivation trigger delayed and selective sleep alterations

## TL;DR

This study shows that combining sleep deprivation with isoflurane anesthesia leads to long-term changes in sleep quality in mice.

## Contribution

The study reveals that pre-anesthetic sleep deprivation causes persistent disruption in REM sleep quality after isoflurane anesthesia.

## Key findings

- Isoflurane causes NREM sleep rebound during recovery sleep in mice.
- Pre-anesthetic sleep deprivation leads to a persistent reduction in theta power during REM sleep after anesthesia.
- Combined sleep deprivation and isoflurane disrupt REM sleep quality for at least three days.

## Abstract

Isoflurane anesthesia (IA) partially compensates NREM sleep (NREMS) and not REM sleep (REMS) requirement, eliciting post-anesthetic REMS rebound. Sleep deprivation triggers compensatory NREMS rebounds and REMS rebounds during recovery sleep as a result of the body’s homeostatic mechanisms. A combination of sleep deprivation and isoflurane anesthesia is common in clinical settings, especially prior to surgeries. This study investigates the effects of pre-anesthetic sleep deprivation on post-anesthetic sleep–wake architecture. The effects of isoflurane exposure (90 min) alone were compared with the effects of isoflurane exposure preceded by experimental sleep deprivation (6 h, gentle handling) on recovery sleep in adult mice by studying the architecture of post-anesthetic sleep for 3 consecutive post-anesthetic days. Effects of isoflurane anesthesia on recovery sleep developed only during the first dark period after anesthesia, the active phase in mice. During this time, mice irrespective of preceding sleep pressure, showed NREMS and REMS rebound and decreased wakefulness during recovery sleep. Additionally, sleep deprivation prior to isoflurane treatment caused a persistent reduction of theta power during post-anesthetic REMS at least for 3 post-anesthetic days. We showed that isoflurane causes NREMS rebound during recovery sleep which suggests that isoflurane may not fully compensate for natural NREMS. The study also reveals that isoflurane exposure preceded by sleep deprivation caused a persistent disruption of REMS quality. We suggest that preoperative sleep deprivation may impair postoperative recovery through lasting disruption in sleep quality.