Short- and long-term follow-up of intensive care unit patients after sedation with isoflurane and midazolam--a pilot study.
OBJECTIVE
To compare memories from the intensive care unit (ICU) and short- and long-term psychological morbidity in patients after sedation with intravenous midazolam or inhaled isoflurane.


METHODS
Prospective long-term follow-up after randomized controlled trial.


METHODS
General ICU at Karolinska University Hospital, Solna, Stockholm.


METHODS
Forty patients in need of sedation during ventilator treatment.


METHODS
Patients were randomized to receive isoflurane or midazolam for goal-directed sedation until extubation or for a maximum of 96 hrs.


RESULTS
For short-term follow-up, doctors', nurses', and physiotherapists' notes from the 4 days following exposure to the study drugs were reviewed for words indicating adequate or pathologic cognitive and psychological recovery. For long-term follow-up, all 6-month survivors received questionnaires including the ICU Memory Tool (ICU-MT), Hospital Anxiety and Depression Scale (HADS), Impact of Event Scale (IES), and Well-Being Index. Additionally, several screening questions for previous posttraumatic stress symptoms were included. In the short term follow-up, no significant differences were found between groups. In the long-term follow-up, a trend toward fewer hallucinations/delusions after isoflurane sedation than after midazolam (two of ten isoflurane patients vs. five of seven midazolam patients) was found (p = .06). None of the five solely isoflurane-sedated patients reported hallucinations/delusions from the ICU. There was no difference in groups in long-term psychological morbidity as measured with HADS and IES. Memories of negative feelings in the ICU (ICU-MT) were associated with high HADS and IES scores (Fisher's exact test, p = .02 and p = .01, respectively).


CONCLUSIONS
Sedation of ICU patients with isoflurane may result in fewer delusional memories or hallucinations from the ICU compared with more commonly used intravenous sedation. Memories of negative feelings from the ICU were associated with symptoms of depression or anxiety or symptoms indicating posttraumatic stress disorder. Further study of memory and cognitive/psychological recovery after prolonged isoflurane sedation beyond 96 hrs is warranted.
Sackey
Peter V
PV
Section of Anesthesiology and Intensive Care Medicine, Karolinska Institutet, Stockholm, Sweden. peter.sackey@karolinska.se
Martling
Claes-Roland
CR
Carlswärd
Christine
C
Sundin
Orjan
O
Radell
Peter J
PJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001007:Anxiety / Q000139:chemically induced; D003072:Cognition Disorders / Q000139:chemically induced; D016292:Procedural Sedation; D003702:Delusions / Q000139:chemically induced; D003863:Depression / Q000139:chemically induced; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006993:Hypnotics and Sedatives / Q000009:adverse effects* / Q000627:therapeutic use; D007362:Intensive Care Units; D007530:Isoflurane / Q000009:adverse effects* / Q000627:therapeutic use; D008297:Male; D008874:Midazolam / Q000009:adverse effects* / Q000627:therapeutic use; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D013997:Time Factors
D006993:Hypnotics and Sedatives; D007530:Isoflurane; D008874:Midazolam