This prospective randomised controlled trial was designed to assess the effectiveness of the Bispectral Index Sedation (BIS) monitor in supporting clinical, sedation management decisions in mechanically ventilated ICU patients.

The primary hypothesis for the study is that patients with Bispectral Index Sedation (BIS) monitoring will receive less sedation then those receiving standard sedation management.

The secondary hypotheses are:

1. Patients with BIS have fewer ventilation days than those receiving standard sedation management.
2. Level of sedation administered will differ according to the critical care experience and qualification of the nurse.

Patients in intensive care units (ICUs) frequently require sedatives and analgesics as part of therapy. Assessing the appropriate dose of sedative and analgesic drugs can be difficult due to the severity of the patient's illness, inability of the patient to communicate, multiple procedures and transports for investigations and the subjectivity of clinical sedation assessment tools. Poorly assessed and managed levels of sedation can result in over sedation, extended ventilation time and a potentially extended ICU stay.

The BIS monitor is derived from the electroencephalogram and provides a numeric value that represents a measure of cerebral activity. Such an objective measure of the patient's level of sedation may provide a useful tool that will enable nurses to titrate sedation more accurately in an attempt to provide the optimal level of sedation for all ICU patients.

The study will be conducted in the Intensive Care Unit at the Alfred Hospital. This study is designed as a prospective randomised control trial with parallel design. This means that participants' will be randomly allocated into either one of two groups - an intervention or control group. Participant's randomised to the intervention group will receive BIS monitoring. The control group will receive standard ICU sedation assessment and management.

To determine if BIS monitoring is useful in ICU, information will be collected by auditing patient charts and determining the average amounts of sedation medication for each nursing shift. In addition, the years of critical care experience and critical care qualification will be recorded for each nurse managing patients recruited to the study.

Inclusion Criteria:

• Intubated and ventilated for at least 24 hours
• Sedated on morphine and midazelam infusions

Exclusion Criteria:

• Intracranial injury
• Status epilepticus
• Facial Burns