Clinical Trial: NICardipine Neuroprotection in AortiC Surgery (NICNACS)

Study Status: Terminated
Recruit Status: Terminated
Study Type: Interventional

Official Title: NICardipine Neuroprotection in AortiC Surgery (NICNACS)

Brief Summary:

Objective

The objective of this study is to discover whether an infusion of nicardipine is able to reduce the time taken to achieve electrocerebral silence (ECS) during cardiopulmonary bypass (CPB) for aortic surgery.

Hypothesis

By inhibiting cold-induced cerebral vasoconstriction, nicardipine will maintain cerebral blood flow and allow more rapid cooling of the brain during CPB. This will manifest as a reduction in the time taken to achieve ECS and also as a reduction in overall CPB time.


Detailed Summary:

Patients undergoing thoracic aortic surgery at Duke University Medical Center (DUMC) requiring hypothermic circulatory arrest (HCA) and neurophysiologic monitoring (NIOM) will give written informed consent and be enrolled into the study. Exclusion criteria will include previously documented allergy to nicardipine and age less than 18 years. Patients will then be randomized to one of two study groups: general anesthesia with or without nicardipine. Pre-operatively they will undergo clinical evaluation determined by the attending surgeon and anesthesiologist. During the pre-induction time period, all usual monitors and intravenous devices will be placed at the discretion of the attending anesthesiologist. In addition to the standard anesthetic monitors (Bispectral Index [BIS] and cerebral oximetry), transcranial Doppler (TCD) will be placed. Furthermore, the neurophysiology technician will place both standard EEG and somatosensory evoked potential (SSEP) electrode configurations. During the pre-induction time period, midazolam use will be at the discretion of the anesthesiologist but will be limited to a maximum dose of 0.1 mg/kg; other benzodiazepines will not be allowed. Opioid (fentanyl) administration will be at the discretion of the anesthesiologist. Total benzodiazepine and opioid doses will be recorded and converted to midazolam and fentanyl equivalents for subsequent analysis.

When ready, patients will be transported into the operating room and anesthesia will be induced. Induction will consist of propofol (1 - 5 mg/kg single intravenous bolus), fentanyl and vecuronium for neuromuscular blockade. Other drugs and dosages of opioids and neuromuscular blockers are at the discretion of the anesthesiologist. After induction and tracheal intubation, patients will receive maintenance anesthesia of 0.5 minimal alveolar concentration (MAC) isoflurane in a 50% air/oxygen bala
Sponsor: Duke University

Current Primary Outcome: Duration From Initiation of Cardiopulmonary Bypass (CPB) to Electrocerebral Silence (ECS), Defined as no Discernable Electroencephalographic Activity at an Amplification of 2 Micro Volts (μV)/mm, Confirmed for 3 Minutes [ Time Frame: Day of surgery ]

Original Primary Outcome: Duration from initiation of CPB to ECS, defined as no discernable electroencephalographic activity at an amplification of 2 μV/mm, confirmed for 3 minutes [ Time Frame: Day of surgery ]

Current Secondary Outcome:

  • Temperature at Which ECS Occurs [ Time Frame: Day of surgery through discharge ]
  • Temperature at Which Ablation of(SSEP)Occurs [ Time Frame: Day of surgery through discharge ]
  • Time Points of EEG Patterns [ Time Frame: Day of surgery through discharge ]
  • Time Points for SSEP Latency and Amplitude Changes [ Time Frame: Day of surgery through discharge ]
  • Bispectral Index Scores (BIS) [ Time Frame: Day of surgery through discharge ]
  • Cerebral Oximetry Measurements [ Time Frame: Day of surgery through discharge ]
  • Transcranial Doppler Measurements [ Time Frame: Day of surgery through discharge ]


Original Secondary Outcome:

  • Temperature at Which ECS Occurs [ Time Frame: Day of surgery through discharge ]
  • Temperature at Which Ablation of(SSEP)Occurs [ Time Frame: Day of surgery through discharge ]
  • Time Points of EEG Patterns [ Time Frame: Day of surgery through discharge ]
  • Time Points for SSEP Latency and Amplitude Changes [ Time Frame: Day of surgery through discharge ]
  • BIS scores [ Time Frame: Day of surgery through discharge ]
  • Cerebral Oximetry Measurements [ Time Frame: Day of surgery through discharge ]
  • Transcranial Doppler Measurements [ Time Frame: Day of surgery through discharge ]


Information By: Duke University

Dates:
Date Received: July 25, 2007
Date Started: January 2008
Date Completion:
Last Updated: July 29, 2014
Last Verified: January 2013