Visual Atlas of Density Spectral Arrays (DSA) in Laparoscopic Cholecystectomy:
Exploring Age and Gender Differences Under Standardized TIVA
Interpreting EEG spectrograms (Density Spectral Arrays, DSA) during anesthesia is often seen as complex and challenging, especially when we combine several anesthetic agents like propofol, opioids, ketamine, lidocaine, dexmedetomidine,etc.
I have decided to compile and share with you some of my cases, but group them by type of surgery. This will simplify the information I saw.
This Visual Atlas was developed to provide a more tangible and relatable representation of DSA patterns. All cases were performed by the same anesthesiologist (myself), with the same surgical team, using a standardized TIVA protocol:
- Propofol bolus followed by continuous infusion.
- Remifentanil continuous infusion starting at 0.08 µg/kg/min.
- Ketamine: 0.2–0.3 mg/kg at the beginning of surgery.
- Lidocaine bolus at induction.
- Morphine (2–3 mg) at the beginning of surgery.
- Adjuvants: paracetamol, ondansetron, and dexamethasone
By maintaining a uniform technique and focusing on the same kind of surgery— laparoscopic cholecystectomy — this collection highlights how DSAs vary across different age groups and between men and women.
In younger patients, I did not find significant differences in DSA patterns between men and women. The most notable differences appear consistently after the age of 55 and in vulnerable brains.
The goal is not only to illustrate the EEG signatures of propofol, and what happened when we ad: remifentanil, and ketamine, etc… but also to stimulate reflection:
- Do we observe consistent gender-related differences?
- How does aging impact the density spectral array under identical anesthetic conditions?
- Can visual familiarity with these patterns lower the barrier to adopting EEG/DSA monitoring in daily practice?
This Atlas is shared as an educational resource — a step towards demystifying EEG interpretation and encouraging anesthesiologists to look beyond indices, into the living language of the brain.
? I hope you find it useful and that you can also see what I am able to see in my patients.
@carolinafrederico