Abdominal insufflation for laparoscopy raises intracranial pressure

By James E. Barone MD

NEW YORK (Reuters Health) - Intracranial pressure may rise to dangerous levels during laparoscopy, say investigators from Boston.

The finding may have implications for patients with co-existing trauma to the brain and abdomen who might be candidates for laparoscopy.

By email, Dr. Michael D. McGonigal, Director of Trauma Services at Regions Hospital in St. Paul, Minnesota, said, "Overall, it's a nice little study that loosely predicts what might happen in real trauma patients."

Dr. Tovy Haber Kamine and colleagues from Beth Israel Deaconess Medical Center looked at the records of 55 patients who underwent laparoscopic-assisted ventriculoperitoneal shunting over a four-year period and found nine who had intracranial pressure (ICP) values recorded.

As reported in JAMA Surgery, a total of 16 ICP measurements were done at insufflation pressures of 15 mmHg in all nine. Three patients had pressures recorded at 12 mmHg, three at 10 mmHg, and one at 8 mmHg.

The ventriculoperitoneal shunts were placed for normal pressure hydrocephalus in five patients, traumatic subdural hematoma in two, and meningioma and metastatic melanoma in one patient each.

With desufflation of the abdomen, ICPs ranged from 0 to 18 cm of H2O. But after insufflation to 15 mmHg, pressures of 8 to 25 cm of H2O were recorded. The average increase in ICP correlated linearly with insufflation pressures (p=0.040).

At 15 mmHg insufflation, the mean increase in ICP was 7.2 cm H2O (p<0.001). Similar significant increases were noted at 12 and 10 mmHg insufflation.

Because the subjects were not trauma patients with a large systemic insult that might prime them for marked pressure changes, Dr. McGonigal was surprised at the study's findings.

"A normal, uninjured brain with normal vascular permeability will tolerate transient increases in ICP without any problem," he said. For example, when we sneeze or lift something heavy, ICP rises but doesn't harm anyone's brain.

"But," he added, "bang it around a bit first, and it becomes very sensitive to changes in pressure, pH and oxygen and carbon dioxide levels."

The authors recognized some limitations of their study, including its small size, its retrospective design, and the inability to correlate the ICP values with blood pressures, which meant they were unable to calculate cerebral perfusion pressures (CPP).

The paper's introduction says, "Diagnostic and therapeutic laparoscopy has emerged as an alternative to trauma laparotomy," but Dr. McGonigal, who didn't participate in the research, points out that references used to support that statement go back to the early days of laparoscopy when people were trying it for everything. He said that today, "most people don't use laparoscopy in the acute setting in place of laparotomy."

He doubts that a prospective study on trauma patients with ventriculostomies can ever be done, but this study "should reinforce the concept that trauma surgeons need to think carefully if they ever consider using a scope in a badly head-injured patient."

If trauma surgeons want to go ahead with laparoscopy on a patient with head trauma, Dr. McGonigal recommends ICP monitoring, and "the procedure should be aborted if CPP declines or ICP increases significantly."

The authors of the paper did not respond to requests for comment.

SOURCE: http://bit.ly/1dAm8ZH

JAMA Surgery 2014.

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