The effect of pneumoperiteum during laparoscopic surgery on the paediatric intestine

During laparoscopic surgery there is a pneumoperitoneum created with carbon
dioxide to create a working space in the abdomen to visualize the target organs
and a proper operating field. An intra-abdominal pressure lower than 14 mmHg is
considered safe in a healthy adult patient, however, this in children lower
pressures are preferred, but there is no limit objectified in which
complications are more prone to occur.
The complications that can occur because of the pneumoperitoneum are based on
the physiological changes resulting from the increased abdominal pressure and
the carbon dioxide used to create the pneumoperitoneum. Low mesenteric blood
supply (due to high abdominal pressure) leads to intestinal injury and the
excretion of iFABP in the circulation. This substance will be excreted in the
urine, and the intestinal damage can be detected in the urine.
in this study the effect of the pneumoperitoneum on the paediatric intestine
will be objectified, in which urinary iFABP will serve as an indicator for
intestinal damage.

In this study the effect of the pneumoperitoneum on the intestine of children
is objectified by measuring the iFABP levels in the urine, as an indicator for
the ischemia or damage to the intestine. To exclude any iFABP increase due to
intestinal damage of the surgical procedure (by manipulation and resection) we
chose to research these levels in children during a laparoscopic Nissen
fundoplication.

Primary Objective:
• Is there an effect of the pneumoperitoneum during laparoscopic procedures in
the paediatric intestine, by elevation in urinary iFABP concentration and
urinary iFABP/creatine ratio?
Secondary Objectives:
• Is there a relation between perioperative urinary iFABP concentration and
postoperative gastro-intestinal functions, measured by enteral feeding
postoperative?
• Is there a relation between perioperative urinary iFABP/creatine ratio and
postoperative gastro-intestinal functions, measured by enteral feeding
postoperative?
• Is there a relation between perioperative urinary iFABP concentration and
postoperative gastro-intestinal functions, measured by defecation habits
postoperative?
• Is there a relation between perioperative urinary iFABP/creatine ratio and
postoperative gastro-intestinal functions, measured by defecation habits
postoperative?

This is an observational prospective cohort study.
The urinary catheter is placed when the patient, and a control sample from the
urine is taken before the surgery. After the pneumoperitoneum is completed
there will be a sample taken every 10 minutes. The last sample during the
surgery is taken 10 minutes after the desufflation of the pneumoperitoneum. The
urinary bladder catheter is removed after the last sample, when the patient is
still under anaesthesia.
The other control measurements, such as intra-abdominal pressure, blood
pressure and urinary output are taken at the same interval points, during the
surgery. Postoperative gastro-intestinal measurements are documented at the
ward, and when the patient is released home, they will document this with their
parents on the questionnaire, for one week postoperative. Any complications
after the surgery will be documented for this research.

The patients will all receive a bladder catheter (CAD) just before the surgery
(when they are under anaesthesia), therefore, there will be no pain of
introducing the catheter. The CAD will stay in situ during the surgery and will
be removed before the patient is awake. The urinary samples can be drawn from
the CAD, which will cause no extra handling of the patient. The risks on
complications from a CAD (urinary track infection and false route) are low.
During regular elective laparoscopic Nissen fundoplication there is no specific
need for a CAD, however, the anaesthesiologist often requests this to have a
proper haemodynamic evaluation during the surgery. The insertion of a CAD
before the introduction of the trocars ensures the bladder to be empty, and
therefore, a safer introduction of the first subumbilical trocar.
The patients/ parents should also fill out a short questionnaire during one
week postoperative, on the enteral feeding and defecation of the patient.
By measuring the iFABP levels during the surgery in upper abdominal surgery (in
which the intestines are not manipulated) a clear effect of the
pneumoperitoneum on the paediatric intestine is visualized. This is useful for
the further use of the pneumoperitoneum and perhaps adaptation of the
insufflation pressures during the laparoscopic procedures in children.