INNOVATIONS The Gravid Watermelon: An Inexpensive Perimortem Caesarean Section Model

Methods: The gravid watermelon is a cost-effective model that uses common materials from the supermarket and emergency department (ED), using a carved-out watermelon as a base, representing the peritoneal cavity. Inexpensive respiratory tubing is used to represent intestine; watered down gelatin and a small doll in a deflated rubber/plastic ball is used to represent a gravid uterus. The bladder is represented by an unused, water-filled exam glove, and watermelon pulp represents blood clots and mesentery. The gravid watermelon is covered with an elastic bandage to represent tough muscle and fascia, and topped with a shower curtain for skin.


Linked objectives and methods:
Rare procedures for life-threatening situations require task trainers for learners to appropriately practice the physical skills required. In this simulation, a low-cost PCS task trainer allows learners to review and practice a PCS. First, learners are put through a case that allows them to recognize the need for and to perform a PCS (objectives 1 and 3). During debriefing, the instructor can review the indications for PCS, review steps of the procedure (objective 2) to allow deliberate practice and fix any errors in performing the procedure (objective 3).

Recommended pre-reading for instructor:
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Implementation Methods:
Two or more participants should be provided an appropriate clinical scenario where early in the case, a gravid mother suffers cardiac arrest, either medical or trauma in etiology. The participants should perform appropriate resuscitation, demonstrate decision-making skills on whether to perform a PCS, and ultimately perform the procedure. For example, a 17year-old gravida 1, para 0 (G1P0) female of unknown gestational age, presents as the restrained driver of a motor vehicle accident going approximately 80 miles per hour. She presents with an open femur fracture, hypotensive, tachycardic. During the trauma exam she becomes less responsive and loses a pulse. During routine resuscitation, participant(s) should palpate a fundal height above the umbilicus and perform a PCS ( Figure 1). After baby is delivered, the uterus should be packed, oxytocin given, and simulation ends.

List of Resources:
Abstract 8 User Guide 9

Recommended Number of Learners per Instructor:
Ideally two learners per instructor to ensure a hands-on experience. The ideal ratio is dependent on a program's supplies and time

Objectives:
At conclusion of the simulation, participants should be able to:

Detailed methods to construct this innovation:
1. Create the peritoneal cavity: Cut the watermelon in half lengthwise, approximately two inches off of center. Proceed to cut only one side of the melon in half. Remove and discard approximately 1.5 inches of the rind of one of the quarters; discard the remaining quarter. Carve/scoop out pulp and set aside for later. Along one edge of the remaining quarter rind, punch three small holes along the edge -one at each apex of the cut and one in the middle. Puncture corresponding holes along the edge of the half rind. Connect the rinds with wire at the puncture sites.
2. Create the uterus: a. Prepare enough gelatin to fill the ball (approximately one box) per the package directions; however, add 1/3 extra water to create a consistency closer to amniotic fluid. b. While the gelatin is being prepared, puncture the rubber/plastic ball and make a hole just large enough to fit the doll. Cut two or three pieces of unused IV tubing, each 15 cm in length. Glue the tubing in a spiral fashion to form an "umbilical cord." Glue one end of the "umbilical cord" to the doll's mid-section. Fill one unused blue exam glove 1/4 of the way with tap water and tie tight. This will represent the placenta. Glue the other end of the "umbilical cord" to the knot of the "placenta." c. Place the doll, "cord," and "placenta" within the ball. You can glue the "placenta" in place to simulate placenta accreta or leave unglued for easy removal. Glue the opening of the "placenta" so that the funnel can just fit in. Using the funnel, fill the "uterus" with gelatin mixture (amniotic fluid) so that the ball is full/distended, but not overflowing. Carefully remove the funnel and glue the remainder of the "uterine" opening shut. Place in the refrigerator overnight to set.