Saving preemies

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Premature births and the resulting complications are some of the most common health problems in newborns. If a baby is born before the end of the 37th week of pregnancy, its organs are not fully adapted to life outside the womb. This causes a series of problems connected with breathing, feeding, and maintaining body temperature.

Premature babies also often have problems with the cardiovascular system. Blood perfusion is vital for the proper functioning of every organ and system, so decreased arterial blood pressure may cause damage to the kidneys, bowels, and brain. Complications involving these organs may influence the future life of the child, resulting in permanent damage and, in the most severe cases, even in death.

Target: cardiovascular system

Evaluating the functioning of the cardiovascular system is an essential part of treating the smallest patients in newborn care units. Evaluation is based on simple elements of a medical examination: assessing skin colour, measuring heart rate, and analyzing indications of monitoring devices (cardiac monitors and pulse oximeters – equipment that monitors, respectively, heart activity and blood oxygenation). The most accurate insight into the operation of the cardiovascular system is provided by echocardiography. This test enables us to examine – in a non-invasive way, without penetrating the child's body –the heart's anatomy and to exclude the presence of congenital defects that may lead to severe blood circulation disorders. Moreover, the test enables us to assess the filling of the heart with blood and to evaluate the contractility of the heart muscle. These two elements determine the amount of blood pumped by the heart to the arteries in the body. Additionally, ultrasonographic examination of organs such as the kidneys, the bowels, and the brain enables us to determine the velocity of blood flow through arteries that supply blood. By evaluating the rate of blood flow, we are able to estimate the perfusion of these organs.

Although echocardiography and ultrasonography have been used for many years, critical blood flow parameters (i.e., parameters that are very likely to lead to ischemia of the organs and severe, long-term complications if exceeded) have yet to be determined. This refers not only to the values characterizing the blood flow determined in the echocardiogram, but also to such simple parameters as arterial blood pressure. The estimation of threshold values of blood flow parameters would enable us to recognize the threat of ischemia early and to introduce appropriate treatment before permanent complications occur.

Preemie with a birth weight of 360 g, photo: archives of Piotr Kruczek,
published with consent of the child's legal guardians

Critical values

The Neonatal Intensive Care Unit of the Children's Hospital of the Jagiellonian University Medical College is a third-degree care reference center, which means that it employs personnel and equipment qualified to provide the highest level of care for the sickest children. Approximately 450 newborns transported from hospitals in southeastern Poland are hospitalized here annually. About one-third of them are babies born prematurely. Cardiovascular function disorders have been the subject of research conducted at the clinic for many years. The unit has two modern ultrasonographs available around the clock. All specialists working at the unit perform ultrasonograms and cardiac echo tests.

Since January 2013, a comprehensive observation-based study has been conducted at the unit, involving the determination of blood flow parameters and their critical values most likely to result in severe medical complications if exceeded. The study involves children born before the 33rd week of pregnancy and with a birth weight below 1500 grams. Ultrasonogram tests, which evaluate blood flow in the main blood vessels of the body and in the arteries supplying blood to the kidneys, bowels and brain, are performed in the 1st, 2nd, 3rd, 5th, 7th, 10th, 14th, 21st and 28th days of life. While such tests are an element of routine care of prematurely born infants, performing them at precise time intervals, pursuant to a pre-determined protocol, enables us to collect reliable information of a scientific value. "The study currently involves sixty children, and we are planning to increase this number to a hundred newborns. The obtained results will be confronted with the complications occurring in individual patients. The application of statistical analysis methods and innovative mathematical techniques will allow us to determine the most important parameters characterizing the blood flow and their critical values," explains Piotr Kruczek, MD, research coordinator.

Together with the head researcher, Piotr Szymański, MD, they hope that the conducted works will allow for a better understanding of the role of cardiovascular disorders in causing prematurity-related complications and that the results will enable guidelines for treatment of prematurely born babies to be developed.

Research team: Piotr Kruczek, MD, PhD; Piotr Szymański, MD; Professor Andrzej Rudziński