Health Awareness blog

Inguinal hernia is a protrusion of abdominal cavity into the inguinal canal. It has a very close relation with premature infants and affecting up to 25% of male infants. Overall incidence is more common in male rather than female gender. Previous study showed that the testicles only descent into the scrotum after 32 completed week gestation follows by the contraction of the processus vaginalis at the inguinal canal. As addition, studies revealed that premature infants having IH were more likely to have had lower gestational age, lower birth weight and required prolonged ventilator assistance.

There are 2 types of inguinal hernia; first is indirect inguinal hernia and second is direct inguinal hernia. Indirect inguinal hernias are congenital hernias. It is more common in males due to the way they develop in the womb. In male fetus, the spermatic cord and both testicles usually descend from intra abdominal cavity into the scrotum through inguinal canal. The entrance of the inguinal canal at the inguinal ring should close just after birth. However, it may not happen sometimes, particularly in premature infant. This will lead to abdominal weakness and allow fat or part of the small intestine slides through into the inguinal canal causing a hernia. The different in females is the indirect inguinal hernia is caused by the female organs or the small intestine sliding into the groin through a weakness in the abdominal wall. There is no canal involve.

Meanwhile, direct inguinal hernia is caused by connective tissue degeneration of the abdominal muscles which weaken during adulthood. It develops gradually because of the continuous stress of the muscles. Direct inguinal hernias can only occur in males. These hernias usually slide back and forth spontaneously and can often be reduced back into the abdomen with gentle massage.

The symptoms of inguinal hernia include a small bulge in one or both sides of the groin that may increase in size and disappear when lying down. Males can present as a swollen or enlarged scrotum. There is often associated with discomfort or sharp pain especially during straining, lifting, or exercising that usually improves when resting. In premature infant, it is mainly the clinical examination as the baby cannot obviously complain any pain. Excessive cry may suggest pain. The hernia may become incarcerated or strangulated. Incarcerated means the hernia cannot be reduce back to abdominal cavity and may later lead to strangulated hernia that require emergency operation. If surgery is not performed right away, the condition can become life threatening. The affected intestine may die and need resection. These two complications are rarely seen in infants.

In term of treatment, inguinal hernia is usually surgically managed. The operation mainly divided by two; open surgery or laparascopy. For adult, the surgeon will do herniorraphy or hernioplasty while in infancy they will do herniotomy. Traditionally in herniorraphy, the weak spot in the muscle wall will be repaired by sewing the edges of the healthy muscle tissue together. Today, a mesh patch (or patches) of synthetic material are now widely use. It will be sewn over the weakened area in the abdominal wall after the hernia is reduced back in the abdominal cavity, hence we get the term ‘hernioplasty’. In herniotomy, the patient processus vaginalis will be excised and ligated. Generally, it will be unnecessary to perform formal repair of the abdominal wall.

References:

1. Newell, SJ. and Darling, JC. Lecture notes paediatrics. Eight edition. Singapore: Blackwell Publishing; 2008.

2. Brooker, RW. and Keenan, WJ. Inguinal hernia: relationship to respiratory disease in prematurity. Journal of Pediatric Surgery. 2006 November. 41 (11): 1818-1821.

3. Kumar, VH.S. , Clive, J. and Rosenkratz, TS, Bourque, MD and Hussain, N.. Inguinal hernia in preterm infants, Pediatrics Surg Int, 2002: 147-152.

4. Yeo, CL. and Gray, PH. Inguinal hernia in extremely preterm infants. Journal Paediatrics Child Health, 1994. 30 : 412-413.

5. Simon, C., Everitt, H. and Kendrick, T. Oxford Handbook of General Practice, Second edition, Oxford: Oxford University Press; 2005.

There are a range of complications of prematurity, including respiratory, neurology, and gastroenterology. Respiratory problems mainly arise because the lung is immature. The lung usually matures at 36 weeks gestation and above. This is the main apprehension in dealing with premature baby. Some examples of respiratory complications are respiratory distress syndrome (RDS), transient tacypnoeic of newborn and bronchopulmonary dysplasia (BPD) or sometimes known as chronic lung disease.

RDS is due to lack of surfactant that important to prevent the lung from collapse. Treatment includes oxygen supplement and doses surfactant. In some severe cases, the baby may need endotracheal intubation and ventilator. Transient tacypnoeic is rapid shallow of breathing effort of the infants. Close observation is mandatory. Oxygen supplement is depending on the child condition. Recovery usually occurs within 3 days and no other treatment require. BPD occurs when a baby’s lung have shown evidence of deterioration. Although some preemies need ventilator, some cannot withstand the constant pressure of the ventilator and lead to other problems. Those need to be ventilated for more than 28 days are at risk. BPD will be explained later in the next part.

Sometimes, the preemies (premature infants) might “forget” to breathe and this lead to apnea and bradycardia. Apnea is the absence of breathing for up to 15 seconds, whereas, bradycardia is the reduction of heart rate. Most of the time, only stimulation of touch is require but in severe case, medication like neulin might be needed. Premature infants also could face risk of congenital pneumonia and infection because their immune system is immature. The child will be put in incubator to keep warm and reduce the potential of infection. In congenital pneumonia, antibiotics will be given as well as oxygen supplemental and intubation. If left untreated, it may evolve to deadly infection like sepsis and meningitis.

Intraventricular hemorrhage (IVH) in bleeding in the brain can affected baby born at less than 34 weeks. This is due to immature blood vessels that sometimes cannot tolerate the changes in circulation that take place during labour process. This may lead to future complications like cerebral palsy, mental retardation and learning difficulties. According to American Pregnancy Association, Intracranial hemorrhage affects about 33.3% of baby born between 24 – 26 weeks gestation. It is estimated that some degree of hemorrhage occurs in 40% of very small babies although it only cause damage in minority of cases.

Gastroenterology problem also commonly affected premature infants. Immature gastrointestinal and digestive system prevent them to absorb nutrients safely. Total parenteral nutrition (TPN) is indicated in severe case. In few cases, premature infants also need to be feed through ryles tube initially because they are still not strong enough to swallow or suck on their own. In unfortunate infants, they may develop necrotizing enterocollitis (NEC). This is the infection of the bowel wall. Very early feeding may also lead to NEC. In this case, intravenous feeding and antibiotics are necessary. Rarely, operation is indicated.

Other complication is inguinal hernia that often affects the premature babies’ particularly male gender. This is due to the nature of the growth itself where the testicles only descent into the scrotum after 32 completed week’s gestation follows by the contraction of the processus vaginalis at the inguinal canal. If the baby need ventilator, persistent increase abdominal pressure also may contribute to this problem. As a treatment, the patients need surgical intervention. Further discussion will be done later.

Patent ductus arteriosus (PDA) is a cardiac cause that causes breathing difficulties after delivery. It is most common in the preterm infant. This is due a failure of ductus arteriosus to close. Ductus arteriosus is a blood vessel that connects the aorta with vena cave to allow blood from the heart to bypass the lung when the baby in utero since the baby does not breathe till after delivery. A chemical compound called Prostaglandin E made in circulates in his or her blood to keep the vessel open and the level falls at full term birth to close that vessel. In premature infants, level of prostaglandin E remains high causing the ductus to open, this is one reason why the infants may have murmur after birth. In few cases the PDA will close spontaneously but in some cases indomethacin (inhibitor of prostaglandin synthesis) is indicated. Spontaneous closure occurs up to 3 months after birth. Today, the surgical intervention like open heart surgery or percutaneous interventional method is rarely done.

Retinopathy of prematurity (ROP) is eye disorder that commonly affect premature infants and has potential to cause blindness if no early intervention. It affects preemies between 24-26 gestations and rarely affects those after 33 weeks gestation. More detail discussion will be held later in this report.

Premature babies are also at risk of hypothermia so they usually were kept warm under warmer. Very low birth weight babies will need incubator nursing. They are also at risk for jaundice due to immature liver. The risk of hearing loss is increase with the degree of prematurity. The entire hearing system is still maturing till as late as 26 weeks and vulnerable to injury afterward. Infection and severe jaundice will increase the risk for hearing impairment. This is why early hearing assessment is mandatory because so that early the treatment and intervention can be start promptly. This to ensure family and the affected babies learn important communication skills.

            Anemia is  another complication of premature infants caused by abnormally low concentrations of red blood cells. One important substance is hemoglobin. This is vital as hemoglobin is necessary to carry oxygen in the circulation. Normal count is 15 grams per litre blood. Blood transfusion is indicated in severe case.

Now we know that there are wide ranges of the complications of premature birth, from head to toe. Prevention is always better than cure. As conclusion, do avoid any possible causes like smoking and infections that might lead to preterm birth.

References:

1.      American Pregnancy Association complications. Premature birth complications.  Available online http://www.americanpregnancy.org/labornbirth/complicationspremature.htm. 2007.

2.      Newell, S.J. and Darling, J.C.Lecture notes paediatrics. Eight edition. Singapore. Blackwell Publishin; 2008.

3.      Brooker, R.W. and Keenan, W.J. Inguinal hernia: relationship to respiratory disease in prematurity. Journal of Pediatric Surgery.2006, November.Vol. 41, issue 11. 1818-1821.