Compared to parametric tests, non parametric tests are seen to be less powerful as they often contend with fewer assumptions, and may use less information from the data. Sample sizes can be smaller. The samples do not have to follow a normal distribution as in parametric tests, and data may be ordinal, ranked or contain outliers that cannot be removed. Therefore nonparametric tests are well suited for these instances and do not need to be used as a last resort. They are not any more complex than parametric tests.

The level of statistical significance is often expressed as a p-value between 0 and 1. The smaller the p-value, the stronger the evidence that you should reject the null hypothesis.A p-value less than 0.05 (typically ≤ 0.05) is statistically significant. It indicates strong evidence against the null hypothesis, as there is less than a 5% probability the null is correct (and the results are random). Therefore, we reject the null hypothesis, and accept the alternative hypothesis.However, this does not mean that there is a 95% probability that the research hypothesis is true. The p-value is conditional upon the null hypothesis being true is unrelated to the truth or falsity of the research hypothesis.A lower p-value is sometimes interpreted as meaning there is a stronger relationship between two variables. However, statistical significance means that it is unlikely that the null hypothesis is true (less than 5%).To understand the strength of the difference between two groups (control vs. experimental) a researcher needs to calculate the effect size.

A periosteal reaction can result from a large number of causes, including injury and chronic irritation due to a medical condition such as hypertrophic osteopathy, bone healing in response to fracture, chronic stress injuries, subperiosteal hematomas, osteomyelitis, and cancer of the bone. This history is consistent with a toddler’s fracture. Here a minor, usually twisting, injury results in a spiral fracture of the tibia. An initial X-ray may appear normal as the periosteum holds the bone together preventing displacement. Ten days later a repeat X-ray will show callous formation and confirm the diagnosis.

Myelomeningocele is the most common type of open neural tube defect and a serious central nervous system disorder associated with significant morbidity. It is also called open spina bifida since the dura, and arachnoid matter herniates through the defect in the vertebral column. The commonest association is the decreased folate levels during early pregnancy. The alpha-fetoprotein levels are raised in the amniotic fluid. CSF leak is a common presentation with associated macrocephaly and hydrocephaly. Prenatal surgical repair is linked to a better prognosis.

The median nerve is a peripheral nerve originating in the cervical roots C5–T1 of the brachial plexus. It supplies motor innervation to the anterior forearm flexors, the thenar muscles, and the two lateral lumbricals as well as sensory innervation to the lateral palm and anterior, lateral three and a half fingers. Motor and sensory deficits depend on whether the lesion is proximal (above the elbow) or distal (below the elbow). While proximal lesions present with the “hand of benediction,” distal lesions present with either the “pinch sign” (anterior interosseous nerve syndrome) or, in the case of carpal tunnel syndrome, with mildly impaired thumb and index finger motion. Both proximal lesions and carpal tunnel syndrome result in reduced sensation in the area of the thumb, index and middle finger. Anterior interosseus nerve syndrome does not cause any sensory deficits. Chronic injuries to the nerve result in atrophy of median nerve innervated muscles while acute injuries do not have this feature. Treatment is mostly conservative and focuses on rest and immobilization.

In the pattern of mendelian inheritance, X- linked dominant inheritance means that all who inherit the X chromosome will present with the condition. In the case of maternal x-linked inheritance sons and daughters have an equal chance of inheriting the condition as there is a 50% chance of inheriting the defective X chromosome from their mother as opposed to a non affected X chromosome from their father. However in paternal X-linked dominant inheritance, sons will be unaffected as they inherit a Y chromosome from their father while daughters are sure to inherit the defective X-chromosome.

While the clinical scenario and the anosmic presentation of the child are highly suggestive of Kallmann’s syndrome, reduced testosterone, FSH and LH levels can confirm the diagnosis.Kallman’s syndrome is a recognised cause of delayed puberty secondary to hypogonadotropic hypogonadism. It is usually inherited as an X-linked recessive trait. Kallman’s syndrome is thought to be caused by a failure of GnRH-secreting neurons to migrate to the hypothalamus.Clinical features of Kallmann’s syndrome include:- Delayed puberty- Hypogonadism, cryptorchidism- Anosmia- Low sex hormone levels – Inappropriately low/normal LH and FSH levels- Some patients can present with associated cleft lip/palate and visual/hearing defects.

Normal QT interval in a 6 months old baby is < 0.44 seconds. A duration exceeding this value is referred to as QT interval prolongation, which is associated with some important congenital syndromes that include Brugada syndrome which is characterized by vasovagal syncope and sudden cardiac death, Jervell and Lange-Nielsen syndrome which is associated with congenital deafness, Andersen syndrome which is marked by bone deformities, and Timothy syndrome with associated heart disease and immunodeficiency. Romano-Ward syndrome is the commonest cause of congenital QT prolongation with no associated extra-cardiac manifestations. Lown-Ganong-Levine syndrome is characterized by a shortened PR interval and a normal QRS duration.

A bone age study helps doctors estimate the maturity of a child’s skeletal system. It’s usually done by taking a single X-ray of the left wrist, hand, and fingers. It is a safe and painless procedure that uses a small amount of radiation. The bones on the X-ray image are compared with X-rays images in a standard atlas of bone development, which is based on data from large numbers of other kids of the same gender and age. The bone age is measured in years.

In nephrotic syndrome, one of the main pathological processes is the excretion of protein by the kidneys. The resultant signs including| low serum albumin, oedema and hypovolemia all occur as a result of fluid escaping into the extracellular space due to a low oncotic pressure. While an albumin infusion may help to increase oncotic pressure, its indications specifically include hypovolemia, which is assessed by a capillary refill time more than 5 seconds, an elevated haematocrit, or severe symptomatic oedema, such as scrotal oedema. Hypertension not an indication for an infusion, and most patients needing an albumin infusion have oliguria.

Unless given IV, a drug must cross several semipermeable cell membranes before it reaches the systemic circulation. Drugs may cross cell membranes by diffusion, amongst other mechanisms. The rate of diffusion of a substance is proportional to the difference in the concentration of the diffusing substance between the two sides of the membrane, the temperature of the solution, the permeability of the membrane and, in the case of ions, the electrical potential difference between the two sides of the membrane.

Findings described are suggestive of Waterhouse-Friderichsen syndrome which develops secondary to meningococcaemia. The reported incidence of Addison’s disease is 4 in 100,000. It affects both sexes equally and is seen in all age groups. It tends to show clinical symptoms at the time of metabolic stress or trauma. The symptoms are precipitated by acute infections, trauma, surgery or sodium loss due to excessive perspiration.

Answer: Congenital diaphragmatic herniaCongenital diaphragmatic hernia (CDH) occurs when the diaphragm muscle — the muscle that separates the chest from the abdomen — fails to close during prenatal development, and the contents from the abdomen (stomach, intestines and/or liver) migrate into the chest through this hole.Examination in infants with congenital diaphragmatic hernias include the following findings:Scaphoid abdomenBarrel-shaped chestRespiratory distress (retractions, cyanosis, grunting respirations)In left-sided posterolateral hernia: Poor air entry on the left, with a shift of cardiac sounds over the right chest| in patients with severe defects, signs of pneumothorax (poor air entry, poor perfusion) may also be foundAssociated anomalies: Dysmorphisms such as craniofacial abnormalities, extremity abnormalities, or spinal dysraphism may suggest syndromic congenital diaphragmatic herniaIleal atresia is a congenital abnormality where there is significant stenosis or complete absence of a portion of the ileum. There is an increased incidence in those with chromosomal abnormalities. Ileal atresia results from a vascular accident in utero that leads to decreased intestinal perfusion and subsequent ischemia a segment of bowel. This leads to narrowing, or in the most severe cases, complete obliteration of the intestinal lumen. In the postnatal period, an abdominal radiograph will show air in the dilated loops of proximal bowel. An ileal atresia is often discovered prenatally at a routine prenatal ultrasound scan or following the development of polyhydramnios. On ultrasound, there is frequently a proximal dilated intestinal segment.Meconium Ileus (MI) is a condition where the content of the baby’s bowel (meconium) is extremely sticky and causes the bowel to be blocked at birth. In most cases the bowel itself is complete and intact but it is just the inside that is blocked.In some cases there has been a twist of the bowel before birth, which has caused the bowel to be blind ending (an atresia). Most babies with meconium ileus (90%) have Cystic Fibrosis (CF) and it is this that has caused the sticky meconium. Meconium ileus is a rare condition affecting only 1 in 25,000 babies. There is normally a delay in your baby passing meconium (black sticky stool normally passed within 24 hours of delivery) and your baby may also be reluctant to feed and may vomit a green fluid called bile which would normally pass through the bowel.Your baby may be uncomfortable because of constipation and trapped air in the bowel and the abdomen (tummy) will become distended. Some babies present at delivery with a distended abdomen and may be unwell due to infection around the bowel.Pyloric stenosis is a problem that affects babies between birth and 6 months of age and causes forceful vomiting that can lead to dehydration. It is the second most common problem requiring surgery in new-borns. The lower portion of the stomach that connects to the small intestine is known as the pylorus. In pyloric stenosis, the muscles in this part of the stomach enlarge, narrowing the opening of the pylorus and eventually preventing food from moving from the stomach to the intestine.

One of the most common congenital viral infections is cytomegalovirus infection. It is caused by herpesvirus type 5. The clinical features include failure to thrive, intellectual disability, epilepsy, and microcephaly. The most common clinical complication is sensorineural deafness. The drug of choice for the treatment of neonatal CMV infection is ganciclovir, an anti-viral drug that has shown to prevent deafness.

It is recommended that a woman wait one month after stopping isotretinoin before trying to become pregnant. Usually, isotretinoin is no longer found in a woman’s blood 4-5 days after the last dose and most of its by-products should be gone within 10 days after the last dose.

Anorexia nervosa is a serious, psychiatric eating disorder characterized by distorted self-image due to which abnormal eating behaviours are adopted. This disorder affects multiple bodily systems, including the gastrointestinal system. The GI manifestations of anorexia are enlarged salivary glands due to purging behaviour, gastritis, gastroparesis, acute gastric dilatation, superior mesenteric artery syndrome, elevated liver transaminases, which cause hepatocyte apoptosis leading to cirrhosis, and steatosis leading to fatty liver. Hepatosplenomegaly is not a recognized complication of anorexia nervosa.

Breast milk jaundice is associated with breast-feeding. It typically occurs one week after birth and can sometimes last up to 12 weeks, but it rarely causes complications in healthy, breast-fed infants. The exact cause of breast milk jaundice isn’t known. However, it may be linked to a substance in the breast milk that prevents certain proteins in the infant’s liver from breaking down bilirubin. The condition may also run in families. Breast milk jaundice is rare, affecting less than 3 percent of infants. When it does occur, it usually doesn’t cause any problems and eventually goes away on its own. It is safe to continue breast-feeding.

Ehlers-Danlos Syndrome (EDS) is a group of genetic connective tissue disorders with over 13 clinical subtypes. Hyper-mobility is common to many of these subtypes. Vascular EDS is identified by thin, translucent skin prone to easy bleeding, as well as the risk of early arterial rupture, gastrointestinal perforation and uterine rupture. Those affected have dysmorphic features including a thin nose and lips, sunken cheeks and large eyes. The other features including| atrophic scars, a dominant family history, hyper extensible skin and kyphoscoliosis are not specific to vascular EDS and overlap in many of the subtypes.

At the age of 6 months, children can begin to be weaned off breastmilk and formula feeds. One healthy and inexpensive way to do this is through infant led weaning as opposed to the conventional spoon feeding method. Children are able to enjoy a variety of soft finger foods even before they grow teeth, so all food does not need to be pureed or sweet. Children should however not be given cow’s milk until the age of 1 year.

Fitz-Hugh-Curtis syndrome (FHCS), or perihepatitis, is a chronic manifestation of pelvic inflammatory disease (PID). It is described as an inflammation of the liver capsule, without the involvement of the liver parenchyma, with adhesion formation accompanied by right upper quadrant pain. A final diagnosis can be made through laparoscopy or laparotomy via direct visualization of violin string-like adhesions or through hepatic capsular biopsy and culture. FHCS is a complication of PID. Microorganisms associated with PID are thought to spread in one of three ways:-Through spontaneous ascending infection, microbes from the cervix or vagina travel to the endometrium, through the fallopian tubes, and into the peritoneal cavity. Complications include endometritis, salpingitis, tubo-ovarian abscess, pelvic peritonitis, and perihepatitis.-Microbes can also spread via lymphatic channels such as an infection of the parametrium from an intrauterine device.-Finally, the hematogenous spread is also possible such as with tuberculosis.

The embryonic period comprises of the first 8 weeks of pregnancy. It is divided into a preembryonic phase (from the 1st to the 3rd week), in which the three germinal layers arise, and into the embryonic phase proper (from the 4th to 8th week), in which the embryonic organ anlagen arise.

Hyperkalaemia presents with high voltage (peaked) T waves on ECG. Other features on ECG include smaller p-waves and wider QRS complexes.

Identify babies as being more likely to develop significant hyperbilirubinemia if they have any of the following factors:- gestational age under 38 weeks- a previous sibling with neonatal jaundice requiring phototherapy- mother’s intention to breastfeed exclusively- visible jaundice in the first 24 hours of life.

Among the options provided, the most characteristic finding that can be expected in his patient’s urine microscopy is RBC casts. Red cell casts are a characteristic feature of acute nephrotic syndrome. Other options:- Hyaline casts may be seen in normal urine, particularly after exercise. – Coarse granular casts occur in glomerular and tubular disease. – Tubular cell casts may be seen in patients with acute tubular necrosis. – The presence of 10 or more white blood cells/mm3 is abnormal and indicates an inflammatory reaction, most commonly due to infection.

Transposition of the great arteries (TGA) is a common congenital heart lesion that presents with severe cyanosis that is likely to appear in the first day of life.

Maternal smoking is one of the most significant risk factors for pyloric stenosis.Remember the three Ps for Pyloric Stenosis:P – palpable massP – peristalsisP – projectile vomiting

ABC : Airway, breathing, circulation is the order of assessment in any patient that is unconscious and apnoeic.

The baby needs more oxygen saturation which could be attempted by increasing the mean airway pressureAfter initial resuscitation and stabilization, the following should be the ventilator settings used:Rate: 30-40/minutePeak inspiratory pressure (PIP) – determined by adequate chest wall movement.An infant weighing less than 1500 grams: 16-28 cm H2O.An infant weighing greater than 1500 grams: 20-30 cm H2O. Positive end expiratory pressure (PEEP): 4 cm of H2O OR 5-6 cm if FiO2 > 0.90.FiO2: 0.4 to 1.0, depending on the clinical situation.Inspiratory time: 0.3-0.5 sec.After 15 to 30 minutes, check arterial blood gases and pH.If the PaO2 or the O2 saturation is below accepted standards, the FiO2 can be raised to a maximum of 1.0. If the PaO2 or O2 saturation is still inadequate, the mean airway pressure can be raised by increasing either the PIP, PEEP, inspiratory time or the rate, leaving inspiratory time constant.If the PaCO2 is elevated, the rate or peak inspiratory pressure can be raised.

In pyloric stenosis a new-born baby presents with a history of vomiting, constipation and deranged electrolytes. Excessive vomiting leads to hypokalaemia. Difficulty in food passing from the stomach to the small intestine causes constipation. Hypokalaemia also causes constipation. None of the other disorders mentioned present with the hypokalaemia, vomiting and constipation triad in a new-born.

The most probable diagnosis for this patient would be torsion of a hydatid cyst of the testis.Note:The differential diagnoses in acute testicular pain/swelling are listed in the possible answers. Testicular torsion typically affects adolescent males and presents with acute painful swelling and a horizontally lying testicle. Other options:- Epididymo-orchitis is diagnosed during surgery when a thickened erythematous epididymis is noted. Ectopic ureteric insertion into the vas must be excluded by ultrasound scan on an out-patient basis. The hydatid cyst or cyst of Morgagni represents the remnants of the Mullerian structure. In the pre-pubertal child, a surge in hormones can stimulate growth and chance of torsion. It is diagnosed by surgical exploration or by a blue dot sign. Idiopathic scrotal oedema tends to be within the scrotum itself, and the testis can be examined in the groin to exclude pain in the testis. All acute scrotal pain must be explored to exclude testicular torsion unless a surgical registrar is convinced of a torted hydatid cyst.- An 8-year-old is more likely to present with a torted hydatid cyst. The blue dot sign is diagnostic and can negate the need for surgical exploration. The age of the child also makes epididymo-orchitis less likely.- Idiopathic scrotal oedema presents with an erythematous and thickened scrotum. This can cross the midline and involve the whole scrotum.- Finally, an inguinal hernia would present with a mass in the groin extending to the scrotum that you cannot get above.