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Treatment of infants suffering birth asphyxia by lowering the core body temperature is now known to be an effective therapy to reduce mortality and improve neurological outcome in survivors, and hypothermia therapy for neonatal encephalopathy begun within 6 hours of birth significantly increases the chance of normal survival in affected infants.
There has long been a debate over whether newborn infants with birth asphyxia should be resuscitated with 100% oxygen or normal air. It has been demonstrated that high concentrations of oxygen lead to generation of oxygen free radicals, which have a role in reperfusion injury after asphyxia. Research by Ola Didrik Saugstad and others led to new international guidelines on newborn resuscitation in 2010, recommending the use of normal air instead of 100% oxygen.
In the United States, intrauterine hypoxia and birth asphyxia were listed together as the tenth leading cause of neonatal death.
Perinatal asphyxia, neonatal asphyxia or birth asphyxia is the medical condition resulting from deprivation of oxygen to a newborn infant that lasts long enough during the birth process to cause physical harm, usually to the brain. Hypoxic damage can occur to most of the infant's organs (heart, lungs, liver, gut, kidneys), but brain damage is of most concern and perhaps the least likely to quickly or completely heal. In more pronounced cases, an infant will survive, but with damage to the brain manifested as either mental, such as developmental delay or intellectual disability, or physical, such as spasticity.
It results most commonly from a drop in maternal blood pressure or some other substantial interference with blood flow to the infant's brain during delivery. This can occur due to inadequate circulation or perfusion, impaired respiratory effort, or inadequate ventilation. Perinatal asphyxia happens in 2 to 10 per 1000 newborns that are born at term, and more for those that are born prematurely. WHO estimates that 4 million neonatal deaths occur yearly due to birth asphyxia, representing 38% of deaths of children under 5 years of age.
Perinatal asphyxia can be the cause of hypoxic ischemic encephalopathy or intraventricular hemorrhage, especially in preterm births. An infant suffering severe perinatal asphyxia usually has poor color (cyanosis), perfusion, responsiveness, muscle tone, and respiratory effort, as reflected in a low 5 minute Apgar score. Extreme degrees of asphyxia can cause cardiac arrest and death. If resuscitation is successful, the infant is usually transferred to a neonatal intensive care unit.
There has long been a scientific debate over whether newborn infants with asphyxia should be resuscitated with 100% oxygen or normal air. It has been demonstrated that high concentrations of oxygen lead to generation of oxygen free radicals, which have a role in reperfusion injury after asphyxia. Research by Ola Didrik Saugstad and others led to new international guidelines on newborn resuscitation in 2010, recommending the use of normal air instead of 100% oxygen.
There is considerable controversy over the diagnosis of birth asphyxia due to medicolegal reasons. Because of its lack of precision, the term is eschewed in modern obstetrics.
A 2008 bulletin from the World Health Organization estimates that 900,000 total infants die each year from birth asphyxia, making it a leading cause of death for newborns.
In the United States, intrauterine hypoxia and birth asphyxia was listed as the tenth leading cause of neonatal death.
Perinatal asphyxia is the medical condition resulting from deprivation of oxygen (hypoxia) to a newborn infant long enough to cause apparent harm. It results most commonly from a drop in maternal blood pressure or interference during delivery with blood flow to the infant's brain. This can occur as a result of inadequate circulation or perfusion, impaired respiratory effort, or inadequate ventilation. There has long been a scientific debate over whether newborn infants with asphyxia should be resuscitated with 100% oxygen or normal air. It has been demonstrated that high concentrations of oxygen lead to generation of oxygen free radicals, which have a role in reperfusion injury after asphyxia. Research by Ola Didrik Saugstad and others led to new international guidelines on newborn resuscitation in 2010, recommending the use of normal air instead of 100% oxygen.
For newborn infants starved of oxygen during birth there is now evidence that hypothermia therapy for neonatal encephalopathy applied within 6 hours of cerebral hypoxia effectively improves survival and neurological outcome. In adults, however, the evidence is less convincing and the first goal of treatment is to restore oxygen to the brain. The method of restoration depends on the cause of the hypoxia. For mild-to-moderate cases of hypoxia, removal of the cause of hypoxia may be sufficient. Inhaled oxygen may also be provided. In severe cases treatment may also involve life support and damage control measures.
A deep coma will interfere with body's breathing reflexes even after the initial cause of hypoxia has been dealt with; mechanical ventilation may be required. Additionally, severe cerebral hypoxia causes an elevated heart rate, and in extreme cases the heart may tire and stop pumping. CPR, defibrilation, epinephrine, and atropine may all be tried in an effort to get the heart to resume pumping. Severe cerebral hypoxia can also cause seizures, which put the patient at risk of self-injury, and various anti-convulsant drugs may need to be administered before treatment.
There has long been a debate over whether newborn infants with cerebral hypoxia should be resuscitated with 100% oxygen or normal air. It has been demonstrated that high concentrations of oxygen lead to generation of oxygen free radicals, which have a role in reperfusion injury after asphyxia. Research by Ola Didrik Saugstad and others led to new international guidelines on newborn resuscitation in 2010, recommending the use of normal air instead of 100% oxygen.
Brain damage can occur both during and after oxygen deprivation. During oxygen deprivation, cells die due to an increasing acidity in the brain tissue (acidosis). Additionally, during the period of oxygen deprivation, materials that can easily create free radicals build up. When oxygen enters the tissue these materials interact with oxygen to create high levels of oxidants. Oxidants interfere with the normal brain chemistry and cause further damage (this is known as "reperfusion injury").
Techniques for preventing damage to brain cells are an area of ongoing research. Hypothermia therapy for neonatal encephalopathy is the only evidence-supported therapy, but antioxidant drugs, control of blood glucose levels, and hemodilution (thinning of the blood) coupled with drug-induced hypertension are some treatment techniques currently under investigation. Hyperbaric oxygen therapy is being evaluated with the reduction in total and myocardial creatine phosphokinase levels showing a possible reduction in the overall systemic inflammatory process.
In severe cases it is extremely important to act quickly. Brain cells are very sensitive to reduced oxygen levels. Once deprived of oxygen they will begin to die off within five minutes.
In the past, treatment options were limited to supportive medical therapy. Nowadays neonatal encephalopathy is treated using hypothermia therapy.
To counter the effects of high-altitude diseases, the body must return arterial p toward normal. Acclimatization, the means by which the body adapts to higher altitudes, only partially restores p to standard levels. Hyperventilation, the body’s most common response to high-altitude conditions, increases alveolar p by raising the depth and rate of breathing. However, while p does improve with hyperventilation, it does not return to normal. Studies of miners and astronomers working at 3000 meters and above show improved alveolar p with full acclimatization, yet the p level remains equal to or even below the threshold for continuous oxygen therapy for patients with chronic obstructive pulmonary disease (COPD). In addition, there are complications involved with acclimatization. Polycythemia, in which the body increases the number of red blood cells in circulation, thickens the blood, raising the danger that the heart can’t pump it.
In high-altitude conditions, only oxygen enrichment can counteract the effects of hypoxia. By increasing the concentration of oxygen in the air, the effects of lower barometric pressure are countered and the level of arterial p is restored toward normal capacity. A small amount of supplemental oxygen reduces the equivalent altitude in climate-controlled rooms. At 4000 m, raising the oxygen concentration level by 5 percent via an oxygen concentrator and an existing ventilation system provides an altitude equivalent of 3000 m, which is much more tolerable for the increasing number of low-landers who work in high altitude. In a study of astronomers working in Chile at 5050 m, oxygen concentrators increased the level of oxygen concentration by almost 30 percent (that is, from 21 percent to 27 percent). This resulted in increased worker productivity, less fatigue, and improved sleep.
Oxygen concentrators are uniquely suited for this purpose. They require little maintenance and electricity, provide a constant source of oxygen, and eliminate the expensive, and often dangerous, task of transporting oxygen cylinders to remote areas. Offices and housing already have climate-controlled rooms, in which temperature and humidity are kept at a constant level. Oxygen can be added to this system easily and relatively cheaply.
A prescription renewal for home oxygen following hospitalization requires an assessment of the patient for ongoing hypoxemia.
The mortality rate of meconium-stained infants is considerably higher than that of non-stained infants; meconium aspiration used to account for a significant proportion of neonatal deaths. Residual lung problems are rare but include symptomatic cough, wheezing, and persistent hyperinflation for up to five to ten years. The ultimate prognosis depends on the extent of CNS injury from asphyxia and the presence of associated problems such as pulmonary hypertension. Fifty percent of newborns affected by meconium aspiration would die fifteen years ago; however, today the percent has dropped to about twenty.
HIE is a major predictor of neurodevelopmental disability in term infants. 25 percent have permanent neurological deficits.
It can result in developmental delay or periventricular leukomalacia.
Compressive asphyxia (also called chest compression) is mechanically limiting expansion of the lungs by compressing the torso, hence interfering with breathing. Compressive asphyxia occurs when the chest or abdomen is compressed posteriorly. In accidents, the term traumatic asphyxia or crush asphyxia usually refers to compressive asphyxia resulting from being crushed or pinned under a large weight or force. An example of traumatic asphyxia includes cases where an individual has been using a car-jack to repair a car from below, and is crushed under the weight of the vehicle. Pythons, anacondas, and other constrictor snakes kill through compressive asphyxia. In cases of co-sleeping ("overlay"), the weight of an adult or large child may compress an infant's chest, preventing proper expansion of the chest. Risk factors include large or obese adults, parental fatigue or impairment (sedation by drugs or alcohol) of the co-sleeping adult and a small shared sleeping space (for example, both adult and infant sharing a couch).
In fatal crowd disasters, compressive asphyxia from being crushed against the crowd causes the large part of the deaths, rather than blunt trauma from trampling. This is what occurred at the Ibrox disaster in 1971, where 66 Rangers fans died; the 1979 The Who concert disaster where 11 died; the Luzhniki disaster in 1982, when 66 FC Spartak Moscow fans died; and at the Hillsborough disaster in 1989, when 96 Liverpool fans were crushed to death in an overcrowded terrace. In confined spaces, people push and lean against each other; evidence from bent steel railings in several fatal crowd accidents have shown horizontal forces over 4500 N (equivalent to a weight of approximately 450 kg, or 1014 lbs). In cases where people have stacked up on each other forming a human pile, estimations have been made of around 380 kg (838 lbs) of compressive weight in the lowest layer.
"Positional" or "restraint" asphyxia is when a person is restrained and left alone prone, such as in a police vehicle, and is unable to reposition himself or herself in order to breathe. The death can be in the vehicle, or following loss of consciousness to be followed by death while in a coma, having presented with anoxic brain damage. The asphyxia can be caused by facial compression, neck compression, or chest compression. This occurs mostly during restraint and handcuffing situations by law enforcement, including psychiatric incidents. The weight of the restraint(s) doing the compression may contribute to what is attributed to positional asphyxia. Therefore, passive deaths following custody restraint that are presumed to be the result of positional asphyxia may actually be examples of asphyxia occurring during the restraint process.
Chest compression is also featured in various grappling combat sports, where it is sometimes called wringing. Such techniques are used either to tire the opponent or as complementary or distractive moves in combination with pinning holds, or sometimes even as submission holds. Examples of chest compression include the knee-on-stomach position; or techniques such as leg scissors (also referred to as body scissors and in budō referred to as "do-jime"; 胴絞, "trunk strangle" or "body triangle") where a participant wraps his or her legs around the opponent's midsection and squeezes them together.
Pressing is a form of torture or execution that works through asphyxia e.g. burking.
MAS is difficult to prevent. Amnioinfusion, a method of thinning thick meconium that has passed into the amniotic fluid through pumping of sterile fluid into the amniotic fluid, has not shown a benefit.
Mild and moderate cerebral hypoxia generally has no impact beyond the episode of hypoxia; on the other hand, the outcome of severe cerebral hypoxia will depend on the success of damage control, amount of brain tissue deprived of oxygen, and the speed with which oxygen was restored.
If cerebral hypoxia was localized to a specific part of the brain, brain damage will be localized to that region. A general consequence may be epilepsy. The long-term effects will depend on the purpose of that portion of the brain. Damage to the Broca's area and the Wernicke's area of the brain (left side) typically causes problems with speech and language. Damage to the right side of the brain may interfere with the ability to express emotions or interpret what one sees. Damage on either side can cause paralysis of the opposite side of the body.
The effects of certain kinds of severe generalized hypoxias may take time to develop. For example, the long-term effects of serious carbon monoxide poisoning usually may take several weeks to appear. Recent research suggests this may be due to an autoimmune response caused by carbon monoxide-induced changes in the myelin sheath surrounding neurons.
If hypoxia results in coma, the length of unconsciousness is often indicative of long-term damage. In some cases coma can give the brain an opportunity to heal and regenerate, but, in general, the longer a coma, the greater the likelihood that the person will remain in a vegetative state until death. Even if the patient wakes up, brain damage is likely to be significant enough to prevent a return to normal functioning.
Long-term comas can have a significant impact on a patient's families. Families of coma victims often have idealized images of the outcome based on Hollywood movie depictions of coma. Adjusting to the realities of ventilators, feeding tubes, bedsores, and muscle wasting may be difficult. Treatment decision often involve complex ethical choices and can strain family dynamics.
Healthy eating can be instituted at any stage of the pregnancy including nutritional adjustments, use of vitamin supplements, and smoking cessation. Calcium supplementation in women who have low dietary calcium reduces the number of negative outcomes including preterm birth, pre-eclampsia, and maternal death. The World Health Organization (WHO) suggests 1.5-2 g of calcium supplements daily, for pregnant women who have low levels calcium in their diet. Supplemental intake of C and E vitamins have not been found to reduce preterm birth rates. Different strategies are used in the administration of prenatal care, and future studies need to determine if the focus can be on screening for high-risk women, or widened support for low-risk women, or to what degree these approaches can be merged. While periodontal infection has been linked with preterm birth, randomized trials have not shown that periodontal care during pregnancy reduces preterm birth rates.
Transient tachypnea of the newborn occurs in approximately 1 in 100 preterm infants and 3.6-5.7 per 1000 term infants. It is most common in infants born by Cesarian section without a trial of labor after 35 weeks' gestation. Male infants and infants with an umbilical cord prolapse or perinatal asphyxia are at higher risk. Parental risk factors include use of pain control or anesthesia during labor, asthma, and diabetes.
Adoption of specific professional policies can immediately reduce risk of preterm birth as the experience in assisted reproduction has shown when the number of embryos during embryo transfer was limited.
Many countries have established specific programs to protect pregnant women from hazardous or night-shift work and to provide them with time for prenatal visits and paid pregnancy-leave. The EUROPOP study showed that preterm birth is not related to type of employment, but to prolonged work (over 42 hours per week) or prolonged standing (over 6 hours per day). Also, night work has been linked to preterm birth. Health policies that take these findings into account can be expected to reduce the rate of preterm birth.
Preconceptional intake of folic acid is recommended to reduce birth defects. There is significant evidence that long-term (> one year) use of folic acid supplement preconceptionally may reduce premature birth. Reducing smoking is expected to benefit pregnant women and their offspring.
Well-designed clinical trials for stroke treatment in neonates are lacking Recent clinical trials show that therapeutic intervention by brain cooling beginning up to 6 hours after perinatal asphyxia reduces cerebral injury and may improve outcome in term infants, indicating cell death is both delayed and preventable
Pancaspase inhibition and Casp3-selective inhibition have been found to be neuroprotective in neonatal rodents with models of neonatal brain injury, which may lead to pharmacological intervention In a study done by Chauvier, "et al.", it is suggested that a Caspase inhibitor, TRP601, is a candidate for neuroprotective strategy in prenatal brain injury conditions. They found a lack of detectable side effects in newborn rodents and dogs. This may be a useful treatment in combination with hypothermia.
MRI has proven valuable for defining brain injury in the neonate, but animal models are still needed to identify causative mechanisms and to develop neuroprotective therapies. In order to model human fetal or neonatal brain injury, one needs a species in which a similar proportion of brain development occurs in utero, the volume of white to grey matter is similar to the human brain, an insult can be delivered at an equivalent stage of development, the physiological outcome of the insult can be monitored, and neurobehavioral parameters can be tested. Some animals that meet these criteria are sheep, non-human primates, rabbits, spiny mice, and guinea pigs.
Transplantation of neural stem cells and umbilical cord stem cells is currently being trialed in neonatal brain injury, but it is not yet known if this therapy is likely to be successful.
Some evidence suggests that magnesium sulfate administered to mothers prior to early preterm birth reduces the risk of cerebral palsy in surviving neonates. Due to the risk of adverse effects treatments may have, it is unlikely that treatments to prevent neonatal strokes or other hypoxic events would be given routinely to pregnant women without evidence that their fetus was at extreme risk or has already suffered an injury or stroke. This approach might be more acceptable if the pharmacologic agents were endogenously occurring substances (those that occur naturally in an organism), such as creatine or melatonin, with no adverse side-effects.
Because of the period of high neuronal plasticity in the months after birth, it may be possible to improve the neuronal environment immediately after birth in neonates considered to be at risk of neonatal stroke. This may be done by enhancing the growth of axons and dendrites, synaptogenesis and myelination of axons with systemic injections of neurotrophins or growth factors which can cross the blood–brain barrier.
Supportive care is the treatment of choice for TTN. This may include withholding oral feeding in periods of extreme tachypnea (over 60 breaths per minute) to prevent aspiration, supplemental oxygen, and CPAP.
Carbon monoxide competes with oxygen for binding sites on hemoglobin molecules. As carbon monoxide binds with hemoglobin hundreds of times tighter than oxygen, it can prevent the carriage of oxygen.
Carbon monoxide poisoning can occur acutely, as with smoke intoxication, or over a period of time, as with cigarette smoking. Due to physiological processes, carbon monoxide is maintained at a resting level of 4–6 ppm. This is increased in urban areas (7–13 ppm) and in smokers (20–40 ppm). A carbon monoxide level of 40 ppm is equivalent to a reduction in hemoglobin levels of 10 g/L.
CO has a second toxic effect, namely removing the allosteric shift of the oxygen dissociation curve and shifting the foot of the curve to the left. In so doing, the hemoglobin is less likely to release its oxygens at the peripheral tissues. Certain abnormal hemoglobin variants also have higher than normal affinity for oxygen, and so are also poor at delivering oxygen to the periphery.
Those infants that have an increased risk of developing hypoglycemia shortly after birth are:
- preterm
- asphyxia
- cold stress
- congestive heart failure
- sepsis
- Rh disease
- discordant twin
- erythroblastosis fetalis
- polycythemia
- microphallus or midline defect
- respiratory disease
- maternal glucose IV
- maternal epidural
- postmaturity
- hyperinssulinnemia
- endocrine disorders
- inborn errors of metabolism
- diabetic mother
- maternal toxemia
- intrapartum fever
Some infants are treated with 40% dextrose (a form of sugar) gel applied directly to the infant's mouth.
Once a child is born prematurely, thought must be given to decreasing the risk for developing NEC. Toward that aim, the methods of providing hyperalimentation and oral feeds are both important. In a 2012 policy statement, the American Academy of Pediatrics recommended feeding preterm infants human milk, finding "significant short- and long-term beneficial effects," including reducing the rate of NEC by a factor of two or more.
A study by researchers in Peoria, IL, published in "Pediatrics" in 2008, demonstrated that using a higher rate of lipid (fats and/or oils) infusion for very low birth weight infants in the first week of life resulted in zero infants developing NEC in the experimental group, compared with 14% with NEC in the control group. (They started the experimental group at 2 g/kg/d of 20% IVFE and increased within two days to 3 g/kg/d; amino acids were started at 3 g/kg/d and increased to 3.5.)
Neonatologists at the University of Iowa reported on the importance of providing small amounts of trophic oral feeds of human milk starting as soon as possible, while the infant is being primarily fed intravenously, in order to prime the immature gut to mature and become ready to receive greater oral intake. Human milk from a milk bank or donor can be used if mother's milk is unavailable. The gut mucosal cells do not get enough nourishment from arterial blood supply to stay healthy, especially in very premature infants, where the blood supply is limited due to immature development of the capillaries, so nutrients from the lumen of the gut are needed.
A Cochrane review published in April 2014 has established that supplementation of probiotics enterally "prevents severe NEC as well as all-cause mortality in preterm infants."
Increasing amounts of milk by 30 to 40 ml/kg is safe in infant who are born weighing very little. Not beginning feeding an infant by mouth for more than 4 days does not appear to have protective benefits.
Data from the NICHD Neonatal Research Network's Glutamine Trial showed that the incidence of NEC among extremely low birthweight (ELBW, <1000 g) infants fed with more than 98% human milk from their mothers was 1.3%, compared with 11.1% among infants fed only preterm formula, and 8.2% among infants fed a mixed diet, suggesting that infant deaths could be reduced by efforts to support production of milk by mothers of ELBW newborns.
Research from the University of California, San Diego found that higher levels of one specific human milk oligosaccharide, disialyllacto-N-tetraose, may be protective against the development of NEC.
Turning the baby, technically known as external cephalic version (ECV), is when the baby is turned by gently pressing the mother’s abdomen to push the baby from a bottom first position, to a head first position. ECV does not always work, but it does improve the mother’s chances of giving birth to her baby vaginally and avoiding a cesarean section. The World Health Organisation recommends that women should have a planned cesarean section only if an ECV has been tried and did not work.
Women who have an ECV when they are 36–40 weeks pregnant are more likely to have a vaginal delivery and less likely to have a cesarean section than those who do not have an ECV. Turning the baby before this time makes a head first birth more likely but ECV before the due date can increase the risk of early or premature birth which can cause problems to the baby.
There are treatments that can be used which might affect the success of an ECV. Drugs called beta-stimulant tocolytics help the woman’s muscles to relax so that the pressure during the ECV does not have to be so great. Giving the woman these drugs before the ECV improves the chances of her having a vaginal delivery because the baby is more likely to turn and stay head down. Other treatments such as using sound, pain relief drugs such as epidural, increasing the fluid around the baby and increasing the amount of fluids to the woman before the ECV could all effect its success but there is not enough research to make this clear.
Turning techniques mothers can do at home are referred to Spontaneous Cephalic Version (SCV), this is when the baby can turn without any medical assistance. Some of these techniques include; a knee to chest position, the breech tilt and moxibustion, these can be performed after the mother is 34 weeks pregnant. Although there is not a lot of evidence to support how well these techniques work, it has worked for some mothers.
Low birthweight, pre-term birth and pre-eclampsia have been associated with maternal periodontitis exposure. But the strength of the observed associations is inconsistent and vary according to the population studied, the means of periodontal assessment and the periodontal disease classification employed. However the best is that the risk of low birth weight can be reduced with very simple therapy. Treatment of periodontal disease during gestation period is safe and reduction in inflammatory burden reduces the risk of preterm birth as well as low birth weight.