Bloxsom air lock

Last updated
Bloxsom air lock
Other namesPositive-pressure oxygen air lock
Specialty Neonatology
Uses Respiratory distress in newborns
Complications Retinopathy of prematurity

The Bloxsom air lock was an incubator used in the treatment of respiratory distress among newly born infants in the 1950s. The device attempted to mimic the rhythm of uterine contractions, which were thought to have a role in stimulating fetal breathing. The device was developed by Dr. Allan Bloxsom, a pediatrician at St. Joseph Hospital and Baylor College of Medicine in Houston, Texas. At its peak, the device was utilized in more than 700 hospitals.

Contents

In 1956, six years after its introduction, the Bloxsom air lock produced unfavorable results in a clinical trial. By that time physicians had also become leery of the link between high-concentration oxygen and eye disease in premature babies, and the device fell out of favor. The Bloxsom air lock is sometimes cited as an example of technology that gained wide acceptance following inadequate evaluation.

Development and acceptance

Allan Bloxsom was a pediatrician at St. Joseph Hospital and a faculty member at Baylor College of Medicine. In the early 1940s, he noted that babies born by cesarean section required resuscitation at birth more often than those born by vaginal delivery. Writing a 1942 article for The Journal of Pediatrics , Bloxsom hypothesized that the uterus played an important role in the initiation of breathing at birth. He thought that contractions of the uterus stimulated the fetal respiratory center, possibly by "the alternate forcing and drawing of blood from the fetal circulation by compressing the placenta." [1] He also noted that uterine compression of the fetus, followed by the release of that pressure, might promote breathing in the baby born by vaginal delivery. [1]

Bloxsom developed the air lock device based on his assumptions about the role of uterine contractions in establishing effective breathing at birth. The air lock was a sealed steel cylinder that delivered warmed and humidified 60% oxygen to newly born babies. The device has been compared to an iron lung, but it did not utilize negative pressure. [2] [3] The pressure inside the chamber alternated between 0.07 and 0.2 atmospheres above sea level. Rather than alternating the pressures at the rate of normal respirations as other devices did, the Bloxsom air lock cycled the pressure once per minute to mimic the rate of uterine contractions in late labor. [4] Babies in distress were placed in the chamber immediately after delivery. [3]

The device was rolled out in 1950. That year, Bloxsom presented a talk on the device at an American Medical Association conference. That led to the air lock being featured in Newsweek , which referred to the device as the "Plexiglass Mother". A Houston company developed a Plexiglass model. In 1952, U.S. Army physicians shared their experience with the device, writing that the air lock was a valuable resuscitation device and that on occasion it appeared to be lifesaving. Though the apparatus was large and loud, one pediatrician pointed out that the infant was protected from "meddlesome and unintelligent treatment" while locked inside the chamber. [3] The air lock, which sold for about $1,000 per unit, was used in more than 700 hospitals by the fall of 1952. [5]

Decline

Dr. Virginia Apgar co-authored a 1953 study that was critical of the device. Virginia Apgar.jpg
Dr. Virginia Apgar co-authored a 1953 study that was critical of the device.

In a 1951 article in The Medical Journal of Australia , pediatrician Kate Isabel Campbell advanced a theory that there was a link between oxygen administration and the occurrence of retinopathy of prematurity (ROP) in preterm infants. ROP had become an increasingly common cause of blindness among newborns. The next year, trials in Europe and the United States linked excessive oxygen and ROP more definitively, though an ideal level of oxygen administration was not clear and there was still no way to monitor an infant's arterial oxygen levels. [6]

In 1953, Virginia Apgar and Joseph Kreiselman conducted a study in which they placed anesthesized dogs inside the chamber. They found that the device did not improve the exchange of carbon dioxide or oxygen in these dogs. Dr. Bloxsom and Sister Mary Angelique published a response to the criticism, pointing out that the device was never intended to help apneic dogs. [7]

The next year, Bloxsom and Angelique published an article in the American Journal of Obstetrics and Gynecology on the 48-hour mortality rate among newborns at St. Joseph. Between 1949 and 1952, this rate had decreased from 63 per 10,000 infants to 37 per 10,000 infants. Bloxsom and Angelique cited the air lock device as a contributor to the improvement in outcomes. However, a 1956 study from Johns Hopkins Hospital failed to show a significant difference in outcomes between infants treated in the Bloxsom air lock versus those cared for in the Isolette brand of incubator. [3]

Following the publication of the study at Johns Hopkins, and as physicians became aware of the link between high-concentration oxygen and eye disease in newborns, the device fell out of favor in the late 1950s. A small number of hospitals continued to utilize the device into the early 1970s. In 2001, Kending et al. wrote, "The Bloxsom AL device experienced a precipitous birth, a rapid acceptance and proliferation of usage, a rapid death, and now extinction." [3] The authors noted that the device was seen as a status symbol by many hospitals, which led these centers to utilize it before it had undergone enough evaluation. [3]

See also

Related Research Articles

<span class="mw-page-title-main">Childbirth</span> Conclusion of the human pregnancy with the expulsion of a fetus from mothers womb

Childbirth, also known as labour, parturition and delivery, is the completion of pregnancy where one or more babies exits the internal environment of the mother via vaginal delivery or caesarean section. In 2019, there were about 140.11 million human births globally. In the developed countries, most deliveries occur in hospitals, while in the developing countries most are home births.

Retinopathy of prematurity (ROP), also called retrolental fibroplasia (RLF) and Terry syndrome, is a disease of the eye affecting prematurely born babies generally having received neonatal intensive care, in which oxygen therapy is used because of the premature development of their lungs. It is thought to be caused by disorganized growth of retinal blood vessels and may result in scarring and retinal detachment. ROP can be mild and may resolve spontaneously, but it may lead to blindness in serious cases. Thus, all preterm babies are at risk for ROP, and very low birth-weight is an additional risk factor. Both oxygen toxicity and relative hypoxia can contribute to the development of ROP.

Fetal distress, also known as non-reassuring fetal status, is a condition during pregnancy or labor in which the fetus shows signs of inadequate oxygenation. Due to its imprecision, the term "fetal distress" has fallen out of use in American obstetrics. The term "non-reassuring fetal status" has largely replaced it. It is characterized by changes in fetal movement, growth, heart rate, and presence of meconium stained fluid.

<span class="mw-page-title-main">Blue baby syndrome</span> Two situations that lead to cyanosis in infants

Blue baby syndrome can refer to conditions that cause cyanosis, or blueness of the skin, in babies as a result of low oxygen levels in the blood. This term has traditionally been applied to cyanosis as a result of:.

  1. Cyanotic heart disease, which is a category of congenital heart defect that results in low levels of oxygen in the blood. This can be caused by either reduced blood flow to the lungs or mixing of oxygenated and deoxygenated blood.
  2. Methemoglobinemia, which is a disease defined by high levels of methemoglobin in the blood. Increased levels of methemoglobin prevent oxygen from being released into the tissues and result in hypoxemia.
<span class="mw-page-title-main">Infant respiratory distress syndrome</span> Human disease affecting newborns

Infant respiratory distress syndrome (IRDS), also known as surfactant deficiency disorder (SDD), and previously called hyaline membrane disease (HMD), is a syndrome in premature infants caused by developmental insufficiency of pulmonary surfactant production and structural immaturity in the lungs. It can also be a consequence of neonatal infection and can result from a genetic problem with the production of surfactant-associated proteins.

At the end of pregnancy, the fetus must take the journey of childbirth to leave the reproductive mother. Upon its entry to the air-breathing world, the newborn must begin to adjust to life outside the uterus. This is true for all viviparous animals; this article discusses humans as the most-researched example.

<span class="mw-page-title-main">Neonatology</span> Medical care of newborns, especially the ill or premature

Neonatology is a subspecialty of pediatrics that consists of the medical care of newborn infants, especially the ill or premature newborn. It is a hospital-based specialty and is usually practised in neonatal intensive care units (NICUs). The principal patients of neonatologists are newborn infants who are ill or require special medical care due to prematurity, low birth weight, intrauterine growth restriction, congenital malformations, sepsis, pulmonary hypoplasia, or birth asphyxia.

<span class="mw-page-title-main">Neonatal intensive care unit</span> Intensive care unit specializing in the care of ill or premature newborn infants

A neonatal intensive care unit (NICU), also known as an intensive care nursery (ICN), is an intensive care unit (ICU) specializing in the care of ill or premature newborn infants. The NICU is divided into several areas, including a critical care area for babies who require close monitoring and intervention, an intermediate care area for infants who are stable but still require specialized care, and a step down unit where babies who are ready to leave the hospital can receive additional care before being discharged.

Perinatal 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. It remains a serious condition which causes significant mortality and morbidity. It is also the inability to establish and sustain adequate or spontaneous respiration upon delivery of the newborn, an emergency condition that requires adequate and quick resuscitation measures. Perinatal asphyxia is also an oxygen deficit from the 28th week of gestation to the first seven days following delivery. It is also an insult to the fetus or newborn due to lack of oxygen or lack of perfusion to various organs and may be associated with a lack of ventilation. In accordance with WHO, perinatal asphyxia is characterised by: profound metabolic acidosis, with a pH less than 7.20 on umbilical cord arterial blood sample, persistence of an Apgar score of 3 at the 5th minute, clinical neurologic sequelae in the immediate neonatal period, or evidence of multiorgan system dysfunction in the immediate neonatal period. Hypoxic damage can occur to most of the infant's organs, 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.

<span class="mw-page-title-main">Bronchopulmonary dysplasia</span> Medical condition

Bronchopulmonary dysplasia is a chronic lung disease which affects premature infants. Premature (preterm) infants who require treatment with supplemental oxygen or require long-term oxygen are at a higher risk. The alveoli that are present tend to not be mature enough to function normally. It is also more common in infants with low birth weight (LBW) and those who receive prolonged mechanical ventilation to treat respiratory distress syndrome. It results in significant morbidity and mortality. The definition of bronchopulmonary dysplasia has continued to evolve primarily due to changes in the population, such as more survivors at earlier gestational ages, and improved neonatal management including surfactant, antenatal glucocorticoid therapy, and less aggressive mechanical ventilation.

<span class="mw-page-title-main">Intrauterine hypoxia</span> Medical condition when the fetus is deprived of sufficient oxygen

Intrauterine hypoxia occurs when the fetus is deprived of an adequate supply of oxygen. It may be due to a variety of reasons such as prolapse or occlusion of the umbilical cord, placental infarction, maternal diabetes and maternal smoking. Intrauterine growth restriction may cause or be the result of hypoxia. Intrauterine hypoxia can cause cellular damage that occurs within the central nervous system. This results in an increased mortality rate, including an increased risk of sudden infant death syndrome (SIDS). Oxygen deprivation in the fetus and neonate have been implicated as either a primary or as a contributing risk factor in numerous neurological and neuropsychiatric disorders such as epilepsy, attention deficit hyperactivity disorder, eating disorders and cerebral palsy.

<span class="mw-page-title-main">Neonatal nursing</span>

Neonatal nursing is a sub-specialty of nursing care for newborn infants up to 28 days after birth. The term neonatal comes from neo, "new", and natal, "pertaining to birth or origin". Neonatal nursing requires a high degree of skill, dedication and emotional strength as they care for newborn infants with a range of problems. These problems vary between prematurity, birth defects, infection, cardiac malformations and surgical issues. Neonatal nurses are a vital part of the neonatal care team and are required to know basic newborn resuscitation, be able to control the newborn's temperature and know how to initiate cardiopulmonary and pulse oximetry monitoring. Most neonatal nurses care for infants from the time of birth until they are discharged from the hospital.

Persistent fetal circulation is a condition caused by a failure in the systemic circulation and pulmonary circulation to convert from the antenatal circulation pattern to the "normal" pattern. Infants experience a high mean arterial pulmonary artery pressure and a high afterload at the right ventricle. This means that the heart is working against higher pressures, which makes it more difficult for the heart to pump blood.

An obstetric labor complication is a difficulty or abnormality that arises during the process of labor or delivery.

Uterine Tachysystole is a condition of excessively frequent uterine contractions during pregnancy. It is most often seen in induced or augmented labor, though it can also occur during spontaneous labor, and this may result in fetal hypoxia and acidosis. This may have serious effects on both the mother and the fetus including hemorrhaging and death. There are still major gaps in understanding treatment as well as clinical outcomes of this condition. Uterine tachysystole is defined as more than 5 contractions in 10 minutes, averaged over a 30-minute period.

Bubble CPAP is a non-invasive ventilation strategy for newborns with infant respiratory distress syndrome (IRDS). It is one of the methods by which continuous positive airway pressure (CPAP) is delivered to a spontaneously breathing newborn to maintain lung volumes during expiration. With this method, blended and humidified oxygen is delivered via short binasal prongs or a nasal mask and pressure in the circuit is maintained by immersing the distal end of the expiratory tubing in water. The depth to which the tubing is immersed underwater determines the pressure generated in the airways of the infant. As the gas flows through the system, it "bubbles" out and prevents buildup of excess pressures.

<span class="mw-page-title-main">St. Joseph Medical Center (Houston)</span> Hospital in Texas, United States

St. Joseph Medical Center (SJMC) is a general acute care hospital in Houston, Texas owned by Steward Health Care. Established in June 1887, SJMC is recognized as the first hospital in Houston. A new hospital was constructed in 1894, but was destroyed by fire soon thereafter. The hospital was rebuilt and it underwent major expansions in 1905 and 1938. The hospital was the largest in the city until the Texas Medical Center was established. The hospital has a capacity of 792 beds. A second location was open in the Houston Heights from 2012 to 2019.

<span class="mw-page-title-main">Neonatal resuscitation</span> An emergency medical procedure

Neonatal resuscitation, also known as newborn resuscitation, is an emergency procedure focused on supporting approximately 10% of newborn children who do not readily begin breathing, putting them at risk of irreversible organ injury and death. Many of the infants who require this support to start breathing well on their own after assistance. Through positive airway pressure, and in severe cases chest compressions, medical personnel certified in neonatal resuscitation can often stimulate neonates to begin breathing on their own, with attendant normalization of heart rate.

Lula Olga Lubchenco (1915–2001) was an American pediatrician. Her family moved from Russian Turkestan to South Carolina when she was a small child, and Lubchenco's higher education and career were spent almost entirely in Colorado. After completing a pediatric residency in Denver, Lubchenco joined the faculty of the University of Colorado School of Medicine and was the first director of the Premature Infant Center at Colorado General Hospital.

<span class="mw-page-title-main">Emergency childbirth</span>

Emergency childbirth is the precipitous birth of an infant in an unexpected setting. In planned childbirth, mothers choose the location and obstetric team ahead of time. Options range from delivering at home, at a hospital, a medical facility or a birthing center. Sometimes, birth can occur on the way to these facilities, without a healthcare team. The rates of unplanned childbirth are low. If the birth is imminent, emergency measures may be needed. Emergency services can be contacted for help in some countries.

References

  1. 1 2 Bloxsom, Allan (February 1942). "The difficulty in beginning respiration seen in infants delivered by cesarean section: An analysis of one hundred consecutive cesarean sections". The Journal of Pediatrics . 20 (2). doi:10.1016/S0022-3476(42)80133-X . Retrieved January 1, 2014.
  2. Goldsmith, Jay, Karotkin, Edward (2011). Assisted Ventilation of the Neonate. Elsevier Health Sciences. p. 4. ISBN   978-1416056249.{{cite book}}: CS1 maint: multiple names: authors list (link)
  3. 1 2 3 4 5 6 Kendig, James W., Maples, Philip G., Maisels, M. Jeffrey (December 1, 2001). "The Bloxsom Air Lock: A Historical Perspective". Pediatrics . 108 (6): e116. doi:10.1542/peds.108.6.e116. PMID   11731643 . Retrieved January 1, 2014.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  4. Comroe, Julius H. (1977). "Retrospectroscope: Man-Cans" (PDF). American Review of Respiratory Disease . 116 (5): 945–950. doi:10.1164/arrd.1977.116.5.945 (inactive 2024-09-18). PMID   335937. Archived from the original (PDF) on January 2, 2014. Retrieved January 2, 2014.{{cite journal}}: CS1 maint: DOI inactive as of September 2024 (link)
  5. "Infant air lock is needed by Anson hospital". Anson Western Observer. October 16, 1952. Retrieved January 2, 2014.
  6. Tin, W, Gupta, S (March 2007). "Optimum oxygen therapy in preterm babies". Archives of Disease in Childhood: Fetal and Neonatal Edition . 92 (2): F143–F147. doi:10.1136/adc.2005.092726. PMC   2675464 . PMID   17337663.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  7. Robertson, Alex F. (2003). "Reflections on Errors in Neonatology: II. The "Heroic" Years, 1950 to 1970". Journal of Perinatology . 23 (2): 154–161. doi:10.1038/sj.jp.7210843. PMID   12673267. S2CID   34236009.