TEMPERATURE REGULATION IN PREMATURE INFANTS

PEDIATRICS ◽  
1964 ◽  
Vol 33 (4) ◽  
pp. 487-495
Author(s):  
Forrest H. Adams ◽  
Tetsuro Fujiwara ◽  
Robert Spears ◽  
Joan Hodgman
Keyword(s):  
Oxygen Consumption ◽  
Ambient Temperature ◽  
Respiratory Rate ◽  
Premature Infants ◽  
Rectal Temperature ◽  
Age Groups ◽  
Carbon Dioxide Production ◽  
High Ambient Temperature ◽  
Ambient Temperatures ◽  
The Mean

Sixteen serial observations of oxygen consumption, carbon dioxide production, R.Q., respiratory rate, rectal temperature, and skin blood flow were made on six premature infants ranging in age from 3 hours to 12 days and weighing from 1.14 to 1.94 kg, utilizing a specially designed climatized chamber at neutral (32-34°C), low (21-23°C), and high (36-38°C) ambient temperatures. Ten premature infants ranging in age from 2½ hours to 18 days were studied at high (36-38°C) ambient temperature. At low ambient temperature, there was a mean increase of 63% in oxygen consumption even in infants under 24 hours of age. At the end of the rewarming period, rectal temperature, which had been lowered during a 20-minute exposure to 21-23°C, nearly recovered to the original level in infants in both of the age groups of 0 to 24 hours and 2 to 5 days, whereas in the 6 to 12 day old group, it returned faster than the former two and it was increased by 0.32 to 1.9°C (mean 0.9°C). At 36-38°C, ambient temperature, the mean oxygen consumption increased 18% in infants ages 2½ to 7½ hours, whereas there was no significant increase in infants ages 10 to 18 days. Sweating and significant vasodilatation generally did not occur even in the older infants. The respiratory rate was increased in most infants. It is suggested that heat loss through the respiratory tract might be important to the premature infant who has a lack of evaporative means at high ambient temperature.

GASEOUS METABOLISM IN PREMATURE INFANTS AT 32-34°C AMBIENT TEMPERATURE

PEDIATRICS ◽  
1964 ◽  
Vol 33 (1) ◽  
pp. 75-82
Author(s):  
Forrest H. Adams ◽  
Tetsuro Fujiwara ◽  
Robert Spears ◽  
Joan Hodgman
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Premature Infants ◽  
Rectal Temperature ◽  
Respiratory Quotient ◽  
Carbon Dioxide Production ◽  
Open Circuit ◽  
Co2 Production ◽  
O2 Consumption ◽  
Rate Of Increase

Thirty-four measurements of oxygen consumption, carbon dioxide production, respiratory quotient, and rectal temperature were made on 22 premature infants with ages ranging from 2½ hours to 18 days. The studies were conducted at 32-34°C utilizing an open circuit apparatus and a specially designed climatized chamber. Oxygen consumption and carbon dioxide production were lowest in the first 12 hours and increased thereafter. The rate of increase in O2 consumption was greater than that of CO2 production, with a consequent fall in respiratory quotient during the first 76 hours of life. A reverse relation of O2 consumption and CO2 production was found following the 4th day of life with a consequent rise in respiratory quotient. There was a close correlation between O2 consumption and rectal temperature regardless of age. A respiratory quotient below the value of 0.707 for fat metabolism was observed in 7 premature infants with ages ranging from 24 to 76 hours.

Thermoregulatory responses to altering hypothalamic temperature in the harbor seal

1977 ◽  
Vol 232 (1) ◽  
pp. R18-R26 ◽  
Author(s):  
H. T. Hammel ◽  
R. W. Elsner ◽  
H. C. Heller ◽  
J. A. Maggert ◽  
C. R. Bainton
Keyword(s):  
Oxygen Consumption ◽  
Ambient Temperature ◽  
Rectal Temperature ◽  
Regression Line ◽  
Harbor Seal ◽  
Threshold Temperature ◽  
Hypothalamic Temperature ◽  
Ambient Temperatures ◽  
Regulate Body Temperature ◽  
Skin Temperatures

The rostral brainstem of the harbor seal Phoca vitulina was cooled and heated 33-41 degrees C while oxygen consumption and rectal, hypothalamic, flipper and dorsal skin temperatures were measured. These experiments were made on restrained seals at ambient temperatures -15 to 30 degrees C. Cooling the preoptic and hypothalamic (POH) tissue increased oxygen consumption in a way that could be approximated by a linear regression line with slope and threshold temperature at which the metabolic rate was minimal. The slope of the regression line was a function of ambient temperature and rectal temperature. At each ambient temperature, the slope was significantly higher for lower rectal temperature. At all rectal temperatures, the slope was significantly higher for lower ambient temperature. The threshold hypothalamic temperatures did not very consistently or significantly with either rectal temperature or ambient temperature. These results on the harbor seal are explicable by suggesting that the thermal-sensitive and reference neurons in the POH which regulate body temperature are inhibited equally by extrahypothalamic cold transducing neural elements.

Metabolism during normoxia, hyperoxia, and recovery in newborn rats

1992 ◽  
Vol 70 (3) ◽  
pp. 408-411 ◽  
Author(s):  
Peter B. Frappell ◽  
Andrea Dotta ◽  
Jacopo P. Mortola
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Carbon Dioxide Production ◽  
Oxygen Availability ◽  
Aerobic Metabolism ◽  
Newborn Rats ◽  
Ambient Temperatures ◽  
Positive Effects

Aerobic metabolism (oxygen consumption, [Formula: see text], and carbon dioxide production, [Formula: see text]) has been measured in newborn rats at 2 days of age during normoxia, 30 min of hyperoxia (100% O2) and an additional 30 min of recovery in normoxia at ambient temperatures of 35 °C (thermoneutrality) or 30 °C. In normoxia, at 30 °C [Formula: see text] was higher than at 35 °C. With hyperoxia, [Formula: see text] increased in all cases, but more so at 30 °C (+20%) than at 35 °C (+9%). Upon return to normoxia, metabolism readily returned to the prehyperoxic value. The results support the concept that the normoxic metabolic rate of the newborn can be limited by the availability of oxygen. At temperatures below thermoneutrality the higher metabolic needs aggravate the limitation in oxygen availability, and the positive effects of hyperoxia on [Formula: see text] are therefore more apparent.Key words: neonatal respiration, oxygen consumption, thermoregulation.

scholarly journals Effects of high ambient temperature on ambulance dispatches in different age groups in Fukuoka, Japan

2018 ◽  
Vol 11 (1) ◽  
pp. 1437882 ◽  
Author(s):  
Kazuya Kotani ◽  
Kayo Ueda ◽  
Xerxes Seposo ◽  
Shusuke Yasukochi ◽  
Hiroko Matsumoto ◽  
...  
Keyword(s):  
Ambient Temperature ◽  
Age Groups ◽  
High Ambient Temperature

Fat-tailed Awassi and German Mutton Merino sheep under semi-arid conditions: 3. Body temperatures and panting rate

1977 ◽  
Vol 89 (2) ◽  
pp. 399-405 ◽  
Author(s):  
A. A. Degen
Keyword(s):  
Ambient Temperature ◽  
Rectal Temperature ◽  
Brain Temperature ◽  
External Auditory Meatus ◽  
Merino Sheep ◽  
Arid Conditions ◽  
Breed Difference ◽  
The Mean ◽  
Skin Temperatures ◽  
Semi Arid

SummaryRectal, external auditory meatus and skin temperatures and panting rates were measured in native fat-tailed Awassi and imported German Mutton Merino (GMM) sheep. The Awassi evolved under desert conditions, have a localized fat deposit, coarse carpet wool, long pendulous ears and long, spiral horns (males). In contrast, the GMM evolved under temperate conditions, have well-distributed fat, medium fine wool, short, straight ears and are polled. The study was carried out during the summer in the northern part of the Negev desert.The mean daily rectal temperature fluctuation was higher (P < 0·01) in the GMM than in the Awassi (1·78 °C v. 1·08 °C). The external auditory meatus temperature was lower than the rectal temperature by 1·5 °C in the GMM and by 1·7 °C in the Awassi, indicating a cooler brain temperature. The maximum skin temperature was similar to the maximum rectal temperature in both breeds, thus sweating was of little importance. The panting rate of the GMM increased fivefold (40·6–199·4 pants/min) whilst the rate of the Awassi increased fourfold (35·3–135·0 pants/min). There was no between-breed difference in either the rectal temperature or panting rate until 25–30 °C ambient temperature and it is thought that the higher rectal temperature of the GMM at this ambient temperature might have triggered off the higher panting rate. It seems that the GMM use panting to a greater extent than the Awassi whereas the Awassi dissipate heat through the skin more efficiently than the GMM. It is concluded that both breeds are thermostable, much of the between-breed difference in rectal temperature can be attributed to their anatomical differences.

The metabolic rates of newborn pigs in relation to floor insulation and ambient temperature

1971 ◽  
Vol 13 (2) ◽  
pp. 303-313 ◽  
Author(s):  
D. B. Stephens
Keyword(s):  
Body Weight ◽  
Oxygen Consumption ◽  
Ambient Temperature ◽  
Regression Coefficients ◽  
Metabolic Rates ◽  
Similar Treatment ◽  
Concrete Floor ◽  
Ambient Temperatures ◽  
Newborn Pigs ◽  
Floor Material

SUMMARY1. The metabolic rates of 58 individual piglets kept either on a straw or on a concrete floor at ambient temperatures near to 10°, 20° or 30°C have been measured with ages ranging from newborn to 9 days, and body weight from 1·0 to 3·2 kg. The oxygen consumption was measured on each floor material at the chosen ambient temperature thus allowing paired comparisons for each animal.2. In comparison with the concrete floor, oxygen consumption on straw was reduced by 18% at 10°C, 27% at 20°C and by 12% at 30°C for pigs 2 to 9 days old. The regression coefficients of mean log (oxygen consumption) on log (body weight) were around 0·66 at 10° and 20°C. At 30°C the value was 0·99 ± 0·14. The regression coefficients were not significantly affected by the presence of a straw floor showing that its effect did not vary with body weight. Corresponding values foi piglets below 24 hours of age were 17% at 10°C, 27% at 20°C and 22% at 30°C ambient temperature.3. Moving a piglet on to a straw floor at 10°C had the same thermal effect as raising the ambient temperature to 18°C. Similar treatment at 30°C was equivalent to raising the ambient temperature to 32°C.4. Lowering ambient temperature to increase the temperature gradient between the homeothermic body of the piglet and the environment progressively increased heat loss in all cases. There was a concomitant decrease in the calculated conductance between core and environment which was more pronounced for the piglets lying on the concrete floor.

Responses of young calves to low ambient temperatures at two levels of feeding

1992 ◽  
Vol 55 (3) ◽  
pp. 397-405 ◽  
Author(s):  
J. W. Schrama ◽  
A. Arieli ◽  
M. J. W. Heetkamp ◽  
M. W. A. Verstegen
Keyword(s):  
Energy Metabolism ◽  
Ambient Temperature ◽  
Rectal Temperature ◽  
Heat Production ◽  
Experimental Period ◽  
Metabolizable Energy ◽  
Ambient Temperatures ◽  
Feeding Level ◽  
Holstein Friesian ◽  
Maintenance Requirements

AbstractSeven groups of five or six Holstein-Friesian male calves were transported to an experimental farm at 2 to 3 days of age. At 6 days of age, heat production (HP) and metabolizable energy (ME) intake were measured for an 8-day period. During this period, calves were exposed to various ambient temperatures: 6, 9, 12 and 15°C. Ambient temperature was constant within days, but changed between days. Calves were fed below (four groups) or near (three groups) the maintenance requirements (290 or 460 kJ ME per kg M0·75 per day).From 6 to 14 days of age the lower critical temperature (Tc) was 12·5°C and HP increased by 8·4 kJ/kg M0·75 per day per °Cfall in ambient temperature below Tc. Both Tc and increase in HP below Tc were not affected by feeding level. Rectal temperature was lower at low ambient temperatures. The decrease in rectal temperature with ambient temperature was greatest at the low feeding level.During the experimental period, calves were not in a steady-state regarding energy metabolism. Heat production decreased with time. This decrease was affected by feeding level and ambient temperature. After arrival, the influence of both ambient temperature and feeding level on the energy metabolism of young calves increased with time.

scholarly journals Respon Fisiologis dan Kualitas Susu Sapi Perah Friesian Holstein pada Musim Kemarau Panjang di Dataran Tinggi

2016 ◽  
Vol 16 (2) ◽  
pp. 131
Author(s):  
Elmy Mariana ◽  
Didik Nurul Hadi ◽  
Nur Qoim Agustin
Keyword(s):  
Body Temperature ◽  
Relative Humidity ◽  
Ambient Temperature ◽  
Dairy Cows ◽  
Pulse Rate ◽  
Rectal Temperature ◽  
Physiological Responses ◽  
Mean Value ◽  
Humidity Index ◽  
The Mean

ABSTRAK. Tujuan dari penelitian ini adalah untuk mempelajari respon fisiologi, produksi dan kualitas susu sapi perah Frisian Holstein pada akhir musim kemarau panjang di Balai Pengembangan Ternak Sapi Perah dan Hijauan Makanan Ternak (BPT-SP HMT) Cikole, Lembang, Bandung.  Penentuan sampel menggunakan metode purposive sampling. Parameter mikroklimat yang diamati antara lain adalah temperatur lingkungan, kelembaban relatif, kecepatan angin, radiasi sinar matahari dalam kandang dan Temperature-Humidity Index (THI). Respon fisiologis yang diamati meliputi suhu rektal, suhu kulit, suhu tubuh, frekuensi respirasi dan denyut jantung. Nilai rerata THI (73.93±5.51) menunjukkan sapi perah berada dalam kondisi  stress ringan. Nilai rerata dari suhu rektal, suhu kulit, suhu tubuh, frekuensi respirasi dan denyut jantung secara berurutan 37.94±0.20°C; 32.15±1.25°C; 37.13±0.32°C; 39.13 ±3.00 dan 79.74±6.19. Nilai rerata persentase bahan kering, lemak dan protein susu secara berurutan 10,19 ± 0,72, 2,14 ± 0,38 dan 2,50 ± 0,32. Temperatur lingkungan yang tinggi  mempengaruhi respon fisiologis antara lain peningkatan denyut jantung yang lebih tinggi dari normal dan kualitas susu yang lebih rendah.   (Physiological responses and milk qualities of holstein friesian during long dry season at high altitude)ABSTRACT. The objectives of this study were to evaluate physiological responses and milk qualities of dairy cows in Balai Pengembangan Ternak Sapi Perah dan Hijauan Makanan Ternak (BPT-SP HMT) Cikole West Bandung at the end of long dry season. Samples were determined by using purposive sampling method. Microclimate parameters  were included  ambient temperature, relative humidity, air velocity, solar radiation and temperature-humidity index (THI). Physiological responses consisted of rectal temperature, skin temperature, body temperature, respiration rate and pulse rate. The mean value of THI (73.93±5.51) showed that dairy cows suffered by heat stress. The mean value of rectal temperature, skin temperature, body temperature, respiration rate and pulse rate were 37.94±0.20°C; 32.15±1.25°C; 37.13±0.32°C; 39.13±3.00 and 79.74±6.19 consecutively. The average percentage value of dry matter, fat and protein content in milk were 10.19±0.72, 2.14±0.38 and 2.50±0.32. High ambient temperature and low relative humidity affected physiological responses such as pulse rate that higher than normal,  and  lower milk yield.

scholarly journals Spirometry with a Fleisch pneumotachograph: upstream heat exchanger replaces heating requirement

1997 ◽  
Vol 82 (4) ◽  
pp. 1053-1057 ◽  
Author(s):  
Martin R. Miller ◽  
Ole F. Pedersen ◽  
Torben Sigsgaard
Keyword(s):  
Heat Exchanger ◽  
Ambient Temperature ◽  
Normal Subjects ◽  
Climate Chamber ◽  
Ambient Temperatures ◽  
The Mean ◽  
Head Temperature ◽  
Exact Temperature ◽  
Subject Differences ◽  
Fleisch Pneumotachograph

Miller, Martin R., Ole F. Pedersen, and Torben Sigsgaard.Spirometry with a Fleisch pneumotachograph: upstream heat exchanger replaces heating requirement. J. Appl. Physiol. 82(4): 1053–1057, 1997.—The exact temperature of the head of an unheated Fleisch pneumotachograph (PT) during recording is not known, and variation in its temperature may lead to errors in measuring spirometric indexes. We measured PT head temperature during blows from five normal subjects, recorded by using a PT with and without an upstream heat exchanger to condition the air to the ambient temperature that was set in a climate chamber. Group mean (±SD) temperature of a thermocouple (TC) placed inside the PT head was 11.8 ± 1.9°C with 7°C ambient, 25.4 ± 1.3°C at 23°C, and was 37.2 ± 0.3°C at 37°C. The between-subject range of temperature for this TC was 7.5° at 7°C, 5.5° at 23°C, and 1.1° at 37°C. The mean within-subject within-blow variation of temperature for this TC was 10.0° and 3.3°C for ambient of 7° and 23°C, respectively. At the usual ambient temperature in a laboratory, these differences in temperature lead to a 3.6% between-subject bias in recording, and the within-subject differences lead to 2.6% underreading of peak expiratory flow and a 0.5% overreading later in the blow, which makesatps-to-btpscorrection erroneous or difficult to perform. With the use of an upstream heat exchanger, the group mean temperature was 8.7 ± 0.4°, 23.2 ± 0.2°, and 37.1 ± 0.2°C at the three ambient temperatures, respectively, and the within-subject within-blow variation was reduced to <1°C. A heat exchanger placed upstream of the PT satisfactorily conditioned expired air to the ambient temperature and removed the error.

A mechanism by which helium increases metabolism in small mammals

1960 ◽  
Vol 199 (2) ◽  
pp. 243-245 ◽  
Author(s):  
H. A. Leon ◽  
S. F. Cook
Keyword(s):  
Thermal Conductivity ◽  
Oxygen Consumption ◽  
Ambient Temperature ◽  
Skin Temperature ◽  
Heat Loss ◽  
Small Mammals ◽  
Thermal Gradient ◽  
Oxygen Mixture ◽  
Ambient Temperatures ◽  
Long Evans

The oxygen consumption of male Long-Evans rats was determined at three different ambient temperatures in air and in an equivalent helium-oxygen mixture. It was found that when the ambient temperature is near the skin temperature of the rat, the effect of helium is insignificant. If the ambient temperature is lowered, helium induces an increased metabolism over air at the same temperature. Since helium has a thermal conductivity about six times greater than nitrogen, it is concluded that the accelerated metabolism is in response to the greater heat loss in the presence of helium and the magnitude of this response is proportional to the thermal gradient between the animal and the environment.

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