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

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.

1969 ◽  
Vol 23 (2) ◽  
pp. 407-413 ◽  
Author(s):  
L. E. Mount

1. Rates of oxygen consumption and carbon dioxide production were measured in pigs from birth to 3 days of age in an open-circuit system.2. The mean respiratory quotient (RQ) during the first 6 h following birth was 0.95 in fasted pigs and 0.91 in pigs which were allowed to feed.3. The RQ fell during the remainder of the first postnatal day to mean values close to 0.85, whether the pigs were allowed to feed from birth or were fasted.4. From 1 to 3 days of age the RQ had a mean value of 0.79.5. There was little difference in the RQ of pigs exposed to environmental temperatures of either 32 or 16°.6. It is concluded that the baby pig is not exclusively dependent on carbohydrate for its energy metabolism.


1986 ◽  
Vol 21 (1) ◽  
pp. 56-62
Author(s):  
Milton E. McGiffen ◽  
John V. Boyne ◽  
John R. Meyer ◽  
Sylvia M. Blankenship

A gas chromatographic technique for measurement of CO2 production in arthropods is described and used to characterize changes in CO2 production as diapause approaches in plum curculio. Carbon dioxide production was statistically compared to oxygen consumption (as measured by a constant pressure respirometer); variance was less for CO2 production, but both assays found significant differences between long-day and short-day plum curculio. Dry weight was not correlated with either CO2 production or O2 consumption. Carbon dioxide production and O2 consumption were positively correlated.


1958 ◽  
Vol 193 (3) ◽  
pp. 495-498 ◽  
Author(s):  
Ruth McClintock ◽  
Nathan Lifson

Measurements of oxygen consumption and carbon dioxide production were made by the Haldane open circuit method on hereditarily obese mice and littermate controls, and the energy expenditures were estimated. Studies were made on mice for short periods under ‘basal’ conditions, and for periods of approximately a day with the mice fasted and confined, fasted and relatively unconfined, and fed and unconfined. The total energy expenditures of fed and unconfined obese mice were found to be higher than those of nonobese littermate controls by virtue of a) increased ‘basal metabolism’, b) greater energy expenditure associated with feeding, and possibly c) larger energy output for activity despite reduced voluntary movement. The values obtained for total metabolism confirm those previously determined by an isotope method for measuring CO2 output.


PEDIATRICS ◽  
1964 ◽  
Vol 33 (4) ◽  
pp. 487-495
Author(s):  
Forrest H. Adams ◽  
Tetsuro Fujiwara ◽  
Robert Spears ◽  
Joan Hodgman

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.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Patrick Lauscher ◽  
Sabine Lauscher ◽  
Harry Kertscho ◽  
Oliver Habler ◽  
Jens Meier

Aim. Ventilation with pure oxygen (hyperoxic ventilation: HV) is thought to decrease whole body oxygen consumption (VO2). However, the validity and impact of this phenomenon remain ambiguous; until now, under hyperoxic conditions,VO2has only been determined by the reverse Fick principle, a method with inherent methodological problems. The goal of this study was to determine changes ofVO2, carbon dioxide production (VCO2), and the respiratory quotient (RQ) during normoxic and hyperoxic ventilation, using a metabolic monitor.Methods. After providing signed informed consent and institutional acceptance, 14 healthy volunteers were asked to sequentially breathe room air, pure oxygen, and room air again.VO2, VCO2, RQ, and energy expenditure (EE) were determined by indirect calorimetry using a modified metabolic monitor during HV.Results. HV reducedVO2from 3.4 (3.0/4.0) mL/kg/min to 2.8 (2.5/3.6) mL/kg/min (P<0.05), whereas VCO2remained constant (3.0 [2.6/3.6] mL/kg/min versus 3.0 [2.6/3.5] mL/kg/min, n.s.). After onset of HV, RQ increased from 0.9 (0.8/0.9) to 1.1 (1.0/1.1). Most changes during HV were immediately reversed during subsequent normoxic ventilation.Conclusion. HV not only reducesVO2, but also increases the respiratory quotient. This might be interpreted as an indicator of the substantial metabolic changes induced by HV. However, the impact of this phenomenon requires further study.


1998 ◽  
Vol 84 (6) ◽  
pp. 2177-2182 ◽  
Author(s):  
Saul Miodownik ◽  
Jose Melendez ◽  
Vittoria Arslan Carlon ◽  
Brian Burda

The methanol-burning lung model has been used as a technique for generating a predictable ratio of carbon dioxide production (V˙co 2) to oxygen consumption (V˙o 2) or respiratory quotient (RQ). Although an accurate RQ can be generated, quantitatively predictable and adjustableV˙o 2 andV˙co 2 cannot be generated. We describe a new burner device in which the combustion rate of methanol is always equal to the infusion rate of fuel over an extended range of O2 concentrations. This permits the assembly of a methanol-burning lung model that is usable with O2 concentrations up to 100% and provides continuously adjustable and quantitativeV˙o 2 (69–1,525 ml/min) and V˙co 2 (46–1,016 ml/min) at a RQ of 0.667.


1987 ◽  
Vol 21 (1) ◽  
pp. 58-65 ◽  
Author(s):  
Keith H Marks ◽  
Patricia Coen ◽  
James R Kerrigan ◽  
Nick A Francalancia ◽  
Elizabeth E Nardis ◽  
...  

PEDIATRICS ◽  
1972 ◽  
Vol 50 (3) ◽  
pp. 361-371
Author(s):  
Elizabeth J. James ◽  
John R. Raye ◽  
Edwin L. Gresham ◽  
Edgar L. Makowski ◽  
Giacomo Meschia ◽  
...  

Metabolic studies were carried out in 22 sheep fetuses free of operative stress. The studies included measurements of umbilical blood flow (175 ± 8 ml/min/kg), fetal oxygen consumption (5.99 ± 0.15 ml/min/kg), carbon dioxide production (5.65 ± 0.17 ml/min/kg), glucose uptake (3.06 ± 0.28 mg/min/kg), respiratory quotient (0.94 ± 0.01), and glucose/oxygen quotient·(0.41 ± 0.03). The studies demonstrated that fetal glucose uptake could be correlated with the glucose concentration difference betsveen maternal arterial and fetal umbilical arterial blood, as well as with maternal arterial glucose concentration. Umbilical arterial glucose concentration was a function of maternal arterial concentration over the concentration range studied. The study demonstrates that the fetal respiratory quotient is significantly less than one. These data suggest that the accumulation of carbon in the fetus for growth represents approximately 40% of the carbon intake in the growing fetal lamb.


2010 ◽  
Vol 53 (3) ◽  
pp. 131-137 ◽  
Author(s):  
Zdeněk Zadák ◽  
Radomír Hyšpler ◽  
Miloslav Hronek ◽  
Alena Tichá

Measurement of parameters of energy requirement, respiratory quotient (RQ), rate of oxygen consumption (VO2) and rate of carbon dioxide production (VCO2) reveal Ringerfundin as an excellent and metabolically stable-acting balanced ionic solution, which does not increase the consumption of O2 or the total energy requirement. In conclusion, Ringerfundin was very well tolerated and in no case were observed undesirable effects.


PEDIATRICS ◽  
1979 ◽  
Vol 63 (4) ◽  
pp. 547-551
Author(s):  
Robert A. Darnall ◽  
Ronald L. Ariagno

Premature infants in single-wall incubators covered with "thermal blankets" made of plastic packing material have large reductions in insensible water loss (IWL) conipared with naked infants. We postulated that such reductions in evaporative heat loss would not result in decreases in caloric expenditure if body temperature were maintained by a servocontrolled heat source. Using an open-circuit technique, we measured oxygen consumption (Vo2), carbon dioxide production (Vco2), heart rate (HR), respiratory rate (RR), and abdominal skin ( Tabd), cheek, thigh, rectal, incubator air, wall, and room air temperatures in ten infants less than 37 weeks gestational age and from 2 to 24 days of age both naked and covered with a plastic thermal blanket. Tabd temperature was maintained between 36.2 and 36.8 C and rectal temperature between 36.8 and 37.2 C in each environment by manual or automatic servocontrol. A "resting state" was defined by using a combination of subjective and objective criteria. The mean values of Vo2 during the "resting state" were 7.31 and 7.59 cc/kg of body weight per minute for naked and covered infants, respectively. There were no significant differences between mean values of VCO2, respiratory quotient, HR, RR, abdominal, cheek, thigh, or rectal temperatures in the two environments. Operant temperatures averaged 0.5 C lower when the infants were covered. These data support the hypothesis that decreases in insensible water loss do not necessarily imply reductions in caloric requirements in infants where Tabd is niaintained by servocontrol.


Sign in / Sign up

Export Citation Format

Share Document