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At least 19 recordsLinked to original sources
PubMed2005

A comparison of target-controlled infusion versus volatile inhalant anesthesia for heart rate, respiratory rate, and recovery time in a rat model.

We conducted this study to determine whether heart rate, respiratory rate, and recovery time differed significantly between rats receiving target-controlled infusion (TCI) and those under volatile inhalant anesthesia. TCI rats received intravenous propofol at an average effect site concentration of 11.3 microg/ml or propofol plus ketamine (5 mg/ml of propofol) at an average effect site concentration of 8.7 microg/ml. Inhalant anesthesia rats received isoflurane (average, 1.8%) delivered in medical-grade air. We used a tail-clamp response test to determine when a surgical plane of anesthesia was attained. Anesthesia was continued for 1 h from the first negative tail-clamp test. During this time the test was repeated every 10 min to confirm that a surgical plane of anesthesia was being maintained. Anesthesia then was discontinued, and the animals were monitored continuously until they recovered. Average heart rate was higher for rats during anesthesia with isoflurane compared with TCI propofol-ketamine (P =0.0053). Average respiratory rate was higher for TCI regimens compared with isoflurane anesthesia, with male rats having consistently faster respiratory rates than females (P <0.001). Recovery time was longer for both TCI regimens compared with isoflurane (P <0.001). Once venous access was accomplished, TCI anesthesia with propofol or propofol combined with a low dose of ketamine was comparable to an isoflurane inhalant regimen in ease of administration and control of the anesthetic event when used in rats for procedures of 1-h duration. Respiratory rate was increased and recovery time was longer for rats receiving the TCI regimens.

Anesthesia Recovery Period↗
PubMed1976

Oxygen consumption, heart rate, respiratory rate and rectal temperature in healthy newborns during the first two hours after birth.

A report is made on the continuous registration of oxygen consumption, heart rate, respiratory rate and rectal temperature in 32 neonates during the first two hours of life. A short account of the registration technique is given. A comparative study shows, that oxygen consumption, heart rate and respiratory rate fall during the period of observation, whereas the rectal temperature rises. 26 out of the 32 neonates demonstrated a approximately linear fall of each of the oxygen consumption values during the period of observation. There is a similar relationship, which is statistically verified, between the oxygen uptake and heart rate. Oxygen consumption and heart rate can be correlated with each other after the first 60 minutes of life. This close and direct relationship between the oxygen consumption and the heart rate, an important parameter of the heart and circulatory system, stresses clearly the importance of the continuous registration of oxygen consumption for monitoring the general condition of the neonate. A change from this situation means a risk for the neonate which must be clarified by blood-gas analysis. A continuous registration of oxygen uptake for the surveillance of the neonate includes numerous vital functions and appears to be a more suitable parameter than single parameters which include only partial functions. The application of the method is simple and safe for the infant.

Age Factors↗
PubMed1989

Effect of anatoxin-a(s) from Anabaena flos-aquae NRC-525-17 on blood pressure, heart rate, respiratory rate, tidal volume, minute volume, and phrenic nerve activity in rats.

The effects of anatoxin-a(s) [antx-a(s)] from the cyanobacterium Anabaena flos-aquae NRC-525-17 on mean arterial blood pressure, heart rate, respiratory rate, tidal volume, minute volume, and phrenic nerve activity were evaluated in anesthetized Sprague-Dawley rats. Anatoxin-a(s) was administered by continuous intravenous infusion. The initial effect of the toxin was to slow the heart rate and reduce arterial blood pressure, followed by much more pronounced reductions in these parameters. The marked decline in heart rate and blood pressure frequently occurred before there was a large decrease in respiratory minute volume [reduced by only 15.4 +/- 3% (mean +/- S.E.) compared to the predose period], suggesting that antx-a(s) has an important muscarinic action on the cardiovascular system in vivo. Phrenic nerve amplitude increased, but, nevertheless, tidal and minute volumes decreased progressively, indicating that antx-a(s), unlike most low-molecular-weight organophosphorus cholinesterase inhibitors, does not have any remarkable inhibitory action on central mediation of respiration.

Animals↗
PubMed1995

The effect of major operations on heart rate, respiratory rate, physical activity, temperature and respiratory gas exchange in infants.

Perioperative changes in heart rate (HR), respiratory rate (RR), physical activity, body temperature, oxygen consumption (VO2), carbon dioxide production (VCO2) and resting energy expenditure (REE) were studied in fourteen infants (weight 3.1 +/- 0.2 kg) who had a major operation. VO2 and VCO2 were measured by indirect calorimetry preoperatively, and postoperatively for the first 12 hours continuously and at 24 hours, 48 hours and 5 days. HR, RR and physical activity were recorded on a minute to minute basis, and rectal temperature was recorded hourly. REE was calculated. HR, RR, VO2, VCO2 and REE increased postoperatively, peaking at 2-4 hours, and returned to baseline levels by 12-24 hours. In all of these variables, peak levels were significantly higher than Baseline levels (p < 0.001 for all variables). Physical activity and rectal temperature did not vary significantly throughout the study. This study demonstrates that newborn infants exhibit a short-lived postoperative increase in HR, RR, VO2, VCO2 and REE, which is not related to any alteration in physical activity or body temperature.

Body Temperature↗
PubMed1991

Effects of prone and supine position on heart rate, respiratory rate and motor activity in fullterm newborn infants.

Polygraphic recordings were obtained for 24 normal full-term neonates on their 4th or 5th day of life. Thirteen of the infants were first fed, laid supine for 3 hours, fed again around noon and laid prone for 3 more hours. The other 11 were first laid prone and then supine. The awake state was observed more in the supine than the prone position (P less than 0.001). Wakefulness occurred at the expense of state 1 and/or state 2. The heart rate (HR) was higher in babies lying prone. It was also higher in the afternoon than in the morning. No such relationship was found for the respiratory rate (RR). There was higher average EMG activity during state 1 in the prone position. The cross-correlation between HR and EMG activity was positive during state 2, and states 4 and 5, regardless of the position. The cross-correlation between the RR and the EMG was usually negative in state 2, and in states 4 and 5, there being many exceptions. The cross-correlation between breathing and heart-beat was mostly negative during state 2, but it eventually became positive due to periodic breathing, central apnoeas with bradycardia, stretches, and crawling movements.

Electrocardiography↗
PubMed1989

Effect of respiratory rate, respiratory depth, and open versus closed mouth breathing on sublingual temperature.

The effect of open mouth breathing, tachypnea, and hyperpnea, either alone or in combination, on sublingual and tympanic membrane temperature in healthy adults was investigated. Seventy-eight subjects maintained randomly assigned breathing patterns for 15 minutes. Temperatures were monitored immediately prior to and for 5 minutes following the breathing protocol. The only statistically significant finding (p less than .01) was a lower sublingual temperature with open mouth breathing. No significant changes in tympanic membrane temperature were seen.

Adolescent↗
PubMed1997

Effect of inspiratory flow rate on respiratory rate in intubated ventilated patients.

It has previously been demonstrated that in normal subjects using a volume-cycled ventilator, increasing inspiratory flow rate increases respiratory rate. We undertook the current study to determine (1) whether this effect is also present in patients with respiratory disease and (2) whether the effect is independent of upper airway receptors. Eight ventilator-dependent patients in the intensive care unit were studied. Patients were ventilated in the assist-control mode with the back-up rate set at 0.5 breaths/min to ensure that all breaths were patient-triggered. While tidal volume was held constant, flow was changed from a baseline flow of 60 L/min. Trials involved changing flow to either 30 or 90 L/min. There was a significant decrease in respiratory rate (-3.4 +/- 0.6 min-1, p < 0.001) when flow was decreased from 60 to 30 L/min. There was a significant increase in respiratory rate (2.3 +/- 0.8 min-1, p < 0.05) when flow was increased from 60 to 90 L/min. As a result of the change in respiratory rate, TE (expiratory time) showed a variable response to changes in flow rate, with some patients actually demonstrating a reduced TE with higher flow rates. No patients experienced the increase in TE that would have been predicted without a change in respiratory rate. We conclude that in intubated ventilated patients, spontaneous respiratory rate is sensitive to inspiratory flow rate. This effect appears to be independent of upper airway receptors, since it was observed with a by-passed upper airway. The increase in respiratory rate seen at higher flow rates undermines attempts to increase TE by increasing flow rates. It may also cause a tendency toward respiratory alkalosis.

Adolescent↗
PubMed1978

Heart rate and respiratory rate differences between preterm and full-term infants during quiet sleep: possible implications for sudden infant death syndrome.

The heart rate and respiratory rate of eight preterm (average gestational age, 33.3 +/- 2.2 weeks) and 13 full-term infants were determined during quiet sleep at home during the first year of life. Both heart rate and respiratory rate were greater in preterm infants throughout the first six months. The difference was maximum at age 10 weeks (21.2 beats per minute and 13.7 breaths per minute), with the difference being statistically significant, at least at the P less than .01 level at ages 10, 12 and 14 weeks, while P greater than or equal to .01 at all other ages. The 10- to 14-week period is precisely the same period during which the incidence of sudden infant death syndrome (SIDS) has been reported to be maximum. These results support the concept that SIDS is linked to a vulnerable phase of cardiorespiratory maturation.

Age Factors↗
PubMed2002

Immediate effects of particulate air pollutants on heart rate and respiratory rate in hypertensive rats.

Time-series studies have shown that the lag time between elevated particulate air pollution (PM) and increases in cardiovascular-related hospital admissions and death is very short 1 d or less. If PM does cause serious cardiovascular effects shortly after exposure, one would expect to see some physiological change during exposure. In this study, spontaneously hypertensive rats (SHRs) with surgically implanted blood pressure transmitters were exposed to concentrated ambient PM (CAPS) for 4 h to determine whether CAPS inhalation causes immediate effects. The rats were also exposed to sulfuric acid aerosols because acid is one of the components of PM that could potentially activate irritant receptors and cause effects during exposure. Exposure to CAPS caused a striking decrease in respiratory rate that was apparent soon after the start of exposure and stopped when exposure to CAPS ceased. The decrease in respiratory rate was accompanied by a decrease in heart rate. Exposure of the same rats to fine-particle-size sulfuric acid aerosol also caused a significant decrease in respiratory rate similar to the effects of CAPS. Ultrafine acid had the opposite effect on respiratory rate compared to CAPS. Because acids have been shown to evoke sensory irritant responses in rodents, the similarity between the effects of fine acid aerosol and CAPS suggests that CAPS activates airway-irritant receptors during exposure.

Aerosols↗
PubMed2004

Autonomic activity in trauma patients based on variability of heart rate and respiratory rate.

OBJECTIVE: To evaluate the effects of sympathetic and parasympathetic nervous system activity on the heart rate and other hemodynamic variables in acute emergency patients with mild to moderately severe trauma. DESIGN: Clinical study. SETTING: Level 1 university-run trauma service. PATIENTS: Fourteen trauma patients studied immediately after admission to the emergency department. INTERVENTIONS: We measured heart rate and respiratory rate variability by spectral analysis in the early period of mildly to moderately injured patients and compared the patterns of the low- (Lfa) and high-frequency (Hfa) areas of variability. MEASUREMENTS AND MAIN RESULTS: The Lfa is the area under the spectral analysis curve within the frequency range of 0.04-0.10 Hz. This area reflects primarily the tone of the sympathetic nervous system as mediated by the cardiac nerve. The respiratory area or Hfa is a 0.12 Hz-wide frequency range centered around the fundamental respiratory frequency defined by the peak mode of the respiratory power spectrum. It is indicative of vagal outflow reflecting parasympathetic nervous system activity. The Lfa/Hfa, or "L/R ratio," reflects the balance between the sympathetic and parasympathetic nervous systems. The hemodynamic effects of bursts of autonomic activity in response to injury were explored by heart rate and respiratory rate variability measured with non-invasive hemodynamic monitoring consisting of bioimpedance cardiac output, heart rate, and mean arterial pressure to measure cardiac function and transcutaneous oxygen (PtcO2) to reflect tissue perfusion. During sudden surges of autonomic activity, we described increased heart rate variability reflecting increased Lfa and to a lesser degree to Hfa. Slightly later there was increased heart rate, mean arterial pressure, and cardiac index but decreased tissue perfusion indicated by the decreased PtcO2/FIO2 ratio. CONCLUSIONS: Surges in autonomic activity in the period immediately after emergency department admission of trauma patients were associated with pronounced increases in cardiac index, mean arterial pressure, and heart rate and reduced tissue oxygenation.

Adolescent↗
PubMed1990

Effects of halothane and isoflurane on mean arterial blood pressure, heart rate, and respiratory rate in adult Pekin ducks.

Although the cardiovascular and respiratory effects of halothane and isoflurane have been documented in a variety of common mammalian laboratory animals, they have not been investigated in birds. In this study, the effects of halothane and isoflurane anesthesia on respiratory rate, heart rate, heart rhythm, and mean arterial pressure in adult Pekin ducks were evaluated. Both anesthetics significantly increased heart rate and depressed blood pressure and respiration. Halothane induced a more profound alteration in heart rate and respiratory rate. With the ducks under halothane anesthesia, abnormal cardiac rhythms included ventricular fibrillation, ventricular bigeminy, and multifocal ventricular rhythms. Other than cardiac tachycardia, isoflurane induced no changes in cardiac rhythm.

Anesthesia↗