Adrenal gland denervation and diving in ducks

1987 ◽  
Vol 252 (6) ◽  
pp. R1143-R1151
Author(s):  
H. J. Mangalam ◽  
D. R. Jones ◽  
A. M. Lacombe
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Adrenal Gland ◽  
Plasma Glucose ◽  
Adrenal Glands ◽  
Blood Gas ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
O2 Partial Pressure ◽  
Before And After

The extreme elevation in plasma levels of free norepinephrine (NE) and free epinephrine (EP), which occurs during forced diving of ducks (Anas platyrhynchos), was studied before and after denervation of the adrenal glands. In intact animals both NE and EP concentration increased by up to two orders of magnitude in a 4-min dive but by a significantly lesser amount if the duck breathed O2 before the dive. Denervating the adrenal glands reduced the amounts of both catecholamines (CA) released during dives, plasma EP decreased to 10%, and NE to 50% of values obtained before denervation. Breathing O2 before a dive virtually eliminated CA release in denervates, indicating that hypoxia was the important non-neural releasing agent. Hypoxia was also the most important neural releasing agent compared with hypercapnia, acidosis, or hypoglycemia. Adrenal denervation did not cause significant changes in heart rate, blood pressure, arterial blood gas tensions, pH, or plasma glucose during dives, although denervation caused increased variation in some of these variables. In ducks CA release in dives is largely due to decreasing arterial O2 partial pressure, and full expression of the response is dependent on intact innervation of the adrenal gland.

scholarly journals Severe hypoxaemia in field-anaesthetised white rhinoceros (Ceratotherium simum) and effects of using tracheal insufflation of oxygen

2004 ◽  
Vol 75 (2) ◽  
Author(s):  
M. Bush ◽  
J.P. Raath ◽  
D. Grobler ◽  
L. Klein
Keyword(s):  
Blood Pressure ◽  
Tracheal Intubation ◽  
Blood Gas ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
White Rhinoceros ◽  
Severe Hypoxaemia ◽  
Before And After ◽  
Tracheal Insufflation ◽  
Free Ranging

White rhinoceros anaesthetised with etorphine and azaperone combination develop adverse physiological changes including hypoxia, hypercapnia, acidosis, tachycardia and hypertension. These changes are more marked in field-anaesthetised rhinoceros. This study was designed to develop a technique to improve safety for field-anaesthetised white rhinoceros by tracheal intubation and oxygen insufflation. Twenty-five free-ranging white rhinoceros were anaesthetised with an etorphine and azaperone combination for translocation or placing microchips in their horns. Once anaesthetised the rhinoceros were monitored prior to crating for transportation or during microchip placement. Physiological measurements included heart and respiratory rate, blood pressure and arterial blood gas samples. Eighteen rhinoceros were intubated using an equine nasogastric tube passed nasally into the trachea and monitored before and after tracheal insufflation with oxygen. Seven rhinoceros were not intubated or insufflated with oxygen and served as controls. All anaesthetised rhinoceros were initially hypoxaemic (percentage arterial haemoglobin oxygen saturation (% O2Sa) = 49 % + 16 (mean + SD) and PaO2 = 4.666 + 1.200 kPa (35 + 9 mm Hg)), hypercapnic (PaCO2 = 8.265 + 1.600 kPa (62 + 12 mm Hg)) and acidaemic (pHa = 7.171 + 0.073 ). Base excess was -6.7 + 3.9 mmol/ℓ, indicating a mild to moderate metabolic acidosis. The rhinoceros were also hypertensive (systolic blood pressure = 21.861 + 5.465 kPa (164 + 41 mm Hg)) and tachycardic (HR = 107 + 31/min). Following nasal tracheal intubation and insufflation, the % O2Sa and PaO2 increased while blood pHa and PaCO2 remained unchanged.Tracheal intubation via the nose is not difficult, and when oxygen is insufflated, the PaO2 and the % O2Sa increases, markedly improving the safety of anaesthesia, but this technique does not correct the hypercapnoea or acidosis. After regaining their feet following reversal of the anaesthesia, the animals' blood gas values return towards normality.

scholarly journals Arterial blood gas levels and cardiovascular function during varying environmental conditions in a mudskipper, periophthalmodon schlosseri

1999 ◽  
Vol 202 (13) ◽  
pp. 1753-1762
Author(s):  
A. Ishimatsu ◽  
N.M. Aguilar ◽  
K. Ogawa ◽  
Y. Hishida ◽  
T. Takeda ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Control Level ◽  
Ammonia Concentration ◽  
Blood Gas ◽  
Air Exposure ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Blood Ph ◽  
Periophthalmodon Schlosseri

Changes in blood gas levels, blood pressure and heart rate were studied in chronically cannulated mudskippers, Periophthalmodon schlosseri, subjected to air exposure (6 h), aquatic hypoxia with access to air (water PO2 <0.9 kPa, 6 h) and forced submersion in normoxic water (12 h) at 30 degrees C. Air exposure did not affect either blood O2 and had little effect on blood CO2 levels, but blood pH increased slightly, but significantly. Blood ammonia concentration was elevated sixfold during air exposure. Aquatic hypoxia caused no significant changes in blood gas levels. When the fish was forcibly submerged, blood O2 saturation decreased rapidly to approximately 30 %. Blood PCO2 and total CO2 also decreased, but blood pH was unaffected by forcible submersion. Air exposure did not affect blood pressure or heart rate. Aquatic hypoxia did not affect blood pressure but transiently increased heart rate. In contrast, forced submersion significantly depressed heart rate throughout the period of submersion, while blood pressure decreased only transiently. Upon emersion, the heart rate immediately increased to above the control level when the fish took its first air breath.

Comparative study on effect of neutral spinal bath and neutral spinal spray on blood pressure, heart rate and heart rate variability in healthy volunteers

2018 ◽  
Vol 16 (2) ◽  
Author(s):  
Arundhati Goley ◽  
A. Mooventhan ◽  
NK. Manjunath
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Healthy Volunteers ◽  
Group Analysis ◽  
Low Frequency ◽  
Single Session ◽  
Arterial Blood ◽  
Before And After ◽  
Instantaneous Heart Rate

Abstract Background Hydrotherapeutic applications to the head and spine have shown to improve cardiovascular and autonomic functions. There is lack of study reporting the effect of either neutral spinal bath (NSB) or neutral spinal spray (NSS). Hence, the present study was conducted to evaluate and compare the effects of both NSB and NSS in healthy volunteers. Methods Thirty healthy subjects were recruited and randomized into either neutral spinal bath group (NSBG) or neutral spinal spray group (NSSG). A single session of NSB, NSS was given for 15 min to the NSBG and NSSG, respectively. Assessments were taken before and after the interventions. Results Results of this study showed a significant reduction in low-frequency (LF) to high-frequency (HF) (LF/HF) ratio of heart rate variability (HRV) spectrum in NSBG compared with NSSG (p=0.026). Within-group analysis of both NSBG and NSSG showed a significant increase in the mean of the intervals between adjacent QRS complexes or the instantaneous heart rate (HR) (RRI) (p=0.002; p=0.009, respectively), along with a significant reduction in HR (p=0.002; p=0.004, respectively). But, a significant reduction in systolic blood pressure (SBP) (p=0.037) and pulse pressure (PP) (p=0.017) was observed in NSSG, while a significant reduction in diastolic blood pressure (DBP) (p=0.008), mean arterial blood pressure (MAP) (p=0.008) and LF/HF ratio (p=0.041) was observed in NSBG. Conclusion Results of the study suggest that 15 min of both NSB and NSS might be effective in reducing HR and improving HRV. However, NSS is particularly effective in reducing SBP and PP, while NSB is particularly effective in reducing DBP and MAP along with improving sympathovagal balance in healthy volunteers.

Role of sinoaortic reflexes in hemodynamic patterns of natural defense behaviors in the cat

1981 ◽  
Vol 240 (3) ◽  
pp. H421-H429 ◽  
Author(s):  
G. Baccelli ◽  
R. Albertini ◽  
A. Del Bo ◽  
G. Mancia ◽  
A. Zanchetti
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Cardiac Output ◽  
Carotid Sinus ◽  
Emotional Behavior ◽  
Natural Defense ◽  
Arterial Blood ◽  
Hemodynamic Pattern ◽  
Before And After

To evaluate whether sinoaortic afferents contribute to the hemodynamic pattern of fighting, cardiovascular changes associated with fighting were studied in cats before and after sinoaortic denervation. Sinoaortic denervation exaggerates the decrease in heart rate, cardiac output, and arterial pressure during immobile confrontation (hissing, staring but no movement). During nonsupportive fighting (fighting with forelimbs while lying on one side) and supportive fighting ( fighting while standing on four feet) sinoaortic denervation reduces the increase in heart rate and cardiac output, minimizes the mesenteric vasoconstriction, induces a fall in arterial blood pressure, but does not affect iliac vasoconstriction or vasodilatation. The hemodynamic pattern of fighting is similarly changed by temporary inactivation of carotid sinus baroreflexes by common carotid occlusion as by chronic section of sinoaortic nerves. It is concluded that sinoaortic reflexes play an important role in the cardiovascular patterns accompanying natural fighting. They favor cardiac action and allow a marked visceral vasoconstriction to occur, thus minimizing or preventing a fall in blood pressure during emotional behavior.

scholarly journals Seasonal changes in the cardiovascular, respiratory and metabolic responses to temperature and hypoxia in the bullfrog rana catesbeiana

1998 ◽  
Vol 201 (5) ◽  
pp. 761-768 ◽  
Author(s):  
P L Rocha ◽  
L G S Branco
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Body Temperature ◽  
Arterial Blood Pressure ◽  
Plasma Glucose ◽  
Rana Catesbeiana ◽  
Breathing Frequency ◽  
Glucose Levels ◽  
Arterial Blood ◽  
The Difference

We assessed seasonal variations in the effects of temperature on hypoxia-induced alterations in the bullfrog Rana catesbeiana by measuring the heart rate, arterial blood pressure, breathing frequency, metabolic rate, blood gas levels, acid-base status and plasma glucose concentration. Regardless of the season, decreased body temperature was accompanied by a reduction in heart and breathing frequencies. Lower temperatures caused a significant decrease in arterial blood pressure during all four seasons. Hypoxia-induced changes in breathing frequency were proportional to body temperature and were more pronounced during winter, less so during spring and autumn and even smaller during summer. Season had no effect on the relationship between hypoxia and heart rate. At any temperature tested, the rate of oxygen consumption had a tendency to be highest during summer and lowest during winter, but the difference was significant only at 35 degrees C. The PaO2 and pH values showed no significant change during the year, but PaCO2 was almost twice as high during winter than in summer and spring, indicating increased plasma bicarbonate levels. Lower temperatures were accompanied by decreased plasma glucose levels, and this effect was greater during summer and smaller during autumn. Hypoxia-induced hyperglycaemia was influenced by temperature and season. During autumn and winter, plasma glucose level remained elevated regardless of temperature, probably to avoid dehydration and/or freezing. In winter, the bullfrog may be exposed not only to low temperatures but also to hypoxia. These animals show temperature-dependent responses that may be beneficial since at low body temperatures the set-points of most physiological responses to hypoxia are reduced, regardless of the season. <P>

scholarly journals Reducing inappropriate arterial blood gas testing in a level III intensive care unit: a before-and-after observational study

2020 ◽  
Vol 22 (4) ◽  
pp. 370-377
Author(s):  
Oliver M Walsh ◽  
◽  
Katelyn Davis ◽  
Jonathan Gatward ◽  
◽  
...  
Keyword(s):  
Intensive Care ◽  
Clinical Guideline ◽  
Ventilatory Support ◽  
Clinical Indication ◽  
Blood Gas ◽  
Stable Patient ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Before And After ◽  
Mortality Ratio

Background: Arterial blood gas (ABG) analysis is the most frequently performed test in intensive care units (ICUs), often without a specific clinical indication. This is costly and contributes to iatrogenic anaemia. Objectives: To reduce the number of ABG tests performed and the proportion that are inappropriate. Design, setting and participants: The indications for ABG analysis were surveyed at a 58-bed level III ICU during fortnightly periods before and after a multifaceted educational intervention which included the introduction of a clinical guideline. The number of ABG tests performed during the period July–December 2017 was compared with that for the period July–December 2018. Tests were predefined as inappropriate if performed at regular time intervals, at change of shift, concurrently with other blood tests or after a treatment was ceased on a stable patient or after ventilatory support or oxygen delivery was decreased in an otherwise stable patient. The study was enrolled on the Quality Improvement Projects Register and ethics approval was waived by the local ethics committee. Results: There was a 31.3% bed-day adjusted decrease in number of ABG tests performed (33 005 v 22 408; P < 0.001), representing an annual saving of A$770 000 and 100 litres of blood. The proportion of inappropriate ABG tests decreased by 47.3% (54.2% v 28.6%; P < 0.001) and the number of inappropriate ABG tests per bed-day decreased by 71% (2.8 v 0.8; P < 0.001). Patient outcomes before and after the intervention did not differ (standardised mortality ratio, 0.65 v 0.63; P = 0.22). Conclusion: Staff education and implementation of a clinical guideline resulted in substantial decreases in the number of ABG tests performed and the proportion of inappropriate ABG tests.

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