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), and a fixed value for the oxygen extraction (F-shunt). The second objective was to assess the influence of blood pressure and positioning on oxygen extraction. The third objective was to perform regression analysis between jugular and mixed venous blood oxygen tensions.

Study design

Prospective, experimental trial.

Animals

The study was performed with seven warmblood horses that were anaesthetized with detomidine, butorphanol, ketamine, diazepam and isoflurane in oxygen.

Methods

Multiple simultaneous arterial, jugular venous and pulmonary arterial blood samples were taken under normotensive and hypotensive conditions in lateral and dorsal recumbency. Arterial, mixed venous, and end-capillary oxygen content were calculated.

Results

A significant correlation between

{\dot{Q}}_{s} / {\dot{Q}}_{t}

and

{\dot{Q}}_{s} / {\dot{Q}}_{t jugular}

was found [intraclass correlation coefficient (ICC) = 0.68, p < 0.001], and Bland–Altman analysis showed a bias of –11.5% and wide limits of agreement (–27.7% to 4.6%). F-shunt significantly correlated with

{\dot{Q}}_{s} / {\dot{Q}}_{t}

(ICC = 0.88, p < 0.001), and Bland–Altman analysis showed a lower bias (–1.97) and narrower limits of agreement (–13.8% to 9.9%). Positioning and blood pressure significantly influenced oxygen extraction. The regression formula was Y = 0.80X + 2.61 (where Y is the calculated mixed venous oxygen tension and X is the jugular venous oxygen tension) when outliers were excluded (ICC=0.82, p < 0.001).

Conclusions and clinical relevance

This study shows that F-shunt provides reasonable estimates of

{\dot{Q}}_{s} / {\dot{Q}}_{t}

but can possibly be improved by using simple algorithms without the need for pulmonary arterial catheterization. These algorithms use blood pressure- and positioning-dependent oxygen extraction and regression analysis between jugular venous and pulmonary arterial oxygen tension. Although promising, the validity of these algorithms needs to be determined in future studies. 相似文献

13.

Investigation of selected respiratory effects of (dex)medetomidine in healthy Beagles

《Veterinary anaesthesia and analgesia》2020,47(5):667-671

相似文献

14.

Postinduction butorphanol administration alters oxygen consumption to improve blood gases in etorphine-immobilized white rhinoceros

Peter Buss Michele Miller Andrea Fuller Anna Haw Eliza Stout Francisco Olea-Popelka Leith Meyer 《Veterinary anaesthesia and analgesia》2018,45(1):57-67

Objective

To investigate the effects of postinduction butorphanol administration in etorphine-immobilized white rhinoceros on respiration and blood gases.

Study design

Randomized crossover study.

Animals

A group of six sub-adult male white rhinoceros.

Methods

Etorphine, or etorphine followed by butorphanol 12 minutes after recumbency, was administered intramuscularly [2.5 mg etorphine, 25 mg butorphanol (1000–1250 kg), or 3.0 mg etorphine, 30 mg butorphanol (1250–1500 kg)]. Sampling started at 10 minutes after initial recumbency, and was repeated at 5 minute intervals for 25 minutes. Arterial blood gases, limb muscle tremors, expired minute ventilation and respiratory frequency were measured at each sampling point. Calculated values included alveolar–arterial oxygen gradient [

P {(A - a)}_{O_{2}}

], expected respiratory minute volume (

\dot{V}

e), tidal volume (Vt), oxygen consumption (

{\dot{V}}_{O_{2}}

) and carbon dioxide production (

{\dot{V}}_{{CO}_{2}}

).

Results

Etorphine administration resulted in an initial median (range) hypoxaemia [arterial partial pressure of oxygen 25.0 (23.0–28.0) mmHg], hypercapnia [arterial partial pressure of carbon dioxide 76.2 (67.2–81.2) mmHg], increased

P {(A - a)}_{O_{2}}

[41.7 (36.6–45.1) mmHg,

{\dot{V}}_{O_{2}}

[11.1 (10.0–12.0) L minute^?1] and muscle tremors. Butorphanol administration was followed by rapid, although moderate, improvements in arterial partial pressure of oxygen [48.5 (42.0–51.0) mmHg] and arterial partial pressure of carbon dioxide [62.8 (57.9–75.2) mmHg]. In rhinoceros administered butorphanol,

{\dot{V}}_{O_{2}}

[4.4 (3.6–5.1) L minute^?1] and

{\dot{V}}_{{CO}_{2}}

[4.2 (3.8–4.4) L minute^?1] were lower than in those not administered butorphanol. Increased arterial oxygen tension was associated with lower oxygen consumption (p = 0.002) which was positively associated with lower muscle tremor scores (p < 0.0001).

Conclusions and clinical relevance

Hypoxaemia and hypercapnia in etorphine-immobilized rhinoceros resulted from an increased [

P {(A - a)}_{O_{2}}

] and increased

{\dot{V}}_{O_{2}}

and

{\dot{V}}_{{CO}_{2}}

associated with muscle tremors. Rather than being associated with changes in

\dot{V}

e, it appears that improved blood gases following butorphanol administration were a consequence of decreased

{\dot{V}}_{O_{2}}

associated with reduced muscle tremoring. 相似文献

15.

Cardiopulmonary responses of free-ranging African elephant (Loxodonta africana) bulls immobilized with a thiafentanil–azaperone combination

《Veterinary anaesthesia and analgesia》2022,49(3):291-298

相似文献

16.

Impact of Trendelenburg (head down) and reverse Trendelenburg (head up) position on respiratory and cardiovascular function in anaesthetized horses

Anna Binetti Martina Mosing Muriel Sacks Luc Duchateau Frank Gasthuys Stijn Schauvliege 《Veterinary anaesthesia and analgesia》2018,45(6):760-771

Objective

To describe the cardiorespiratory effects of a change in table position in anaesthetized horses.

Study design

Prospective, crossover, randomized, experimental study.

Animals

Six adult horses (mean body weight 621 ± 59 kg, aged 13 ± 4 years).

Methods

The horses were anaesthetized twice in dorsal recumbency. They were either placed in the Trendelenburg position (head down; HD) followed by reverse Trendelenburg position (head up; HU) or in reverse order. Every position was maintained for 90 minutes. The order of positions was randomly assigned at initial anaesthesia. Extensive cardiorespiratory monitoring was performed. Statistical analysis consisted of a mixed model with horses as random effect and time, position, section of anaesthesia and interaction between those as fixed effects (p < 0.05).

Results

When HU was applied during the first section of anaesthesia, PaO₂, (p = 0.012), oxygen saturation (SaO₂, p < 0.01) and oxygen content (CaO₂, p < 0.01) were significantly higher, while venous admixture (

\dot{Q}

s/

\dot{Q}

t, p < 0.01), mean arterial (p = 0.039), right atrial (p < 0.01) and mean pulmonary arterial pressure (p < 0.01) were lower than in HD. After changing from HU to HD, PaO₂ and SaO₂ remained higher and

\dot{Q}

s/

\dot{Q}

t lower compared to the inverse order. Independent of the order, in the HD position

\dot{Q}

s/

\dot{Q}

t (p = 0.019) increased while PaO₂ (p < 0.01), SaO₂ (p = 0.011), CaO₂ (p < 0.01), venous PO₂ (P

\bar{v}

O₂; p = 0.019), venous saturation (p = 0.004) and venous oxygen content (p = 0.010) decreased over time. No significant differences were found for cardiac output, oxygen delivery, oxygen consumption and dobutamine requirement between the two positions.

Conclusions and clinical relevance

Gas exchange is better preserved in HU compared to HD, especially if applied from the start of the anaesthesia. 相似文献

17.

Evaluation of intramuscular sodium nitroprusside injection to improve oxygenation in white-tailed deer (Odocoileus virginianus) anesthetized with medetomidine–alfaxalone–azaperone

Sarifa Lakhdhir Nigel Caulkett Tanya Duke-Novakovski Murray Woodbury Søren Boysen 《Veterinary anaesthesia and analgesia》2021,48(1):65-73

相似文献

18.

Wildlife Responses to Long-Term Application of Biosolids to Grasslands in North Carolina

Brian E. Washburn Michael J. Begier 《Strength and Conditioning Journal》2011,64(2):131-138

相似文献

19.

Agreement between invasive blood pressure measured centrally and peripherally in anaesthetized horses

Keely AT. Wilson Anthea L. Raisis Eleanor A. Drynan Martina Mosing Guy D. Lester Jemma Hayman Giselle L. Hosgood 《Veterinary anaesthesia and analgesia》2018,45(4):467-476

Objective

To determine the agreement of invasive blood pressure measured in the facial, metatarsal and carotid arteries, and evaluate the effects of two haemodynamic conditions on agreement.

Study design

Prospective randomized study.

Animals

A group of eight horses aged 7 (4–23) years with a body weight of 493 ± 33 kg.

Methods

Horses were anaesthetized and positioned in dorsal recumbency. Invasive blood pressure was measured simultaneously via catheters placed in the facial, metatarsal and carotid arteries. Cardiovascular function and agreement between arteries was assessed before and during administration of phenylephrine and sodium nitroprusside. These were administered until carotid mean pressure (MAPc) increased or decreased from baseline (65 ± 5) to >90 or <50 mmHg, respectively. Data recorded at each sample time included systolic (SAP), mean (MAP) and diastolic (DAP) arterial pressures for carotid (c), facial (f) and metatarsal (m) arteries as well as cardiac output (

\dot{Q} t

) and systemic vascular resistance (SVR). Bland–Altman analysis was used to assess agreement between peripheral and central sites, and regression analysis to determine influence of

\dot{Q} t

and SVR.

Results

The largest difference was observed in SAPc and SAPm with a bias and limits of agreement (LOA) of 2 (?15 to 19) mmHg. The bias (LOA) for MAPc and MAPf was 2 (?4 to 9) mmHg and for MAPc and MAPm was 5 (?4 to 14) mmHg. The best agreement for DAP was seen between DAPc and DAPf with bias (LOA) of 1 (?3 to 5) mmHg. Regression analysis indicated marginal influence on agreement by

\dot{Q} t

on MAPc and MAPf.

Conclusions and clinical relevance

MAP and DAP of the carotid artery were higher than those of the peripheral arteries, which may lead to overzealous treatment of hypotension, albeit maintaining central pressures.

\dot{Q} t

and SVR did not largely influence the difference between sites. 相似文献

20.

Growth and production of Donax Sordidus Hanley on an Open Sandy Beach in Algoa Bay

A. McLachlan 《African Zoology》2013,48(2):61-66

A population of Donax sordidus (Mollusca, Pelecypoda) has been studied for two years on an open sandy beach. There were summer and winter settlements each year with the former being larger. Growth was rapid, the animals reaching 20 mm length within one year. Few live longer than 17 months. Production averaged 168,7 mg dry matter m^-2y^-1 and the steady state

\bar{P} / \bar{B}

was 1,30y^-1. Energy values averaged 17,84 kJg^-1dry tissue and had a seasonal cycle with maximum values before spawning. 相似文献