scholarly journals Anaesthesia for Neurosurgery in the Sitting Position: A Practical Approach

2005 ◽  
Vol 33 (3) ◽  
pp. 323-331 ◽  
Author(s):  
C. M. Domaingue
Keyword(s):  
Superior Vena ◽  
Venous Pressure ◽  
Vena Cava ◽  
Air Embolism ◽  
Transoesophageal Echocardiography ◽  
Systemic Circulation ◽  
Right Atrial ◽  
Sitting Position ◽  
Volume Loading ◽  
Venous Air Embolism

Neurosurgery in the sitting position offers advantages for certain operations. However, the approach is associated with potential complications, in particular venous air embolism. As the venous pressure at wound level is usually negative, air can be entrained. This air may follow any of four pathways. Most commonly it passes through the right heart into the pulmonary circulation, diffuses through the alveolar-capillary membrane and appears in expelled gas. It may pass through a pulmonary-systemic shunt such as a probe patent foramen ovale (paradoxical air embolism); it may collect at the superior vena cava-right atrial junction. Rarely it may traverse through lung capillaries into the systemic circulation. Many monitors, such as the precordial Doppler, capnography, pulmonary artery catheter, transoesophageal echocardiography are useful for venous air embolism detection, with transoesophageal echocardiography being today's gold standard. Various manoeuvres, including neck compression and volume loading, are also useful in reducing the incidence of venous air embolism. Volume loading, in particular, is very helpful as it reduces the risk of hypotension. Other particular concerns to the anaesthetist are airway management, avoidance of pressure injuries, and the risk of pneumocephalus, oral trauma, and quadriplegia. Newer anaesthetic agents have made the choice of anaesthetic technique easier. An appreciation of the implications of neurosurgery in the sitting position can make the procedure safer.

Effects of positive end-expiratory pressure ventilation on cerebral venous pressure with head elevation in dogs

2000 ◽  
Vol 88 (2) ◽  
pp. 655-661 ◽  
Author(s):  
Thomas J. K. Toung ◽  
H. Aizawa ◽  
Richard J. Traystman
Keyword(s):  
Prone Position ◽  
Venous Pressure ◽  
Air Embolism ◽  
Right Atrial ◽  
Sitting Position ◽  
Positive End Expiratory Pressure ◽  
Jugular Veins ◽  
Venous Air Embolism ◽  
Head Elevation ◽  
Cerebral Venous Pressure

Mechanical ventilation with positive end-expiratory pressure (PEEP) may prevent venous air embolism in the sitting position because cerebral venous pressure (Pcev) could be increased by the PEEP-induced increase in right atrial pressure (Pra). Whereas it is clear that there is a linear transmission of the PEEP-induced increase in Pra to Pcev while the dog is in the prone position, the mechanism of the transmission with the dog in the head-elevated position is unclear. We tested the hypothesis that a Starling resistor-type mechanism exists in the jugular veins when the head is elevated. In one group of dogs, increasing PEEP linearly increased Pcev with the dog in the prone position (head at heart level, slope = 0.851) but did not increase Pcev when the head was elevated. In another group of dogs, an external chest binder was used to produce a larger PEEP-induced increase in Pra. Further increasing Pra increased Pcev only after Pra exceeded a pressure of 19 mmHg (break pressure). This sharp inflection in the upstream (Pcev)-downstream (Pra) relationship suggests that this may be caused by a Starling resistor-type mechanism. We conclude that jugular venous collapse serves as a significant resistance in the transmission of Pra to Pcev in the head-elevated position.

scholarly journals A closed-circuit heart-lung preparation.—Effect of alterations in the peripheral resistance and the capacity of the circulation

1926 ◽  
Vol 99 (697) ◽  
pp. 306-325 ◽  
Keyword(s):  
Vascular System ◽  
Superior Vena ◽  
Venous Pressure ◽  
Peripheral Resistance ◽  
Vena Cava ◽  
Systemic Circulation ◽  
Arterial System ◽  
Diastolic Filling ◽  
Arterial Blood ◽  
Lung Preparation

Investigations of “resistance” and “capacity” effects in relation to the control which they exert upon the vascular system have been carried out by many physiologists, notably by Weber (1), Volkmann (2), Donders (3), de Jager (4), Bayliss and Starling (5), and L. Hill (6, 7). According to Weber, the rise in arterial blood pressure due to arteriole vaso-constriction is caused by an increase in peripheral resistance and by a diminution in the capacity of the circulation. Bayliss and Starling (5) brought forward evidence in favour of this view and pointed out that the venous pressure was in part determined by a balance between these two factors. In opposition to Weber’s view, L. Hill and Barnard (6) hold that capacity changes have no effect on the venous pressure since the vascular system is not filled to distension. In a later paper L. Hill (7) states that reduction in the capacity of the splanchnic area is of importance in so far as it increases the diastolic filling, and so the output of the heart, but that the mean hydrostatic pressure cannot be considered to contribute to this result. The part played by constriction of the veins in altering the venous and arterial pressure is discussed in a paper by Connet (8) in which a full bibliography is given. In a paper published in the ‘ Journal of Physiology ’ (9) I described a modification of Starling’s heart-lung preparation, in which the blood circuit was converted to a closed system, so as to imitate more closely the conditions ruling in the animal body, while maintaining the various factors fully under control of the experimenter. The arrangement is shown in fig. 1. The blood from the aorta flows through a cannula placed in the brachio-cephalic artery (A), the velocity of flow being recorded by a Pitot tube (B) or by a Henderson’s cardiometer. The peripheral resistance is regulated by a compressible fingerstall (D), a second resistance (D') being inserted for studying the effects of shunt circuits. The blood then passes to the venous reservoir (K) which consists of a rubber bag of approximately 250 c.c. capacity. The distal end of the venous reservoir is connected to the superior vena cava. A finger-stall (C) joined by a side tube to the arterial system represents the elasticity of the arterial sytem ; this finger-stall and the venous reservoir K when enclosed in plethysmographs enable the experimeter to study alterations in the volume of the systemic circulation.

Caveats on Abdominal Central Venous Pressure Measurement

PEDIATRICS ◽  
1992 ◽  
Vol 90 (3) ◽  
pp. 479-479
Author(s):  
THOMAS R. LLOYD ◽  
RICHARD L. DONNERSTEIN ◽  
ROBERT A. BERG
Keyword(s):  
Inferior Vena Cava ◽  
Pressure Measurement ◽  
Inferior Vena ◽  
Superior Vena ◽  
Venous Pressure ◽  
Vena Cava ◽  
Right Atrial ◽  
Central Venous ◽  
Intraperitoneal Pressure ◽  
Extrinsic Compression

In Reply.— We appreciate Dr Tong's kind comments on our study. As we stated, "Abdominal vena cava pressure may be significantly higher than right atrial pressure...(in) patients with extrinsic compression of the inferior vena cava," and this may well occur in patients with severely elevated intraperitoneal pressure due to the presence of fluid or air. It is worth pointing out that the same caveat applies to intrathoracic venous pressure measurement in the presence of extrinsic compression of the superior vena cava or right atrium (eg, by pneumomediastinum).

Single-Patch Fold-Back Technique for Augmentation of the Superior Vena Cava in Sinus Venosus Atrial Septal Defect Associated with Partial Anomalous Pulmonary Venous Return

2015 ◽  
Vol 17 (6) ◽  
pp. 282
Author(s):  
Suguru Ohira ◽  
Kiyoshi Doi ◽  
Takeshi Nakamura ◽  
Hitoshi Yaku
Keyword(s):  
Atrial Septal Defect ◽  
Superior Vena Cava ◽  
Septal Defect ◽  
Venous Return ◽  
Superior Vena ◽  
Pulmonary Veins ◽  
Vena Cava ◽  
Sinus Venosus ◽  
Right Atrial ◽  
Anomalous Pulmonary Venous Return

Sinus venosus atrial septal defect (ASD) is usually associated with partial anomalous pulmonary venous return (PAPVR) of the right pulmonary veins to the superior vena cava (SVC), or to the SVC-right atrial junction. Standard procedure for repair of this defect is a patch roofing of the sinus venosus ASD and rerouting of pulmonary veins. However, the presence of SVC stenosis is a complication of this technique, and SVC augmentation is necessary in some cases. We present a simple technique for concomitant closure of sinus venosus ASD associated with PAPVR and augmentation of the SVC with a single autologous pericardial patch.

scholarly journals Obstruction of the inferior vena cava following bicaval orthotopic heart transplantation: a case series

2021 ◽  
Vol 5 (2) ◽  
Author(s):  
Anas Abudan ◽  
Brent Kidd ◽  
Peter Hild ◽  
Bhanu Gupta
Keyword(s):  
Inferior Vena Cava ◽  
Heart Transplantation ◽  
Inferior Vena ◽  
Rare Complication ◽  
Vena Cava ◽  
Case Series ◽  
Transoesophageal Echocardiography ◽  
Right Atrial ◽  
Orthotopic Heart Transplantation ◽  
Eustachian Valve

Abstract Background Inferior vena cava (IVC) obstruction is a rare complication of orthotopic heart transplantation (OHT) and is unique to bicaval surgical technique. The clinical significance, diagnosis, complications, and management of post-operative IVC anastomotic obstruction have not been adequately described. Case summary Two patients with end-stage heart failure presented for bicaval OHT. Post-operative course was complicated with shock refractory to fluid resuscitation and inotropic/vasopressor support. Obstruction at the IVC-right atrial (RA) anastomosis was diagnosed on transoesophageal echocardiography (TOE), prompting emergent reoperation. In both cases, a large donor Eustachian valve was found to be restricting flow across the IVC-RA anastomosis. Resection of the valve resulted in relief of obstruction across the anastomosis and subsequent improvement in haemodynamics and clinical outcome. Discussion Presumably rare, we present two cases of IVC obstruction post-bicaval OHT. Inferior vena cava obstruction is an under-recognized cause of refractory hypotension and shock in the post-operative setting. Prompt recognition using TOE is crucial for immediate surgical correction and prevention of multi-organ failure. Obstruction can be caused by a thickened Eustachian valve caught in the suture line at the IVC anastomosis, which would require surgical resection.

Increased cardiac output following occlusion of the descending thoracic aorta in dogs

1982 ◽  
Vol 243 (1) ◽  
pp. R152-R158 ◽  
Author(s):  
J. K. Stene ◽  
B. Burns ◽  
S. Permutt ◽  
P. Caldini ◽  
M. Shanoff
Keyword(s):  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Thoracic Aorta ◽  
Vascular System ◽  
Superior Vena ◽  
Vena Cava ◽  
Right Atrial ◽  
Mean Systemic Pressure ◽  
Extracorporeal Bypass

Occlusion of the thoracic aorta (AO) in dogs with a constant volume right ventricular extracorporeal bypass increased cardiac output (Q) by 43% and mean arterial pressure by 46%, while mean systemic pressure (MSP) was unchanged. We compared AO with occlusion of the brachiocephalic and left subclavian arteries (BSO) which decreased cardiac output by 5%, increased mean arterial pressure by 32%, and increased MSP by 11%. We feel these results confirm that AO elevates preload by transferring blood volume from the splanchnic veins to the vascular system drained by the superior vena cava. If the heart is competent to keep right arterial pressure at or near zero, this increase in preload will elevate Q above control levels. Comparing our data with results of other authors who have not controlled right atrial pressure, emphasizes the importance of a competent right ventricle in allowing venous return to determine Q.

Influence of right atrial stretch on plasma renin activity in the conscious rat

1987 ◽  
Vol 65 (2) ◽  
pp. 257-259 ◽  
Author(s):  
Susan Kaufman
Keyword(s):  
Plasma Renin Activity ◽  
Superior Vena ◽  
Vena Cava ◽  
Extracellular Fluid ◽  
Plasma Renin ◽  
Renin Activity ◽  
Right Atrial ◽  
Balloon Inflation ◽  
Conscious Rat ◽  
Basal Plasma

Rats were prepared with inflatable balloons at the superior vena cava – right atrium junction. After recovery 1 week later, when blood was taken from conscious, normovolaemic animals plasma renin activity was found not to be influenced by right atrial stretch. Plasma renin activity was then measured in rats in which an extracellular fluid deficit had been produced by peritoneal dialysis against a hyperoncotic, isotonic solution. Although basal plasma renin activity was elevated (6.8 ± 0.9 from 1.5 ± 0.2 ng∙mL∙h, n = 19), no depression was observed in the experimental group after 15 or 90 min of balloon inflation. In rats pretreated with isoprenaline (10 μg/kg body wt.) plasma renin activity was also increased over basal levels, but again balloon inflation caused no reduction in plasma renin activity. It would appear that right atrial stretch has little, if any, influence on renin release in the conscious rat.

Hydrocephalus resulting from superior vena cava thrombosis in an infant

1975 ◽  
Vol 42 (5) ◽  
pp. 597-601 ◽  
Author(s):  
Floyd L. Haar ◽  
Carole A. Miller
Keyword(s):  
Superior Vena Cava ◽  
Superior Vena ◽  
Venous Pressure ◽  
Vena Cava ◽  
Normal Pressure ◽  
Dural Sinus ◽  
Communicating Hydrocephalus ◽  
Content Type ◽  
Venous Structure ◽  
Vena Cava Thrombosis

✓ The authors report an unusual case of superior vena cava thrombosis in an infant who subsequently developed communicating hydrocephalus; they also review previously reported cases of dural sinus hypertension, and separate them into two groups. Patients in the first group develop hydrocephalus and those in the second develop a pseudotumor-like syndrome. The former patients tend to have generalized increase in intracranial venous pressure while the latter have a normal pressure in some major intracranial venous structure(s). The absence of venous cushioning of the choroid plexus pulse wave is proposed as the cause of ventricular enlargement in the former group. In addition, patients in the large-ventricle group were younger than patients in the small-ventricle group.

Sign in / Sign up

Export Citation Format

Share Document