Central Venous Pressure Levels Research Articles

IMPACT OF CENTRAL VENOUS PRESSURE AND DIURESIS ON RENAL GRAFT FUNCTION

Introduction: Renal graft function in the immediate posttransplant period is directly associated with patients hemodynamic condition during graft revascularization and early postoperative period. Our aim was to evaluate correlation between average daily value of central venous pressure (CVP) and renal perfusion, in first seven posttransplant days.Patients and methods: We recruited 74 patients, who underwent renal transplantation. We evaluated the influence of CVP and 24 h urine output on renal graft function. In order to assess the renal graft function, following parameters were evaluated: glomerular filtration rate (GFR), creatinine clearance, 24-hour urine output, and from the serum levels of K+, Na++, urea and creatinine.Results: Statistically significant positive correlation between mean values of CVP and 24 h urine output was found on the first (r=0.5422; p=0.0001) but not on the third postoperative day (r=0.1116; p=0.344). Statistically significant inverse correlation between mean values of creatinine and diuresis was found on the first (r=-0.2824; p=0.015) and third (r=-0.2976; p=0.01) postoperative day but on the seventh postoperative day a positive statistically significant correlation between these parameters was registered (r=0.4114; p=0.0001). There is a statistically significant difference between GFR and urine output on the first (r=0.2771; p= 0.017) and seventh day (r=0.4114; p=0.0001). We have not found any significant correlation between mean values of creatinine clearance and diuresis on the first posttransplant day (r=0.1760; p=0.134), but when same parameters were examined on the seventh day a positive statistical significance was found (r=0.4248; p=0.0001).Conclusion: Renal graft survival in early postoperative period is largely influenced by recipient hemodynamic condition. This study proved that 24-hour urine output directly depended on CVP level; it also proved existence of statistically significant correlation between mean values of diuresis, creatinine clearance, GFR and serum creatinine.

The introduction of a simple maneuver to reduce the risk of postoperative bleeding after major hepatectomies

In major hepatectomies, postoperative increases in central venous pressure (CVP) may cause suture failure and massive bleeding. The aim of our study is to test the application of an intraoperative maneuver to reduce the risk of postoperative bleeding. Our study included 172 consecutive patients who had major liver resection with selective hepatic vascular exclusion and sharp transection of the liver parenchyma. An intraoperative maneuver (5 s occlusion of the hepatic vein) was applied in an alternating way, and the patients were assigned to two groups: Cohort A (n = 86), that was granted the maneuver, and Cohort B (n = 86), that was used as a control group. In Cohort A, application of the maneuver was successful in demonstrating bleeders under low CVP levels. Cohort A had lower rate of massive bleeding requiring emergency reoperation (2.3 vs 5.8%, P = 0.049), less postoperative blood transfusions (13 vs 24%, P = 0.042), lower morbidity (20 vs 35%, P < 0.045) and shorter hospital stay compared to Cohort B. Hepatectomies conducted under low CVP are prone to postoperative hemorrhage which can be prevented if the final bleeding control is performed under high pressure in the hepatic veins. Application of our testing maneuver effectively unmasked previously undetectable bleeding veins.

Uppermost Blood Levels of the Right and Left Atria in the Supine Position

To eliminate the influence of hydrostatic pressure, proper transducer positions for central venous pressure and pulmonary artery wedge pressure are at the uppermost blood levels of right atrium (RA) and left atrium (LA). This study was performed to investigate accurate reference levels of central venous pressure and pulmonary artery wedge pressure in the supine position. Chest computed tomography images of 96 patients without history of cardiothoracic surgery, heart disease, or cardiothoracic anatomical abnormality were retrospectively reviewed. The anteroposterior (AP) diameter of the thorax and the vertical distances from the skin on the back to the most anterior portion of RA (RA height) and LA (LA height) were measured. Their ratios were abbreviated, respectively, as RA height/AP diameter and LA height/AP diameter. Data are expressed as mean +/- SD (range). There was a significant difference [4.6 +/- 1.0 (1.6-6.4) cm; P < 0.001] between RA and LA heights. AP diameter was positively correlated with RA and LA heights (R = 0.839 and 0.700, respectively; P < 0.001). There was also a significant difference between RA height/AP diameter [0.83 +/- 0.03 (0.71-0.91)] and LA height/AP diameter [0.62 +/- 0.04 (0.52-0.72)] (P < 0.001). In the supine position, a central venous pressure transducer should be positioned approximately 4.6 cm higher than a pulmonary artery wedge pressure transducer. The external reference level for central venous pressure seems to be at approximately four fifths of the AP diameter of the thorax from the back, and that for pulmonary artery wedge pressure seems to be at approximately three fifths of the AP diameter.

The vertical difference between the reference levels of central venous pressure and pulmonary capillary wedge pressure in the supine position

The vertical difference between the reference levels of central venous pressure and pulmonary capillary wedge pressure in the supine position

Early goal-directed therapy: An evidence-based review

In 2003, critical care and infectious disease experts representing 11 international organizations developed management guidelines for early goal-directed therapy that would be of practical use for the bedside clinician, under the auspices of the Surviving Sepsis Campaign, an international effort to increase awareness and improve outcome in severe sepsis. The process included a modified Delphi method, a consensus conference, several subsequent smaller meetings of subgroups and key individuals, teleconferences, and electronic-based discussion among subgroups and among the entire committee. The modified Delphi methodology used for grading recommendations built on a 2001 publication sponsored by the International Sepsis Forum. We undertook a systematic review of the literature graded along five levels to create recommendation grades from A to E, with A being the highest grade. Pediatric considerations to contrast adult and pediatric management are in the article by Parker et al. on p. S591. During the first 6 hrs of resuscitation of sepsis-induced hypoperfusion, specific levels of central venous pressure, mean arterial pressure, urine output, central venous (or mixed venous) oxygen saturation should be targeted. When central venous oxygen saturation remains low, despite achieving central venous pressure and mean arterial pressure targets, packed red blood cells or dobutamine should be considered. Increasing cardiac index to achieve an arbitrarily predefined elevated level is not recommended.

Hemodynamic physiology and thermoregulation in liposuction.

Little is known about the physiology of large-volume liposuction. Patients are exposed to prolonged procedures, general anesthesia, fluid shifts, and infusion of high doses of epinephrine and lidocaine. Consequently, the authors examined the thermoregulatory and cardiovascular responses to liposuction by assessing multiple physiologic factors. The aims of their study were to serially determine hemodynamic parameters perioperatively, to quantify perioperative and postoperative plasma epinephrine levels, and to chronologically document fluctuations in core body temperature. Five female volunteers with American Society of Anesthesiologists' physical status I and II underwent moderate- to large-volume liposuction. Heart rate, blood pressure, mean pulmonary arterial pressure, cardiac index, and central venous pressure were monitored. Serum epinephrine levels and core body temperature were assessed perioperatively. The hemodynamic responses to liposuction were characterized by an increase in cardiac index (57 percent), heart rate (47 percent), and mean pulmonary arterial pressure (44 percent) (p < 0.05). Central venous pressure was not significantly altered. Maximum epinephrine levels were observed 5 to 6 hours after induction. Significant correlations between cardiac index and epinephrine concentrations were shown intraoperatively (r = 0.75). All patients developed intraoperative low body temperatures (mean 35.5 degrees C). An overall enhanced cardiac function was observed in patients subsequent to large-volume liposuction. The etiology of the altered cardiac parameters was multifactorial but may have been attributable in part to the administration of epinephrine, which counters the effects of general anesthesia and operative hypothermia. Additional explanations for raised cardiac output may be hemodilution or emergence from general anesthesia. Elevated mean pulmonary arterial pressure may be a result of subclinical fat embolism demonstrated in previous porcine studies, although fat was not observed in urine. The unchanged central venous pressure levels indicate that young healthy patients with compliant right ventricles can accommodate the fluid loads of large-volume liposuction. Overall hemodynamic parameters remained within safe limits. Within these surgical parameters, patients should be clinically screened for cardiovascular and blood pressure disorders before liposuction is undertaken, and preventative measures should be taken to limit intraoperative hypothermia.

THE EFFECT OF AUTOLOGOUS BLOOD DONATION ON THE CENTRAL VENOUS PRESSURE, BLOOD LOSS AND BLOOD TRANSFUSION DURING LIVING DONOR HEPATECTOMY

P470 Aims: To evaluate the effect of autologous blood donation(ABD) 2-3 days before operation on the intraoperative central venous pressure(CVP) levels, blood loss and blood transfusion during living donor hepatectomy. Methods: Eighty eight patients undergoing living donor hepatectomy were retrospectively divided in GI and GII according to have donated 250-300 ml blood 2-3 days before living donor hepatectomy or not. The same patients were also divided into left hepatectomy group (GIII) and right hepatectomy group(GIV), un-regard having ABD or not. Intraoperative CVP levels, blood loss and requirement of blood transfusion between groups were analyzed and compared with Mann Whitney U test Results: Intraoperative CVP changes between GI (n=37) and GII (n=51) up to graft procurement were the same, subsequently the blood loss (65 ± 54 vs 94.4 ± 85 ml; p=0.06), but ABD resulted in significantly lower perioperative hemoglobin (Hb) levels in GI. The blood loss of GIV (n=22) under the same CVP was significantly more in comparison to GIII (n=66)(67 ± 64 vs 127 ± 90 ml; p <0.005)) Conclusions: Since none of the patients required blood product perioperatively, all the predonated bloods were discarded after the patients being discharged from the hospital. It indicates that ABD in current series had no any beneficial effects, in term of cost, lowering the CVP, blood loss and reduce the use of banked blood products, but resulted in significant lower Hb in perioperative period. ABD is not always necessary and is not recommended living donor hepatectomy if the perioperative blood loss can be minimized.

Use of Corfolsin Dalopate following Cardiac Surgery in a Neonate

A FEMALE neonate, weighing 2,690 g, developed severe cyanosis immediately after birth, and was diagnosed as having complex heart anomaly (truncus arteriosus, interruption of aortic arch, aortopulmonary septal defect, patent ducts arteriosus, and persistent foramen ovale). Despite support with dopamine, dobutamine, and epinephrine, congestive heart failure developed. Therefore, total correction surgery was scheduled to take place on the patient's twenty-first day of life. Anaesthesia was induced and maintained with fentanyl (25 μg/kg) and midazolam (0.3 mg/kg). Surgery was performed under the moderately hypothermic (25°C) cardiopulmonary bypass (CPB) with a total flow of 2.8 l.min -1 .m 2 , CPB was started 55 min after the anesthetic induction. The interval from the start of CPB to the initial attempt to wean the patient from CPB with sufficient body temperature recovery (36.2°C) was 5 h and 20 min. The attempt was made to discontinue CPB with the aid of dopamine (4 - 8 μg.kg -1 .min -1 ) and dobutamine (5-8 μg.kg -1 .min -1 ). However, decreasing the bypass flow to less than 1.5 l.min -1 .m -2 resulted in sustained hypotension. Adding epinephrine (0.5 μg/kg/min) and isoproterenol (0.1 μg.kg -1 .min -1 ) did not improve the patient's hemodynamics; her systemic mean arterial pressure while still on partial bypass was ≤ 30 mmHg, while her central venous pressure (CVP) was approximately 17 mmHg. The addition of an infusion of milrinone (0.5 (μg.kg -1 .min -1 ) for approximately 40 min also had no significant effect. Echocardiography (using an epicardial probe) showed an adequate surgical repair. At this point, with the patient back on full bypass support all inotropic agents were discontinued. We next administered a combination of colforsin dalopate HCI (0.25 μg.kg -1 .min -1 ') and dopamine (5 μg.kg -1 .min -1 ). The patient's CPB flow rate decreased to 1.0 l.min -1 .m -2 and CVP was controlled at 8-11 mmHg. Over the next 30 min, the patient's mean arterial pressure increased from 35 to 65 mmHg, and her heart rate increased from 140 to 170 beats/min. After approximately 20 min of stable conditions, CPB was successfully discontinued. Her postweaning hemodynamic parameters showed heart rate, mean systemic arterial pressure, and CVP levels in the ranges of 170-180 beats/min, 55-65 mmHg, and 11-13 mmHg, respectively, Arterial blood gas analysis did not show metabolic acidosis, hypercarbia, or hypoxemia, The surgery terminated 2 h after the CPB weaning, Hemodynamic parameters recorded after each attempt to discontinue bypass are summarized in table 1. After being transferred to the intensive care unit, the patient's heart rate continued to increase, reaching 190 beats/min. Her colforsin infusion was discontinued while dopamine was maintained. Two hours later, her mean arterial pressure decreased to 35 mmHg from 60 mmHg, her heart rate decreased to 140 beats/min from 170 beats/min, and CVP increased from 11 mmHg to 17 mmHg. An infusion of epinephrine was added, but without success. Therefore, approximately 1 h later, colforsin dalopate HCl infusion (0.25 μg.kg -1 .min 1 ) was restarted. Mean arterial pressure and heart rate quickly increased to 65 mmHg and 178 beats/min, respectively. Colforsin was discontinued without difficulty 5 h later.

Measures to prevent renal impairment after resection of retroperitoneal neuroblastoma.

Postoperative renal impairment has been reported after kidney-preserving resection of retroperitoneal neuroblastomas (NB). To avoid renal damage, intraoperative procedures include monitoring of central venous pressure (CVP) and diuresis, i.v. administration of electrolyte solutions, mannitol, and furosemide, and local application of lidocaine to the renal vessels. During the first 5 postoperative (p.o.) days, CVP, diuresis, body temperature (T), and lactate dehydrogenase (LDH) levels were monitored; color Doppler ultrasound (CDUS) was also performed on the 7th p.o. day. Simultaneous increases of T (>38.5 degrees ) and LDH (>1,500 IU/l) and/or reduction of urinary flow (< 1.5 ml/kg.h) were indicative of renal damage: in these cases dopamine was administered and CDUS performed. If renal blood flow was normal on CDUS, dopamine was administered for another 2 days; if a vascular thrombosis was detected, fibrinolytic agents (urokinase 4,000 IU/kg bolus and then 4,000 IU/kg.h for 24 h) were utilized. Between May 1997 and June 2000, 29 children (9 F, 20 M, aged) 6-72 months (median 39) affected by grade II inoperable, grade III, and grade IV NB underwent these preventive procedures at the time of surgical excision of the mass after chemotherapy 23 had an uneventful p.o. course. CDUS at 7 days was normal in 22; in 1 (polar resection at operation) it demonstrated a slight reduction of blood flow in the renal cortex. For all 23 patients, the CDUS at 3, 6, and 12 months was negative. Three patients showed a single altered parameter; the CDUS p.o. and during follow-up did not show any alteration. The other 3 patients had two or more altered parameters and were treated with dopamine: in 1 the initial CDUS was normal, but it later showed moderate hypotrophy; in 2 patients a vascular thrombosis was documented. Treatment with urokinase was successful in only 1 patient who had a normalized CDUS after 3 months. The 2nd child developed renal failure and needed hemodyalisis. In our experience, elevation of serum LDH and T and/or oliguria were good indicators of renal impairment. CDUS was also useful in detecting renal blood flow reduction and artery occlusion. These preliminary results show these intra- and postoperative measures to reliably avoid renal impairment in these children. Long-term follow-up could confirm the efficacy of these methods.

Baroreceptor dysfunction induced by nitric oxide synthase inhibition in humans

OBJECTIVESWe sought to investigate baroreceptor regulation of sympathetic nerve activity and hemodynamics after inhibition of nitric oxide (NO) synthesis.BACKGROUNDBoth the sympathetic nervous system and endothelium-derived substances play essential roles in cardiovascular homeostasis and diseases. Little is known about their interactions.METHODSIn healthy volunteers, we recorded muscle sympathetic nerve activity (MSA) with microneurography and central hemodynamics measured at different levels of central venous pressure induced by lower body negative pressure.RESULTSAfter administration of the NO synthase inhibitor NG-monomethyl-l-arginine (L-NMMA, 1 mg/kg/min), systolic blood pressure increased by 24 mm Hg (p = 0.01) and diastolic blood pressure by 12 mm Hg (p = 0.009), while stroke volume index (measured by thermodilution) fell from 53 to 38 mL/min/m2 (p < 0.002). Administration of L-NMMA prevented the compensatory increase of heart rate, but not MSA, to orthostatic stress. The altered response of heart rate was not due to higher blood pressure, because heart rate responses were not altered during infusion of the alpha-1-adrenoceptor agonist phenylephrine (titrated to an equal increase of systolic blood pressure). In the presence of equal systolic blood pressure and central venous pressure, we found no difference in MSA during phenylephrine and L-NMMA infusion.CONCLUSIONSThis study demonstrates a highly specific alteration of baroreceptor regulation of heart rate but not muscle sympathetic activity after inhibition of NO synthesis in healthy volunteers. This suggests an important role of NO in reflex-mediated heart rate regulation in humans.

Does intensive perioperative dialysis improve the results of coronary artery bypass grafting in haemodialysed patients?

Between January 1996 and April 1998, 17 chronic haemodialysed patients underwent coronary artery bypass grafting (CABG). Two of them simultaneously had valve replacement. Except for two cases in which CABG was performed in an emergency, 15 patients (CRF group) received 3 consecutive days of haemodialysis in the preoperative period, intraoperative haemodialysis connected to cardiac pulmonary bypass (CPB) and continuous hemodiafiltration in the early postoperative period. The perioperative clinical parameters of the CRF group were compared with those of 17 age-matched patients with normal renal function undergoing CABG as the control (NRF group). When the perioperative variables were compared, no significant differences were seen in total operation time and CPB time, but we noted significant increases in the mean volume of transfused blood in the 6 perioperative days, postoperative intubation time, postoperative fasting time, and time spent in the intensive care unit. Levels of central venous pressure, systolic blood pressure, respiratory index (PaO2/FiO2) and daily fluid balance of the CRF group were the same as the control group in the early postoperative period. In addition, the levels of serum creatinine, urea nitrogen, potassium and hematocrit of CRF group remained almost constant in the early postoperative period. After all, the hospital morbidity of the CRF group was not more serious than that of the NRF group, and hospital mortality of the CRF and NRF groups was 0%. Our intensive perioperative dialysis programme could successfully manage the perioperative clinical course of haemodialysed patients undergoing CABG.

Determinants of atrial natriuretic factor secretion in dogs expanded with isotonic saline or colloid solutions

Through increments in blood volume and atrial pressure are thought to be the primary stimuli for ANF secretion, plasma levels of this peptide do not always behave as a simple function of volume status. To outline the relationship between the latter and cardiac ANF release, we used five different volume-expansion protocols in anesthetized dogs. A stepwise expansion of plasma volume (PV) was achieved by two consecutive infusions: 0.9% saline followed or preceded by 4 or 25% bovine serum albumin (BSA), 4 or 25% dextran (Dx), or homologous plasma. Saline expansion led to a two- to four-fold increase in arterial plasma ANF level in all five protocols. Both 4 and 25% BSA caused no or very modest increase in plasma ANF, while all other colloid expanders caused the expected ANF release. In all protocols, plasma ANF closely correlated with central venous pressure (CVP). BSA expansion was the only protocol with no correlation between PV and ANF release. Changes in serum Ca2+ could not explain this finding. During BSA expansion, the lack of atrial response was related to the absence of increment (or even fall) in CVP despite the expanded PV. Similarly, urinary Na+ excretion was correlated both with CVP and ANF level but not with PV in BSA expansion. When the dogs were depleted of histamine before BSA infusion, the atrial secretory response was restored, suggesting that this colloid was associated with augmented capillary leakiness and vascular fluid efflux. These results show that the expansion of PV leads neither to ANF release nor to Na+ excretion if it is not accompanied by an expanded central blood volume with elevated atrial pressure.

Clinical studies on dirofilarial hemoglobinuria: Central venous pressure before and after heartworm removal.

Central venous pressure (CVP) was measured before and immediately after surgical heartworm removal from the jugular vein in 22 dogs with dirofilarial hemoglobinuria (caval syndrome). In 19 cases which recovered by sugical removal, CVP was considerably high from 32 mmH2O to 187 mmH2O with a mean of 101.6±35.1(S.D.)mmH2O before heartworm removal. CVP fell in all cases immediately after heartworm removal. The mean CVP after heartworm removal was 61.0±42.9 mmH2O. This level was significantly lower than that before heartworm removal (p<0.001). After heartworm removal, systolic cardiac murmur and jugular pulse improved and hemoglobinemia and hemoglobinuria disappeared. Two of 3 cases, which died after heartworm removal, indicated a high CVP over 200 mmH2O and showed the signs of severe circulatory failure (right heart failure). They also displays terminal signs such as prostration and low body temperature. After heartworm removval, systolic murmur improved passably, but high CVP levels over 175 mmH2Oremained in both cases. Another case did not indicate a high CVP level (66 mmH2O) before heartworm removal. Forty-seven heartworms were removed from this case. However, there was no recovery of the systolic murmur, and CVP fell only 5 mmH2O. In this case, the knotting of a heartworm around the tricuspid chordae was confirmed by autopsy. It was considered that the existence of heartworm mass at the tricuspid valve orifice would be the cause of the high CVP level in this disease. And it was suggested that the tricuspid insufficiency by heartworm mass at the tricuspid valve orifice would be the direct cause of acute circulatory insufficiency that indicates the onset of dirofilarial hemoglobinuria together with many symptoms.

Venous Return and Cardiac Filling in Varanid Lizards

ABSTRACT The duration of ventricular diastole relative to the cardiac cycle length is much shorter (46%) in varanids than in mammals (&amp;gt;70%). Atrial systolic pressures were high (15–20 cmH2O), and atrial contraction was apparent in pressure waveforms from the ventricular cavum arteriosum and cavum pulmonale. Atrial contraction coincides with the short period of ventricular diastole and represents the filling agent for the ventricular cava. Increased central venous flow coincides with ventricular contraction, which by reducing the intrapericardial pressure will promote the expansion and filling of the atria and central veins, implying a suctional element of cardiac filling. Inspiration during spontaneous breathing will reduce central venous pressure, steepen the pressure gradient towards the heart and aid flow towards central veins. There is a positive correlation between the systolic level of central venous pressure and cardiac cycle duration.

A Continuous Indicator of the Zero Level of Central Venous Pressure

A Continuous Indicator of the Zero Level of Central Venous Pressure