Vacuum-assisted venous drainage during fetal cardiopulmonary bypass

Fetal bypass presents several perfusion challenges, including the need for high arterial flow rates using flexible arterial and small venous cannulae. We hypothesized that vacuum-assisted venous drainage (VAVD) would improve drainage and allow perfusion at higher flow rates which are thought to prevent placental dysfunction induced by fetal bypass. We conducted bypass for 60 minutes in 14 fetal lambs (90-105 days gestation; approximately 1-1.5 kg) using a roller pump and various angled venous cannulae (8-12 Fr). VAVD at -20 mm Hg or -40 mm Hg was compared with gravity drainage. Average flow using gravity drainage was 139 ml/kg/min; after VAVD, we achieved average flows of 285 ml/kg/min (range, 109-481 ml/kg/min). VAVD at -40 mm Hg caused right atrial trauma in four fetuses; no injury was seen at -20 mm Hg. Venous air entrainment during repair of the injuries did not result in any apparent air embolism. Spontaneous pulmonary hemorrhage occurred in two fetuses at the highest flows (> or = 400 ml/kg/min). In all but one case, termination of bypass was followed by placental dysfunction within 120 minutes. VAVD can be safely applied during fetal bypass provided pressures are kept < or = -20 mm Hg. However, the achieved higher flow rates do not prevent postbypass placental dysfunction and may indeed be detrimental to the fetus.     

End-tidal carbon dioxide monitoring indicates recovery from cardiogenic shock in patients receiving percutaneous cardiopulmonary support

The aim of this study was to examine the prognostic value of monitoring end-tidal carbon dioxide (ETCO₂) levels for patients in cardiogenic shock undergoing percutaneous cardiopulmonary support (PCPS). Fifteen patients in whom PCPS was used to treat cardiogenic shock were enrolled in this study. For hemodynamic measurements, a thermodilution catheter was inserted into the pulmonary artery and an infrared absorption sensor was placed in the main stream of exhaled air between the respiration tube and the respirator to measure ETCO₂ levels. Nine patients (group II, 60%) died of multiple organ failure. In the six survivors (group I), there was a significant increase in average ETCO₂ level from 8.8 ± 3.9 mmHg before treatment to 20.5 ± 2.1 mmHg 24 h after the start of PCPS compared with values in group II patients (8.8 ± 3.9 mmHg, P = 0.0411). Also, serum lactate concentrations fell significantly in group I patients (group I 2.8 ± 0.47 mmol/l, group II 9.0 ± 2.31 mmol/l, P = 0.0435). The mean ETCO₂ level in group I patients gradually returned to 23 mmHg, which was within the normal healthy range; these patients were successfully weaned from PCPS. These results suggest that, in cardiogenic shock patients, ETCO₂ level is a possible index of cardiac recovery during PCPS support.     

Hemodynamic profile of intravenous fenoldopam in patients with hypertensive crisis

Summary Fenoldopam, a newly developed intravenous dopaminergic DA₁ receptor agonist, was used in an open, prospective study for blood pressure control in 12 patients presenting with hypertensive crisis. At a dose of 0.2–0.5 g kg^–1 min^–1 fenoldopam decreased systolic blood pressure from 209±13 to 151±17 mmHg and diastolic blood pressure from 114±10 to 78±10 mmHg. Blood pressure was controlled in all 12 patients within 5–50 min. In none of the patients did rebound hypertension occur upon termination of the study medication, nor was any adverse event reported. Major hemodynamic changes induced by fenoldopam were a decrease in total peripheral resistance from 1853±611 to 1193±368 and in pulmonary vascular resistance from 252±170 to 180±74 dyne s^–1 cm^–5. In patients with high left ventricular filling pressure at study pulmonary capillary wedge pressure decreased while the stroke volume index and mixed venous oxygen saturation increased under fenoldopam. Thus, fenoldopam appears to be a rapid-acting, well-tolerated, and highly effective intravenous substance for the treatment of severe hypertension.     

Use of a soft reservoir bag in a fully heparin-coated closed-loop cardiopulmonary bypass system for distal aortic perfusion during aortic surgery

A fully heparin-coated closed-loop cardiopulmonary bypass system has recently been introduced into clinical practice. Without a venous reservoir, however, it does not allow control of the preload to the heart. We connected a soft reservoir bag in parallel with a centrifugal pump to enable preload control and clinically evaluated this modified system for distal aortic perfusion during aortic surgery. We have used the modified system in 17 patients since November 2002. For venous drainage, we use long narrow cannulae (21 ± 2 French). We administered 1 mg/kg heparin without cardiotomy suction and 2 mg/kg heparin with suction. We compared the clinical results with those in 13 patients who underwent distal aortic perfusion with an open cardiopulmonary bypass circuit between January 2002 and February 2004. We also analyzed factors affecting the coagulation system in these 30 patients using multiple regression analysis. With the modified system, venous drainage was adequate despite the use of smaller cannulae, and heparin reduction was not associated with thrombotic complication or elevated D-D dimer levels. Abrupt rises in proximal aortic pressure on aortic cross-clamping could be avoided by allowing blood to drain into the soft reservoir bag. Clinical results were not different from those with an open system. In the multiple regression analysis, the peak activated clotting time tended to correlate with postoperative platelet counts. This system is effective in controlling the preload to the heart and allows the safe reduction of heparin dosage. It therefore seems useful for distal aortic perfusion during aortic surgery.     

Delivery of gaseous microemboli with vacuum-assisted venous drainage during pulsatile and nonpulsatile perfusion in a simulated neonatal cardiopulmonary bypass model

This study investigated delivery of gaseous microemboli (GME) with vacuum-assisted venous drainage (VAVD) at various flow rates and perfusion modes in a simulated neonatal cardiopulmonary bypass (CPB) model. Four transducers (postpump, postoxygenator, postfilter, and venous line) of the emboli detection and classification (EDAC) quantifier were inserted into the CPB circuit to detect and classify GME. Four negative pressures (0, -15, -30, and -45 mm Hg), 3 flow rates (750, 1,000, and 1,250 ml/min), and 2 perfusion modes (pulsatile and nonpulsatile) were tested. After injecting 10 ml air into the venous line via an 18G needle, 2-minute segments of data were recorded simultaneously through 4 transducers. This entire process was repeated 6 times for each unique combination of pressure, flow rate, and perfusion mode, yielding a total of 144 experiments. Independent of perfusion mode and flow rate, the use of VAVD with higher negative pressures delivered significantly more GME at the postpump site. There was no difference in delivery at the postfilter site. The majority of GME were trapped by the Capiox Baby-RX hollow-fiber membrane oxygenator. Compared with nonpulsatile flow, pulsatile flow transferred more GME at the postpump site at all 3 flow rates. Our results suggest that VAVD with higher negative pressures, increased flow rates, and pulsatile flow could deliver more GME at the postpump site when a fixed volume air is introduced into the venous line. The Emboli Detection and Classification Quantifier is a sensitive tool for the detection and classification of GME as small as 10 microns in this simulated neonatal model.     

经腹路径腹腔镜解剖性逆行肾上腺切除术的临床研究

目的　介绍改进的经腹路径腹腔镜解剖性逆行肾上腺切除术的手术技巧和临床经验。 方法　回顾性分析2009年1月至2013年1月间行经腹路径腹腔镜解剖性逆行肾上腺切除术47例患者的临床资料, 并与同期采用后腹腔镜肾上腺手术36例的临床结果进行比较。 结果　经腹路径腹腔镜解剖性逆行肾上腺切除组均取得成功。与后腹腔镜组相比,此术式可明显缩短手术时间（45.6±23.4 min vs.115.5±18.2 min）;减少术中出血量（25.3±10.6 ml vs.110.6±30.3 ml）。组间比较差异有显著性意义（P＜0.001）。无术后并发症发生（0 vs.13.8%）。 结论　经腹路径腹腔镜解剖性逆行肾上腺切除术分离组织范围小,定位、切除肾上腺快捷,术中出血少,是肾上腺良性病变可靠、安全的腹腔镜手术方式。     

QRS width does not reflect ventricular dyssynchrony in patients with heart failure

The purpose of this study was to evaluate QRS width as an indication for cardiac resynchronization therapy. This study group consisted of 64 heart failure patients (51 men, age average 60.5 ± 15.5 years) with a left ventricular ejection fraction (LVEF) of less than 35%. Patients were divided into two groups according to their QRS width; the wide QRS group (QRS width greater than or equal to 120 ms, 31 patients) and the narrow QRS group (QRS width less than 120 ms, 33 patients). The ventricular dyssynchrony (VD), i.e., the inter- and intraventricular dyssynchrony, of the two groups was compared. The correlation between QRS width and VD was evaluated in all patients. There were no significant differences between the wide and the narrow QRS groups concerning interventricular dyssynchrony [28.4 ± 26.1 ms vs. 25.3 ± 18.2 ms, not significant (NS)] or intraventricular dyssynchrony (99.0 ± 43.8 ms vs. 109.0 ± 56.6 ms, NS). Nor were there any differences in the LVEF (26.6 ± 6.6% vs. 28.2 ± 5.1%, NS), brain natriuretic peptide (BNP) (567.0 ± 319.0 pg/ml vs. 390.0 ± 375.8 pg/ml, NS), and New York Heart Association (NYHA) class (2.4 ± 0.8 vs. 2.0 ± 1.0, NS). QRS width did not correlate with interventricular (r = 0.026, NS) or intraventricular dyssynchrony (r = 0.052, NS). There were no differences in VD between the two groups based on differences in QRS width. There was also no correlation between QRS width and VD. It is suggested that QRS width is not an absolute indication for cardiac resynchronization therapy.     

Vacuum-assisted venous drainage in single-access minimally invasive cardiac surgery

 This retrospective study evaluated the influence of vacuum-assisted venous drainage in single-access minimally invasive cardiac surgery. A total of 104 patients who underwent cardiac surgery via minimal access incision were included in this study. Cardiopulmonary bypass was initiated with gravity alone, and vacuum-assisted venous drainage was applied only when the bypass flow was 2.2 l/min/m² or less. We compared intraoperative variables of the patients to whom vacuum-assisted venous drainage (vacuum group) was applied with those who underwent gravity venous drainage alone (gravity group). In the 13 patients who most recently underwent isolated valve operations without maze procedures, free hemoglobin was measured to evaluate hemolysis. Vacuum-assisted venous drainage was required in 77 (72.6%) patients. Except for a smaller body surface area in the gravity group (P = 0.0118), patient characteristics did not differ significantly between the two groups. Free hemoglobin 60 mins after the beginning of cardiopulmonary bypass was higher in the vacuum group than in the gravity group (21.5 ± 7.3 vs 11.1 ± 7.1 mg/dl, P = 0.0284). Operative mortality and morbidity did not differ significantly between the groups. We found vacuum-assisted venous drainage to be a safe, simple, and effective technique in cases of minimally invasive cardiac surgery. However, there is a potential risk of hemolysis and air embolism, as shown in our findings and previous reports. Received: May 14, 2002 / Accepted: October 28, 2002 Present address: Department of Cardiovascular Surgery, Sayama Hospital, 1-33 Unoki, Sayama, Saitama 350-1323, Japan Tel. +81-42-953-6611; Fax +81-42-953-8040 e-mail: hykiyama@da2.so-net.ne.jp Correspondence to:H. Kiyama     

Effects of candesartan and propranolol combination therapy versus propranolol monotherapy in reducing portal hypertension

Background/Aims

Angiotensin receptor blockers (ARBs) inhibit activated hepatic stellate cell contraction and are thought to reduce the dynamic portion of intrahepatic resistance. This study compared the effects of combined treatment using the ARB candesartan and propranolol versus propranolol monotherapy on portal pressure in patients with cirrhosis in a prospective, randomized controlled trial.

Methods

Between January 2008 and July 2009, 53 cirrhotic patients with clinically significant portal hypertension were randomized to receive either candesartan and propranolol combination therapy (26 patients) or propranolol monotherapy (27 patients). Before and 3 months after the administration of the planned medication, the hepatic venous pressure gradient (HVPG) was assessed in both groups. The dose of propranolol was subsequently increased from 20 mg bid until the target heart rate was reached, and the candesartan dose was fixed at 8 mg qd. The primary endpoint was the HVPG response rate; patients with an HVPG reduction of >20% of the baseline value or to <12 mmHg were defined as responders.

Results

The mean portal pressure declined significantly in both groups, from 16 mmHg (range, 12-28 mmHg) to 13.5 mmHg (range, 6-20 mmHg) in the combination group (P<0.05), and from 17 mmHg (range, 12-27 mmHg) to 14 mmHg (range, 7-25 mmHg) in the propranolol monotherapy group (P<0.05). However, the medication-induced pressure reduction did not differ significantly between the two groups [3.5 mmHg (range, -3-11 mmHg) vs. 3 mmHg (range, -8-10 mmHg), P=0.674]. The response rate (55.6% vs. 61.5%, P=0.435) and the reductions in mean blood pressure or heart rate also did not differ significantly between the combination and monotherapy groups.

Conclusions

The addition of candesartan (an ARB) to propranolol confers no benefit relative to classical propranolol monotherapy for the treatment of portal hypertension, and is thus not recommended.     

术中应用不同假体对全膝关节置换术后引流的影响

目的 探讨术中使用后方稳定型（posterior cruciate stabilization, PS）与后交叉韧带保留型（posterior cruciate retention, CR）假体对全膝关节置换术（total knee arthroplasty, TKA）术后引流的影响。方法 回顾性分析2018年6月至2018年10月终末期骨性关节炎行全膝关节置换的患者102例，其中62例采用后交叉韧带保留型（CR）假体（CR组），40例采用后稳定型（PS）假体（PS组）。所有患者术中均使用止血带、关节腔注射氨甲环酸（tranexamic acid, TXA），术后患肢屈曲1 h、引流管夹毕1 h、患肢冰敷24 h。收集术后2、4、24、48 h引流量和引流液中血红蛋白（hemoglobin, HB）含量，以及术后2、24、48 h静脉血中的血红蛋白（HB）含量。统计术后输血情况、早期感染并发症例数。结果 102例患者随访3个月，术后总引流量CR组（292.9±128.3）mL比PS组引流量为（355.2±136.8）mL少，两组比较差异有统计学意义（P＜0.05）。术后1 d的CR组的引流量比PS组少，两组比较差异有统计学意义（P＜0.05）。术后24 h的CR组引流液中血红蛋白含量比PS组明显下降，两组比较差异有统计学意义（P＜0.05）。术后24、48 h的PS组静脉血中血红蛋白含量比CR组明显下降，两组比较差异有统计学意义（P＜0.05）。CR组2例输了2 U红细胞，PS组2例输了1 U红细胞、9例输了2 U红细胞。102例患者术后早期均未出现感染并发症。结论 与PS假体相比，采用CR假体可减少患者的失血量、术后引流量少、降低全膝关节置换术后贫血的发生、减少围术期输血率。     

Acute but not chronic metabolic acidosis potentiates the acetylcholine-induced reduction in blood pressure: an endothelium-dependent effect

Metabolic acidosis has profound effects on vascular tone. This study investigated the in vivo effects of acute metabolic acidosis (AMA) and chronic metabolic acidosis (CMA) on hemodynamic parameters and endothelial function. CMA was induced by ad libitum intake of 1% NH4Cl for 7 days, and AMA was induced by a 3-h infusion of 6 M NH4Cl (1 mL/kg, diluted 1:10). Phenylephrine (Phe) and acetylcholine (Ach) dose-response curves were performed by venous infusion with simultaneous venous and arterial blood pressure monitoring. Plasma nitrite/nitrate (NOx) was measured by chemiluminescence. The CMA group had a blood pH of 7.15±0.03, which was associated with reduced bicarbonate (13.8±0.98 mmol/L) and no change in the partial pressure of arterial carbon dioxide (PaCO2). The AMA group had a pH of 7.20±0.01, which was associated with decreases in bicarbonate (10.8±0.54 mmol/L) and PaCO2 (47.8±2.54 to 23.2±0.74 mmHg) and accompanied by hyperventilation. Phe or ACh infusion did not affect arterial or venous blood pressure in the CMA group. However, the ACh infusion decreased the arterial blood pressure (ΔBP: -28.0±2.35 mm Hg [AMA] to -4.5±2.89 mmHg [control]) in the AMA group. Plasma NOx was normal after CMA but increased after AMA (25.3±0.88 to 31.3±0.54 μM). These results indicate that AMA, but not CMA, potentiated the Ach-induced decrease in blood pressure and led to an increase in plasma NOx, reinforcing the effect of pH imbalance on vascular tone and blood pressure control.     

Glomerular ultrafiltration in rabbits with superficial glomeruli

The determinants of glomerular ultrafiltration in superficial glomeruli of a strain of English cross-breed rabbits have been studied using micropuncture techniques. Mean arterial blood pressure in the anaesthetised rabbits was 70±2 mmHg. The glomerular filtration rate in the kidney prepared for micropuncture was 4.4±0.4 ml/min, the filtration fraction was 22±1% and renal blood flow was 33±3 ml/min, and these values were comparable to values in conscious rabbits. Glomerular capillary pressure (P _gc) averaged 31±1 mmHg, the single-nephron glomerular filtration rate (SNGFR) averaged 25±2 nl/min, and the mean ultrafiltration pressure (calculated using the whole-kidney filtration fraction) averaged 7±1 mmHg. A net positive pressure at the efferent end of the glomerular capillaries (4.4±0.9 mmHg) indicated that a state of filtration pressure disequilibrium existed, under the experimental conditions of this study, in rabbit glomeruli. The calculated glomerular ultrafiltration coefficient (K _f) was 0.08±0.01 nl s^–1 mmHg^–1. Thus, compared to the Munich-Wistar rat, SNGFR is lower in the rabbit. This reflects the substantially lower glomerular ultrafiltration pressure in the rabbit, although this was offset partially by a higher K_f.     

ANF-Konzentrationen und Drücke im kleinen Kreislauf unter Belastung vor und nach Koronardilatation

Summary According to several reports of close correlations between pulmonary artery pressure and ANF plasma levels it would be convenient to replace invasive pressure monitoring by ANF determination.Mean pulmonary artery and right atrial pressures and pulmonary artery as well as peripheral venous ANF plasma concentrations were measured in 24 patients before and after coronary angioplasty (PTCA) continuously at rest and during exercise: At rest, both pressure and ANF-values remained unchanged before and after PTCA. At exercise, there was a decrease of mean pulmonary artery pressure (from 41.3±8.6 to 31.5±7.4 mmHg,p<0.001), mean right atrial pressure (from 11.9±3.0 to 9.0±2.3 mmHg,p< 0.001), pulmonary artery (282.5±191.0 to 207.3±157.2 pg/ml,p<0.05) and peripheral venous (112.7±48.0 to 97.1±53.2 pg/ml, n.s.) ANF concentration after PTCA. We found no correlation between PTCA-induced changes of right arterial pressures and ANF concentrations, while changes of pulmonary artery pressures were significantly correlated to changes of peripheral venous (r=0.79,p<0.001) as well as pulmonary artery (r=0.59,p<0.01) ANF concentrations at exercise. In 6 of the 24 patients, however there was an inverse relationship between changes of pulmonary artery pressures and ANF concentrations. — Our data demonstrate a significant correlation between changes of ANF plasma level and pulmonary artery pressure values at exercise after PTCA. In the individual case however invasive pressure monitoring cannot be replaced by determination of ANF plasma levels.

---

Abkürzungsverzeichnis ANF Atrialer natriuretischer Faktor - PTCA Perkutane transluminale Koronarangioplastie - PPa mittlerer pulmonalarterieller Druck - PPc mittlerer pulmonalcapillärer Druck - PRA mittlerer rechtsatrialer Druck Herrn Prof. Dr. med F. Scheler zum 65. Geburtstag gewidmet     

Perkutane transfemorale Valvuloplastie bei Patienten mit kalzifizierter Aortenstenose und deutlich erhöhtem Operationsrisiko: Klinischer Verlauf und Wertigkeit der Dopplersonographie zur Beurteilung des Therapieerfolges

Summary Percutaneous transluminal valvuloplasty (PTV) was performed in 24 patients (aged 67–86 years, mean: 76±5.7 years) with calcific aortic stenosis and high operative risk. The gradient between maximal left ventricular and aortic pressures (peak-to-peak gradient, PPPG) could be reduced by 52% from 73±21 to 34±12 mmHg (p<0.001). Peak pressure gradient (PPG), as assessed by continuous wave Doppler, could be reduced from 80±28 to 58±21 mmHg (p<0.001). Aortic valve area (AVA) as determined by Doppler and two dimensional echocardiography increased significantly from 0.39±0.14 to 0.61±0.3 cm² (p<0.05). Clinical symptoms were found to be improved in 5 of 8 patients with impaired ejection fraction and in 11 of 16 patients with normal ejection fraction during the first week after PTV. Complications due to the procedure were surgical revision of femoral artery puncture site in one patient and hemodynamic relevant pericardial effusion in another patient. Transmitral early (E) and late (L) diastolic filling integrals were measured by pulsed Doppler: the ratio E/L decreased significantly after PTV from 0.9±0.5 to 0.63±0.31 (p<0.03) indicating further reduction of left ventricular early diastolic filling. Ejection fraction, stroke volume and cardiac output did not significantly change immediately after PTV.The results indicate, that PTV can successfully reduce aortic pressure gradients and improve symptoms in patients with calcific aortic stenosis and high operative risk. Doppler echocardiography provides an adequate method to noninvasively evaluate the initial outcome of PTV and seems valuable for the assessment of long term results.

---

Abkürzungsverzeichnis AKE prothetischer Aortenklappenersatz - AoP maximaler systolischer Aortendruck - AVA Aortenklappenöffnungsfläche - E Integral frühdiastolischer Füllungsgeschwindigkeiten - EF Ejektionsfraktion - HR Herzfrequenz - HZV Herzzeitvolumen - L Integral spätdiastolischer Füllungsgeschwindigkeiten - LVP maximaler systolischer linksventrikulärer Druck - NYHA New York Heart Association - PPG peak pressure gradient - PPPG peak-to-peak pressure gradient - PTV Perkutane transmfemorale Valvuloplastie - SEP Systolische Ejektionsperiode - SV Schlagvolumen     

Effects of inspiratory impedance on hemodynamic responses to a squat–stand test in human volunteers: implications for treatment of orthostatic hypotension

Recent studies in our laboratory demonstrated that spontaneous breathing through an inspiratory impedance threshold device (ITD) increased heart rate (HR), stroke volume (SV), cardiac output (Q), and mean arterial blood pressure (MAP) in supine human subjects. In this study, we tested the effectiveness of an ITD as a countermeasure against development of orthostatic hypotension, provoked using a squat-to-stand test (SST). Using a prospective, randomized blinded protocol, 18 healthy, normotensive volunteers (9 males, 9 females) completed two-counterbalanced 6-min SST protocols with and without (sham) an ITD set to open at 0.7 kPa (7-cm H₂O) pressure. HR, SV, Q, total peripheral resistance (TPR), and MAP were assessed noninvasively with infrared finger photoplethysmography. Symptoms were recorded on a 5-point scale (1=normal; 5=faint) of subject perceived rating (SPR). The reduction in TPR produced by SST (–35±5 %) was not affected by the ITD. Reduction in MAP with ITD during the transient phase of the SST (–3.6±0.5 kPa or –27±4 mmHg) was less (P=0.03) than that measured while breathing through a sham device (–4.8±0.4 kPa or –36±3 mmHg) despite similar (P<0.926) elevations in HR of 15±2 bpm. SV (+2±4 %) and Q (+22±5 %) with the ITD were higher (P<0.04) than SV (–8±4 %) and Q (+10±6 %) without the ITD. SPR was 1.4±0.1 with ITD compared to 2.0±0.2 with the sham device (P<0.04). This reduction in orthostatic symptoms with application of an ITD during the SST was associated with higher MAP, SV and Q. Our results demonstrate the potential application of an ITD as a countermeasure against orthostatic hypotension.     

负压引流器及改良引流技术用于ERCP术后鼻胆管引流的临床研究

目的:观察负压引流器及改良引流技术在ERCP术后鼻胆管引流中的临床价值。 方法:选择100例行ERCP患者进行前瞻性研究,按随机数字表分为观察组与对照组,各50例。观察组采用负压引流器联合改良引流技术,对照组应用常规留置引流袋进行引流并予常规引流护理。比较两组每日引流量、导管堵塞发生率、住院时间、住院费用、术后并发症（包括高淀粉酶血症、胆管炎、胰腺炎等）总发生率、不适反应与导管不良事件总发生率。 结果:观察组每日引流量显著高于对照组（P<0.05）;观察组导管堵塞发生率、住院时间、住院费用显著低于对照组（P<0.05）。两组胆管炎与胰腺炎发生率未见统计学意义（P>0.05）;观察组高淀粉酶血症与并发症总发生率分别为12.00%与14.00%,显著低于对照组的28.00%与40.00%（P<0.05）。观察组不适反应与导管不良事件总发生率为4.00%,显著低于对照组的22.00%（P<0.05）。 结论:ERCP术后采用负压引流器进行鼻胆管引流,可获得理想引流效果,降低导管堵塞率,减少术后并发症与不适症状,改良引流技术还可进一步降低导管脱出率,确保引流通畅,可加速患者恢复,使住院时间缩短。     

高负压与常规引流对人工髋关节置换术后失血量与切口愈合影响的研究

目的比较高负压引流与常规引流对人工髋关节置换术后失血量与切口愈合的影响,以期为临床合理选择提供依据。方法回顾性分析2017年1月至2018年12月在本院行髋关节置换手术的85例患者的临床资料,根据术后引流方式的不同,将患者分为高负压引流组(A组,44例)和常规引流组(B组,41例),比较两种方式的术后血红蛋白量(HGB)和红细胞比容(HCT)、术后引流量和总失血量、术后切口愈合时间、切口并发症发生率、切口感染率、术后VAS评分等指标。结果两组患者均获得随访,随访时间1～3个月。高负压引流组术后HGB为(96.71±10.21)g/L、术后HCT为(30.15%±3.69%),均低于常规引流组术后HGB(105.93±11.08)g/L、术后HCT(34.90%±4.11%);高负压引流组术后引流量为(394.36±101.23) mL、总失血量为(1 180.23±150.15)mL,均高于常规引流组术后引流量(221.24±75.53)mL、总失血量(1 006.92±162.32)mL;高负压引流组术后切口愈合时间(15.73±3.75)d、切口并发症发生率(6.82%,3/44)和术后VAS评分(2.38±0.76)分均低于常规引流组术后切口愈合时间(18.53±4.38)d、切口并发症发生率(19.51%,8/41)和术后VAS评分(2.90±0.84)分,以上指标比较差异均有统计学意义(P0.05)。两组患者在切口感染率方面比较差异无统计学意义(P0.05)。结论人工髋关节置换术后高负压引流较常规引流切口愈合快、并发症少和疼痛轻,但术后HGB和HCT低,引流量和失血量大,应根据患者具体情况选择应用。     

Impeded venous drainage: Novel view of chronic venous disease pathophysiology

Venous valve incompetence role as the primary pathology occurring in patients with chronic venous diseases (CVD) has long been exaggerated. Management strategies based on the current pathophysiological concepts are far from perfect. A novel concept is introduced describing the importance of patency of axial venous system with “Pressure gradient model” providing the venous system architecture required for efficient venous drainage. The roles of calf muscle pump, perforators and venous valves according to the novel concept are described. Impeded venous drainage (IVD) plays the key role in the pathophysiology of CVD. Management of CVD should be directed to correction of IVD instead of correction or ablation of valve incompetence.     

Central transmural venous pressure and plasma arginine vasopressin during negative pressure breathing in man

Summary After overnight food and fluid restriction, 8 normal healthy males were examined in the upright sitting position before (prestudy), during and after (recovery) negative pressure breathing (NPB) with a pressure (P=difference between airway pressure and barometric pressure) of –9.6±0.5 to –10.4±0.4 mm Hg for 30 min. Plasma arginine vasopressin (pAVP) did not change significantly comparing prestudy with 10 and 30 min of NPB or comparing recovery with NPB at 10, 20 or 30 min. However, at 20 min of NBP, pAVP was slightly lower than at prestudy (p<0.05). Central venous pressure (CVP) decreased significantly during NPB, and central transmural venous pressure (CVP—P) increased significantly from –0.9±0.8 mm Hg to 3.8±0.7, 4.3±0.7 and 4.5±0.6 mm Hg (p<0.001) after 10, 20 and 30 min, respectively. Systolic, diastolic and mean arterial pressure and heart rate did not change significantly during NPB. Diuresis, natriuresis, kaliuresis, osmotic excretion and clearance were slightly increased during the recovery hour after NPB compared to prestudy, while urine osmolality decreased during NPB (n=6). However, none of these changes were significant. There was no significant correlation between CVP—P and pAVP. In conclusion, –10 mm Hg NPB for 30 min in upright sitting subjects did not change pAVP consistently, while CVP—P was significantly increased and HR and arterial pressures were unchanged. This lends support to the concept that arterial baroreceptors and not cardiopulmonary mechanoreceptors are of importance in regulating AVP secretion in man.This investigation was supported by the Danish Space Board grant no. 1112-13/84, 1112-19/84, 1112-33/84, and 1112-34/84     

Whole-body heating slows carotid baroreflex response in human subjects

Heat stress increases sympathetic activity and decreases parasympathetic activity to the heart. To test the hypothesis that carotid baroreflex responses of heart rate (HR) and systemic blood pressure become slowed with altered autonomic nerve activities during whole-body heat stress, we determined changes in HR and mean arterial pressure (MAP) in response to ~5 s of 40 mmHg neck pressure (NP) and of –65 mmHg neck suction (NS) in normothermia and during whole-body heating produced by a hot water-perfused suit. The NP and NS stimuli were triggered by R waves of an ECG during held expiration in the supine position. Whole-body heating did not alter the onset time of the HR and MAP responses during NP and NS. Whole-body heating significantly increased the time from onset of the HR response until peak of the response during NP (2.53±0.33 s in normothermia and 3.46±0.28 s during heating, P<0.05) and NS (1.20±0.23 s and 2.24±0.29 s, P<0.05). Whole-body heating significantly increased the time from onset of the MAP response until peak of the response during NP (4.31±0.46 s in normothermia, 6.67±0.56 s during heating, P<0.05) but not during NS (5.06±0.47 s and 4.50±0.60 s). These findings suggest that heat stress prolongs the response time of carotid-cardiac and carotid-vasomotor baroreflexes.