Alveolar mobilization maneuver (recruitment): solved and unsolved problems

Acute respiratory distress syndrome (ARDS) is a common complication in patients with critical condition. Studies of pathophysiological changes in the lung in this condition give rise to new methods of respiratory therapy, one of which is alveolar mobilization maneuver (recruitment). This procedure considerably improves oxygenation in patients with ARDS, but at the same time, there is a risk of developing various complications (barotraumas, lowered cardiac output). Further studies of the efficiency of this method and development of well-defined clinical guidelines that will be able to answer the most important questions: "who", "when", and "how" the alveolar recruiting maneuver should perform are currently under way.     

Alveolar mobilization maneuver during intensive care of neonatal respiratory distress syndrome

The research is devoted to the assessment of the impact of the method of anesthesia on the psychoneurological status of a newborn during surgical delivery. It is revealed that subarachnoid anesthesia does not adversely affect the central nervous system of a newborn and is one of the best options for anesthetic management during surgical delivery because it provides a sufficient level of analgesia and is of a greatest safety for mother and child.     

The specific features of renal dysfunction in cardiosurgical patients

Subclinically insignificant glomerular filtration disturbances were found during operations under extracorporeal circulation. After termination of perfusion, dysfunction of the proximal portion of renal tubules was recorded in all patients. This may be associated with that the proximal tubules were more susceptible to ischemia. Further impairments of the distal portions of renal tubules suggest the persistence of ischemic lesions of the tubular apparatus.     

Recruiting maneuver used in the treatment of respiratory heart failure in cardiosurgical patients

The possibility of performing the recruiting artificial ventilation technique with a high plateau and positive end-expiratory pressure was studied in 32 cardiosurgical patients, including those with cardiovascular insufficiency. The lung opening maneuver, by using the artificial ventilation adjustable by pressure and the monitoring peak pressure, PDKV, tidal volume, and dynamic compliance, by accurately determining the points of opening and closure is the method of choice in alveolar recruitment. This method permits a significant improvement of arterial oxygenation and dynamic compliance of the lung in patients with acute respiratory failure. This maneuver using the high airway pressures adversely affects hemodynamics particularly in patients with lowered reserves of the cardiovascular system. In this connection, a careful monitoring of hemodynamic parameters is required for the timely provision of cardiotonic and vasopressor support.     

Comparative assessment of criteria for postoperative renal dysfunction in cardiosurgical patients

The paper presents data on comparison of the detection rate of renal dysfunction after cardiac surgery, by using the criteria developed by Cockroft-Gault, C. M. Mangano, L.-G. Andersson, and G. Zanardo. It is shown that it is expedient to calculate creatinine phosphokinase by the Cochroft-Gault formula that using a patient's individual parameters provides a more objective approach to making the diagnosis of renal dysfunction. The rate of development of renal dysfunctions in patients who have undergone cardiac surgery under extracorporeal circulation (EC) depends on the type of an operation and the duration and temperature of perfusion. By postoperative day 14, renal function became normal in the vast majority of patients. Renal function became chronic in 1% of the patients operated on the heart under EC.     

Effect of various colloidal solutions on pulmonary oxygenizing function in patients with acute lung lesion

The effects of 6% hydroxyethyl starch and 10% albumin solution on the parameters of central hemodynamics and pulmonary extravascular water were studied in acute lung lesion. The patients were divided into 2 groups that did not significantly differ by the baseline severity of a condition (APACHE II and Murray scales). Groups 1 and 2 patients were transfused 6% hydroxyethyl starch and 10% albumin solution, respectively. The "PICCO PLUS" system was used to determine the parameters of central hemodynamics, pulmonary extravascular water, and oxygenation before and after infusion of the test colloidal solutions. Unlike 10% albumin solution, 6% hydroxyethyl starch was found to significantly increase preload parameters, without deteriorating pulmonary oxygenizing function due to the accumulation of extravascular liquid.     

Continuous epidural infusion of ropivacaine hydrochloride (naropin) during postoperative analgesia in cardiosurgical patients

An efficiency and safety of continuous infusion of naropin in the epidural analgesia of 38 patients after coronary artery bypass grafting were demonstrated. A variation of combined anesthesia, which was elaborated at the Russian Research Center of Surgery of the Russian Academy of Medical Sciences and which comprises (as a basic component of anesthetic management) a high thoracal epidural block (T2-T4) by continuous infusion of a 2% solution of naropin at a velocity of 5 +/- 2 ml/h. Anesthesia was supported by isoflurane (0.5 +/- 0.9%). The patients were extubated in the operated theater and taken to the resuscitation unit with continuous infusion of 0.2% naropin solution. All studied parameters were registered after discharge from the operating theater and 1, 3, 6, and 16-18 hours after surgery. The pain-syndrome intensity was measured at the verbal scale with 0 to 3 points. The mean duration of continuous naropin infusion was 16.7 +/- 0.5 h, mean dose--2.2 +/- 0.2 ml/h. Naropin was administered at a dose of 1-3 ml/h in 89.7% of cases and at a dose of 6 ml/h only in 2.9% of cases. The drug, when used in small doses, ensured a high anesthetic efficiency. A total lack of pain or a mild pain of 0.1 points was observed in 86.5% of patients at stage 5 of examinations and in 100% of patients at stage 3. Naropin infusion did not entail any impairment in ventilation or gaseous metabolism. A reliable decrease of arterial pressure (AP) and of central venous pressure (CVP), (p < 0.05) were registered beginning from stage 2. CVP decrease versus stage 1 was ensured in 38.% of patients by stage 4 and the number of patients with a decreased CVP (less than 60 mm H) went up, versus stage 1, by 3 times. APsyst of less than 90-80 mm Hg was registered in 15 (39.8%) of patients at different examination stages, which necessitated the use of noradrenalin at mean dose of 174 +/- 21 ng/kg.min. The infusion of naropin at dose of 1-6 ml/h did not entail any impairment in the central nervous system (hallucinations, convulsions, and headache).     

Clinical and laboratory evaluation of 20% albumin (plasbumin) used in cardiosurgical patients

A randomized comparative study of the effect of 20% Albumin (Plasbumin) solution and 4% succinylated gelatin (helofusin) solution on homeostasis was conducted in 36 cardiosurgical patients when the solutions were used as components to fill a pump oxygenator (PO). A comparative analysis has indicated that the use of albumin in the primary volume of PO at a concentration of 2-3% provides a higher level of total protein and better maintains colloid osmotic pressure during extracorporeal circulation than that of helofusin. At the end of an operation, the oxygen index was higher in the patients given albumin (Plasbumin). It has been also ascertained that plasbumin is well tolerated, causes no adverse reactions, and produces no dose-dependent effect.     

PI metabolism and Ca mobilization in patients with platelet dysfunction]

The effect of STA2, thrombin and NaF on PI metabolism and Ca mobilization was investigated in patients with three kinds of platelet dysfunction, one each with platelet cyclo-oxygenase deficiency (A), defective aggregation to A23187 (B) and defective aggregation to STA2 (C). These responses were normal in patient (A), suggesting cyclooxygenase activity did not affect PI metabolism and Ca mobilization. PI metabolism was also normal in (B), although Ca mobilization in response to A23187 was delayed and that in response to thrombin was defective in the presence of extracellular Ca2+. This suggests that the patient's platelets have a defective IP3-induced Ca mobilization pathway. STA2 selectively failed to induce IP3 formation and Ca mobilization in (C), although 3H-labelled thromboxane ligand (3H-U46619) bound to the patient's platelets normally. It was suggested that the patient's platelets have a defect in postreceptor signal transduction, especially thromboxane receptor-mediated PLC activation pathway.     

Intensive therapy for multiple organ dysfunction in neonatal infants after cardiosurgical interventions

This study was undertaken to evaluate the efficiency of complex intensive therapy for multiple organ dysfunction syndrome (MODS) after cardiosurgical interventions at the resuscitative and intensive care unit of the A. N. Bakulev Research Center of Cardiovascular Surgery, Russian Academy of Medical Sciences. In 2003-2004, MODS developed in 70 (37%) of the neonatal infants operated on the heart and vessels. The babies' age ranged from 6 hours of life to 1 month (8.3 +/- 2.1 days of life, their body weight was from 1.7 to 4.1 kg (3.0 +/- 0.49 kg). All the patients were found to have significant renal and respiratory failures. There were more than 4 (4.1 +/- 0.5) failing vital viscera. The use of phosphodiesterase (III) inhibitors in therapy for acute left ventricular insufficiency significantly improved the performance of the left heart whereas nitric oxide inhalation significantly lowered pulmonary pressure in babies with acute right ventricular insufficiency and improved oxygenation in patients with MODS. The efficiency of nitric oxide inhalation in MODS significantly increased when it was used in combination with endotracheal administration of a surfactant and high-frequency oscillatory ventilation. Peritoneal dialysis effectively replaced renal function when acute renal failure (ARF) developed. Nevertheless, the development of ARF in the pattern of MODS is a marker of high mortality (89% in ARF versus 46% in MODS without ARF).     

Alveolar phospholipids in pulmonary alveolar proteinosis

The biochemical compositions of lung lavage fluid from three patients and that of the lung tissue obtained by a biopsy from a patient with alveolar proteinosis were analyzed. The lung lavage fluid was separated to the supernatant and the insoluble precipitate fractions by a brief centrifugation and the lung tissue was separated to surfactant and residual fractions by sucrose density gradient centrifugation. The supernatant of lung washing contained larger quantities of protein and less lipid which was mainly composed of lecithin and sphingomyelin. In contrast, the insoluble material of lung washing contained 4--8 fold of lipid as compared with the supernatant, and lecithin was a predominant phospholipid. From the analysis of fatty acid and individual molecular species of major phospholipids, the higher contents of dipalmitoyllecithin and sphingomyelin containing palmitate were found in the insoluble material. The phospholipid composition and fatty acid composition of lecithin were similar between the precipitate fraction of lung washing and the surfactant fraction of lung tissue. The ratio of protein to phospholipid in the precipitate fraction was similar to that of lung washing. These analytical data suggest that the materials accumulated in the alveoli of the patients may be derived mainly from the lung surfactant fraction. The metabolic studies showed that lecithin synthesis through de novo and lysolecithin pathways works in human lung with this disease as actively as in rat lung. The secretion of lung lecithin to the surfactant fraction also appeared to be normal. From these analytical and metabolic findings, the causes for the accumulation of the materials which cover alveolar surface and impair gaseous exchange in the alveoli of pulmonary alveolar proteinosis, were discussed.     

Alveolar recruitment maneuver in patients with subarachnoid hemorrhage and acute respiratory distress syndrome: A comparison of 2 approaches

Purpose

The purpose of the study was to compare 2 alveolar recruitment maneuvers (ARMs) approaches in patients with subarachnoid hemorrhage (SAH) and acute respiratory distress syndrome (ARDS).

Material and Methods

Sixteen SAH patients with ARDS were randomized in 2 similar groups. One received ARM with continuous positive airway pressure (CPAP) of 35 cm H₂O for 40 seconds (CPAP recruitment), whereas the other received pressure control ventilation with positive-end expiratory pressure of 15 cm H₂O and pressure control above positive end-expiratory pressure of 35 cm H₂O for 2 minutes (pressure control recruitment maneuver [PCRM]). Intracranial pressure (ICP) and cerebral perfusion pressure (CPP) were measured before and after ARM. The ratio of arterial oxygen tension to fraction of inspired oxygen was measured before and 1 hour after the ARM.

Results

After ARM, ICP was higher in CPAP recruitment (20.50 ± 4.75 vs 13.13 ± 3.56 mm Hg; P = .003); and CPP was lower in CPAP recruitment (62.38 ± 9.81 vs 79.60 ± 6.8 mm Hg; P = .001). One hour after the ARM, the ratio of arterial oxygen tension to fraction of inspired oxygen increased significantly only in PCRM (108.5 to 203.6; P = .0078).

Conclusion

In SAH patients with ARDS, PCRM did not affect ICP and decreased CPP in safe levels, besides improving oxygenation.     

Recruitment maneuver and high positive end-expiratory pressure improve hypoxemia in patients after pulmonary thromboendarterectomy for chronic pulmonary thromboembolism

OBJECTIVES: To investigate the effects of a recruitment maneuver and high positive end-expiratory pressure (PEEP) on oxygenation and hemodynamics in hypoxemic patients with pulmonary hypertension after pulmonary thromboendarterectomy for chronic pulmonary thromboembolism. DESIGN: Prospective, observational, clinical study. SETTING: A surgical intensive care unit in a national heart institute. PATIENTS: Fourteen consecutively admitted patients who developed acute lung injury (Pa(O2) <300 torr at F(IO2) 1.0) and pulmonary hypertension (mean pulmonary artery pressure >25 mm Hg) after pulmonary thromboendarterectomy for chronic pulmonary thromboembolism. INTERVENTIONS: The recruitment maneuver was an increase of PEEP to 30 cm H2O in one step for 1 min at F(IO2) 1.0. The level of pressure control ventilation during the recruitment maneuver was the same as before the maneuver. Subsequently, PEEP was decreased in 15-min intervals from 15 to 10, 5, and 0 cm H2O. MEASUREMENTS AND MAIN RESULTS: Hemodynamics and respiratory variables were analyzed before and during the recruitment maneuver and at each PEEP level. At F(IO2) 1.0, Pa(O2) increased from 240 +/- 62 torr to 470 +/- 83 torr at 15 cm H2O of PEEP and 469 +/- 75 torr at 10 cm H2O of PEEP after the recruitment maneuver (p < .001). At 15 cm H2O of PEEP, cardiac index decreased (from 2.7 +/- 0.6 at baseline to 2.2 +/- 0.3 L.min(-1).m(-2), p < .01) and mean blood pressure decreased (from 86 +/- 8 at baseline to 74 +/- 11 mm Hg, p < .05), but they returned to the baseline levels at 10 cm H2O of PEEP (2.5 +/- 0.4 L.min(-1).m(-2) and 83 +/- 9 mm Hg). There were no differences in mean pulmonary artery pressure at different levels of PEEP. CONCLUSIONS: In hypoxemic patients with pulmonary hypertension after pulmonary thromboendarterectomy for chronic pulmonary thromboembolism, oxygenation was improved by the recruitment maneuver followed by high PEEP. However, hemodynamics were transiently suppressed and overall oxygen delivery did not change.     

Regional citrate anticoagulation during continuous hemofiltration in cardiosurgical patients

Different citrate anticoagulation protocols are widely used during continuous renal replacement therapy. The investigation was to study the efficiency and safety of citrate coagulation in patients after cardiovascular interventions. Thirty-eight patients underwent continuous hemofiltration (CHF) with anticoagulation with 0.2% Prismocitrate 10/2 solution by the protocol of the company (Gambra Medical) after operations on the heart and large vessels. The clinical data, changes in azotemia, blood electrolytes and gases, as well as the mean values of citrate anticoagulation, and mean hemofilter life span were studied. The mean duration of citrate anticoagulation was 68 +/- 13.7 hours and its maximum duration wa 18 days. Predilution administration of Prismocitrate 10/2 along with postdilution replacement with routine solutions ensured the CHF dose of 35 ml/kg/hr. But for terminal conditions, volume metabolic control and effective anticoagulation were achieved without negative metabolic sequels and clinical complications. The mean life span of a hemofilter, with its mandatory replacement every 35-48 hours, was 40 hours. It is concluded that Prismocitrate 10/2 anticoagulation is an effective, safe, and easy-to-use method for CHF after cardiosurgical operations, which may be widely recommended when use of heparin is contraindicated.     

俯卧位肺复张对重症肺部感染患者血流动力学的影响

目的 在肺保护性通气策略的基础上,评价俯卧位条件下肺复张对重症肺部感染患者血流动力学的影响.方法 选择江西省赣州市人民医院重症监护病房(ICU)接受机械通气的重症肺部感染患者97例,行定容控制通气,在小潮气量(8 ml/kg)+呼气末正压(PEEP)6 cm H2O(1 cm H2O=0.098 kPa)的通气基础上,先后行仰卧位肺复张和俯卧位肺复张[PEEP 20 cm H2O+压力控制(PC)20 cm H2O].监测不同体位下肺复张前后心率(HR)、平均动脉压(MAP)、脉搏血氧饱和度(SpO2)、动脉血及混合静脉血的血气分析数据,并经颈内或锁骨下静脉穿刺置入双腔深静脉导管,经股动脉置入脉搏指示连续心排血量(PiCCO)监测导管,持续监测心排血指数(CI)、每搏量指数(SVI)、外周血管阻力指数(SVRI)、胸内血容量指数(ITBVI)、血管外肺水指数(EVLWI)、全心舒张期末容积指数(GEDVI)、全心射血分数(GEF)、每搏量变异(SVV)及中心静脉压(CVP)等参数.结果 ①与肺复张前比较,仰卧位和俯卧位肺复张后HR、MAP均无显著变化,而SpO2明显升高(仰卧位:0.954±0.032比0.917±0.025,俯卧位:0.982±0.028比0.936±0.039,均P＜0.05);且俯卧位肺复张后SpO2明显高于仰卧位(P＜0.05).②与肺复张前比较,仰卧位和俯卧位肺复张即刻CI (L·min-1·m-2)、SVI( ml/m2)、GEDVI( ml/m2)、GEF均明显下降(仰卧位:CI 3.2±0.4比3.8±0.6,SVI 32.4±5.6比38.8±6.5,GEDVI 689±44比766±32,GEF 0.267±0.039比0.305±0.056;俯卧位:CI 3.1±0.5比3.6±0.4,SVI 31.2±5.8比37.3±5.0,GEDVI 678±41比758±36,GEF 0.268±0.040比0.288±0.053,均P＜0.05),CVP(cm H2O)、SVV明显升高[仰卧位:CVP 10.7±1.5比8.2±2.5,SVV(11.2±3.3)％比(8.3±4.7)％;俯卧位:CVP 10.3±1.8比8.1±2.5,SVV(12.7±3.4)％比(9.1±3.6)％,均P＜ 0.05],但复张结束后即恢复至复张前水平;SVRI、ITBVI、EVLWI肺复张前后均无显著变化.仰卧位和俯卧位肺复张期间各指标比较差异无统计学意义.结论 俯卧位条件下实施肺复张较仰卧位肺复张可更有效改善氧合,除肺复张即刻SVI和GEF短暂降低外,对血流动力学影响轻微.     

Endothelial dysfunction in patients with Bechterew's disease (ankylosing spondylitis)

The aim of the study was to assess signs of endothelial dysfunction and lesion in patients with ankylosing spondylitis (AS) of different degrees of activity. Forty-four male patients aged 20 to 45 (mean age 34.2 +/- 6.6 years) with a valid diagnosis of AS and no manifest cardiovascular pathology were examined. According to the degree of disease activity, the patients were divided into two groups: group one included 19 patients with low or moderate disease activity, and group two consisted of 25 patients with a high degree of disease activity. Conventional cardiovascular risk factors were screened, and total coronary risk (TCR) and the risk of fatal cardiovascular events were determined. The functional condition of endothelium was assessed by Doppler examination of the brachial artery in re-reactive hyperemia tests (endothelium-dependent vasodilation--EDVD), and in nytroglycerine test (endothelium-independent vasodilation--EIVD). The level of circulating endothelial cells (CEC) was measured as a marker of endothelial lesion. No significant differences were observed between the groups in terms of most conventional cardiovascular risk factors, TCR, and the risk of fatal cardiovascular events. EDVD was significantly less in patients with a high AS activity vs. patients with low or moderate activity and controls. EIVD after nytroglycerine intake was significantly stronger in both groups not only by comparison with that in controls, but also by comparison with the degree of EDVD, which can also be judged as a manifestation of endothelial dysfunction. The level of CEC in high-activity patients was significantly higher than that in the low to moderate activity group and controls. Thus, patients suffering from AS display signs of endothelial dysfunction and lesion, which are most prominent in high activity of the disease and manifest by a decrease in EDVD with a simultaneous increase in EIVD and CEC level elevation. This shows that patients with high activity of AS are at a higher risk of developing cardiovascular pathology than those with a low level of disease activity and age- and sex-comparable healthy individuals.