Precordial compression without airway management induces lung injury in the rodent cardiac arrest model with central apnea.

To investigate whether the lung injury induced by precordial compression without ventilation or not, in the cardiac-arrest animal model with central apnea. Thirty male Sprague-Dawley rats were anesthetized with halothane. The cardiac arrest was induced by 100 mg/kg ketamine (IV) and accompanied with central apnea. They were allocated to four groups by means of resuscitation. Group A was treated with only precordial compression without the other treatments. In group B with tracheotomy and precordial compression. In group C was performed tracheotomy, oxygenation, and precordial compression. The animals in group D were treated with tracheotomy, oxygen administration, artificial ventilation, and precordial compression. Four minutes after cardiac arrest, the resuscitation was started and continued for 20 min. PaCO(2) in the group without mechanical ventilation increased significantly after the start of the resuscitation. All animals were sacrificed after resuscitation procedure. The wet/dry weight ratio of lung in group A (6.9+/-0.8) was significantly higher than that of the other groups B, C and D (5.9+/-0.6, 5.7+/-0.4 and 5.6+/-0.4, P<0.05 in each). The pathological findings also demonstrated the lung injuries, such as edema, migration, and destruction of structure in group A. The precordial compression alone did not improve CO(2) elimination in the gasping-less cardiac arrest model, as well as maybe inducing more severe lung injury than that with the protective management. This experimental model raises the possibility that chest compressions without airway management might result in lung injury.

Partial liquid ventilation decreases serum tumor necrosis factor-alpha concentrations in a rat acid aspiration lung injury model.

OBJECTIVE: To examine the hypothesis that partial liquid ventilation (PLV) with perfluorocarbon would decrease serum tumor necrosis factor-alpha concentrations in a rat acid aspiration lung injury model. DESIGN: Prospective, controlled animal study. SETTINGS: Research laboratory in a university setting. SUBJECTS: Male Sprague-Dawley rats. INTERVENTIONS: Treatment with intratracheal perflubron or control mechanical ventilation beginning 30 mins after acid aspiration. MEASUREMENTS AND MAIN RESULTS: PLV with perfluorocarbon compared with control ventilation resulted in significantly greater mean arterial blood pressures at 3 and 4 hrs and greater arterial Po2 at all times. Serum tumor necrosis factor-alpha at 2, 3, and 4 hrs was significantly less than that observed in the control group (4-hr values: 80+/-64 pg/mL vs. 658+/-688 pg/mL; p<.05), although no significant difference in tracheal fluid tumor necrosis factor-alpha concentrations (1425+/-1347 pg/mL vs. 2219+/-1933 pg/mL) was found. CONCLUSION: We conclude that the effects of PLV with perfluorocarbon can extend beyond improvements in pulmonary physiology and that PLV may be beneficial in reducing systemic sequelae of acute lung injury and inflammation.

[Effect of positive end-expiratory pressure on respiration and hemodynamics in dogs with pulmonary edema caused by increased membrane permeability].

The effect of PEEP on the extravascular lung water, respiratory mechanics and hemodynamics were studied in dogs with oleic acid-induced pulmonary edema. The dogs were randomized into one of three groups according to PEEP of 0, 5 and 10 cmH2O, 60 minutes after oleic acid (0.1 ml.kg-1) injection. PEEP improved oxygenation accompanied by increased FRC and DLco. However, oxygen delivery decreased in association with the decreased cardiac index caused by application of PEEP. PEEP failed to decrease the extravascular lung water volume measured by double-indicator dilution technique after lung edema formation.

[The effect of nicardipine hydrochloride upon the pulmonary arterial pressure].

This study examines the effects of induced hypotension with intravenous administration of nicardipine hydrochloride (NIC) upon pulmonary arterial pressure (PAP) undergoing modified radical mastectomy with neuroleptanesthesia (NLA-group; 3 cases) and inhalation anesthesia (N2O+ isoflurane; GOI-group; 3 cases). Systolic arterial pressure was reduced and maintained at 80 mmHg. During and after induced hypotension in NLA-group, heart rate (HR), cardiac index, pulmonary arterial pressure (PAP) increased remarkably. On the other hand, systemic vascular resistance index was reduced. In GOI group, no significant changes were seen in PAP. The acceleration of the autonomic baro-reflex induced by decreased blood pressure produced by NIC may be depressed under anesthesia to initiate this difference in response of HR to NIC. The data indicate that this depressive effect of NLA on this reflex is weak, and NIC is a potent systemic vasodilator with hyperdynamic hemodynamic effects in addition to an increase in right ventricular function, and PAP was increased.

[The evaluation of cuff-occluded rate of rise of peripheral venous pressure (CORRP) for monitoring blood volume status].

Cuff-occluded rate of rise of peripheral venous pressure (CORRP) was evaluated for perioperative monitoring. We investigated the CORRP in 6 patients undergoing open laparotomy. These patients were given general anesthesia, and monitoring lines were inserted. Heart rate, blood pressure (BP), right atrial pressure (RAP), pulmonary capillary wedge pressure (PCWP), pulmonary artery pressure (PAP), cardiac output (CO) and CORRP were monitored. CORRP is defined as the average rate (in millimeters of mercury per minute) of rise of peripheral venous pressure after proximal occlusion of that vein by a tourniquet (select pressure: 50 mmHg). In the actual measurement of CORRP, only the first 90% of the curve after occlusion of the tourniquet is used. CORRP correlated with RAP (r = 0.69 +/- 0.10), and PCWP (r = 0.79 +/- 0.07). On the other hand, there was no significant correlation between CORRP and BP, or PAP and CO. Snyder et al. described that CORRP seems to be an excellent indicator of acute volume change in the hyper- and hypovolemic canine model. We conclude that in these laparotomy patients, CORRP appears to be a sensitive and minimally invasive method of assessing volume status.

Clavicular approach to intraosseous infusion in adults.

We attempted a clavicular approach to intraosseous infusion (clavicular IO) as a new procedure in adults, and compared the flow rates of subclavian venous infusion, and clavicular, iliac and tibial IO. Furthermore, we observed enhanced roentgenograms of each IO by contrast media. As a result, clavicular IO indicated 11.9 +/- 0.68 mL/kg/hr (mean +/- SD, n = 29), iliac IO 32.2 +/- 4.48 (n = 21), tibial IO 18.9 +/- 1.28 (n = 15), and subclavian venous infusion 15.2 +/- 1.48 (n = 15). There were no statistically significant differences between subclavian venous infusion and clavicular IO. In roentgenograms, the contrast media entered the inferior vena cava from iliac IO, and via the femoral vein by tibial IO. The superior vena cava was enhanced through the subclavian vein in clavicular IO. No complications such as fractures or transclavicular penetrations by the IO needle occurred. In conclusion, clavicular IO may be an alternative infusion technique to provide the fluids into the subclavian vein in adults.

[Changes in urine oxygen tension (PuO2) during anesthesia with isoflurane and sevoflurane].

Leonhardt and coworkers have suggested that PuO2 may indicate degree of renal medullary perfusion and function. The changes in PuO2 during N2O-O2-isoflurane anesthesia (GOI) and N2O-O2-sevoflurane anesthesia (GOS) were studied in 20 patients (GOI group: 10 cases, GOS group: 10 cases) who underwent elective surgeries. In the GOI group, PuO2 decreased significantly 30 and 60 minutes after the beginning of surgical incision, and it returned to the previous value immediately after the cessation of isoflurane. In the GOS group PuO2 decreased starting 30 minutes after the beginning of surgical incision until 10 minutes after the cessation of sevoflurane. These results suggest that isoflurane and sevoflurane administration caused a reduction in renal medullary perfusion, and that the low perfusion during sevoflurane anesthesia lasted longer than during isoflurane anesthesia. Measurement of PuO2 has a number of problems, but we believe that PuO2 is useful as an indicator of renal medullary blood flow.

[Intrapleural regional analgesia in pain management after chest trauma].

Twelve chest trauma patients with severe pain were studied. All of them had multiple rib fractures, hemopneumothorax or pulmonary contusion, and needed the continuous chest drainage. 16 G epidural block catheter was introduced 20 cm into the apex of the pleural space. Furthermore, another catheter was placed into the base of the pleural space. After injecting 1% lidocaine 10 ml, the analgesic effect, the analgesic range according to injected point (apex or base), and the changes of vital signs, PaO2/FIO2 and PaCO2 were evaluated. The average pain scale before interpleural regional analgesia (IPA) was 2.9 and 1.0 after 15 min. The time to return to pre-IPA condition took about 150 min. The mean blood pressure did not show significant changes, although pulse and respiratory rate decreased. PaCO2 did not show significant changes, although PaO2/FIO2 increased significantly. The present study indicates that IPA in chest trauma reduces pain and improves PaO2/FIO2 significantly without circulatory changes. It was reported that it was difficult to obtain effective pain relief after thoracotomy. However, when the catheter is placed at the apex, it seems to be effective to relief pain on the chest site. In conclusion, IPA seems to be simple, effective and useful to remove pain from chest trauma when epidural block is difficult to induce.

[A study of postoperative respiratory function].

The purpose of this study is to investigate the causes of postoperative respiratory failure from the point of view of respiratory movement and respiratory function, using a respigraph. Thirty patients who had laparotomy, thoracotomy or both were studied. A-aDo2 increased after operation. The values recovered slowly in the order of thoracotomy, laparotomy, was thoraco-laparotomy group. Percent vital capacity (% VC), one second timed force expiratory volume (FEV1), and peak expiratory flow (PEF) were suppressed immediately after operations and increased slowly, but showed still lower values even on the 7th day. VT, V min, f, TI/TT, VT/TI and PaCO2 were almost at the same levels among the three groups. Percent rib cage (% of RC) increased and remained high on the 7th day after laparotomy and thoraco-laparotomy, but showed no remarkable changes after thoracotomy. Between A-aDo2 and % RC in laparotomy group, there was a good correlation. Not only FRC but also the change of % RC seemed to have caused postoperative hypoxemia. The movement of the abdomen affected respiratory dysfunction more than the movement of the thorax after thoracic and abdominal surgery.