Transcutaneous pressure at which the internal jugular vein is collapsed on ultrasonic imaging predicts easiness of the venous puncture.

Even though we use ultrasound guidance for central venous puncture, we sometimes experience difficulties. We infer that in such cases the vein is collapsed and that the transcutaneous ultrasound probe pressure at which the vein is collapsed (P (tc)) may predict the easiness of the venous puncture. We measured P (tc) and the diameter of the internal jugular vein in 47 adult patients in our ICU. After successful puncture, we also measured venous pressure (P (v)). The patients were divided into two groups based on the number of puncture attempts: ≥3 attempts constituted the "difficult group" and <3 attempts was considered the "easy group:" 33 patients were in the easy group and 14 patients were in the difficult group. The easy group showed significantly higher P (tc) value (9.3 ± 3.8 vs. 3.5 ± 0.9 cmH(2)O, P < 0.0001) and larger vertical diameter (9.2 ± 3.1 vs. 6.8 ± 2.2 mm, P = 0.013) than the difficult group. We observed a clear border between the minimum P (tc) in the easy group (6 cmH(2)O) and the maximum value in the difficult group (5 cmH(2)O). In conclusion, venous collapsibility and vertical diameter determine difficulty in performing venous puncture.

Hemorrhagic shock 3 days after catheterization from the axillary vein.

A 72-year-old woman presented pulmonary embolism. Continuous intravenous administration of heparin was controlled with values of activated clotting time targeted from 150 to 180 s. On the sixth intensive care unit (ICU) day, a central vein (CV) catheter was inserted through the right axillary vein. On the ninth ICU day, her blood pressure dropped and her right breast was obviously larger than the left. Chest computed tomography showed a large hematoma under the greater pectoral muscle. CV catheterization under anticoagulant therapy is risky for bleeding, but catheterization of the internal jugular vein rarely leads to hemorrhagic shock, even if it causes airway obstruction. The axillary vein is in a compartment filled with loose tissue. As there is no structure to cover the bleeding site, the hematoma would expand from the lateral region of the thorax to near the fifth or sixth rib, to which greater and smaller pectoral muscles are attached. Ultrasound-guided catheterization from the axillary vein is introduced as a new and promising alternative to that from the subclavian vein because of its safety, but we should be conservative about applying the axillary approach to patients with anticoagulant therapy, especially in case of an unskilled operator, and be aware of the possibility of late-onset bleeding.

Frequency and risk factors for subsyndromal delirium in an intensive care unit.

OBJECTIVE: Delirium and subsyndromal delirium in critically ill patients are important determinants of long-term functional disability and cognitive impairment. However, few outcome studies on sub-syndromal delirium have been reported. Thus, this study aimed to evaluate the incidence of delirium and sub-syndromal delirium as well as the risk factors and progression to delirium. DESIGN: A prospective cohort study. SETTING: Six bed medical and surgical intensive care unit in Otsu Municipal Hospital in Japan. METHODS: Delirium and sub syndromal delirium were evaluated using the Intensive Care Delirium Screening Checklist scores and the demographic data of the patients recorded. Statistical analyses were conducted using the Mann-Whitney U test and chi-square test for comparison. We also compared groups using multivariate analyses. RESULTS: Of the 380 patients who were screened, 15.8% and 33.9% had delirium or sub syndromal delirium, respectively and 9.5% of patients progressed from a state of sub syndromal delirium to delirium. Older age, predisposing cognitive impairment, blood transfusion, higher Acute Physiology and Chronic Health Evaluation II (APACHE II) score, low red blood cell count and high C-reactive protein levels were the risk factors highly associated with subsyndromal delirium symptoms. Older age, acute admission, steroid use, the utilisation of restraints and lower PaO2 were the determinants of progression to delirium. CONCLUSIONS: A high incidence of sub syndromal delirium was observed in critically ill patients. Patient with sub syndromal delirium must be promptly identified and treated due to the risk of progression to delirium.

[Case of cerebral salt wasting syndrome with difficulty in controling excessive urine volume].

Symptoms of hyponatremia and diuresis due to cerebral salt wasting syndrome (CSWS) are often observed after aneurysmal subarachnoid hemorrhage (SAH). Inadequately treated CSWS is known to work as a trigger of symptomatic vasospasm in SAH patients. Therefore, it is indispensable to detect and treat CSWS as early as possible in ICU. A 36-year-old man with SAH was admitted to our ICU. His urine volume increased excessively 3 days after ICU admission, and it reached a peak (39,250 ml x day(-1)) on the 6th day in ICU. Since infusion volume was controlled with regard to daily urinary output, hyponatremia was not noticeable and excessive urine volume stood out conspicuously. Though vasopressin and desmopressin were administered, the symptoms of natriuresis and hyponatremia were aggravated, associated with hyper secretion of natriuretic peptides (ANP 160 pg x dl(-1), BNP 172 pg x dl(-1)). Recent studies revealed that hyponatremia and hypovolemia following SAH might be caused by exaggerated secretion of natriuretic peptides. Experimental studies showed that the administration of vasopressin and desmopressin cause excessive secretion of natriuretic peptides under the circumstance of volume expansion in rats. We infer that the administration of vasopressin and desmopressin to our patient deterionated natriuresis in CSWS as in the previous experimental findings.

Continuous measurement of oxygen consumption using the reversed fick method.

We developed a continuous oxygen consumption (Vo2) measurement system employed the reversed Fick method, in which Vo2 in computed from continuously measured sured arterial and mixed venous oxygen saturation assed by pulse oximetry and mixed venous oximetry, respectively, and cardiac output by the heat deprivation technique. This system was compared with the conventional intermittent reversed fick method in 7 patients during surgery and with indirect calorimetry in 4 intensive care unit (ICU) patients. The Vo2 measured by the continuous reversed Fick method showed a high correlation with those simultaneously measured by the intermittent Fick method (r=0.97,P<0.01) and by indirect calorimetry (r=0.74,P<0.01). The 95% confidence limits (bias±2 SD) of the continuous reversed Fick method were -0.6±45 ml·min-1 with the intermittent Fick method and -31±56 ml·min-1 with indirect calorimetry. The continuous Fick method is in satisfactory agreement with the conventional methods for the measured of Vo2 and potentially allows for convenient assessment of Vo2 in critically ill patients.

Changes of oxygen transport variables and serum lactate during open-chest cardiac massage in dogs.

The aim of this study was to investigate the influence of critically low cardiac output (CO) upon oxygen transport. We especially focused on the changes of mixed venous oxygen saturation (S-vO2) in the presence of oxygen consumption ([Formula: see text]) debts. Additionally, we examined the correlation between the cumulative oxygen deficit (Def[Formula: see text]) and serum lactate. Def[Formula: see text] was calculated as the integrated area under the tissue[Formula: see text]) deficit (baseline[Formula: see text]-acutal[Formula: see text]) and time curve. To produce severe low CO, we performed openchest cardiopulmonary resuscitation (CPR) in 11 anesthetized dogs for 1 h. We made the measurements before (baseline values) and during the CPR at 10-min intervals. Supplydependent[Formula: see text] was observed when CO decreased below 40 ml·min-1·kg-1. The mean value of S-vO2 in the range of supply-dependent[Formula: see text] was 13±2% and did not change significantly during 1 h of CPR. The changes of lactate from baseline values were linearly correlated with Def[Formula: see text] (r=0.62,P<0.01), but absolute values of serum lactate were not.

[Plasma ionized magnesium concentration following cardiopulmonary bypass].

We performed a retrospective study to analyze plasma ionized magnesium concentration following cardiopulmonary bypass. Severe decrease of ionized magnesium concentration associated with frequent abnormal ECG sign was found in a patient with magnesium-free cardioplegia. Cardioplegia containing 16 mmol.l-1 of magnesium ion maintained ionized magnesium concentration within normal ranges without postoperative magnesium loading. Use of cardioplegia containing magnesium or adequate magnesium supplement is thought to be essential for patients receiving cardiopulmonary bypass.

[Mechanical supports for stunned myocardium after esophagectomy].

Coronary vasospasm can cause a wide spectrum of clinical syndromes ranging from transient myocardial ischemia to irreversible infarction. A 72-year-old male patient had intense vasospasms intraoperatively, which led to stunned myocardium. Though MB fraction of creatine kinase after the spasms was almost within normal limits, postoperative transcutaneous echocardiogram showed diffuse hypokinesis of heart wall motion. He developed low output syndrome, acute respiratory distress syndrome and acute renal failure. He was treated with mechanical supports (intra-aortic balloon pumping, high frequency oscillatory ventilation, and continuous hemodiafiltration), in addition to intravenous administration of cathecolamines, on the first postoperative day. It took 6 days to wean the patient from these mechanical supports and catecholamine infusion. This case suggests stunned myocardium after coronary vasospasm, despite the rapid disappearing ST elevation, and of importance of mechanical supports for the circulatory failure.