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Biomedical subjects

Naoki Aikawa

Publications and source records attributed to Naoki Aikawa.

45 records · Page 3Linked to original sources
PubMed2002

Acute subdural hematoma caused by ruptured cerebral aneurysms: diagnostic and therapeutic pitfalls.

On rare occasions, rupture of a cerebral aneurysm causes acute subdural hematoma (SDH) in addition to subarachnoid hemorrhage (SAH). The frequency of SDH resulting from aneurysmal rupture is summarized, and its clinical and radiological characteristics, as well as potential pitfalls in the diagnosis and the management of this life-threatening condition are described. Among 641 patients with nontraumatic SAH treated between 1992 and 2000, 12 patients (1.9%) presented with SDH due to aneurysmal rupture. The SAH grade on admission was grade II in one patient, grade IV in three patients, and grade V in eight patients. Four underwent both hematoma evacuation and clipping of the aneurysm, four underwent hematoma evacuation alone, and the other four patients were treated conservatively. The outcome was good recovery in two patients, severe disability in one patient, and death in nine patients. Patients with a good outcome had a better SAH grade on admission, smaller midline shift, and smaller SDH volume on the initial CT scan, and they had been treated by both SDH evacuation and clipping of the aneurysm. Emergency one-stage operations may be beneficial for aneurysmal SDH patients who are in good SAH grade, or those who are in poor SAH grade but show some neurological recovery after resuscitation. It should also be mentioned that there are cases of aneurysmal SDH without recognizable SAH on the CT scans, and that a case of aneurysmal SDH may present as a case of 'head trauma' after an accident, because of the disturbance of consciousness resulting from aneurysmal rupture.

Adult↗
PubMed2002

Cardiopulmonary arrest induced by anaphylactoid reaction with contrast media.

Anaphylactoid reactions to iodinated contrast media can cause life-threatening events and even death. A 44-year-old woman presented with cardiopulmonary arrest (CPA) immediately following the administration of nonionic iodinated contrast media for an intravenous pyelography. Her cardiac rhythm during CPA was asystole. She was successfully resuscitated by the radiologists supported by paged emergency physicians using the prompt intravenous administration of 1 mg of epinephrine. Neither laryngeal edema nor bronchial spasm was observed during the course of treatment, and she was discharged on the 4th day without any complications. The patient did not have a history of allergy, but had experienced a myocardial infarction and aortitis. She had undergone 11 angiographies and had been taking a beta-adrenergic receptor antagonist. Planned emergency medical backup is advisable to ensure resuscitation in the event of an anaphylactoid reaction to the use of contrast media in-hospital settings.

Adrenergic Agonists↗
PubMed2002

Correlation between QT dispersion and burn severity.

QT dispersion, defined as the maximal-minus-minimal QT interval on a 12-lead electrocardiogram, has emerged as a non-invasive measurement for quantifying the spatial inhomogeneity of ventricular repolarization under various conditions, including acute stress. Because burn injuries elicit acute stress reactions, it was hypothesized that QT dispersion increases with the severity of the burn injury. To test the hypothesis, 13 burned patients (age range of 22-76 years, nine males, ranging from 4.0 to 75.0% of total body surface area burned) in whom a measurable 12-lead electrocardiogram had been obtained within 4h after arrival at the emergency department were identified retrospectively, and their QTc intervals, i.e. QT intervals corrected for heart rate by the standard Bazett formula, were measured. QTc dispersion (QTcd) was then calculated, and correlations were assessed with burn severity (burn index, BI; prognostic burn index, PBI). Of the 13 patients, nine patients had a prolonged QTcd (>40 ms), and linear correlation analyses showed significant positive correlations between QTcd and both BI and PBI (r=0.61 and 0.62, respectively). In conclusion, QT dispersion was greater in the burned patients, and although the pathophysiology was unclear from the present study, the findings suggested that acute stress contributed to the spatial inhomogeneity of ventricular repolarization.

Adult↗
PubMed2002

Thrombolysis candidates for the treatment of stroke at an emergency department in Japan.

OBJECTIVES: To study the proportion and characteristics of potential candidates for the intravenous administration of tissue plasminogen activator (IV-tPA) among patients with cerebral infarction in a Japanese emergency department (ED). METHODS: A retrospective observational study was performed using patients who had been transported by ambulance between August 1988 and April 2000 to an urban ED of a university hospital located in the Tokyo metropolitan area. Potential candidates for IV-tPA were identified using the criteria of the National Institute of Neurological Disorders and Stroke (NINDS) study. RESULTS: Of all 30,064 patients transported by ambulance, 526 were diagnosed as having cerebral infarction. Among them, 190 patients arrived at the ED within two hours of symptom onset (early ED arrivers). In comparison of their demographics with late ED arrivers (n = 319), atrial fibrillation, male gender, and consciousness disturbance were related with early ED arrivers, while aging and diabetes were related with late ED arrivers. As to the stroke subtype, patients with an embolic infarction accounted for 76.8% among early ED arrivers. Application of exclusion criteria identified 114 patients, who were suitable for the thrombolysis treatment, indicating that the proportion of potential IV-tPA candidates was 21.7% among all cerebral infarction patients and 0.38% among all ED patients. CONCLUSIONS: The number of potential IV-tPA candidates among patients transported to the ED by ambulance in Japan was substantial, where the proportion of embolic infarction cases was extremely high.

Aged↗
PubMed2002

Characteristics of elderly patients presenting to the emergency department with injury.

BACKGROUND: In Japan, emergency departments (ED) receive a large proportion of elderly patients each year. As such, injuries in the elderly are a common reason for presentation to the ED. Knowledge about the characteristics of injuries presenting to the ED would be invaluable in devising strategies to prevent injury in the elderly. OBJECTIVE: To analyze the characteristics of injuries in the elderly presenting to the ED and compare them with those of the younger population. SETTING: The ED at Keio University Hospital, a large inner city teaching hospital located in Tokyo. METHOD: A retrospective analysis of data extracted from the ED database of the Keio University Hospital. Information regarding patients aged 65 years or above presenting with injury was analyzed and compared with those aged less than 65 years. Prehospital triage by emergency personnel was adopted as the severity of patients, namely "life-threatening" or "non life-threatening". RESULTS: 20% of all ED presentations of elderly patients were injury related compared to 39% of non-elderly. Compared to the non-elderly, elderly patients presenting to the ED with injury were more likely to be female, sustained injury from trauma unrelated to motor vehicle accidents (MVA) and requiring hospital admission as a result of "non life-threatening" injuries. They were less likely to have injuries from MVA or burns. The number of "life-threatening" injury cases and mortality in both groups were similar. There was evidence that the number of ED presentations relating to injury is increasing in the elderly population. CONCLUSION: Elderly injury patients are a distinct group with distinctive demographics, mechanism of injury and outcomes. This information would be useful in the planning of injury prevention programs, with particular emphasis on elderly females and MVA-unrelated trauma.

Adult↗
PubMed2002

[Bacteria isolated from surgical infections and their susceptibilities to antimicrobial agents. Special references to bacteria isolated between April 1999 and March 2000].

The annual multicenter studies on isolated bacteria from infections in general surgery and their antimicrobial susceptibility have been conducted in Japan since July 1982. In this paper, the results obtained in the academic year 1999 (from April 1999 to March 2000) have been summarized. Two hundred seven cases were investigated, and 411 strains were isolated from 169 cases (81.6%). Of those strains, 184 and 227 strains were from primary infections and postoperative infections, respectively. In primary infections, the isolation rates of anaerobes, Streptococcus spp., and Escherichia coli were higher than in postoperative infections, while in postoperative infections, those of Gram-positive aerobes were higher than in primary infections. Staphylococcus aureus were most frequently isolated among Gram-positive aerobes, Peptostreptococcus prevotii among Gram-positive anaerobes, E. coli among Gram-negative aerobes, and Bacteroides fragilis among Gram-negative anaerobes. In primary infections, the percentage of Gram-negative aerobes, which gradually increased by the year 1998, decreased in the year 1999. The percentage of Gram-negative anaerobes increased, while that of Gram-negative bacteria was equivalent to that in the last year. In postoperative infections, the percentage of Gram-negative anaerobes, which continuously increased after the year 1990, decreased, while that of Gram-positive aerobes, which decreased in the last year, increased. Methicillin-resistant S. aureus accounted for 70.7% of S. aureus (41 strains). Either the number of strain or the percentage of MRSA decreased. The susceptibilities of E. coli and Klebsiella pneumoniae decreased against third and forth generation cephems, oxacephems, and monobactams. The susceptibilities of P. aeruginosa to carbapenems tend to decrease after the year 1997. S. aureus showed good susceptibilities to the tested drugs including arbekacin, vancomycin, and teicoplanin.

Anti-Bacterial Agents↗
PubMed2002

[Bacteria isolated from surgical infections and their susceptibilities to antimicrobial agents--special references to bacteria isolated between April 2000 and March 2001].

Tendency of isolated bacteria from infections in general surgery and their antimicrobial susceptibilities during the period from April 2000 to March 2001 were investigated in a multicenter study in Japan, and the following results were obtained. The number of cases investigated as objectives was 234 for one year. A total of 388 strains (136 strains from primary infections and 252 strains from postoperative infections) were isolated from 165 cases (70.5% of total cases). In primary infections, anaerobic Gram-positive bacteria were predominant, while from postoperative infections, aerobic Gram-positive bacteria were predominant. Among aerobic Gram-positive bacteria, the isolation rate of Enterococcus faecalis was the highest, followed by that of Staphylococcus aureus from postoperative infections. Among anaerobic Gram-positive bacteria, the isolation rate of Peptostreptococcus spp. was the highest from both types of infections. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Klebsiella pneumoniae and Pseudomonas aeruginosa in this order, and from postoperative infections, P. aeruginosa was the most predominantly isolated, followed by Enterobacter spp. and Klebsiella spp. Among anaerobic Gram-negative bacteria, the isolation rate of Bacteroides fragilis group was the highest from both types of infections. There was no vancomycin-resistant S. aureus nor Enterococcus spp. Among anaerobic bacteria, there were many resistant strains against penicillins and cephems with MICs higher than 100 micrograms/ml, and the same trend was observed among other Bacteroides spp. and Prevotella spp.

Anti-Bacterial Agents↗