Quantitative measurement of airborne particles during endoscopic and microscopic ear surgery in the operating room

OBJECTIVE

This study aimed to quantitatively investigate airborne particle load in the operating room during endoscopic or microscopic epitympanectomy or mastoidectomy.

METHOD

In the transcanal endoscopic ear surgery group, drilling was performed underwater. A particle counter was used to measure the particle load before, during and after drilling during transcanal endoscopic ear surgery or microscopic ear surgery. The device counted the numbers of airborne particles of 0.3, 0.5 or 1.0 μm in diameter.

RESULTS

The particle load during drilling was significantly higher in the microscopic ear surgery group (n = 5) than in the transcanal endoscopic ear surgery group (n = 11) for all particle sizes (p < 0.01). In the transcanal endoscopic ear surgery group, no significant differences among the particle load observed before, during and after drilling were seen for any of the particle sizes.

CONCLUSION

Bone dissection carries a lower risk of airborne infection if it is performed using the endoscopic underwater drilling technique.

Perioperative management protocols for children with moyamoya disease

Protocols for prevention of cerebral ischemic attacks caused by hyperventilation resulting from crying, as observed in perioperative pediatric moyamoya patients, were evaluated. The first protocol involved the use of sedation when staff were setting up the intravenous lines, performing neuroimaging studies, and controlling postoperative pain. The second involved the use of wound-handling techniques designed to ease postoperative wound care; these included steristrip closure, use of paraffin gauze and not using adhesive tapes. We compared 14 and 11 surgical cases handled before and after the protocols were introduced, respectively. The number of patients with perioperative cerebral infarction decreased from 2 to 0. Appropriate sedation reduced the incidence of transient ischemic attacks from 28.6% to 3.7%. The average postoperative hospital stay was similarly reduced, from 21.3 days to 16.1 days, as a consequence of the reduced incidence of complications. It is concluded that the perioperative risks can be minimized when invasive procedures are managed according to our protocols.

T cell malignant lymphoma in the central nervous system after acute lymphoblastic leukemia in a child

A malignant lymphoma developed in the central nervous system (CNS) of a 7-year-old boy 5 years after he had received chemotherapy and cranial irradiation for acute lymphoblastic leukemia (ALL). Bone marrow analysis of the original leukemia showed a pre-B cell phenotype, whereas the resected brain tumor showed a T cell phenotype on immunophenotypic analysis. Because of this difference in immunophenotype, and because the patient had received multiple-drug chemotherapy and 1,800 cGy of cranial irradiation for the original ALL, we consider that the malignant lymphoma was a second neoplasm. This is a very rare case in two respects: it was a malignant lymphoma arising in the CNS as a second neoplasm after ALL and a T cell lymphoma occurring in a child.

[Spinal cord stimulation therapy at an early stage for unresponsive patients with hypoxic encephalopathy]

Recently, spinal cord stimulation (SCS) has been used for the treatment of patients in prolonged coma. However, the results of SCS in unresponsive patients with hypoxic encephalopathy at the chronic stage have not been satisfactory. Considering these circumstances, we began SCS from one month after the onset of hypoxic encephalopathy and evaluated its effect. Twelve patients (5 males and 7 females) with hypoxic encephalopathy, ranging in age from 7 to 72 years, were treated with SCS. The causes of hypoxia were acute cardiac failure in 4, automobile exhaust gas poisoning in 2, and asthma, pneumothorax, anaphylaxis, asphyxia, drowning and hypotension during aortic surgery in one patient each. One month after the onset, an electrode for electrical stimulation was implanted in the epidural space at the C2-C4 level under general anesthesia. The spinal cord was stimulated for 8 hours each day, starting on the day after implantation, and was continued for 3 months. Magnetic resonance imaging (MRI), cerebral blood flow (CBF) measurement using xenon-computed tomography (Xe-CT), and measurement of auditory evoked potential (AEP) and somatosensory evoked potential (SEP) were carried out 3 weeks after the onset for presurgical evaluation. Among the 12 patients, 7 (58%) showed clinical improvement, beginning within two weeks after starting stimulation. They were able to communicate with others and to express their emotion. However, disturbance of writing, picture drawing and calculation were not improved by stimulation. From presurgical evaluation, cases in which SCS therapy was effective had the following features: 1) No hemorrhagic infarction in the basal ganglia was demonstrable by MRI. 2) Mean hemispheric CBF measured by the Xe-CT method exceeded 25 ml/100 g per min. 3) The mean increase in hemispheric CBF 20 min after acetazolamide administration exceeded 5 ml/100 g per min. 4) An N20 peak was evident on the median nerve SEP, SCS appears to be an effective supplementary for unresponsive patients with hypoxic encephalopathy at the subacute stage, in addition to rehabilitation and drug therapy.