Clinical information system services and capabilities desired for scalable, standards-based, service-oriented decision support: consensus assessment of the Health Level 7 clinical decision support Work Group.

A standards-based, service-oriented architecture for clinical decision support (CDS) has the potential to significantly enhance CDS scalability and robustness. To enable such a CDS architecture, the Health Level 7 CDS Work Group reviewed the literature, hosted multi-stakeholder discussions, and consulted domain experts to identify and prioritize the services and capabilities required from clinical information systems (CISs) to enable service-oriented CDS. In addition, relevant available standards were identified. Through this process, ten CIS services and eight CIS capabilities were identified as being important for enabling scalable, service-oriented CDS. In particular, through a survey of 46 domain experts, five services and capabilities were identified as being especially critical: 1) the use of standard information models and terminologies; 2) the ability to leverage a Decision Support Service (DSS); 3) support for a clinical data query service; 4) support for an event subscription and notification service; and 5) support for a user communication service.

Conservative management of acoustic neuromas. 1992.

An expectant, nontreatment strategy for acoustic neuromas implies an understanding of the natural biologic behavior of these tumors. This study describes the long-term follow-up of a group of unoperated acoustic neuroma patients. Patterns of tumor growth are discussed in light of clinical outcome. Patient selection and a follow-up protocol are recommended for those individuals in whom a nontreatment strategy is contemplated.

A novel method in predicting immediate postoperative facial nerve function post acoustic neuroma excision.

UNLABELLED: To determine whether the percentage calculated by dividing the amplitude of postexcision direct facial nerve stimulus responses (at pontomedullary junction) by the amplitude of distal ipsilateral transcutaneous (stylomastoid region) maximal stimulus responses and response amplitude progression by increasing stimulus intensities have predictive value for determining normal or near-normal (House-Brackmann Grade 1 or 2) immediate postoperative facial nerve function. STUDY DESIGN: Intraoperative recordings of three muscle groups: 1) frontalis, 2) orbicularis oculi, and 3) orbicularis oris. Postexcision direct facial nerve stimulation at the pontomedullary junction and transcutaneous maximal facial nerve stimulation at the ipsilateral stylomastoid region and their associated response amplitudes were recorded. SETTING: Tertiary referral center. PATIENTS AND METHODS: Patients who underwent acoustic neuroma surgery from January 2004 to March 2006 with intraoperative facial nerve monitoring and an intact facial nerve after tumor excision were included. Recordings were available for 38 patients. RESULTS: With a stimulus intensity of 0.3 mA at the root exit zone, there was an 81% positive predictive value in patients that exhibited a compound action potential of greater than 20% of maximum (sensitivity, 81%). This increased to 93% when the compound action potential was greater than 50% of maximum. When the amplitude increase was greater than 5 microV, there was a 77% positive predictive value (sensitivity, 87%). CONCLUSION: The percentage of the response amplitude of direct facial nerve stimulation at the pontomedullary junction when compared with the maximum response amplitude of ipsilateral transcutaneous stimulation at the stylomastoid foramen is a good predictor of normal to near-normal immediate postoperative facial nerve function. Progression of amplitude response also seems to be a good predictor of normal to near-normal immediate postoperative facial nerve function.

Unilateral acoustic neuromas: long-term hearing results in patients managed with fractionated stereotactic radiotherapy, hearing preservation surgery, and expectantly.

INTRODUCTION: Hearing preservation is invariably a consideration when exploring treatment options for acoustic neuromas. We reviewed the long-term hearing results of patients who were treated using 1) hyperfractionated stereotactic radiotherapy (HSR), 2) hearing preservation tumor excision surgery (HPTES), and 3) expectantly (no treatment). METHODS AND MATERIALS: Single institution retrospective chart review of 42 patients managed with HSR (1993-2003), 113 patients in whom HPTES was carried out, and 86 patients who were untreated (1974-2003). Hearing levels were graded according to the Gardner-Robertson classification. RESULTS: The percent of patients managed with HSR initially who had serviceable hearing (class 1-2) was 68.8%. This fell to 6.7% in the follow-up interval. Of the group treated with HPTES, 100% had preoperative serviceable hearing. This dropped to 15.9% in the follow-up interval. The percent of patients managed expectantly who initially had serviceable hearing was 77.3%. This dropped to 33.3% during the follow-up interval. Mean follow-up periods were 4.0, 9.5, and 6.8 years in the HSR, HPTES, and expectant groups, respectively. CONCLUSIONS: Hearing acuity statistically worsened over the long term (P < .01) in all three groups. There was a significant proportion of patients in whom hearing deteriorated from serviceable to nonserviceable hearing (P < .01) during the follow-up interval. The decline was most significant in the groups treated with HPTES and HSR compared with the group treated expectantly (P < .05). Hearing outcomes, in our experience, continue to be poor, but this is especially so in patients treated with HPTES or HSR.

Comparison of monitoring techniques for intraoperative cerebral ischemia.

OBJECTIVE: To prospectively compare somatosensory evoked potentials, electroencephalography (EEG) and transcranial Doppler ultrasound (TCD) for detection of cerebral ischemia during carotid endarterectomy (CEA). METHODS: Somatosensory evoked potentials and EEG recordings were attempted in 156 consecutive CEAs and TCD was also attempted in 91 of them. Recordings from all three modalities were obtained for at least 10 minutes before CEA, during CEA and for at least 15 minutes after CEA. Somatosensory evoked potentials peak-to-peak amplitude decrease of >50%, EEG amplitude decrease of >75%, and ipsilateral middle cerebral artery mean blood flow velocity (mean VMCAi) decrease >75% persisting for the entire period of internal carotid artery occlusion were individually considered to be diagnostic of cerebral ischemia. Clinical neurological examination was performed immediately prior to surgery and following recovery from general anaesthesia. RESULTS: Somatosensory evoked potentials, EEG, and TCD were successfully obtained throughout the entire period of internal carotid artery occlusion in 99%, 95%, and 63% of patients respectively. Two patients (1.3%) suffered intraoperative cerebral infarction detected by clinical neurological examination and subsequent magnetic resonance imaging. Somatosensory evoked potentials accurately predicted intraoperative cerebral infarction in both instances without false negatives or false positives, EEG yielded one false negative result and no false positive results and VMCAi one true positive, four false positive and no false negative results. Transcranial Doppler ultrasound detection of emboli did not correlate with postoperative neurological deficits. Nevertheless the sensitivity and specificity of each test was not significantly different than the others because of the small number of disagreements between tests. CONCLUSION: A >50% decrease in the cortically generated P25 amplitude of the median somatosensory evoked potentials, which persisted during the entire period of internal carotid artery occlusion, appears to be the most reliable method of monitoring for intraoperative ischemia in our hands because it accurately detected both intraoperative strokes with no false positive or false negative results.

Acoustic neuroma surgery: the results of long-term hearing preservation.

OBJECTIVE: To report the long-term outcome hearing results following acoustic neuroma surgery. To determine whether changes, if any, in the thresholds of the operated ear are mirrored in the contralateral unoperated side. In addition, to identify predictive factors, if any, that may predispose individuals to hearing loss in the operated ear in the late post-operative period. STUDY DESIGN: Retrospective patient chart review. SETTING: University Tertiary Referral Centre. PATIENTS: From 1978 to 1997, one hundred and twenty six patients with small acoustic neuromas (less than 2 cm as measured within in the cerebellopontine angle) underwent excision via the suboccipital (retrosigmoid) approach with the patient in the prone position. Hearing preservation was successful in 43 patients (34.1%). The audiometric data of thirty patients with a minimum follow-up interval of 36 months was analyzed. The mean follow-up period was 113.4 months (range 36-264, SD=57.8) and the mean age at surgery was 47.3 years (range 32 to 64, SD = 7.3). OUTCOME MEASURES: Speech Reception Thresholds (SRT), Speech Discrimination Scores (SDS) and Pure-tone Audiometry (PTA, 0.5, 1 & 2 kHz) were noted on the operated and unoperated ears. The AAO Classification according to the Committee on Hearing and Equilibrium guidelines for the evaluation of hearing preservation in acoustic neuroma was used to assess hearing serviceability. RESULTS: Subsequent to including corresponding changes in the unoperated ear, the means of the SRT and PTA in the operated ear between the early and late post-operative periods were statistically significantly different (p=0.0012 & 0.034 respectively). Twelve (40%) patients demonstrated significant deterioration in hearing thresholds over time. Pre-operatively, 96.7% of patients had serviceable hearing (Class A & B). This falls to 76.6% in the early post-operative period and to 56.7% in the late post-operative period. CONCLUSION: Our study highlights the finding that over time a significant number of individuals realize a greater ongoing hearing loss in the post tumour excision ear than the contralateral ear.