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Biomedical subjects

R Tempelhoff

Publications and source records attributed to R Tempelhoff.

44 records · Page 3Linked to original sources
PubMed1989

Use of computerized electroencephalographic monitoring during aneurysm surgery.

The clinical usefulness of intraoperative electroencephalographic (EEG) monitoring of cerebral perfusion during aneurysm surgery has received little attention, primarily due to problems with electrode placement over the operative site, which is the area of maximal risk. In this report, 27 patients undergoing surgery for anterior circulation aneurysms were monitored intraoperatively with a two-channel computerized EEG complex using a bilateral frontal-occipital montage. In 16 patients, a normal EEG pattern was observed throughout surgery; all 16 awoke neurologically intact and their postoperative angiograms did not reveal cerebral vasospasm. In the other 11 patients, one of two patterns of persistent EEG abnormalities was identified. 1) In six of these patients a marked attenuation of EEG activity was observed ipsilaterally which coincided with various intraoperative events including brain retraction, hypotension, and aneurysm dissection/clipping. Five of these six patients awoke with new neurological deficits which persisted beyond 12 hours in two, both of whom had angiographically proven vasospasm 24 hours after surgery. 2) In the remaining five patients, a distinct abnormal EEG pattern consisting of marked hyperactivity in the delta, theta, and alpha frequency ranges was observed ipsilaterally. Four of these five patients had a poor neurological outcome and vasospasm on their angiogram 24 hours after surgery. Thus, EEG monitoring which spans the operative area during aneurysm surgery is practicable and appears to be of value in the detection of compromised cerebral perfusion during aneurysm surgery. The possible significance of the two abnormal EEG patterns identified in this report is discussed.

Cerebral Angiography↗
PubMedDate not supplied

Accelerated recovery from pipecuronium in patients treated with chronic anticonvulsant therapy.

STUDY OBJECTIVE: To determine whether chronic anticonvulsant therapy affects recovery time from pipecuronium. DESIGN: Open-labeled, controlled study. SETTING: Inpatient neurosurgical service at a university medical center. PATIENTS: ASA physical status II and III patients within 30% of their ideal body weight and without significant history of ethanol abuse or renal or hepatic disease. Nineteen patients were admitted into the study and were divided into three groups based on the number of anticonvulsant medications (MED) they were taking: MED = 0, control group (6 patients); MED = 1, one anticonvulsant (6 patients); MED = 2, two or more anticonvulsants (7 patients). INTERVENTIONS: Intravenous (IV) administration of pipecuronium 80 micrograms/kg with general anesthesia after thiopental sodium 4 to 6 mg/kg IV, maintained with 70% nitrous oxide in oxygen, 0.2% to 0.3% end-tidal isoflurane, and fentanyl. MEASUREMENTS AND MAIN RESULTS: The evoked compound electromyogram (ECEMG) of the adductor pollicis brevis muscle was measured after stimulation of the ulnar nerve by train-of-four (TOF) supramaximal impulses at 2 Hz repeated every 20 seconds. Measurements include T-1% (ECEMG signal at 25%, 50%, and 75% of baseline), TR% (TOF ratio), and recovery index (RI). Patients administered chronic anticonvulsant therapy recovered more rapidly from pipecuronium than untreated patients. For instance, time to 25% recovery of baseline (T-1 25%) was 123 +/- 13 minutes for MED = 0, 91 +/- 7 minutes for MED = 1, and 58 +/- 5 minutes for MED = 2 (p < 0.05). TOF recovery to 20% (TR 20%) and RI were similarly affected. CONCLUSIONS: Patients treated with chronic anticonvulsant therapy recovered from pipecuronium more rapidly than unmedicated patients. Furthermore, there seemed to be a dose-effect relationship between the number of anticonvulsants received and a decreased time to recovery from pipercuronium neuromuscular blockade.

Adolescent↗
PubMedDate not supplied

EEG-controlled "overdosage" of anesthetics in a patient with a history of intra-anesthetic awareness.

In spite of the ever-growing pharmacologic arsenal available for induction and maintenance of anesthesia, to our knowledge no treatment regimen exists that will provide full protection against intraoperative awareness. To date, no single monitoring technique is able to detect awareness or predict recall. Although the frequency of these complications is rare, the occurrence of any such event can be very distressful for the patient. Based on our clinical experience with a patient with a history of recall and a marked resistance to benzodiazepines, we present electroencephalogram-based anesthetic management as a technique to address this difficult problem.

Adult↗