Postoperative cognitive deficit after cardiopulmonary bypass with preserved cerebral oxygenation: a prospective observational pilot study.

BACKGROUND: Neurologic deficits after cardiac surgery are common complications. Aim of this prospective observational pilot study was to investigate the incidence of postoperative cognitive deficit (POCD) after cardiac surgery, provided that relevant decrease of cerebral oxygen saturation (cSO2) is avoided during cardiopulmonary bypass. METHODS: cSO2 was measured by near infrared spectroscopy in 35 patients during cardiopulmonary bypass. cSO2 was kept above 80% of baseline and above 55% during anesthesia including cardiopulmonary bypass. POCD was tested by trail making test, digit symbol substitution test, Ray's auditorial verbal learning test, digit span test and verbal fluency test the day before and 5 days after surgery. POCD was defined as a decline in test performance that exceeded - 20% from baseline in two tests or more. Correlation of POCD with lowest cSO2 and cSO2 - threshold were determined explorative. RESULTS: POCD was observed in 43% of patients. Lowest cSO2 during cardiopulmonary bypass was significantly correlated with POCD (p = 0.015, r2 = 0.44, without Bonferroni correction). A threshold of 65% for cSO2 was able to predict POCD with a sensitivity of 86.7% and a specificity of 65.0% (p = 0.03, without Bonferroni correction). CONCLUSIONS: Despite a relevant decrease of cerebral oxygen saturation was avoided in our pilot study during cardiopulmonary bypass, incidence of POCD was comparable to that reported in patients without monitoring. A higher threshold for cSO2 may be needed to reduce the incidence of POCD.

Management of the predicted difficult airway: a comparison of conventional blade laryngoscopy with video-assisted blade laryngoscopy and the GlideScope.

BACKGROUND AND OBJECTIVE: We investigated whether the use of two different video laryngoscopes [direct-coupled interface (DCI) video laryngoscope and GlideScope] may improve laryngoscopic view and intubation success compared with the conventional direct Macintosh laryngoscope (direct laryngoscopy) in patients with a predicted difficult airway. METHODS: One hundred and twenty adult patients undergoing elective minor surgery requiring general anaesthesia and endotracheal intubation presenting with at least one predictor for a difficult airway were enrolled after Institutional Review Board approval and written informed consent was obtained. Repeated laryngoscopy was performed using direct laryngoscope, DCI laryngoscope and GlideScope in a randomized sequence before patients were intubated. RESULTS: Both video laryngoscopes showed significantly better laryngoscopic view (according to Cormack and Lehane classification as modified by Yentis and Lee = C&L) than direct laryngoscope. Laryngoscopic view C&L >or= III was measured in 30% of patients when using direct laryngoscopy, and in only 11% when using the DCI laryngoscope (P < 0.001). The GlideScope enabled significantly better laryngoscopic view (C&L >or= III: 1.6%) than both direct (P < 0.001) and DCI laryngoscopes (P < 0.05). Clinically relevant improvement in the specific 36 patients with insufficient direct view (C&L >or= III) could be achieved significantly more often with the GlideScope (94.4%) than with the DCI laryngoscope (63.8%; P < 0.01). Laryngoscopy time did not differ between instruments [median (range): direct laryngoscope, 13 (5-33) s; DCI laryngoscope, 14 (6-40) s; GlideScope, 13 (5-34) s]. In contrast, tracheal intubation needed significantly more time with both video laryngoscopes [DCI laryngoscope, 27 (17-94) s, P < 0.05 and GlideScope, 33 (18-68) s, P < 0.01] than with the direct laryngoscope [22.5 (12-49) s]. Intubation failed in four cases (10%) using the direct laryngoscope and in one case (2.5%) each using the DCI laryngoscope and the GlideScope. CONCLUSION: We conclude that the video laryngoscope and GlideScope in particular may be useful instruments in the management of the predicted difficult airway.

Assessment of sensorimotor functions after traumatic brain injury (TBI) in childhood - Methodological aspects.

Various basic qualitative and quantitative methods for the evaluation of sensorimotor functions after Traumatic Brain Injury (TBI) are introduced and discussed. Methodological aspects are illustrated by a single case follow-up study of a child after severe TBI (age 11; 7-12;1 yrs; 6, 8 and 12 month post TBI) in comparison to an age-matched healthy control group (N=16). The evaluation consisted of neurological investigation, Barthel-Index, Terver Numeric Score for Functional Assessment, Rappaport Disability Rating Scale (modified version), a coordination-test for children (KTK), a pilot-tested Motor Function Score, quantitative evaluation of spatiotemporal gait parameters on a walkway and on a treadmill, and the kinematic assessment of hand motor functions. Quantitative movement analyses revealed two general types of motor disorder: Slowing of movements and compensatory motor strategies. Averaged z-scores showed deficits, which were pronounced in fine motor skills (hand movements: 1.86, gait: 1.3). During follow-up, a strong improvement rate during the first (-0.48 z-scores) and nearly no improvement rate (-0.03 z-scores) during the second time interval was seen. Clinical scores and developmental tests were not able to document the whole restitutional course, whereas motor tests with special emphasis on functional aspects and the quantitative movement assessment seemed to be suitable methods. We conclude that a sufficient evaluation of sensorimotor functions after TBI in childhood needs an increase in procedural uniformity on onehand and the combination of various qualitative and quantitative methods on the other hand. To connect both claims, further research is necessary.