Heidi Tymkew

Prevalence of undiagnosed obstructive sleep apnea among adult surgical patients in an academic medical center.

BACKGROUND Obstructive sleep apnea (OSA) affects approximately 20% of US adults, of whom about 90% are undiagnosed. While OSA may increase risk of perioperative complications, its prevalence among surgical patients is unknown. We tested the feasibility of screening surgical patients for OSA and determined the prevalence of undiagnosed OSA. METHODS In a prospective, observational study adult surgical patients were screened for OSA in an academic hospital. Patients without an OSA diagnosis who screened high-risk were offered a home sleep study to determine if they had OSA. The results were compared with polysomnography (PSG) when available. Charts of high-risk patients were examined for postoperative complications. High-risk patients received targeted interventions as part of a hospital safety initiative. RESULTS There were 2877 patients screened; 661 (23.7%) screened high-risk for OSA, of whom 534 (81%) did not have diagnosed OSA. The portable sleep study detected OSA in 170/207 (82%) high-risk patients without diagnosed OSA. Twenty-six PSGs confirmed OSA in 19 of these patients. Postoperatively there were no respiratory arrests, two unanticipated ICU admissions, and five documented respiratory complications. CONCLUSION Undiagnosed OSA is prevalent in adult surgical patients. Implementing universal screening is feasible and can identify undiagnosed OSA in many surgical patients. Further investigation is needed into perioperative complications and their prevention for patients with undiagnosed OSA.

A Randomized Study in Diabetic Patients Undergoing Cardiac Surgery Comparing Computer-Guided Glucose Management With a Standard Sliding Scale Protocol

OBJECTIVE The aim of this study was to compare a standard insulin protocol with a computer-guided glucose management system to determine which method achieves tighter glucose control. DESIGN A prospective, randomized trial. SETTING A cardiothoracic intensive care unit (ICU) in a large academic medical center. PARTICIPANTS Forty patients with diabetes mellitus who were scheduled for cardiac surgery. INTERVENTIONS After induction of anesthesia and for the first 9 hours in the ICU, each subject received a standardized infusion of a 10% glucose solution at a rate of 1.0 mL/kg/h (ideal body weight). The subjects were then randomized to have their glucose controlled by either a paper-based insulin protocol or by a computer-guided glucose management system (CG). The desired range for blood glucose was set between 90 and 150 mg/dL. MEASUREMENTS AND MAIN RESULTS There were no differences between groups in baseline characteristics. Patients in the CG group spent more time in the desired range during both the intraoperative phase (49% v 27%, p = 0.001) and the ICU phase (84% v 60%, p < 0.0001). There were no statistical differences between groups in the number of hypoglycemia episodes. CONCLUSIONS The computer-guided glucose management system achieved tighter blood glucose control than a standard paper-based protocol in diabetic patients undergoing cardiac surgery. However, the low proportion of blood glucose recordings within the desired range in both groups during the intraoperative period reflects the challenges associated with achieving normoglycemia during cardiac surgery.

Cardiothoracic Anesthesia, Respiration and Airway

PurposeThis study was designed to examine the efficacy of low-dose intrathecal morphine (ITM) on extubation times and pain control after cardiac surgery.Methods43 patients undergoing elective cardiac surgery were enrolled in this prospective, randomized, double-blind placebo controlled trial. Patients were given a pre-induction dose of ITM (6 μg·kg-1 per ideal body weight in 5 mL normal saline, group ITM) or 5 mL of intrathecal normal saline (group ITS). Anesthesia was induced with thiopental (3 mgkg-1), sufentanil, midazolam and rocuronium. The total allowable doses of sufentanil and midazolam for the entire case were limited to 0.5 μg·kg-1 and 0.045 mg·kg-1 respectively. Anesthesia was maintained with isoflurane before and during cardiopulmonary bypass (CPB), and with propofol after CPB. In the postanesthesia care unit, patients received nurse-administered morphine followed by patient-controlled analgesia morphine. Serial visual analogue scale pain scores, morphine use, mini-mental state examinations and pulmonary function tests were measured for 48 hr. Patient satisfaction questionnaires were completed at the time of discharge.ResultsMean times to extubation from the application of dressings were short and did not differ between groups (ITM = 41.4 ± 33.0 min, ITS = 39.2 ± 37.1 min). During the first 24 hr postoperatively, the ITM group had improved pain control and a lower iv morphine requirement than the control group, both at rest and during deep breathing. Both forced expiratory volume in one second and forced vital capacity were improved in the ITM group. There were no differences in spinal-related side effects or in the overall complication rates. Patient satisfaction was high in both groups.ConclusionLow-dose ITM for cardiac surgery did not delay early extubation, but it improved postoperative analgesia and pulmonary function.RésuméObjectifVérifier ľefficacité ďune faible dose de morphine intrathécale (MIT) sur le temps ďextubation précoce et le contrôle de la douleur après une opération en cardiochirurgie.MéthodeĽétude prospective, randomisée et à double insu contre placebo a été menée auprès de 43 patients de cardiochirurgie élective. Les patients ont reÇu une dose de MIT avant ľinduction (6 μg·kg-1 par poids corporel idéal dans 5 mL de solution salée, groupe MIT) ou 5 mL de solution salée intrathécale (groupe SIT). Ľanesthésie a été induite avec du thiopental (3 mg·kg-1), du sufentanil, du midazolam et du rocuronium. Les doses totales permises de sufentanil et de midazolam pour toute ľopération ont été respectivement limitées à 0,5 μg·kg-1 et à 0,045 mg·kg-1. Ľanesthésie a été maintenue avec de ľisoflurane avant et pendant la circulation extracorporelle (CEC), et avec du propofol après la CEC. À la salle de réveil, les patients ont reÇu de la morphine administrée par une infirmière, puis par injection auto-contrôlée. Les séries de scores de douleur de ľéchelle visuelle analogique, la consommation de morphine, les mini-examens de ľétat mental et ľexploration respiratoire fonctionnelle ont été mesurés pendant 48 h. Des questionnaires sur la satisfaction des patients ont été remplis au moment du départ.RésultatsLe temps moyen écoulé entre ľapplication de pansement et ľextubation a été court et comparable ďun groupe à ľautre (MIT = 41,4 ± 33,0 min, SIT = 39,2 ± 37,1 min). Pendant les 24 premières heures après ľopération, les patients du groupe MIT ont été mieux soulagés de leurs douleurs et ont utilisé moins de morphine iv que ceux du groupe témoin, et ce, au repos et pendant la respiration profonde. Le volume expiratoire maximum par seconde et la capacité vitale forcée ont été améliorés dans le groupe MIT. Il n’y avait pas de différence intergroupe entre les complications liées à ľinjection rachidienne ou les autres complications en général. La satisfaction des patients a été élevée dans les deux groupes. Conclusion : Une faible dose de MIT ne retarde pas ľextubation précoce et améliore ľanalgésie postopératoire et la fonction pulmonaire après une opération en cardiochirurgie.PURPOSE This study was designed to examine the efficacy of low-dose intrathecal morphine (ITM) on extubation times and pain control after cardiac surgery. METHODS 43 patients undergoing elective cardiac surgery were enrolled in this prospective, randomized, double-blind placebo controlled trial. Patients were given a pre-induction dose of ITM (6 microg x kg(-1) per ideal body weight in 5 mL normal saline, group ITM) or 5 mL of intrathecal normal saline (group ITS). Anesthesia was induced with thiopental (3 mg x kg(-1)), sufentanil, midazolam and rocuronium. The total allowable doses of sufentanil and midazolam for the entire case were limited to 0.5 microg x kg(-1) and 0.045 mg x kg(-1) respectively. Anesthesia was maintained with isoflurane before and during cardiopulmonary bypass (CPB), and with propofol after CPB. In the postanesthesia care unit, patients received nurse-administered morphine followed by patient-controlled analgesia morphine. Serial visual analogue scale pain scores, morphine use, mini-mental state examinations and pulmonary function tests were measured for 48 hr. Patient satisfaction questionnaires were completed at the time of discharge. RESULTS Mean times to extubation from the application of dressings were short and did not differ between groups (ITM = 41.4 +/- 33.0 min, ITS = 39.2 +/- 37.1 min). During the first 24 hr postoperatively, the ITM group had improved pain control and a lower iv morphine requirement than the control group, both at rest and during deep breathing. Both forced expiratory volume in one second and forced vital capacity were improved in the ITM group. There were no differences in spinal-related side effects or in the overall complication rates. Patient satisfaction was high in both groups. CONCLUSION Low-dose ITM for cardiac surgery did not delay early extubation, but it improved postoperative analgesia and pulmonary function.

Peripartum Substitution of Inhaled for Intravenous Prostacyclin in a Patient with Primary Pulmonary Hypertension

WE report a parturient with severe primary pulmonary hypertension who was receiving chronic intravenous prostacyclin (epoprostenol, PGI 2 , Flolan®; GlaxoSmith-Kline, Research Triangle Park, NC) and changed to inhaled prostacyclin prepartum. Our strategy was to take advantage of the selective pulmonary artery (PA) vasodilation afforded by inhaled prostacyclin to minimize systemic side effects such as arterial hypotension and antiplatelet effects seen with intravenous administration. We theorized that this approach would allow for uninterrupted PA vasodilation while simultaneously minimizing the risk of antiplatelet effects and would thereby permit safer epidural catheter placement necessary for effective analgesia for planned forceps-assisted vaginal delivery.

Use of the Patient State Index (PSI) to assist in the diagnosis of perioperative neurological injury and brain death.

We present a series of three postoperative cases that were admitted to a cardiothoracic intensive care unit (ICU) after major surgery. Due to the possible presence of residual postoperative neuromuscular blockade after surgery, a processed electroencephalograph (EEG) was applied prior to starting sedation. This was markedly abnormal in all three cases, and not in keeping with the residual anesthesia. The patients were immediately transported for a CT scan. In all three cases there was severe neurological injury incompatible with survival and end of life decisions were made. Although the utility of quantitative EEG technology, like the Bispectral index (BIS) or Patient State Analyzer (PSA), is becoming better defined in the operating room, the role in the ICU is less clear. We propose that the ICU use of the PSA 4000 may have affected our decision weighing the risk versus benefit of transporting a fresh postoperative case to the radiology suite, expedited the neurological diagnosis, and may have reduced overall ICU resource utilization.