Effect of dexmedetomidine on dynamic cerebral autoregulation and carbon dioxide reactivity during sevoflurane anesthesia in healthy patients / 대한마취과학회지

Background@# There are conflicting opinions on the effect of dexmedetomidine on cerebral autoregulation. This study assessed its effect on dynamic cerebral autoregulation (dCA) using a transcranial Doppler (TCD). @*Methods@# Thirty American Society of Anesthesiologists physical status I and II patients between 18 and 60 years, who underwent lumbar spine surgery, received infusions of dexmedetomidine (Group D) or normal saline (Group C), followed by anesthesia with propofol and fentanyl, and maintenance with oxygen, nitrous oxide and sevoflurane. After five minutes of normocapnic ventilation and stable bispectral index value (BIS) of 40-50, the right middle cerebral artery flow velocity (MCAFV) was recorded with TCD. The transient hyperemic response (THR) test was performed by compressing the right common carotid artery for 5-7 seconds. The lungs were hyperventilated to test carbon dioxide (CO2) reactivity. Hemodynamic parameters, arterial CO2 tension, pulse oximetry (SpO2), MCAFV and BIS were measured before and after hyperventilation. Dexmedetomidine infusion was discontinued ten minutes before skin-closure. Time to recovery and extubation, modified Aldrete score, and emergence agitation were recorded. @*Results@# Demographic parameters, durations of surgery and anesthesia, THR ratio (Group D: 1.26 ± 0.11 vs. Group C: 1.23 ± 0.04; P = 0.357), relative CO2 reactivity (Group D: 1.19 ± 0.34 %/mmHg vs. Group C: 1.23 ± 0.25 %/mmHg; P = 0.547), blood pressure, SpO2, BIS, MCAFV, time to recovery, time to extubation and modified Aldrete scores were comparable. @*Conclusions@# Dexmedetomidine administration does not impair dCA and CO2 reactivity in patients undergoing spine surgery under sevoflurane anesthesia.

Causes of tracheal re-intubation after craniotomy: a prospective study

Re-intubation of neurosurgical patients after a successful tracheal extubation in the operating room is not uncommon. However, no prospective study has ever addressed this concern. This study was aimed at analyzing various risk factors of re-intubation and its effect on patient outcome. Patients aged between 18-60 years and of ASA physical status 1 and 2 undergoing elective craniotomies over a period of two years were included. A standard anesthetic technique using propofol, fentanyl, rocuronium, and isoflurane/sevoflurane was followed, in all these patients. 'Re-intubation' was defined as the necessity of tracheal intubation within 72 hrs of a planned extubation. Data were collected and analyzed employing standard statistical methods. One thousand eight hundred and fifty patients underwent elective craniotomy, of which 920 were included in this study. A total of 45 [4.9%] patients required re-intubation. Mean anesthesia duration and time of re-intubation were 6.3 +/- 1.8 and 24.6 +/- 21.9 hrs, respectively. The causes of re-intubation were neurological deterioration [55.6%], respiratory distress [22.2%], unmanageable respiratory secretion [13.3%], and seizures [8.9%]. The most common post-operative radiological [CT scan] finding was residual tumor and edema [68.9%]. Seventy-three percent of the re-intubated patients had satisfactory post-operative cough-reflex. The ICU and hospital stay, and Glasgow outcome scale at discharge were not significantly affected by different causes of re-intubation. Neurological deterioration is the most common cause of re-intubation following elective craniotomies owing to residual tumor and surrounding edema. A satisfactory cough reflex may not prevent subsequent re-intubation in post-craniotomy patients

Anesthetic management in children with Hurler's syndrome undergoing emergency ventriculoperitoneal shunt surgery

Mucopolysaccharidoses [MPSs] are a group of lysosomal storage disorder characterized by progressive multiorgan accumulation of glycosaminoglycans. Patients with MPS I [Hurler's syndrome] present as one of the most difficult airway problems to be managed by anesthesiologists. Hydrocephalus with increased intracranial pressure is a frequent complication seen in these patients. The rarity of the syndrome accounts for the small number of case reports and anecdotal information on the intracranial manifestations of this syndrome. We describe the successful anesthetic management of 2 children with Hurler's syndrome who underwent ventriculoperitoneal shunt surgery for acute hydrocephalus

Application of indigenous continuous positive airway pressure during one lung ventilation for thoracic surgery

During one lung ventilation [OLV] hypoxemia may occur due to ventilation-perfusion mismatch. It can be prevented with application of ventilation strategy that prevents atelectasis while minimally impairing perfusion of the dependant lung. Here, two cases are reported who required OLV and in whom hypoxemia could be prevented with the application of continuous positive airway pressure to the deflated or non-dependant lung, using an indigenous technique. We suggest use of this technique which is easy to be employed during the intraoperative period