Fire Hazard in an Anesthesia Machine: A Case Report.

An operating room (OR) fire is a rare event but may cause critical harm to patients and health care personnel. We present 2 fire incidents in the rear cabinet of an anesthesia machine, not previously reported in the literature. An anesthesia machine in standby mode is considered safer than in use, but in the first case, the fire occurred while the machine was on standby mode. In another case, the fire erupted while surgery was in progress. Here, we discuss the management of an anesthesia machine fire and emphasize the need for improved fire safety in advanced anesthesia machines.

Comparison of Propofol and Ketofol on Transcranial Motor Evoked Potentials in Patients Undergoing Thoracolumbar Spine Surgery.

STUDY DESIGN: This was a double-blind randomized study. PURPOSE: The primary purpose was to compare the effects of propofol and ketofol on amplitudes and latencies of transcranial motor evoked potentials (TcMEPs) during thoracolumbar spine surgery. In addition, intraoperative hemodynamics and muscle power were compared. OVERVIEW OF LITERATURE: Propofol is commonly used during intraoperative TcMEP monitoring. However, propofol inhibits TcMEP amplitudes and causes hypotension in a dose-dependent fashion. METHODS: Amplitude and latency of TcMEPs were recorded bilaterally from the abductor pollicis brevis (APB) and abductor hallucis (AH) muscles in 38 adult American Society of Anesthesiologists I and II patients undergoing thoracolumbar spine surgery. Baseline recordings of TcMEPs in both groups were recorded under propofol infusion. Group X patients then received propofol and fentanyl (1 mcg/kg/hr), and group Y patients received ketofol and fentanyl (1 mcg/kg/hr). Bispectral index was maintained at 40-60 in both groups. Amplitude and latency were recorded at 30 minutes intervals for 2 hours. RESULTS: Propofol caused no significant changes in amplitude and latency in any muscle. In contrast, amplitude increased significantly at all time points in the bilateral APB muscles and 60, 90, and 120 minutes in the left AH muscle without changes in latency in response to ketofol. When the two groups were compared, ketofol induced significantly higher amplitudes at 60, 90, and 120 minutes in the (left) APB, at all time points in the (right) APB, and at 120 minutes in both AH muscles, compared with propofol. Blood pressures were lower and fluid and vasopressor requirements were higher in group X. Muscle power was similar between the two groups. CONCLUSIONS: Ketofol facilitates TcMEP amplitudes without affecting latency. Use of ketofol resulted in a better and more stable hemodynamic profile than did use of propofol.

Iatrogenic Seizures during Intraoperative Transcranial Motor-Evoked Potential Monitoring.

Intraoperative neurophysiological monitoring (IONM) is an important tool for early detection of inadvertent damage and guide intra-operative manipulation during complex neurosurgical procedures. However trans-cranial stimulation can evoke an iatrogenic seizure and it remains a real concern while using Tc-MEP. We report a case of intra-operative seizure during transcranial electrical stimulation for motor evoked potential monitoring in a patient without seizure disorder, who underwent surgery for thoracic intra-medullary tumor excision.

Intraoperative Management of a Patient for Deep Brain Stimulation with Severe Dyskinesia and Tremors: Ketamine to the Rescue!

The loss of dopaminergic neurons from the substantia nigra pars compacta characterizes the classical pathology of Parkinson's disease (PD). Deep brain stimulation (DBS) has become an increasingly common treatment for PD. Sometimes excessive tremors due to exacerbated PD hinder the surgery and may almost make it impossible. This is a case report highlights use of IV ketamine for intraoperative sedation of a patient with PD, with severe dyskinesia & tremors, posted for DBS. IV ketamine resulted in prompt abolition of tremors and dyskinesia, which were unresponsive to previous traditional sedative drugs.

Comparison of 20% mannitol and 3% hypertonic saline on intracranial pressure and systemic hemodynamics.

Mannitol and hypertonic saline (HS) are most commonly used hyperosmotic agents for intraoperative brain relaxation. We compared the changes in ICP and systemic hemodynamics after infusion of equiosmolar solutions of both agents in patients undergoing craniotomy for supratentorial tumors. Forty enrolled adults underwent a standard anesthetic induction. Apart from routine monitoring parameters, subdural ICP with Codmann catheter and cardiac indices by Vigileo monitor, were recorded. The patients were randomized to receive equiosmolar solutions of either 20% mannitol (5ml/kg) or 3% HS (5.35ml/kg) for brain relaxation. The time of placement of ICP catheter was marked as T0 and baseline ICP and systemic hemodynamic variables were noted; it was followed by recording of the same parameters every 5min till 45min (Study Period). After the completion of study period, brain relaxation score as assessed by the neurosurgeon was recorded. Arterial blood gas (ABG) was analysed every 30min starting from T0 upto one and half hours (T90), and values of various parameters were recorded. Data was analysed using appropriate statistical methods. Both mannitol and HS significantly reduced the ICP; the values were comparable in between the two groups at most of the times. The brain relaxation score was comparable in both the groups. Urine output was significantly higher with mannitol. The perioperative complications, overall hospital stay, and Glasgow outcome score at discharge were comparable in between the two groups. To conclude, both mannitol and hypertonic saline in equiosmolar concentrations produced comparable effects on ICP reduction, brain relaxation, and systemic hemodynamics.

Anaesthesia for awake craniotomy: A retrospective study of 54 cases.

BACKGROUND AND AIMS: The anaesthetic challenge of awake craniotomy is to maintain adequate sedation, analgesia, respiratory and haemodynamic stability in an awake patient who should be able to co-operate during intraoperative neurological assessment. The current literature, sharing the experience on awake craniotomy, in Indian context, is minimal. Hence, we carried out a retrospective study with the aim to review and analyse the anaesthetic management and perioperative complications in patients undergoing awake craniotomy, at our centre. METHODS: Medical records of 54 patients who underwent awake craniotomy for intracranial lesions over a period of 10 years were reviewed, retrospectively. Data regarding anaesthetic management, intraoperative complications and post-operative course were recorded. RESULTS: Propofol (81.5%) and dexmedetomidine (18.5%) were the main agents used for providing conscious sedation to facilitate awake craniotomy. Hypertension (16.7%) was the most commonly encountered complication during intraoperative period, followed by seizures (9.3%), desaturation (7.4%), tight brain (7.4%), and shivering (5.6%). The procedure had to be converted to general anaesthesia in one of patients owing to refractory brain bulge. The incidence of respiratory and haemodynamic complications were comparable in the both groups (P > 0.05). There was less incidence of intraoperative seizures in patients who received propofol (P = 0.03). In post-operative period, 20% of patients developed new motor deficit. Mean intensive care unit stay was 2.8 ± 1.9 day (1-14 days) and mean hospital stay was 7.0 ± 5.0 day (3-30 days). CONCLUSIONS: 'Conscious sedation' was the technique of choice for awake craniotomy, at our institute. Fentanyl, propofol, and dexmedetomidine were the main agents used for this purpose. Patients receiving propofol had less incidence of intraoperative seizure. Appropriate selection of patients, understanding the procedure of surgery, and judicious use of sedatives or anaesthetic agents are key to the success for awake craniotomy as a procedure.