AIRWAY MANAGEMENT IN NEUROANESTHESIA.

Neurosurgical patients have specific airway management. Various conditions and diagnoses make intubation difficult and may also cause neurological damage. Spinal pathology, neurotrauma, cervical spine surgery, and pituitary gland surgery are just some examples. The aim of this review article is to present a broad spectrum of neurosurgical operations and potential complications in maintaining airway patency related to these issues. Quality perioperative preparation is a prerequisite to avoid the potentially irreversible consequences of difficult airways with a poor neurological or even fatal outcome. Patients with tumors of the pituitary region who present with Cushing's disease are prone to difficult ventilation, tracheal obstruction and difficult intubation. Awake craniotomy is also a challenge for the anesthesiologist, given that access to the airway is problematic due to the fixed frame. Unstable cervical spine occurs in cases of rheumatoid arthritis or blunt trauma, requiring precautions to be taken with spinal stabilization during intubation and induction. Pharyngeal edema and hematomas, possible complications of cervical spine surgery can endanger airway patency after extubation; postoperative patient supervision is thus required. Due to the potential threat to the patient's airway during neurosurgical procedures, quality anesthetic preoperative preparation is necessary to avoid irreversible damage and death.

Hypermagnesemia disturbances in rats, NO-related: pentadecapeptide BPC 157 abrogates, L-NAME and L-arginine worsen.

AIM: Stable gastric pentadecapeptide BPC 157, administered before a high-dose magnesium injection in rats, might be a useful peptide therapy against magnesium toxicity and the magnesium-induced effect on cell depolarization. Moreover, this might be an NO-system-related effect. Previously, BPC 157 counteracts paralysis, arrhythmias and hyperkalaemia, extreme muscle weakness; parasympathetic and neuromuscular blockade; injured muscle healing and interacts with the NOS-blocker and NOS-substrate effects. MAIN METHODS: Assessment included magnesium sulfate (560 mg/kg intraperitoneally)-induced muscle weakness, muscle and brain lesions, hypermagnesemia, hyperkalaemia, increased serum enzyme values assessed in rats during and at the end of a 30-min period and medication (given intraperitoneally/kg at 15 min before magnesium) [BPC 157 (10 µg, 10 ng), L-NAME (5 mg), L-arginine (100 mg), alone and/or together]. In HEK293 cells, the increasing magnesium concentration from 1 to 5 mM could depolarize the cells at 1.75 ± 0.44 mV. KEY FINDINGS: L-NAME + magnesium-rats and L-arginine + magnesium-rats exhibited worsened severe muscle weakness and lesions, brain lesions, hypermagnesemia and serum enzymes values, with emerging hyperkalaemia. However, L-NAME + L-arginine + magnesium-rats exhibited all control values and normokalaemia. BPC 157 abrogated hypermagnesemia and counteracted all of the magnesium-induced disturbances (including those aggravated by L-NAME or L-arginine). Thus, cell depolarization due to increasing magnesium concentration was inhibited in the presence of BPC 157 (1 µM) in vitro. SIGNIFICANCE: BPC 157 likely counteracts the initial event leading to hypermagnesemia and the life-threatening actions after a magnesium overdose. In contrast, a worsened clinical course, higher hypermagnesemia, and emerging hyperkalaemia might cause both L-NAME and L-arginine to affect the same events adversely. These events were also opposed by BPC 157.

BPC 157: The counteraction of succinylcholine, hyperkalemia, and arrhythmias.

After the demonstration of its life-saving effect in severe hyperkalemia and the recovery of skeletal muscle after injury, pentadecapeptide BPC 157 has been shown to attenuate the local paralytic effect induced by succinylcholine, in addition to systemic muscle disability (and consequent muscle damage). Hyperkalemia, arrhythmias and a rise in serum enzyme values, were counteracted in rats. Assessments were made at 3 and 30min and 1, 3, 5, and 7 days after succinylcholine administration (1.0mg/kg into the right anterior tibial muscle). BPC 157 (10µg/kg, 10ng/kg) (given intraperitoneally 30min before or immediately after succinylcholine or per-orally in drinking water through 24h until succinylcholine administration) mitigated both local and systemic disturbances. BPC 157 completely eliminated hyperkalemia and arrhythmias, markedly attenuated or erradicated behavioral agitation, muscle twitches, motionless resting and completely eliminated post-succinylcholine hyperalgesia. BPC 157 immediately eliminated leg contractures and counteracted both edema and the decrease in muscle fibers in the diaphragm and injected/non-injected anterior tibial muscles. Therefore, the depolarizing neuromuscular blocker effects of succinylcholine were successfully antagonized.

BPC 157 antagonized the general anaesthetic potency of thiopental and reduced prolongation of anaesthesia induced by L-NAME/thiopental combination.

AIM: We hypothesized that certain effects of the general anaesthetic thiopental are dependent on NO-related mechanisms, which were consequently counteracted by stable gastric pentadecapeptide BPC 157. MAIN METHODS: (1) All rats intraperitoneally received thiopental (20, 30, 40, and 50 mg/kg) while medication BPC 157 (10 µg/kg, 10 ng/kg, and 10 pg/kg) was given intraperitoneally at 5 min before thiopental. (2) To determine NO-related mechanisms, all rats received intraperitoneally thiopental 40 mg/kg while BPC 157 (10 µg/kg), L-NAME (10 mg/kg) and L-arginine (30 mg/kg) were applied alone and/or combined. BPC 157 was given at 25 min before thiopental while L-NAME, L-arginine, alone and/or combined, were applied at 20 min before thiopental. KEY FINDINGS: (1) BPC 157 own effect on thiopental anaesthesia: BPC 157 (10 ng/kg and 10 µg/kg) caused a significant antagonism of general anaesthesia produced by thiopental with a parallel shift of the dose-response curve to the right. (2) L-NAME-L-arginine-BPC 157 interrelations: L-NAME: Thiopental-induced anaesthesia duration was tripled. L-arginine: Usual thiopental anaesthesia time was not influenced. Active only when given with L-NAME or BPC 157: potentiating effects of L-NAME were lessened, not abolished; shortening effect of BPC 157: abolished. BPC 157 and L-NAME: Potentiating effects of L-NAME were abolished. BPC 157 and L-NAME and L-arginine: BPC 157 +L-NAME +L-arginine rats exhibited values close to those in BPC 157 rats. SIGNIFICANCE: Thiopental general anaesthesia is simultaneously manipulated in both ways with NO system activity modulation, L-NAME (prolongation) and BPC 157 (shortening/counteraction) and L-arginine (interference with L-NAME and BPC 157).

Peripheral arterial catheter related infections in the neurosurgical intensive care unit.

Intravascular device infections could be serious complications with significant contributable morbidity and mortality. The aim of this prospective clinical study is to demonstrate the infection rate related to peripheral arterial catheters and their clinical significance in neurosurgical intensive care unit (ICU) patients. After removal, all arterial catheter tips were cultivated by semiquantitative method and clinical data were collected. During a period of two years, 186 arterial catheters were placed in 105 neurosurgical ICU patients. In 6 cases (3.2%) infection was presumably related to the arterial catheter. The rate of such probable catheter related infections was found to be 5/1000 catheter days. The isolated microorganisms were: Methicillin resistant Staphylococcus epidermidis (MRSE) in 4 cases, Corynebacterium species and Candida albicans each in one case respectively. Thirteen cases (7.0%) were interpreted as contamination and one as colonization. An association was found between the presence of infection from different sources and significant bacterial growth on the catheter. Patients with positive catheter culture had a significantly longer ICU stay, more cumulative catheter days, and a higher mortality rate than those with sterile catheters. We can conclude that the rate of probable peripheral arterial catheter related infection is low. A higher mortality rate in patients who experienced probable catheter related infection does not seem to be a consequence of the aforementioned infection. A more suitable explanation would be that patients with nosocomial infections and higher mortality risk have prolonged ICU stays. There is an increased chance of developing a catheter related infection in those patients who have more cumulative catheter days.

Lidocaine suppository for transrectal ultrasound-guided biopsy of the prostate: a prospective, double-blind, randomized study.

AIMS: To investigate analgesia using lidocaine suppositories for prostate biopsy. METHODS: From 2007 to 2009, 160 patients underwent transrectal ultrasound-guided prostate biopsy at the Department of Urology, KBC Zagreb. 80 patients received a 60-mg lidocaine suppository intrarectally at different time points from 15 to 120 min before biopsy and 80 patients received a glycerin suppository as placebo. The pain level was evaluated using a visual analogue scale (VAS). RESULTS: There were no statistically significant differences between the groups, i.e. they were similar regarding patients' age, prostate-specific antigen levels, prostate volume and the incidence of diagnosis of malignancy on biopsy. The mean pain score in the lidocaine group (3 ± 1) was significantly lower than the mean pain score in the glycerin group (4.1 ± 1.3) (p < 0.001). A noticeable trend towards lower pain scores in the lidocaine group was observed with more time elapsing from placing the suppository till the biopsy and the optimal time for performing biopsy starting approximately 1 h after placing the suppository. CONCLUSIONS: Lidocaine suppositories are an easy-to-use, self-applicable (by the patient) and cheap method of local analgesia, with acceptable results. Possible complications related to this procedure are insignificant.

Sole stenting of large and giant intracranial aneurysms with self-expanding intracranial stents-limits and complications.

BACKGROUND: Intracranial aneurysms may be difficult for endovascular treatment due to size, fusiform shape, or wide neck. In such patients, intracranial stents are used to support the coils in the aneurysm sac, or they may be used as a sole stenting technique to divert the blood flow without coils. The aim of this paper is to contribute to the existing data by reviewing the risks of sole stenting of large and giant aneurysms. METHODS: We treated seven patients with nine aneurysms by self-expanding intracranial stents, either by a single or multiple stents in a stent-in-stent configuration. The follow-up was performed by digital subtraction angiography with a mean follow-up time of 6 months. RESULTS: A positive response to stenting occurred in five out of seven patients (71%) and six out of nine aneurysms (67%). The aneurysms were occluded in two patients, and incomplete results were noted in three patients. The symptoms due to the compression of cranial nerves resolved in four patients (57%). Procedure-related subarachnoid hemorrhage occurred in two out of seven patients (29%), with death of one patient as a result of hemorrhage (14%). CONCLUSIONS: Sole stenting of large and giant aneurysms with self-expanding intracranial stents may be associated with a higher risk than previously reported. The effect of stenting on intra-aneurysmal flow in such aneurysms, even after the placement of multiple overlapping stents, seems to be unpredictable.

[Role of anesthesiologist in endovascular management of intracranial aneurysms]. / Uloga anesteziologa pri endovaskularnom pristupu rjesavanja intrakranijskih aneurizmi.

The aim is to give a review of the anesthesiological approach to neuroradiological endovascular treatment of intracranial aneurysm in Croatia since 2004, when the first procedure was done. It took place at University Department of Radiology, Zagreb University Hospital Center. The optimal conduct of anesthesia in the neuroradiology suite requires careful planning of each individual procedure. Essential components are detailed patient evaluation and due understanding of the underlying neuropathology. An open channel of communication between the radiologist and the anesthesiologist is important for routine care but is crucial in case of disasters that may occur during the procedure. In the patient management the basic principles of neuroanesthesia cannot be avoided. This includes optimization of CBF, perfusion pressure, control of intracranial pressure (ICP) and close monitoring of blood pressure (BP), fluid status and body temperature. The choice of anesthetic agents and techniques remains in the hands of the anesthesiologist. The needs of the neuroradiologist and the procedure have to be considered. Most institutions have their protocols and some favor conscious sedation whereas others prefer general anesthesia. There is little evidence in favor of either technique. The better image quality obtained from the motionless patient during digital subtraction angiography favors the use of general anesthesia over any other technique. Since the procedure is becoming very complex, the need for precise BP control and preparation for potential catastrophic complication are considerations for general anesthesia. Aneurysm rupture during endovascular procedures is not common but remains a potential risk. The incidence ranges from 2.3% to 3% and even higher in patients with already ruptured aneurysms. The mortality rate is up to 20% in case of rupture, especially if massive subarachnoid hemorrhage occurs. Anesthesiologic treatment depends on the severity of bleeding and includes maintaining CPP, lowering ICP, reversal of anticoagulation and patient transfer to the neurosurgical operating room if immediate ventriculostomy is needed. During a six month period, 55 patients underwent endovascular treatment of cerebral aneurysm at our hospital. They all were managed under general anesthesia. Since one of the critical roles of the anesthesiologist in the interventional radiology suite is to provide anticoagulation, the protocol of giving clopidogrel was followed, loading dose of 225 mg p. o. to each patient on the day of the procedure and immediately upon introducing microcatheter, heparin iv 70 IU/kg (average of 5000 IU), followed by boluses of 15 IU/kg (approx. 1000 IU) every 60 minutes. Activated clotting time was monitored for the effect of heparin. All patients except four were brought out of anesthesia at the table, immediately after the procedure for their neurological status to be assessed. None of the patients died during the procedure or within the first 24 hours. The mortality was up to 3.6% (two patients died on days 3 and 5 of the procedure). We had only one case of aneurysm rerupture during embolization with Guglielmi detachable coil, followed by cardiac arrest, but the patient (a 32-year-old woman) was resuscitated successfully and underwent standard neurosurgical procedure with full recovery in ICU after 14 days. There were 4 (7.2%) cases of vasospasm followed by ischemia, nimodipine treated, 2 with transient neurological dysfunction and another 2 with permanent hemianopsia. Interventional neuroradiology is rapidly and continually evolving, providing opportunities for the anesthesiologist to be part of this branch of medicine. It is essential to keep up-to-date in the knowledge of neuroanesthesia, neuropathology and interventional neuroradiology. In spite of the relatively non-invasive nature of the procedures, serious, even fatal complications may occur. Therefore, the role of anesthesiologist and his/her cooperation with neuroradiologist is crucial for successful results.