Mg Of Vecuronium Research Articles

Reverse Takotsubo Stress Cardiomyopathy During Liver Transplantation

Reverse Takotsubo Stress Cardiomyopathy During Liver Transplantation

Ease in Bag and Mask Ventilation: Is Ankyloglossia in a Child with Micrognathia a Blessing in Disguise?

Sir, A review of the pediatric closed claim cases reveals inadequate ventilation or failed intubation among common causes of anesthesia-related deaths. Unlike adults, no validated classification exists for difficult airway assessment in pediatric population.[1] Anticipated difficult airway includes congenital syndromes or anatomy such as temporomandibular joint dysfunction or neck contracture. A common feature of many of these syndromes is micrognathia, ankyloglossia, or both leading to difficult glottic visualization.[2] Mallampati classification does not accurately predict a poor glottis visualization in the pediatric population.[1] We discuss difficult airway management of a 3-year-old male child with micrognathia and ankyloglossia, diagnosed with Grade V left vesicoureteric reflux and listed for laparoscopic transperitoneal left ureteric reimplantation [Figure 1].Figure 1: Child with micrognathiaAfter adequate nil per oral status, the child was brought to operating room without any premedication. Routine anaesthesia monitors was placed and age appropriate difficult airway trolley was kept on standby. Anesthesia was induced with inhaled sevoflurane 6–8%, intravenous access secured; midazolam 0.3 mg, fentanyl 30 μg, and propofol 10 mg were administered. Under spontaneous ventilation, conventional direct laryngoscopy (DL) with straight blade was attempted. A Cormack and Lehane (CL) Grade IV laryngoscopic view was encountered owing to the tongue falling on either side of the blade. A repeat attempt was done with curved blade, but the tongue could not be deviated to the left side because of ankyloglossia. Two failed attempts at DL prompted us to use GlideScope® video laryngoscope (GVL) which enabled a CL Grade III glottic visualization, and we were able to intubate the trachea with 4.5 sized uncuffed endotracheal tube. Subsequently, the child was paralyzed with 2 mg of vecuronium and maintained with oxygen, air, and sevoflurane mixture. During the entire episode till successful intubation, we were able to maintain oxygenation. After completion of surgery and return of spontaneous ventilation, muscle relaxation was reversed and child extubated. Keeping in mind the nature, duration, and positioning during surgery, we ruled out the use of laryngeal mask airway (LMA) as our first tool to secure the airway. Kuzma et al. used LMA assisted fiberoptic-guided intubation for a child with Escobar syndrome.[3] Airtraq optical laryngoscope and GVL have been used successfully in pediatric patients with the craniofacial anomalies.[4] We are of the opinion that ankyloglossia, by preventing tongue fall, allowed us to ventilate the patient and gave us precious time to exercise other options of securing the airway. While ankyloglossia made bag-mask ventilation easy, it along with micrognathia resulted in limited space for blade maneuverability during DL and GVL, thereby hampering glottic visualization. Although we used GVL to secure the airway, we wish to suggest that rather than taking multiple attempts at DL or GVL, fiberoptic-guided intubation should be the first choice for endotracheal intubation. Further, a child with micrognathia should always be evaluated for ankyloglossia during preanesthetic evaluation. However, a larger study in children with ankyloglossia and micrognathia is required to further cement our suggestion. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

A misplaced and entrapped pulmonary artery catheter

A misplaced and entrapped pulmonary artery catheter

No explicit memory after skin incision without anesthetic except for remifentanil infusion

To the Editor: Awareness and memory during general anesthesia is a serious problem. We experienced no explicit memory in a patient who was accidentally not administered anesthetic during skin incision before abdominal surgery. During that time, remifentanil alone was infused continuously. A 76-year-old woman, height 156.8 cm, weight 52 kg, was scheduled for peritoneal metastatic tumor resection. She had no complications or past history, except for lower anterior resection of the rectum with laparoscopic surgery 24 months prior. No premedication was administered. Anesthesia was induced with 200 mg thiopental and continuous infusion of remifentanil at the rate of 0.5 lg/kg/ min. She underwent tracheal intubation with the aid of 7 mg of vecuronium. The ventilation was controlled with 35% oxygen in air. After the induction of anesthesia, we planned to provide inhaled 3% sevoflurane during mask ventilation and 1% after tracheal intubation. We used the sevoflurane vaporizer 953 for servo 900C ventilator (MAQUET Critical Care AB, Solna, Sweden). This vaporizer requires activation of another switch in addition to adjusting the concentration dial to initiate sevoflurane inhalation (Fig. 1). We inadvertently forgot to activate the vaporizer switch to the ‘‘on’’ position. Accordingly, no sevoflurane was inhaled. After intubation, we decreased the rate of remifentanil infusion to 0.25 lg/kg/min during surgical-site sterilization and draping. Just before skin incision, we increased the rate of remifentanil infusion to 0.5 lg/kg/min. Twenty-four minutes after the administration of thiopental, skin incision was performed as usual. There was no apparent change of blood pressure or heart rate. The laparotomy was then continued, and there were no apparent changes in her vital signs. About 6 min after the skin incision, we noticed that the end-tidal concentration of sevoflurane on the monitor (S5, GE Healthcare Japan, Tokyo) was zero, and activated the vaporizer switch. We initially administered 3% sevoflurane, followed by 1–1.5% sevoflurane with 0.1–0.5 lg/kg/min of remifentanil. No other sedatives were administered. The operation was completed uneventfully with a total operation time of 1 h 39 min. The emergence from anesthesia was uneventful, with a total duration of anesthesia of 2 h 29 min. We asked the patient about her memories of the operation later on that same day and the next day. She had no explicit memory during the operation and expressed her thanks for a good anesthetic experience. The hypnotic that we administered to this patient was 200 mg of thiopental alone. Clinically, patients awaken from a single dose of thiopental about 5–10 min after administration because the drug levels in the brain decrease as a result of redistribution [1]. Accordingly, about 15 min after the end of the hypnotic action of thiopental, the patient was sedated only with remifentanil of 0.25–0.5 lg/kg/min. During the procedure, we had closed the eyelids of the patient using a sticking tape. The ears of the patient were free, but the sound in the operating room was minimal. Accordingly, it is possible that the patient was not aware of any stimuli except for the surgical procedure. Remifentanil has some sedative action and has been used for analgesia-based sedation [2, 3]. No implicit or explicit memory was found when a high concentration of remifentanil combined with low hypnotic concentration of propofol was maintained with high bispectral index (BIS) values [4]. Remifentanil 0.5 lg/kg/min might have been M. Yasuda R. Kubota T. Adachi (&) Department of Anesthesiology, Kitano Hospital, The Tazukekofukai Medical Research Institute, 2-4-20 Ohgimachi, Kita-ku, Osaka 530-8480, Japan e-mail: t-adachi@kitano-hp.or.jp

Medical litigation as a result of awareness during general anaesthesia

In the literature, little attention has been paid to the medico-legal implications of awareness during general anaesthesia, a complication which has been reported with an incidence of 0.5-2%. We present the case of a 39-year-old nurse who experienced awareness during salpingo-adnexectomy for tubo-ovarian pregnancy. The operation was performed as an emergency, due to severe haemorrhage. Anaesthesia was induced with 125 mg of thiopental sodium and 60 mg of succinylcholine, and then maintained with repeated doses of fentanyl and 7 mg of vecuronium. In the court settlement, medical liability was rejected, because her awareness during anaesthesia was ascribed to the need to use small quantities of anaesthetics, due to severe hypotension, and not to medical error. The case presented here and a brief review of the literature indicate that awareness during anaesthesia is not always a consequence of medical negligence.

Intraoperative Apnea: Medication Error with Disclosure (Simulation Case Scenario)

Intraoperative Apnea: Medication Error with Disclosure (Simulation Case Scenario)

Prebypass Muscle Relaxant: To the Patient or the Pump?

The objective of this study was to assess the difference in muscular relaxation, produced by administration of the prebypass relaxant dose to the patient or in the bypass circuit. This prospective study was conducted on 100 patients scheduled to undergo elective coronary artery bypass grafting. All patients received 2 mg of vecuronium as prebypass relaxant, with neuromuscular junction monitoring using an accelograph. The patients in Group A (n=50) received the prebypass relaxant dose directly through the central venous cannula during heparinisation while group B patients (n=50) received it into the bypass circuit after initiation of bypass. Further doses of the relaxant were administered, if the train of four ratio was more than 10% at anytime after 5 min of bypass. The train of four ratio before heparinisation was similar in both groups, 12+/-6% in Group A and 13+/-5% in Group B, but after the prebypass relaxant dose, it was 1+/-2% in Group A and 15+/-3% in Group B (P<0.05). On bypass, in Group A it was 3+/-2%, 5+/-2%, 6+/-3% and 6+/-3% at 1, 5, 10 and 15 min at normothermia, while in Group B it was 29+/-6%, (P<0.01) at 1 min, 19+/-7%, (P<0.05) at 5 min, 13+/-6% at 10 min and 3+/-2% at 15 min. Additional doses of relaxant on bypass were required in 48 patients in Group B and none in Group A (P<0.01). It is concluded that the degree of muscle relaxation is significantly more profound when the prebypass relaxant dose is given to the patient directly before initiating the bypass, than when it is added to the bypass circuit after initiating the bypass. Time taken is longer and dose needed is larger, to produce the same effect.

Systemic spread of vecuronium following use in peribulbar regional anaesthesia

With reference to G. Reah et al. [1], I would like to report an unfortunate if not entirely unpredictable side-effect of employing vecuronium to augment peribulbar anaesthesia. In common with Reah et al., I have experienced some unpredictable levels of akinesia when performing peribulbar blocks and was intrigued to read their groundbreaking study. Being most interested to employ their technique and using their paper as a reference, I started my own series. Eventually, I performed 30 peribulbar blocks employing vecuronium to improve the akinesia through its neuromuscular blocking action. All patients had intravenous access established pre-anaesthesia and were monitored with pulse oximetry and ECG. Neuromuscular monitoring was not felt to be necessary as (apart from being painful) the patients, being conscious, would be able to report any decrease in muscle power. Starting with a solution of 9.5 ml of plain lidocaine 2% with 300 units hyalase and 0.25 ml (0.5 mg) vecuronium, I used 1 ml of amethocaine 1% topically to the cornea followed by a single median injection with a 25-mm 25 G needle. A Honans balloon was inflated to 30 cm water pressure and was applied for 5 min. After 15 patients, my results were subjectively no better than normal. This perhaps is not surprising as Reah et al. also found that in their vecuronium group they still described 11/30 blocks as poor. Because of this and also believing incorrectly that significant systemic spread via intravenous injection would be heralded by the predominant effects of the local anaesthetic (a view shared by Reah et al.), I increased my dose of vecuronium to 0.5 ml (1 mg) for the following 10 cases. No adverse effects were detected but, unfortunately, neither was any noticeable improvement in akinesia. In the last five cases, 2 mg of vecuronium was used and in the last of these a problem arose. A 72-year-old woman presented for cataract surgery and received the same anaesthetic as I have described. Five minutes after the block, the Honans balloon was removed and adequate akinesia was demonstrated. The patient was then transferred to the operating room and prepared for surgery. Exactly 9 min postinjection the patient complained, in a whisper, that she was having some difficulty in speaking and 1 min later she reported some respiratory distress. At this point, surgical preparation was discontinued and the patient was sat up in order to assist her breathing. A rapid neurological examination showed that she had reduced power but normal sensation in all four limbs. Her blood pressure was 210/70 mmHg, indicating that inadvertent intrathecal injection was unlikely to be the cause. Suspecting systemic spread of the vecuronium, the patient was immediately given neostigmine 0.75 mg and glycopyrrolate 0.15 mg. In less than 1 min she had made a complete recovery. Surgery was postponed, however, and the patient was observed in recovery for 1 h before returning to the ward. That evening the patient was discharged home. In the Reah study, the vecuronium dose was one-quarter of that which I used and this is most likely to explain why I observed an episode of clinically significant systemic spread, whereas they did not. On top of this, their solution contained 1 : 440 000 epinephrine, which may also have been a contributory factor in reducing systemic spread. The Reah study, however, was, as they attest, relatively small and inferences as to the safety of the technique should be made with caution. With only 30 in their treatment group, the upper limit of the 95% confidence interval for the occurrence of such complications may still be as high as 10% [2]. Given this, and the fact that Reah still observed a high proportion of poor blocks (an observation with which I concur), it may be that the margin of safety between minimum effective and maximum safe dose is very small. The use of vecuronium in this way cannot therefore be recommended unless larger more powerful studies can confirm its safety in the future. Ironically, in their discussion, Reah et al. propose that with the current trend towards topical anaesthesia for certain ophthalmic work, any benefit from the use of vecuronium might soon be rendered obsolete. For my own part, I think I will avoid using it henceforth. As for my 72-year-old patient, she was re-admitted 1 month later and had an uneventful procedure under regional anaesthesia without vecuronium.

A case of awareness with sevoflurane and epidural anesthesia in ovarian tumorectomy

We experienced a case of awareness during ovarian tumorectomy in a patient who was anesthetized with sevoflurane and epidural anesthesia. A 74-year-old woman was scheduled for resection of an ovarian tumor. After epidural catheter insertion, anesthesia was induced with 60 mg of propofol and 6 mg of vecuronium, and anesthesia was maintained with epidural anesthesia (1% mepivacaine), 1 to 2% sevoflurane, and 66% nitrous oxide in oxygen. The operative course was uneventful and the total operation time was 2 hours and 50 minutes. Two days after the operation, we were surprised to learn that the patient complained of awareness during the surgery.

Carotid body chemoreceptor function is impaired by vecuronium during hypoxia.

Neuromuscular blocking agents reduce the human ventilatory response to hypoxia at partial neuromuscular block. It was hypothesized that vecuronium impairs carotid body chemoreceptor function during hypoxia. The effect of systemic administration of vecuronium on single chemoreceptor activity during hypoxia, as recorded from a single nerve fiber preparation of the carotid sinus nerve, was studied in seven mechanically ventilated New Zealand White rabbits during continuous thiopental anesthesia. During normoventilation, the isocapnic hypoxic chemosensitivity of the single carotid body chemoreceptor was measured at four levels of oxygenation; these measurements were repeated at six separate occasions: control recording before injection, after intravenous administrations of 0.1 mg and 0.5 mg of vecuronium, and then at three occasions during a 90-min recovery period. Chemoreceptor chemosensitivity during isocapnic hypoxia was expressed as a hyperbolic function: Chemoreceptor output (Hz) = a + b x PaO2(-1) (mmHg). Chemosensitivity was reduced after both 0.1 mg and 0.5 mg vecuronium intravenous administration compared with control measurements; the hypoxic response curve was significantly depressed after both doses (P < 0.05). Notably, there was variation in the effect of vecuronium; some chemoreceptor preparations showed only minimal impairment, whereas some showed an almost abolished response to hypoxia. The chemosensitivity remained significantly depressed at 30 and 60 min but had recovered spontaneously at 90 min after 0.5 mg vecuronium. It is concluded that vecuronium depresses carotid body chemoreceptor function to a varying extent during hypoxia and that the depression recovers spontaneously.

Respiratory Depression After 5 [micro sign]g of Intrathecal Sufentanil

Respiratory Depression After 5 [micro sign]g of Intrathecal Sufentanil

Eyelid Movement During Complete Neuromuscular Block

Eyelid Movement During Complete Neuromuscular Block

Quantifying Oral Analgesic Consumption Using a Novel Method and Comparison with Patient-Controlled Intravenous Analgesic Consumption

Quantifying Oral Analgesic Consumption Using a Novel Method and Comparison with Patient-Controlled Intravenous Analgesic Consumption

Unexplained intraoperative hypotension, acute ischemic hepatitis, and pancreatitis associated with aortorenal bypass surgery

A 69-year-old male smoker who had severe atherosclerotic renovascular disease associated with progressive deterioration of kidney function, poorly controlled hypertension, and a 5-cm solid fight renal mass was scheduled for partial nephrectomy and hepatorenal bypass. He had no history of other cardiovascular disease or prior abdominal surgery. The physical examination was unremarkable except for a blood pressure of 170/90 mmHg. Laboratory studies included normal white blood cell count, hematocrit, platelet count, liver function tests, and clotting characteristics. The blood urea nitrogen concentration was 25 mg/dL (normal, 8 to 25 mg/dL); creatinine, 2.2 mg/dL (normal, 0.7 to 1.4 mg/dL); and creatinine clearance, 25 mL/min. Carbon dioxide arteriography was performed 1 month before the surgery and showed bilateral proximal 80% renal artery stenosis. A lateral aortogram showed a mild proximal celiac trunk stenosis with patent splenic, hepatic, and superior mesenteric arteries, and occluded inferior mesenteric artery. The right hepatic artery originated from the superior mesenteric artery and had a 50% to 60% osteal stenosis. The preoperative electrocardiogram and thallium stress test were normal; a carotid duplex ultrasound showed a 40% to 59% stenosis of the fight internal carotid artery. Under general endotracheal anesthesia (induction and endotracheal intubation with 150 mg of propofol and 10 mg of vecuronium, and maintenance with oxygen, nitrous oxide, and isoflurane), a bilateral subcostal incision was made, and a Bookwalter retractor was positioned. At exploration, a decreased pulse was noted in the porta hepatis area; therefore, an aortorenal rather than a hepatorenal bypass was performed. After resection of the kidney mass under cold ischemia (duration, 45 minutes), the anterolateral side of the aorta was clamped, and an aortorenal bypass with a reversed greater saphenous vein graft was performed with warm ischemia time of 25 minutes. The patient received no systemic heparinization and only regional arterial heparin flushes (up to 1,000 U) were used during the revascularization. The operation lasted about 4 hours. During the first 2 hours, the systolic blood pressure was between 100 and ll0 mmHg, and a continuous intravenous dopamine drip (dose, 1 to 3 ~tg/kg/min) was administered. The central venous pressure was 15 to 18 mmHg. During the last 2 hours of the surgery, the systolic blood pressure was maintained between 90 to 100 mmHg (despite relatively low blood loss and light anesthesia with 0.2% to 0.3% isoflurane) with increased fluid administration, and dopamine and epinephrine infusions at 12 ~g/kg/min and 0.03 to 0.07 pg/kg/min, respectively. The estimated blood loss during the entire operation was 1,500 mL, and the patient received 2 U of packed red blood cells. In

Paraplegia After Intraoperative Celiac Plexus Block

Paraplegia After Intraoperative Celiac Plexus Block

Prolonged paralysis after continuous infusion of vecuronium in a patient after cardiac surgery

Prolonged paralysis of 7 days in a patient who received 360mg of vecuronium infused continuously for 114 hours is reported.A 63-year old male patient who had no evidence of neurological disorder entered the ICU after cardiac surgery. After cessation of continuous infusion of vecuronium, maximum levels of serum vecuronium and its metabolite, 3-hydroxyvecuronium, were 53.1 and 142.4ng·ml-1 respectively.This suggests that the reason for the prolonged paralysis was the protracted period required metabolize and eliminate the vecuronium and its metabolite due to drug-induced liver dysfunction. Hypoproteinemia and the drugs used to treat it (antibiotics, Ca-channel blockers and diuretics) seemed to enhance the paralysis. We recommend the use of a peripheral nerve stimulator when the use of a muscle relaxant is necessary in a critical case setting.

A noninvasive method in the differential diagnosis of vecuronium-induced and magnesium-induced protracted neuromuscular block in a severely preeclamptic patient

The occurrence of neuromuscular blockade and the resulting potentiation of muscle relaxants during magnesium sulfate (MgSO 4) administration is well known. However, a method to differentiate the neuromuscular block induced by magnesium from that induced by curariform nondepolarizing muscle relaxant in the clinical setting has never been reported. We report a case in which the duration of action of 1 mg of vecuronium lasted 4 hours in a patient with severe preeclampsia whose serum magnesium level was in the therapeutic range. We believe this is a remarkable potentiation on record in the literature. We also describe a new, noninvasive method to assess magnesium-induced neuromuscular block when curariform muscle relaxant was given simultaneously.

Intraoperative Ventricular Tachycardia Responsive to Adenosine

Intraoperative Ventricular Tachycardia Responsive to Adenosine

Changes in acetylcholine receptor number in muscle from critically ill patients receiving muscle relaxants

Previous reports have described prolonged paralysis after the administration of muscle relaxants in critically ill patients. The purpose of this study was to examine possible pathophysiologic causes for this paralysis by measuring muscle-type, nicotinic acetylcholine receptor number in necropsy muscle specimens from patients who had received muscle relaxants to facilitate mechanical ventilation before death. Prospective laboratory study of human muscle collected at autopsy. Medical and surgical intensive care units (ICUs) at a university hospital and a research laboratory. Fourteen critically ill patients, with a variety of diagnoses, all of whom required mechanical ventilatory support before their deaths in the ICU and who underwent post mortem examination. Patients were arbitrarily divided into three groups, according to their total vecuronium dose and number of days mechanically ventilated before death. Three patients were in the control group (defined as dying within 72 hrs of initiation of ventilatory support and receiving a total dose of < 5 mg of vecuronium). Six patients were in the low-dose group (defined as requiring ventilatory support for > 3 days before death and receiving a total vecuronium dose of < or = 200 mg). Five patients were in the high-dose group (defined as requiring ventilatory support for > 3 days before death and receiving a total vecuronium dose of > 200 mg). None. Nicotinic acetylcholine receptor numbers as measured by specific 125I-alpha-bungarotoxin binding to human rectus abdominis muscle obtained at autopsy were determined. In general, receptor number reflected the clinical requirements for the muscle relaxants of each patient. Patients who had increasing requirements for muscle relaxants before death had increases in receptor number, as compared with control values. The increase in nicotinic acetylcholine receptor number in muscle from patients with an increasing requirement for muscle relaxants before death suggests that nicotinic acetylcholine receptor up-regulation may underlie the increased requirements for muscle relaxants seen in some patients. Furthermore, these findings suggest that muscle relaxant-induced, denervation-like changes may at least be partially responsible for prolonged muscle paralysis after the long-term administration of muscle relaxants. This study may provide the first information into the molecular mechanisms underlying prolonged paralysis.

Vecuronium-Thiopentone Induction for Emergency Caesarean Section under General Anaesthesia

Induction of general anaesthesia for emergency caesarean section has always been hazardous. Acid aspiration syndrome and adverse reactions to suxamethonium are well recognised problems, in spite of which "crash" induction using thiopentone and suxamethonium remains a common induction technique. Recent case reports suggest that the use of medium duration nondepolarising relaxants in place of suxamethonium achieves satisfactory intubating conditions in the emergency caesarean section patient. This study was undertaken to investigate the following aspects of rapid-sequence vecuronium-thiopentone induction for emergency caesarean section. 1. To establish whether 8 mg of vecuronium provides effective intubating conditions. 2. To establish whether placental transfer of vecuronium used in the above dosage has any clinically detectable effect upon the newborn. 3. To establish the limit of lead time by which vecuronium may precede thiopentone to minimise the dangerous period between loss of consciousness and intubation. 4. To detect instances of acid regurgitation or aspiration. 5. To confirm that relaxant reversal is clinically effective at the completion of surgery. In this series of thirty cases, vecuronium 8 mg preceding thiopentone 250 mg and atropine 0.6 mg by 20 seconds provided effective induction and easy intubating conditions without clinical effects on the newborn, maternal acid aspiration, or clinical signs of persistent paralysis after reversal.