Tulay Sahin Yildiz

The incidence and risk factors of difficult mask ventilation

PurposeThe ability to ventilate and oxygenate a patient using a bag-mask breathing system may be lifesaving in the case of failure of the initial intubation attempt. In this study, we aimed to determine the incidence of difficult mask ventilation (DMV) and to find preoperative risk factors for this procedure.MethodsBased on methods used for overcoming some difficulties with bag-mask ventilation (MV), classification has been made into four categories: easy MV, awkward MV, difficult MV, and impossible MV. A univariate analysis was performed to identify potential risk factors predicting DMV, followed by a stepwise forward binary logistic regression, and the odds ratio and 95% confidence interval were calculated.ResultsA total of 576 patients were studied. Incidence of easy MV, awkward MV, and difficult MV were found to be 75.5% (n = 435), 16.7% (n = 96), and 7.8% (n = 45), respectively. Height, weight, age, male gender, increased Mallampati class, history of snoring, lack of teeth, and beard were found to be DMV risk factors (P < 0.05). Using a multivariate analysis, Mallampati class 4, male, history of snoring, age, and weight were found to be significantly associated with DMV. Although the incidence of DMV in general was 7.8% (n = 45), the incidence of DMV among patients with difficult intubation (n = 123) was found to be 15.5% (n = 19).ConclusionsMallampati class 4, male patients, history of snoring, increasing age, and increasing weight were found to be risk factors for DMV in our study.

Clonidine addition prolongs the duration of caudal analgesia.

Background:  In this study, using a dose‐ranging design, we examined the effects of clonidine with 0.125% bupivacaine on the duration of post‐operative analgesia in caudal anaesthesia in children.

Comparison of laryngeal tube with laryngeal mask airway in anaesthetized and paralysed patients.

BACKGROUND AND OBJECTIVE The laryngeal mask has become a widely accepted alternative to endotracheal intubation and mask ventilation. The laryngeal tube is a relatively new supraglottic airway device for airway management. We compared the new version of the laryngeal tube with the laryngeal mask. METHODS In a randomized design, either a laryngeal tube (n = 66) or a laryngeal mask (n = 66) were inserted. Ease of insertion, oxygenation and ventilation, spirometry data and postoperative airway morbidity were determined. RESULTS After successful insertion, it was possible to maintain oxygenation and ventilation in all the patients. Insertion success rates after the first, second and third attempts were 84.8% (n = 56), 12.1% (n = 8) and 3% (n = 2) for the laryngeal tube compared with 56.1% (n = 37), 25.8% (n = 17) and 18.2% (n = 12) for the laryngeal mask (P = 0.001). There was no significant difference in peak airway pressure, and dynamic compliance between the groups (P > 0.05). Blood on the cuff after removal of the device was noted in one patient with the laryngeal tube and in 10 patients with the laryngeal mask. Six patients in the laryngeal mask group complained of hoarseness (P = 0.012). CONCLUSION With respect to clinical function, the new version of the laryngeal tube and the laryngeal mask are similar and either device can be used to establish a safe and effective airway in paralysed patients.Background and objective: We compared heart rate dynamics during surgical levels of propofol and sevoflurane anaesthesia in a highly standardized setting. Methods: We recorded electrocardiography from 24 anaesthetized healthy male subjects. In the first parallel part of the study, the subjects were anaesthetized either with sevoflurane (n = 8) or propofol (n = 8) targeted to match 1.0, 1.5 and 2.0 minimal alveolar concentration/effective concentration 50. In the second part, a separate group (n = 8) underwent four different anaesthetic regimens targeted to bispectral index 40: sevoflurane alone, sevoflurane + 70% nitrous oxide, propofol alone and propofol + 70% nitrous oxide. The electrocardiography data were analysed using conventional time and frequency domain methods, and the approximate entropy method, which estimates the complexity of the data. Results: The induction of anaesthesia was followed by an overall reduction of heart rate variability, evident in all frequency bands in the spectral analysis, and also in the time domain measures. Approximate entropy decreased at 1 effective concentration 50 with propofol and at 2 minimal alveolar concentration with sevoflurane. In the second part of the study, the time domain variables and high‐frequency spectral power were all similarly reduced by sevoflurane and propofol anaesthesia, with and without nitrous oxide. Approximate entropy tended to decrease during propofol anaesthesia. Conclusions: Hypnotic levels of sevoflurane and propofol anaesthesia suppressed the heart rate variability measured using conventional analysis methods. Deeper surgical levels of anaesthesia also reduce the complexity of heart rate variability.

Continuous venovenous hemodiafiltration to treat controlled‐release carbamazepine overdose in a pediatric patient

Carbamazepine (CBZ) intoxication is an important issue in acute poisoning practice. Highly protein‐bound, CBZ is not removed efficiently through conventional hemodialysis. We describe the use of continuous venovenous hemodiafiltration (CVVHDF) in a 2‐year‐old boy who developed general tonic clonic seizure and respiratory depression due to controlled‐release formula of CBZ overdose (peak drug level of >20 μg·ml−1, therapeutic range: 5–10 μg·ml−1). Serum CBZ concentrations fell to 0.25 μg·ml−1 at the end of hemodiafiltration. The patient recovered rapidly and was discharged from hospital 4 days from the time of ingestion with no complications or neurologic impairment.

Hearing Loss after Spinal Anesthesia: The Effect of Different Infusion Solutions

OBJECTIVE: We speculate that the preoperative volume replacement with a convenient solution may protect the inner ear function after spinal anesthesia. METHODS: The patients were randomized in a single-blind fashion into two groups: group LR (n = 40) received lactated Ringers and group GF (n = 40) received gelatin polysuccinate 4% (Gelofusine). Spinal anesthesia was performed with a 25 G Quincke needle and was given bupivacaine 0.5% 10 mg and fentanyl 25 jxg. Audio-grams were performed preoperatively and 2 days postoperatively. RESULTS: The overall incidence of hearing loss was 7.5%. The hearing loss was unilateral in two and bilateral in four patients. Hearing loss occurred within the low-frequency range and the hearing thresholds returned to normal by the fifth postoperative day. CONCLUSIONS: Although the incidence of hearing loss for the lactated Ringers group was higher than the Gelofusine group, there was no statistically significant difference between the groups. For medicolegal and ethical reasons, patients should be informed about the possibility of hearing loss after spinal anesthesia.

Levobupivacaine–tramadol combination for caudal block in children: a randomized, double‐blinded, prospective study1

Background:  The aim of this prospective study was to compare the postoperative analgesic efficacy and duration of analgesia after caudal levobupivacaine 0.125% or caudal tramadol 1.5 mg·kg−1 and mixture of both in children undergoing day‐case surgery.

The Gorham-Stout syndrome: one lung ventilation with a bronchial blocker. A case of Gorham's disease with chylothorax.

the use of a glidecope can be valuable in attaining a superior view of the anterior palatoglossal arch to block the glossopharyngeal nerve (Figure 1) and can be especially useful in infants when direct visualization may be difficult. The advantage of using the glidescope is the ability to displace the tongue downward and laterally with a magnified and illuminated view of the anatomic structures when compared to the traditional technique of direct visualization with a tongue depressor. A limitation for both the glidescope and tongue depressor is the potential for gagging when topical anesthesia of the tongue is inadequate. This is of particular concern in neonates and small infants in whom small volumes can result in toxic doses of local anesthetic solution. We are currently in the process of collecting data on a series of patients with known airway difficulty in which the glossopharyngeal nerves were blocked resulting in better tolerance of LMA insertion in awake infants. Narasimhan Jagannathan* Lisa E. Sohn† Santhanam Suresh *Assistant Professor of Anesthesiology, Northwestern University Feinberg School of Medicine, Children’s Memorial Hospital, Chicago, IL, USA †Instructor in Anesthesiology, Northwestern University Feinberg School of Medicine, Children’s Memorial Hospital, Chicago, IL, USA Professor of Anesthesiology and Pediatrics, Northwestern University Feinberg School of Medicine, Children’s Memorial Hospital, Chicago, IL, USA (email: simjag2000@yahoo.com) References

Alagille syndrome and anesthesia management

1 Nargozian CD. The difficult airway in the pediatric patient with craniofacial anomaly. Anesthsiol Clin North Am 1998; 16: 839–852. 2 Ball KA. Basic Endoscopic Equipment. Mosby’s Perioperative Nursing Series Endoscopic Surgery. Nancioon: Mosby Year Book 1997; pp. 111–136, Chap. 9. 3 Benumof JL. Management of the difficult adult airway. Anesthesiology 1991; 75: 1087–1110. 4 Ravishankar M, Kundra P, Agrawal K et al. Rigid nasoendoscope with video camera system for intubation in infants with Pierre Robin sequence. Br J Anaesth 2001; 87: 728–731.

Unexpected prolonged paralysis after mivacurium in a patient with Bamforth syndrome.

SIR—Several cases of prolonged neuromuscular block (NMB) have been reported following the administration of muscle relaxants such as suxamethonium and mivacurium (1,2), but to our knowledge there has been no report about the experience of prolonged neuromuscular block for patients with Bamforth syndrome in the literature. Mivacurium is a short-acting nondepolarizing neuromuscular blocking agent (1). Deficiency or abnormality of plasma cholinesterase (also called pseudocholinesterase – PChE, butyrylcholinesterase – BChE) may cause the duration of action of mivacurium to be greatly prolonged (3). In this case report, a 3-month-old baby, who required a gastrostomy because of a severe nutritional problem secondary to cleft palate, who experienced prolonged neuromuscular block for 4 h after a single dose of mivacurium, is described with an inherited syndrome of congenital hypothyroidism, spiky hair, choanal atresia, and cleft palate. A 3 month old, weighing 4 kg, female infant was scheduled for gastrostomy operation. She had congenital hypothyroidism and dysmorphic features comprising spiky hair, curly eyelash, cleft palate, and bilateral septal hypertrophy (Figure 1) diagnosed as Bamforth syndrome (4). She was on thyroxine replacement therapy (50 lg) and levels of thyroid hormones were found as free T4: 1.52 (0.8–1.9) ngÆdl, free T3: 3.40 (1.57–4.71) pgÆml, and thyroid stimulating hormone: 22.4 (0.4–4.0) lIUÆml . Other laboratory tests were normal. Family members’ thyroid functions were normal. She was monitored using noninvasive blood pressure, pulse oximetry, ECG and temperature; capnography was added after intubation. Rectal temperature was monitored and maintained at 37 ± 1 C using warm clothes and blanket throughout surgery. Anesthesia was induced via facemask with increasing concentration of sevoflurane in 50% nitrous oxide (N2O) and oxygen (O2). An intravenous (i.v.) catheter was placed and tracheal intubation facilitated with mivacurium 0.15 mgÆkg i.v. After tracheal intubation, anesthesia was maintained with N2O/O2 (50%/50%) and sevoflurane. Ventilation was controlled mechanically, adjusted to keep endtidal CO2 4.6–5.2 kPa (35–40 mmHg). After completion of surgery, for 30 min, she did not recover as quickly as expected. Duration of NMB was the time until normal respiration was regained and extubation was possible. Mechanical ventilation and sedation were continued until spontaneous return of full neuromuscular function. Muscle relaxation was reversed with atropine 0.02 mgÆkg i.v. and neostigmine 0.04 mgÆkg i.v. and 3 h after the mivacurium, she showed signs of spontaneous respiration and at 4 h was extubated and fully recovered. Postoperatively, the patient was transferred to the recovery unit for continuous monitoring. After the operation, PChE activity was determined and she was found to have a marked decrease in PChE activity compared with her parents and brother. The enzyme activities were 408 IUÆl for patient, 4953 IUÆl for mother, 4594 IUÆl for father and 6513 IUÆl for brother (normal 5400–13 200). The DNA sample of the patient and family members were analyzed for the presence of two most common BChE variants; Asp70Gly (A-variant) and Ala539Thr (K-variant) according to Asanuma et al. (5) and Maekawa et al. (6), respectively (Table 1). Restriction analysis of the polymerase chain reaction products revealed that the patient, her consanguineous parents and unaffected brother were negative for these variants (Figure 2). Our patient with Bamforth syndrome experienced prolonged paralysis for 4 h after a single dose of 0.15 mgÆkg of mivacurium because of a major PChE deficiency. Congenital hypothyroidism occurs in one of 3– 4000 newborns and often seems to be associated with other congenital abnormalities (7). Bamforth et al. (4) described two brothers with hypothyroidism, spiky hair, choanal Figure 1 The patient with Bamforth syndrome.