SummaryThis study compared the quality of anaesthesia and surgical access afforded by two techniques for the administration of anaesthesia during paediatric chair dental procedures. A total of 50 ASA 1 paediatric day case patients were randomly assigned to receive anaesthesia through either the traditional Goldman nasal mask or through a nasopharyngeal airway. Patients in the nasal mask group were judged to have significantly worse airway patency (p = 0.0001) and significantly more episodes of airway obstruction (14 vs. 4; p = 0.0032) than those in the nasopharygeal airway group. Anaesthetic, surgical and oxygen saturation data did not differ significantly between the two groups. Operating conditions were universally graded as excellent in the nasopharyngeal airway group, while those in the nasal mask group were graded as excellent/good in only 79% of cases (p < 0.0001). These results suggest that better quality anaesthesia and operating conditions can be achieved by using a nasopharyngeal airway rather than the traditional nasal mask for the administration of anaesthesia to paediatric chair dental patients.Keywords Anaesthesia; dental. Equipment; nasopharyngeal airway, tracheal tube, nasal mask.. ..................................................................................... Correspondence to: Dr O. Bagshaw Accepted: 3 February 1997 Paediatric chair dental surgery is a challenge to both the anaesthetist and the surgeon. The children are outpatients, not previously assessed by an anaesthetist, unpremedicated and often frightened and uncooperative. The anaesthetist and the surgeon have to share the airway and the problems of airway obstruction, oxygen desaturation and poor surgical access are common [1, 2].The technique of using a nasopharyngeal airway for both the maintainance of airway patency and the administration of general anaesthesia is historically well described [3][4][5], but there have been no recent reports of its usefulness as an alternative to the nasal mask. Traditionally, the nasopharyngeal airway has been made from rubber and was of a fixed length, which varied depending on the size of the airway selected. Recently, we have been using this technique substituting disposable tracheal tubes for the rubber airway. These have the advantages of being single-use, the length can be readily altered and they can be easily connected to a standard anaesthetic breathing system. The aim of this study was to compare the quality of anaesthesia and surgical access afforded by these two techniques and to note any associated morbidity. MethodsLocal Ethics Committee approval for the study was obtained. The majority of children presenting for daycase chair dental surgery were eligible for inclusion in the study. Children requiring tracheal intubation for conservation work were not studied. Informed consent was obtained from a parent.A total of 50 ASA 1 children were randomly assigned to either the Nasal Mask group or the Nasopharyngeal 786ᮊ 1997 Blackwell Science Ltd Airway group. All patients were unprem...

SummaryWe compared the effect of alfentanil 10 mg.kg 21 and esmolol 1.5 mg.kg 21 on the cardiovascular responses to laryngoscopy and double-lumen endobronchial intubation in two groups of 20 ASA 2±3 patients undergoing pulmonary surgery, in a randomised double-blind study. Arterial pressure and heart rate decreased after induction of anaesthesia and increased after intubation in both groups (p , 0.05) but remained at or below baseline values, and changes were comparable in both groups. Plasma catecholamine concentrations decreased after induction of anaesthesia in both groups (p , 0.05). Epinephrine concentrations increased in the esmolol group after intubation (p , 0.05) but remained below baseline in the alfentanil group (p , 0.05). Norepinephrine concentrations increased significantly in both groups after intubation but were higher in the esmolol group (p , 0.05). Although both esmolol 1.5 mg.kg 21 and alfentanil 10 mg.kg 21 similarly attenuated the arterial pressure and heart rate response to endobronchial intubation, plasma catecholamine concentrations increased in the esmolol group to values greater than previously reported after tracheal intubation. Laryngoscopy and intubation with a double-lumen endobronchial tube is accompanied by increased heart rate, arterial blood pressure and plasma catecholamine concentrations [1], mediated by increased sympathetic nervous activity [2,3]. The increases in heart rate and arterial pressure are of similar magnitude and duration to the well-described responses to laryngoscopy and tracheal intubation, i.e. mean increases of 15±20 beats.min 21 and 30±40 mmHg, respectively, for approximately 5±6 min. These responses may result in myocardial ischaemia in susceptible individuals [4], and patients presenting for surgery which requires double-lumen endobronchial intubation (mostly pulmonary surgery) are a high-risk group for coexisting ischaemic heart disease. We have previously shown that the haemodynamic changes to double-lumen endobronchial intubation were attenuated by the administration of intravenous esmolol 1.5 mg.kg 21 [1]. However, plasma norepinephrine concentrations were significantly increased after intubation in those who received esmolol compared with control subjects, suggesting that although esmolol diminished the endorgan response to intubation, sympathetic nervous system activity was increased. This may be because esmolol, by decreasing the haemodynamic changes, prevented a baroreflex-mediated inhibition of central sympathetic activity, which occurred in the control group.Several drugs have been shown to attenuate the cardiovascular responses to laryngoscopy and intubation [3] and intravenous opioids, e.g. alfentanil [5,6]

High-frequency ventilation (HFV) has been used with good results in a variety of clinical situations where conventional ventilation has proved ineffective. However, all of the reports so far have involved the use of a specially purchased specifically designed ventilator which tends to be unfamiliar to most medical and nursing staff responsible for its use. A case where HFV was used in combination with differential lung ventilation in the treatment of unilateral pulmonary atelectasis is described using a Servo 900B as the high-frequency ventilator. It serves to demonstrate that the Servo 900B can be used as an occasional high-frequency ventilator as required, thus avoiding the expense of purchasing a specialized ventilator.