Yang Qy

Lightwand guided intubation in paediatric patients with a known difficult airway : a report of four cases

The anaesthetic management of children with craniofacial abnormalities often presents unique challenges because soft tissue and bony abnormities can affect the airway and influence airway management. We report four paediatric patients with predicted difficult airways due to craniofacial abnormalities. They all had a laryngeal view of Cormack–Lehane grade IV and were impossible to intubate using direct laryngoscopy. Fibreoptic intubation was also repeatedly attempted but was not successful. All the tracheal intubations were completed using a lightwand on the first attempt in less than 30 s. We consider that lightwand guided intubation technique may be a useful alternative approach to fibreoptic intubation technique in managing the difficult paediatric airway.

The effects of head flexion on airway seal, quality of ventilation and orogastric tube placement using the ProSeal™ laryngeal mask airway*

This prospective self‐controlled study was designed to evaluate the influences of head flexion on airway seal, quality of ventilation, and orogastric tube placement through the ProSeal™ laryngeal mask airway (ProSeal LMA™) in 80 anaesthetised, paralysed adult patients.

Different small-dose remifentanil blunting the cardiovascular response to laryngoscopy and intubation in children: a randomized double-blind comparison.

Background: The available data provide inconsistent results on the efficacy of small‐dose remifentanil attenuating the cardiovascular response to intubation in children. Therefore, this randomized double‐blind study was designed to assess the ability of different small doses of remifentanil on the cardiovascular intubation response in children, with the aim of determining the optimal dose of remifentanil for this purpose. Methods: One hundred and twenty‐four children aged 3‐9 yr were randomized to one of four groups to receive the following in a double‐blind manner: normal saline (Group 1), remifentanil 0.75 &mgr;g kg−1 (Group 2), remifentanil 1 &mgr;g kg−1 (Group 3) and remifentanil 1.25 &mgr;g kg−1 (Group 4). Non‐invasive blood pressure and heart rate were recorded before anaesthesia induction (baseline value), immediately before intubation (postinduction values), at intubation and at 1 min intervals for 5 min after intubation. Results: Tracheal intubation caused significant increases in systolic blood pressure and heart rate in Groups 1‐3 compared with the baseline values. The maximum percent increases of systolic blood pressure and heart rate were 10% and 26% of the baseline values, respectively, in Group 2; 5% and 14% in Group 3; and 1% and 8% in Group 4 compared with 27% and 37% in Group 1. Except for the Group 3 vs. Group 4 comparison, there were significant differences among the four groups in the maximum percent increases of systolic blood pressure and heart rate. Conclusions: When used as part of anaesthesia induction with propofol and vecuronium in children, bolus administration of remifentanil resulted in a dose‐related attenuation of the cardiovascular intubation response.

Combined morphine and limb remote ischaemia postconditioning may produce an enhanced cardioprotection.

The limb remote ischaemia postconditioning (RIPOC), a newly conceived idea of applying brief limb ischaemic stimulus after onset of the myocardial ischaemia but prior to the reperfusion, can offer the possibility of applying this cardioprotective strategy to the patients with acute myocardial infraction. Although increasing numbers of circles and duration of limb ischaemia may augment the protective effect of the limb RIPOC, these ways are not feasible in a clinical setting. Morphine, a classic opioid drug, has been proven to enhance the cardioprotection obtained by the other interventions. Because both the RPIOC and opioid drugs produce the cardioprotection by multiple pathways, and there may be overlaps and cross talk in their mechanisms, we hypothesize that a combination of morphine and the limb RIPOC may produce an enhanced cardioprotection.

Different small-dose sufentanil blunting cardiovascular responses to laryngoscopy and intubation in children: a randomized, double-blind comparison

BACKGROUND Sufentanil is a potent opioid analgesic frequently used in clinical anaesthesia. This prospective, randomized, double-blind study was designed to assess the efficacy of different small-dose sufentanil attenuating the cardiovascular intubation response in healthy children, aiming at determining the optimal dose of sufentanil for this purpose. METHODS A total of 165 children aged 3-9 yr were randomized to one of four groups to receive the following in a double-blind manner: normal saline (Group 1), sufentanil 0.1 microg kg(-1) (Group 2), sufentanil 0.2 microg kg(-1) (Group 3), and sufentanil 0.3 microg kg(-1) (Group 4). Anaesthesia was induced with propofol 2.5 mg kg(-1) and vecuronium 0.1 mg kg(-1). Non-invasive blood pressure (BP) and heart rate (HR) were recorded before induction of anaesthesia (baseline value), at immediately before intubation (post-induction values), at intubation, and at 1 min intervals for 5 min after intubation. The per cent changes of systolic blood pressure (SBP) and HR during the observation were calculated. RESULTS Except for Group 4, tracheal intubation caused significant increases in BP and HR in Groups 1, 2, and 3 compared with baseline values. BP and HR at intubation and their maximum values during the observation were significantly different among the four groups. The maximum per cent increases of SBP and HR during the observation were 20 and 28% of baseline values, respectively, in Group 2, 13 and 13% in Group 3, and 0 and 4% in Group 4 compared with 24 and 37% in Group 1. Except for the Group 3 vs Group 4 comparison, the incidences of SBP and HR per cent increases >30% of baseline values were also significantly different among the four groups. CONCLUSIONS In combination with propofol for induction of anaesthesia in children, the bolus administration of sufentanil can produce a dose-related attenuation of the cardiovascular intubation response and sufentanil 0.3 microg kg(-1) can completely abolish the cardiovascular intubation response.

Bolus dose remifentanil and sufentanil blunting cardiovascular intubation responses in children: a randomized, double-blind comparison

Background and objective The present randomized controlled study was designed to compare the efficacy of remifentanil 2 μg kg−1 and sufentanil 0.2 μg kg−1 by bolus injection on the cardiovascular response to intubation in healthy children. Methods One hundred and five children, ASA 1–2 and scheduled for elective plastic surgery under general anaesthesia, were randomly divided into one of two study groups to receive the following treatments in a double-blind manner: remifentanil 2 μg kg−1 (group R) and sufentanil 0.2 μg kg−1 (group S). Blood pressure and heart rate (HR) were recorded before anaesthesia induction (baseline values), immediately before intubation (postinduction values), at intubation and every minute for 5 min after intubation. The percentage changes in systolic blood pressure (SBP) and HR relative to baseline values were calculated. The incidences of SBP and HR percentage changes of more than 30% of baseline values during the observation were recorded. Results As compared with baseline values, blood pressure and HR at intubation and their maximum values during the observation increased significantly in group S, but decreased significantly in group R. Blood pressure and HR at intubation and their maximum values during the observation were significantly different between the groups. There were significant differences between the groups in the percentage changes of SBP and HR relative to baseline values and their maximum percentage changes during the observation. The incidences of SBP and HR percentage increases of more than 30% of baseline values were not significantly different between the groups, but the incidences of SBP and HR percentage decreases of more than 30% of baseline values were significantly higher in group R than in group S. Conclusion In combination with propofol for anaesthesia induction in children, sufentanil 0.2 μg kg−1 by bolus injection fails to depress the cardiovascular intubation response. Remifentanil 2 μg kg−1 by bolus injection can completely abolish the cardiovascular intubation response, but causes more adverse cardiovascular depression.

The circulatory responses to tracheal intubation in children: a comparison of the oral and nasal routes

The circulatory responses to laryngoscopic tracheal intubation in 62 healthy children undergoing surgery requiring tracheal intubation were studied. They were randomly assigned to receive either the oral or nasal route for intubation. Baseline non‐invasive blood pressure and heart rate were recorded following induction of anaesthesia, at intubation and then every minute for 5 min. The percentage changes of systolic blood pressure and heart rate during the measurement period were calculated. The results demonstrated that intubation time was significantly longer in the nasal group. Both oral and nasal intubation caused significant increases in blood pressure and heart rate compared to baseline and postinduction values. However, there were no significant differences found between the two groups in relation to blood pressure and heart rate. The two groups were similar with respect to the percentage changes of systolic blood pressure and heart rate during the observation period. It is concluded that oral and nasal intubation using a direct laryngoscopy can result in a similar circulatory response in anaesthetised children.

Cholinergic agonists may produce preservation of myocardial ischaemia/reperfusion injury

The best treatment for myocardial infarction is to restore blood flow in the ischaemic region, though it will bring new myocardial damage known as myocardial ischaemia/reperfusion (I/R) injury. Both the ischaemia preconditioning and the ischaemia postcondioning have been shown to reduce the myocardial I/R injury, but their deficits restrict wide clinical availability. It has been demonstrated that inflammation plays a critical role in the I/R injury process. Also plasma levels of cytokines and inflammation response can be regulated by specifically augmenting cholinergic signaling via the efferent vagus nerve and alpha7 subunit-containing nicotinic acetylcholine receptor (alpha7nAChR). Because cholinergic modalities, acting through vagus nerve- and/or alpha7nAChR-mediated mechanism, have been confirmed to suppress excessive inflammation during the I/R injury in kidney, liver, lung and intestine, therefore, we hypothesize that cholinergic agonists may also provide a protection for the myocardial I/R injury.

The modified ventilating tube changer to facilitate tracheal intubation using the GlideScope® in patients with a limited mouth opening

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Hemodynamic Responses to Tracheal Intubation with the GlideScope ® Videolaryngoscope: A Comparison of Oral and Nasal Routes

BACKGROUND Although there have been numerous favorable reports on the uses of the GlideScope videolaryngoscope (GSVL) in oral and nasal intubations, no study has compared the hemodynamic responses to oral and nasal intubations with the GSVL in a single clinical trial. The purpose of this randomized clinical study was to determine whether there was a clinically relevant difference between the hemodynamic responses to oral and nasal intubations with the GSVL. METHODS A total of 71 patients, ASA physical status I, aged 18-50 years, scheduled for elective plastic surgery under general anesthesia, were randomly allocated to the oral intubation group (OI group) and the nasal intubation group (NI group). Noninvasive blood pressure (BP) and heart rate (HR) were recorded before (baseline values) and after anesthesia induction (postinduction values), at intubation and every minute for a further 5 minutes. Maximum values of BP and HR during the observation were noted. The product of HR and systolic blood pressure (rate pressure product, RPP), the percent changes of systolic blood pressure (SBP) and HR relative to the baseline values at every measuring point, and the areas under the SBP and HR versus time curves were calculated. RESULTS The intubation time was significantly longer in the NI group than in the OI group. The total incidence of difficulties encountered during laryngoscopy and intubation were higher in the OI group than in the NI group (29% vs. 6%, p < 0.05). BP at all measuring points, the maximum values of BP, the area under the SBP versus time curve, and the incidence of SBP percent increase more than 30% of baseline value did not differ significantly between the two groups. However, HR and RPP at intubation and their maximum values during the observation, the area under the HR versus time curve, and the incidence of HR percent increase more than 30% of baseline value were significantly higher in the OI group than in the NI group (p < 0.05). As compared with the NI group, the times required to reach the maximum values of SBP and HR were significantly shorter and the times required for recovery of SBP and HR to postinduction values were significantly longer in the OI group (p < 0.05). CONCLUSION In anesthetized adult patients, oral and nasal intubations with the GSVL can result in a similar pressor response. However, the tachycardic response to nasal intubation using a GSVL is smaller and of shorter duration than that to oral intubation using a GSVL.