Audit of intensive care unit admissions from the operating room

An audit of 265 intensive care unit (ICU) admissions from the operating room was performed for the year 1991. In a quality assurance exercise we identified 34 unanticipated ICU admissions (UIAs) by a retrospective peer review of the medical charts. Of these UIAs, 16 were deemed predictable and seven preventable. Five of the seven potentially preventable UIAs were judged to have had inappropriate intravenous fluid management. This has prompted changes in our education programme. In an assessment of our resource management, we evaluated prospectively collected data on the Apache II scores on the day of admission, the incidence of ICU-specific interventions, length of stay in ICU, and outcomes. ICU-specific interventions were not initially required in 36% of admissions and these patients had a low risk (1.1%) of eventually requiring ICU-specific interventions. In comparison with patients requiring ICU-specific interventions, they had lower Apache II scores (10.2 vs 13.1), shorter ICU stays (medians of one vs two days), lower ICU mortality (0 vs 8.2%), P < 0.05, but hospital mortality was not different (7.4 vs 15.3%). This audit has prompted re-organisation of our intensive care services, so that patients not requiring ICU-specific interventions will be managed in an intermediate care area with nurse.patient ratios of 1:3 or 4, in comparison with 1:1 or 2 ratios in the intensive care area.     

全麻诱导前预注芬太尼“先发镇痛”效应临床研究

目的：探讨全麻预注芬太尼的先发镇痛效应。／方法：选择40例择期全麻病人,随机分成试验组与对照组（n=20例）,术前常规用药,试验组诱导前用芬太尼5ug/kg,对照组将芬太尼改切皮后静注,术中麻醉维持相同,手术结束后病人自然清醒。术后有镇痛药使用意愿者均使用哌替啶镇痛。结果：两组病人一般情况及芬太尼总用量无显著性差异（P＞0．05）,试验组初次使用镇痛药时间明显延长（P＜0．01）,用药次数及剂量也显著少于对照组（P＜0．01）,试验组术后仅7（35％）例使用派替啶,而对照组使用哌替啶者达15（75％）例,两组差异性显著（P＜0．05）,结论：全麻前预注芬太尼具有良好的先发镇痛效应。     

Epidural anaesthesia for elective Caesarean section does not influence fetal umbilical artery blood flow indices

This prospective study was completed to determine the influence of epidural anaesthesia on the fetoplacental circulation of normal subjects. Thirty-seven normal pregnant patients at term, undergoing elective Caesarean section, had Doppler measurements of the fetal umbilical artery blood flow velocity before and after epidural anaesthesia using lidocaine 2% without epinephrine. There were no differences in systolic/diastolic, resistance or pulsality indices following epidural anaesthesia. These results suggest that this technique has no adverse effect on fetoplacental circulation in normal non-labouring subjects. Cette étude prospective a pour but de déterminer l’influence de l’anesthésie épidurale sur la circulation foeto-placentaire dans le contexte d’une grossesse normale. Des indices de vélocité du flot de l’artère ombilicale foetale ont été mesurés par Doppler chez trentesept patientes gravides à terme, sans complications, programmées pour une césarienne élective, avant et après une anesthèsie épidurale utilisant la lidocaine 2% sans épinéphrine. Les indices de rapport systole/diastole, de résistance et de pulsatilité sont demeurés inchangés après l’induction de l’anesthésie épidurale. Ces constatations suggèrent que l’anesthésie épidurale n’a pas d’influence sur la circulation foetoplacentaire chez des patientes enceintes normales à terme qui ne sont pas en travail.     

Anaesthesia and the Sturge-Weber syndrome

We report a series of 13 patients with Sturge-Weber syndrome anaesthetised on 17 occasions. Anaesthesia management varied depending on the clinical manifestations which ranged from localized, superficial skin lesions to extensive systemic involvement. These patients tolerate anaesthesia well but anaesthetic management includes evaluation for associated anomalies. Difficulty with intubation may occur due to angiomas of the mouth and upper airway. Anaesthesia should be planned to avoid trauma to the haemangiomata and increases in intraocular and intracranial pressure. Nous rapportons une série d’observations concernant des porteurs du syndrome de Sturge-Weber anesthésiés à 17 occasions. L’anesthésie a varié selon les manifestations cliniques qui allaient de la lésion superficielle localisée à l’atteinte systémique grave. Ces patients tolèrent bien l’anesthésie mais celle-ci nécessite une recherche des anomalies associées pour fin d’évaluation. La présence d’angiomes de la bouche et des voies respiratoires supérieures peut rendre l’intubation difficile. La planification de l’anesthésie doit inclure la prévention du traumatisme aux hémangiomes et de l’augmentation de la tension intraoculaire et cérébrale.     

Awake intubation of the adult trachea using the Bullard laryngo-scope

Awake intubation using the Bullard laryngoscope can be comfortably and easily performed in the adult. Five cases are presented in which tracheal intubation was performed under topical anaesthesia with light intravenous sedation. In each case, topical anaesthesia was performed by insertion of a Guedel oral airway, with lidocaine ointment applied to the inferior and posterior surfaces. In one case, Bullard intubation was successful where direct laryngoscopy and multiple attempts at bronchoscopic intubation by three different operators had failed. We conclude that the Bullard laryngoscope can be easily used in awake patients and may be a useful alternative where other methods for awake intubation have failed.     

The influence of baricity on the haemodynamic effects of intrathecal bupivacaine 0.5%

This study compared the haemodynamic effects of subarachnoid block with plain bupivacaine 0.5% (dextrose-free), heavy bupivacaine 0.5% (in dextrose 8%) and a mixture of these two solutions, i.e. bupivacaine 0.5% in dextrose 4%. Thirty-six male patients, aged 55-89 years, undergoing transurethral surgery were recruited. Invasive systolic arterial and central venous pressures were recorded at 5-s intervals after the block was initiated using a computerised data-collection system. The height of sensory blockade was recorded at 5-min intervals. No preload was given and episodes of hypotension were treated with colloid (8 ml x kg(-1)) and, if this was ineffective, a metaraminol infusion. Systolic arterial and central venous pressures decreased in all three groups following block (p < 0.05). These decreases were more rapid in onset in the heavy bupivacaine group compared with plain bupivacaine group (p < 0.005). Patients in the heavy bupivacaine group also had a greater requirement for early treatment of hypotension (< 10 min) and treatment with metaraminol (p < 0.05). The onset of sensory blockade was more rapid in the heavy group compared with the mixed group, although final sensory levels were similar. The onset of haemodynamic and sensory changes are more rapid when using heavy bupivacaine intrathecally. This leads to a higher and earlier incidence of hypotension and requirement for treatment.     

Molecular mechanisms of general anaesthesia

This review aims to give a balanced view of the various mechanisms which have been proposed to explain the phenomenon of general anaesthesia on both a molecular and whole animal level. An attempt is made to interrelate these and produce one cohesive model.     

The effect of combined spinal‐epidural (CSE) anaesthesia and size of spinal needle on postoperative hearing loss after elective caesarean section

The effect of combined spinal epidural (CSE) anaesthesia and size of spinal needle on postoperative hearing loss after elective caesarean section The exact aetiology of vestibulocochlear dysfunction after spinal anaesthesia is unknown. Low‐frequency hearing loss occurs after spinal anaesthesia. The aim of this study was to investigate the effects of combined spinal–epidural (CSE) anaesthesia and size of spinal needle on vestibulocochlear dysfunction, using pure tone audiometry performed pre‐ and on the first and the second day postoperatively. Forty‐five patients who were to undergo elective caesarean section were evaluated. In group I, CSE anaesthesia (18 G Tuohy, 25 G Whitacre pencil‐point‐design spinal needles) was performed in 15 patients. In group II, spinal anaesthesia was performed in 15 patients with 25 G Whitacre pencil‐point‐design spinal needles and, in group III, spinal anaesthesia was performed in 15 patients with 22 G Whitacre pencil‐point‐design spinal needles. In the pre‐ and on the first and the second day postoperatively, the pure tone audiogram was performed in the audiology laboratory of our hospital, using a calibrated Kamplex Diagnostic Audiometer AC 40 in a noise‐free room. When the CSE anaesthesia group and 22 G spinal group were compared for change in hearing between the pre‐ and postoperative periods, a statistically significant difference was observed at R‐right ear 125 Hz (P < 0.025) and at L‐left ear 125 Hz (P < 0.023), and at L‐left ear 1000 Hz (P < 0.036) and at R‐right ear 1500 Hz (P < 0.006), and at L‐left ear 1500 Hz (P < 0.022). At other frequencies, the difference was insignificant. When the CSE anaesthesia group and 25 G spinal group were compared for change in hearing between the pre‐ and postoperative periods, no statistically significant difference was detected at any frequency tested. When 22 G spinal group and 25 G spinal group were compared for change in hearing between the pre‐ and postoperative periods, there was some hearing loss at low frequency, although this difference did not reach statistical significance. The positive correlation of low‐frequency hearing loss and increased pressure in the epidural space (which decrease the risk of cerebrospinal fluid leakage through the dura) suggests that cerebrospinal fluid leakage via the spinal puncture hole is not the only factor involved. Perioperative fluid replacement alone may not prevent hearing loss but CSF loss through the dural puncture site should also be prevented.     

乙醇对丁卡因凝胶透皮和局麻作用的影响

目的 :考察透皮吸收促进剂乙醇对丁卡因凝胶透皮和局麻作用的影响。方法 :以卡波姆 940为基质配制含 2 0 %和 70 %乙醇的丁卡因 (4 % ,w w)凝胶。采用Franz扩散小池和紫外分光光度法进行小鼠离体皮肤渗透试验 ;用VonFrey镇痛试验考察丁卡因凝胶的局麻作用。结果 :离体皮肤渗透试验表明 2 0 %和 70 %乙醇对丁卡因凝胶均有较强的促渗作用 (P <0 .0 5 ) ,其渗透速率K分别提高了 1 .5 3倍和 2 .1 2倍 ,其中 70 %乙醇的促渗作用明显强于2 0 %乙醇 (P <0 .0 1 ) ,但是 70 %乙醇在一定程度上延长了丁卡因凝胶的滞后时间 ;VonFrey镇痛试验显示含 70 %乙醇的丁卡因凝胶局麻镇痛作用于用药后 1h达高峰 ,痛觉抑制百分率为 1 1 3 % ,镇痛作用持续 5h。结论 :含 70 %乙醇的丁卡因凝胶剂具有较强的透皮作用和局麻效果     

丁卡因凝胶剂的研制与药效测定

 目的：研究各种透皮促进剂对丁卡因经皮渗透的影响，找出一种起效时间较短的丁卡因凝胶剂。方法：配制不同处方的丁卡因凝胶剂，采用Franz扩散小池，HPLC检测药物浓度进行离体皮肤渗透实验，然后采用针刺法进行在体药效测定。结果：月桂氮酮使丁卡因透皮速率提高，但滞后时间延长，在体麻醉效果不佳；单用乙醇不延长滞后时间，在体麻醉起效时间缩短。结论：含乙醇的丁卡因凝胶剂局麻效果最好，可以开发利用。