Cancellation of elective operations on the day of intended surgery in a Hong Kong hospital: point prevalence and reasons.

OBJECTIVE: To determine the point prevalence of elective surgical case cancellations and the reasons. DESIGN: Cross-sectional study. SETTING: Teaching hospital, Hong Kong. PATIENTS; Operating theatre records of elective surgery cancellations from 1 January 2009 to 31 December 2009 were retrospectively reviewed. MAIN OUTCOME MEASURES. Cancellation of scheduled elective surgery on the day of surgery and the corresponding reasons. RESULTS: Of 6234 cases scheduled, 476 were cancelled, which yielded a point prevalence of 7.6%, with a 95% confidence interval of 7.0-8.3%. The highest number of cancellations occurred in patients scheduled for major general surgical procedures (n=94, 20%), major urological procedures (n=64, 13%), major orthopaedic surgery (n=38, 8%), and ultra-major cardiothoracic surgery (n=29, 6%). The most common category for cancellation was facility (73%), followed by work-up (17%), patient (10%), and surgeon (1%). No available operating room time due to overrun of the previous surgery was the most common reason for case cancellation (n=310). Compared to general surgery, the odds of no available operating time was significantly less in orthopaedics (odds ratio=0.26; 95% confidence interval, 0.17-0.39), otolaryngology (0.25; 0.13-0.46), neurosurgery (0.36; 0.16-0.70), paediatrics (0.53; 0.31-0.87), gynaecology (0.18; 0.11-0.29), ophthalmology (0.19; 0.07-0.41), and dentistry (0.10; 0.00-0.60). CONCLUSIONS. Case cancellations were mainly due to facility factors, such as no operating room time being available. The odds of having no operating room time available varied between surgical specialties.

Utility of a preoperative assessment clinic in a tertiary care hospital.

OBJECTIVES: To assess the utilisation rate of a preoperative assessment clinic and its impact on length of stay and discharge destinations. DESIGN: Retrospective case series with internal comparisons. SETTING: A tertiary hospital in Hong Kong. PATIENTS: All medical records of elective surgical admissions to a hospital in Hong Kong from April to June 2008 were retrieved. Medical records of patients who did not attend the preoperative assessment clinic were further reviewed by surgeons to assess if the patients could have been referred to the clinic. MAIN OUTCOME MEASURES: Total length of stay, preoperative and postoperative length of stay, and the discharge destinations of the patients attending and not attending the clinic were compared. RESULTS. In all, 640 patients underwent elective operations, of whom 22 (3%) patients were seen in the preoperative assessment clinic. In patients who had a major operation, the mean (standard deviation) total length of stays for clinic attenders and non-attenders were: 5.2 (3.6) versus 13.2 (18.8) days (P<0.001). The respective figures for preoperative and postoperative length of stay were: 1.3 (2.3) versus 4.5 (8.9) days (P=0.001), and 3.9 (2.9) versus 8.7 (14.5) days (P<0.001). For patients who had an intermediate operation, the respective mean (standard deviation) length of hospital stays were 2.4 (2.0) versus 7.3 (13.9) days (P=0.002) and the figures for postoperative length of stays were 1.3 (0.5) versus 4.5 (9.3) days (P=0.001). Surgeons had classified 108 (17%) of the cases as possible preoperative assessment clinic users. Among the latter, 71 (66%) had no special reason to stay in the hospital. The discharge destination was not associated with the use of preoperative assessment clinic for patients having major (Chi squared=0.18, P=0.912) or intermediate (Chi squared=0.34, P=0.468) operations. CONCLUSION: Successful implementation of preoperative assessment clinic service requires close collaboration between surgeons, anaesthetists, clinicians, and also the re-engineering of health service delivery.

Real-time ultrasound-guided paramedian epidural access: evaluation of a novel in-plane technique.

BACKGROUND: Current methods of locating the epidural space rely on surface anatomical landmarks and loss-of-resistance (LOR). We are not aware of any data describing real-time ultrasound (US)-guided epidural access in adults. METHODS: We evaluated the feasibility of performing real-time US-guided paramedian epidural access with the epidural needle inserted in the plane of the US beam in 15 adults who were undergoing groin or lower limb surgery under an epidural or combined spinal-epidural anaesthesia. RESULTS: The epidural space was successfully identified in 14 of 15 (93.3%) patients in 1 (1-3) attempt using the technique described. There was a failure to locate the epidural space in one elderly man. In 8 of 15 (53.3%) patients, studied neuraxial changes, that is, anterior displacement of the posterior dura and widening of the posterior epidural space, were seen immediately after entry of the Tuohy needle and expulsion of the pressurized saline from the LOR syringe into the epidural space at the level of needle insertion. Compression of the thecal sac was also seen in two of these patients. There were no inadvertent dural punctures or complications directly related to the technique described. Anaesthesia adequate for surgery developed in all patients after the initial spinal or epidural injection and recovery from the epidural or spinal anaesthesia was also uneventful. CONCLUSIONS: We have demonstrated the successful use of real-time US guidance in combination with LOR to saline for paramedian epidural access with the epidural needle inserted in the plane of the US beam.

Surgeons' attitudes and perception of an acute pain service.

OBJECTIVE: To evaluate the attitude and perception of surgeons about postoperative pain management, and an anaesthesiologist-based acute pain service. DESIGN: Questionnaire survey. SETTING: Tertiary university teaching hospital, Hong Kong. PARTICIPANTS: All surgical staff members (specialists and trainees) of the Departments of Surgery, Orthopaedics and Traumatology, and Obstetrics and Gynaecology. MAIN OUTCOME MEASURES: Opinions on postoperative pain management, different pain management modalities, and services provided by the acute pain service. RESULTS: Of the 147 questionnaires, 104 (71%) were returned. The majority (97%) agreed that effective pain control improves patient recovery and 88% believed that anaesthetists should be involved in postoperative pain management. Overall, 85% of the respondents were satisfied with the acute pain service. However, about one third of them wanted to maintain an active role in postoperative pain management and only 54% thought that the acute pain service has a significant impact on patient outcomes. In addition, only 10% of surgeons agreed that patients receiving acute pain service intervention would be discharged earlier. The respondents also thought that, compared to intravenous patient-controlled analgesia, epidural analgesia required more nursing care and was less cost-effective. Areas of the acute pain service warranting improvement included: education of surgeons on postoperative pain and its management (92%), communication (74%), and referral systems (80%). CONCLUSION: The majority of surgeons were satisfied with the acute pain service and agreed that anaesthetists should be involved in postoperative pain management. However, a proportion wanted to maintain an active role in postoperative pain management.

Characteristics, management process, and outcome of patients suffering in-hospital cardiopulmonary arrests in a teaching hospital in Hong Kong.

OBJECTIVES: To examine the demographics, process indicators of adult in-hospital cardiopulmonary arrest resuscitation, and outcomes in a teaching hospital in Hong Kong. DESIGN: Retrospective study. SETTING: A university-affiliated tertiary referral hospital with 997 acute adult beds in Hong Kong. PATIENTS: Those who suffered a cardiopulmonary resuscitation event, as documented in retrieved records of all in-patients during the inclusive period January 2002 to December 2005. RESULTS: There were 531 resuscitation events; the mean (standard deviation) age of the corresponding patients was 70.7 (15.4) years. Most (83%) occurred in non-monitored areas and most (97%) were cardiopulmonary arrests. The predominant initial rhythm was asystole (52%); only 8% of patients had ventricular tachycardia/fibrillation. All the resuscitations were initiated by on-site first responders. The median times from collapse to arrival of the resuscitation team, to defibrillation, to administration of adrenaline, and to intubation were: 5 (interquartile range, 2-6) minutes, 5 (1-7) minutes, 5 (3-10) minutes, and 9 (5-13) minutes, respectively. The overall hospital survival (discharge) rate was 5%. The survival rate was higher among patients in monitored areas (9 vs 4%, P=0.046), among patients with isolated respiratory arrests (61 vs 3%, P<0.001), primary ventricular tachycardia/fibrillation arrests (13 vs 4%, P<0.001), shorter interval times from collapse to medication (1.5 vs 5 min, P=0.013), and longer interval times to intubation (12 vs 8 min, P=0.013). CONCLUSION: Hospital survival after in-hospital cardiopulmonary arrests was poor. Possible strategies to improve survival include shorten time interval to defibrillation, and provision of more monitored beds.

Does patient position during liver surgery influence the risk of venous air embolism?

BACKGROUND: It is generally believed that positioning of the patient in a head-down tilt (Trendelenberg position) decreases the likelihood of a venous air embolism during liver resection. METHODS: The physiological effect of variation in horizontal attitude on central and hepatic venous pressure was measured in 10 patients during liver surgery. Hemodynamic indices were recorded with the operating table in the horizontal, 20 degrees head-up and 20 degrees head-down positions. RESULTS: There was no demonstrable pressure gradient between the hepatic and central venous levels in any of the positions. The absolute pressures did, however, vary in a predictable way, being highest in the head-down and lowest during head-up tilt. However, on no occasion was a negative intraluminal pressure recorded. CONCLUSION: The effect on venous pressures caused by the change in patient positioning alone during liver surgery does not affect the risk of venous air embolism.

Thoracic paravertebral block for management of pain associated with multiple fractured ribs in patients with concomitant lumbar spinal trauma.

BACKGROUND AND OBJECTIVES: The need for continual neurological assessment in patients with lumbar spinal injury poses a challenge for effective management of pain associated with multiple fractured ribs. Two cases are presented to illustrate the benefits of using thoracic paravertebral block to control the pain of multiple fractured ribs without compromising the ongoing neurological assessment. CASE REPORT: Thoracic paravertebral block was used in 2 patients with concomitant multiple fractured ribs and lumbar spinal injury. Case 2 also had a head injury and there was moderate coagulopathy. The thoracic paravertebral catheter was placed in the upper thoracic region and radiological imaging was used to delineate spread before the injection of relatively small volumes (10 to 15 mL) of local anesthetic. In case 1, the thoracic paravertebral block produced ipsilateral segmental thoracic anesthesia, providing excellent pain relief for the fractured ribs. It also spared the lumbar and sacral nerve roots, preserving neurological function in the lower extremities and bladder sensation. In case 2, effective analgesia without systemic sedation and opioids resulted in the patient regaining consciousness, which allowed continuous assessment of central and peripheral neurological function. CONCLUSION: Thoracic paravertebral block is an option for managing pain associated with multiple fractured ribs in the presence of concomitant lumbar spinal injury requiring continual neurological assessment.

Local anaesthesia outside the operating room.

An increasing number of minor surgical procedures are performed under local anaesthesia in clinical settings outside the operating room, where monitoring and resuscitation equipment--as well as personnel skilled in resuscitation--may not be readily available. Serious adverse effects and even fatalities may result from the use of local anaesthetic agents, arising from a variety of causes such as systemic toxicity, allergy, vasovagal syncope, and reaction to additives present in the local anaesthetic. This article briefly reviews the pharmacology of local anaesthetic agents, and describes various techniques commonly used for local anaesthesia, with special emphasis on safety. Clinical features of toxicity, and its differential diagnosis and management, are also discussed.

Early extubation after transthoracic oesophagectomy.

OBJECTIVES: To assess patient outcome following transthoracic (Ivor-Lewis) oesophagectomy and the effects of epidural analgesia and early extubation compared with overnight sedation and ventilation. DESIGN: Retrospective study. SETTING: University teaching hospital, Hong Kong. SUBJECTS AND METHODS: A retrospective review of patients undergoing oesophagectomy during two periods, 1990 to 1994 (n=65) and 1995 to 1998 (n=83), was completed. In the latter period, factors associated with early extubation were also evaluated. RESULTS: Between 1990 and 1994, only three (4.6%) of 65 patients were extubated early compared with 34 (41.0%) of 83 patients between 1995 and 1998 (P<0.001). Comparing these two periods, there were no differences in respiratory complications or hospital mortality. In the period 1995 to 1998, more patients who were extubated early had received epidural analgesia (85% versus 41%, P<0.001). There were no differences between the early and late extubation groups in terms of respiratory complications and hospital mortality. Patients extubated early had shorter stays in the intensive care unit (1 versus 2 days, P=0.005). Epidural analgesia was an independent factor associated with early extubation (odds ratio=9.4; 95% confidence interval, 2.8-31.2). CONCLUSION: After transthoracic oesophagectomy, early extubation is safe and can lead to a shorter stay in the intensive care unit. Epidural analgesia appears to facilitate early extubation.

Anaesthetic clinical indicators in public hospitals providing anaesthetic care in Hong Kong: prospective study.

OBJECTIVES: To assess the quality of anaesthetic services as defined in the six anaesthetic clinical indicators against preset standards and to identify risk factors for adverse events in the recovery room. DESIGN: Prospective study. SETTING: All public hospitals providing anaesthetic care in Hong Kong. PATIENTS: Eighteen thousand, seven hundred and fifty-nine patients receiving elective or emergency anaesthesia administered by anaesthetists from June 1998 to July 1998. MAIN OUTCOME MEASURES: Patient demographics, American Society of Anesthesiologists status, category and nature of operation, presence of preoperative anaesthetic visit in ward, type of anaesthesia, reasons for a recovery room stay of more than a 2-hour duration, intubation to relieve respiratory distress in the recovery room, presence of hypothermia in the recovery room for operations lasting more than 2 hours, and dental or ocular injuries attributable to anaesthesia. RESULTS: There are two major findings from this study. Firstly, a high incidence of hypothermia in the recovery room was reported. Secondly, a greater risk of prolonged stay in the recovery room was identified for patients older than 65 years, major operations, and anaesthetic techniques using combined general and regional anaesthesia. CONCLUSION: The six anaesthetic clinical indicators reflected the provision of anaesthetic care in public hospitals in Hong Kong. Good compliance to the preset standard of the anaesthetic clinical indicators was achieved during the study period.

Acute pain services in Hong Kong: facilities, volume, and quality.

Acute pain services in public hospitals in Hong Kong were studied. Audit data on the volume and quality of acute pain services were collected prospectively from 1997 to 1999, and data on related facilities were collected in 2000. About 20% of patients undergoing a major operation received an acute pain service; of these, 78.6% were satisfied with the treatment provided. In 2000, 86% (18/21) of hospitals providing anaesthetic services were running an acute pain service. Staffing was better in hospitals providing a high volume of acute pain services, ranging from a full-time specialist anaesthesiologist assisted by a half-time trainee to a half-time specialist assisted by a full- or half-time trainee. However, only four hospitals were staffed with pain nurses. In total, 57% of patients received intravenous patient-controlled analgesia and 32% epidural analgesia. The mean duration of acute pain service treatment was 3.1 days. Currently anaesthesiologist-based acute pain services take care of a limited number of patients. To expand the coverage, there should be a move towards an anaesthesiologist-led, pain nurse-based, acute pain service. The present shortage of pain nurses should be addressed.

Anesthesia in a patient with undiagnosed salicylate poisoning presenting as intraabdominal sepsis.

An 81-year-old woman with unintentional salicylate intoxication presented with features of sepsis, abdominal pain, and tenderness. Laparotomy was performed to rule out acute cholecystitis. Anesthesia was complicated by severe hypercarbia despite hyperventilation, and progressive cardiovascular and neurologic deterioration postoperatively. The adverse neurologic, respiratory, and hepatic effects of abdominal surgery and general anesthesia probably potentiated salicylate toxicity and increased patient morbidity. Anesthesiologists should be aware of the protean manifestations of salicylate poisoning and consider it as a cause of "medical abdomen."

Ultrasound-guided sciatic nerve block: description of a new approach at the subgluteal space.

Sciatic nerve block is frequently used for anaesthesia or analgesia during orthopaedic foot surgery and there are several different approaches to the sciatic nerve. This report describes a new approach to the sciatic nerve using ultrasound. Local anesthetic was injected into the 'subgluteal space' under ultrasound guidance which was effective in producing sciatic nerve block in a small series of five patients. The anatomy, sonographic features, technique of identifying the subgluteal space, and potential advantages of this approach to the sciatic nerve are discussed.

Randomised double-blind comparison of fentanyl, mivacurium or placebo to facilitate laryngeal mask airway insertion.

In a double-blind randomised study, we compared conditions during insertion of the laryngeal mask airway in 150 patients who received either fentanyl 1 microg.kg-1, mivacurium 0.04 mg.kg-1 or normal saline, before induction of anaesthesia with propofol 2 mg.kg-1. Insertion conditions, including mouth opening, swallowing, gagging or coughing, head or limb movement and ease of insertion, were each graded using a three-point scale. The median (interquartile range) summed insertion scores were more favourable with the use of fentanyl [8.0 (7.0-9.0)] and mivacurium [7.5 (6.8-8.3)] than with normal saline [9.0 (7.8-10.3); p < 0.01]. Fentanyl and mivacurium decreased swallowing and head or limb movement, and mivacurium improved mouth opening. Insertion conditions were similar between fentanyl and mivacurium, while both prolonged apnoea. Fentanyl and mivacurium are equally effective in facilitating insertion of the laryngeal mask airway following anaesthetic induction with propofol.

The use of mini-dose suxamethonium to facilitate the insertion of a laryngeal mask airway.

The use of mini-dose suxamethonium to facilitate the insertion of a laryngeal mask airway was investigated. Sixty patients were assigned randomly in a double-blind manner to receive 0.9% sodium chloride or suxamethonium 0.1 mg.kg-1 intravenously, following intravenous induction with propofol 2.5 mg.kg-1. The laryngeal mask was inserted after the first attempt in 87% of patients. Mini-dose suxamethonium improved the correct positioning of the laryngeal mask during the first attempt (93 vs. 67%, p < 0.02), decreased the incidence of swallowing (p < 0.001), gagging (p < 0.001) and head or limb movement (p < 0.05). Laryngeal mask insertion was graded as easy in 93% of patients who had mini-dose suxamethonium, compared with 60% in the placebo group (p < 0.01). The duration of apnoea between the two groups was not significantly different (0.54 vs. 0.61 min, p = 0. 46). The total dose of propofol needed to insert the laryngeal mask was lower in the suxamethonium group (2.57 vs. 3.25 mg.kg-1, p < 0. 01) and was associated with less hypotension (p < 0.05). Fasciculation (17%) and mild myalgia (23%) were common despite the small dose of suxamethonium used. In conclusion, mini-dose suxamethonium facilitates laryngeal mask insertion. Myalgia is common and the technique is not recommended for patients who are prone to suxamethonium myalgia.

Propofol and midazolam act synergistically in combination.

We have studied interactions between i.v. propofol and midazolam for induction of anaesthesia in 200 unpremedicated female patients undergoing elective gynaecological surgery. Using end-points of "hypnosis" (loss of response to verbal command) and "anaesthesia" (loss of response to a 5-s transcutaneous tetanic stimulus), we determined dose-response curves for propofol and midazolam alone and in combination. For hypnosis, synergistic interaction was found (P less than 0.01), the combination having 1.44 times the potency of the individual agents. Although midazolam failed to produce anaesthesia in the dose range used, the dose of propofol required to produce anaesthesia was reduced by 52% in the presence of midazolam (P less than 0.01). The reduction in arterial pressure at induction was the same for the combination as for the individual agents. The cause of the synergism was not clear, but may have been interaction at CNS GABAA receptors.

A double-blind randomised trial comparing postoperative analgesia after perioperative loading doses of methadone or morphine.

This double-blind randomised study compared postoperative analgesia after a loading regimen of methadone or morphine in thirty women undergoing abdominal hysterectomy. Methadone or morphine, 0.25 mg.kg-1, was given intravenously at induction of anaesthesia with further increments in the recovery room for analgesia if required. The mean (SD) total doses of methadone and morphine required were 0.43 (0.13) mg.kg-1 and 0.45 (0.15) mg.kg-1 respectively. Patients in the methadone group had lower pain scores in the subsequent 48 hours (P less than 0.001) and required less supplementary intramuscular opioids (P less than 0.001). Ten patients in the methadone group did not request any further opioid analgesics while all patients in the morphine group made at least two requests for opioids. The overall postoperative course was remembered as less painful by patients in the methadone group (P less than 0.001). There was no significant respiratory depression or excessive sedation in either group.

The use of low-dose mivacurium to facilitate insertion of the laryngeal mask airway.

Ninety patients were assigned randomly in a double-blind manner to receive 0.9% sodium chloride, mivacurium 0.04 mg.kg-1 or mivacurium 0.08 mg.kg-1 intravenously, followed by propofol 2.5 mg.kg-1. A laryngeal mask airway (LMA) was inserted 90 s later. The LMA was positioned correctly during the first attempt in 87% of patients and this was not significantly altered by the use of mivacurium. However, mivacurium decreased the incidence of swallowing, coughing, movement and laryngospasm (p < 0.05). LMA insertion was graded as easy in 88% of patients who had mivacurium, compared with 50% in patients who had propofol alone (p < 0.05). The conditions during LMA insertion were similar after 0.04 or 0.08 mg.kg-1 of mivacurium. Patients were apnoeic for a mean (SD) time of 0.67 (0.72) min after propofol alone, compared with 1.72 (1.06) min and 3.05 (1.36) min in patients who also received mivacurium 0.04 and 0.08 mg.kg-1, respectively (p < 0.01). Patients who received mivacurium had a lower incidence of postoperative sore throat (24-30% vs. 53%) (p < 0.05). In conclusion, low-dose mivacurium facilitates LMA insertion and decreases the incidence of postoperative sore throat.

A comparison between ketorolac and diclofenac in laparoscopic sterilization.

We compared ketorolac and diclofenac for the prevention and treatment of post-operative pain in patients undergoing laparoscopic sterilization. Fifty ASA I or II women were allocated randomly to receive either diclofenac 75 mg or ketorolac 30 mg intramuscularly 30-90 min before general anaesthesia. Pain scores were assessed half-hourly in the recovery room and then at 2 h and 4 h in the ward. In the recovery room, pain was treated with a second dose of the study drug, followed by parenteral pethidine if necessary. Four patients in the diclofenac group and five patients in the ketorolac group requested no analgesics after surgery. Fifteen patients from each group had satisfactory analgesia after the second dose of study drug. Pain scores were similar between groups at all times. The median (range) initial pain score in the recovery room was 5 (0-9.5) in the diclofenac group and 5 (1-9) in the ketorolac group. Pain at the injection site was more common after diclofenac than ketorolac (12 vs. 3, P < 0.05). In conclusion, both intramuscular diclofenac and ketorolac were relatively ineffective in controlling the pain after laparoscopic sterilization. The drugs were equally well tolerated, but more patients complained of pain at the injection site after diclofenac.

PIP: A comparison of two non-steroidal anti-inflammatory drugs (NSAIDs), ketorolac and diclofenac, indicates both were relatively ineffective for treating pain after laparoscopic sterilization. NSAIDs produce analgesia by inhibiting the synthesis of prostaglandins. Patients were randomly assigned to receive intramuscular injections of either 75 mg of diclofenac (n = 25) or 30 mg of ketorolac (n = 25) 30-90 minutes before surgery. There were no major anesthesia or surgical complications. The median duration of surgery, time from initial dose of NSAID to arrival in the recovery room, and length of stay in the recovery room were 20, 75, and 60 minutes, respectively, in both groups. Only 4 women in the diclofenac group and 5 in the ketorolac group did not require further analgesia after surgery, but 60% had adequate analgesia after a second NSAID dose. Pain scores, postoperative nausea and vomiting, and the requirement for anti-emetics did not differ between groups. Injection site pain lasted 15-30 minutes after ketorolac compared with 8-12 hours after diclofenac. While the analgesic potency of ketorolac is about 5 times that of diclofenac, the anti-inflammatory potency of ketorolac is only twice that of diclofenac.

Subcutaneous emphysema, pneumomediastinum and pneumothorax complicating laparoscopic vagotomy. Report of two cases.

Two patients developed subcutaneous emphysema and pneumomediastinum during laparoscopic vagotomy. One of the patients also had a pneumothorax which produced a sudden increase in end-tidal carbon dioxide concentration preceding arterial oxygen desaturation. The pneumothorax was drained with an intercostal cannula. The patient required a twofold increase in minute ventilation to maintain normocarbia, probably because of the additional absorption of carbon dioxide through the pleural cavity. Despite the presence of a peritoneo-pleural communication, surgery was successfully completed. We believe that gas under tension in the peritoneal cavity dissected along tissue planes around the oesophagus opened up during surgery. Thus pneumomediastinum, subcutaneous emphysema and pneumothorax are definite risks associated with this new procedure.