Risk factors of post-anaesthesia care unit delirium in patients undergoing non-cardiac surgery in Singapore

INTRODUCTION@#Post-anaesthesia care unit (PACU) delirium affects 5%-45% of patients after surgery and is associated with postoperative delirium and increased mortality. Up to 40% of PACU delirium is preventable, but it remains under-recognised due to a lack of awareness of its diagnosis. The nursing delirium screening scale (Nu-DESC) has been validated for diagnosing PACU delirium, but is not routinely used locally. This study aimed to use Nu-DESC to establish the incidence and risk factors of PACU delirium in patients undergoing non-cardiac surgery in the surgical population.@*METHODS@#We conducted an audit of eligible patients undergoing major surgery in three public hospitals in Singapore over 1 week. Patients were assessed for delirium 30-60 min following their arrival in PACU using Nu-DESC, with a total score of ≥2 indicative of delirium.@*RESULTS@#A total of 478 patients were assessed. The overall incidence rate of PACU delirium was 18/478 (3.8%), and the incidence was 9/146 (6.2%) in patients aged > 65 years. Post-anaesthesia care unit delirium was more common in females, patients with malignancy and those who underwent longer operations. Logistic regression analysis showed that the use of bispectral index (P < 0.001) and the presence of malignancy (P < 0.001) were significantly associated with a higher incidence of PACU delirium.@*CONCLUSION@#In this first local study, the incidence of PACU delirium was 3.8%, increasing to 6.2% in those aged > 65 years. Understanding these risk factors will form the basis for which protocols can be established to optimise resource management and prevent long-term morbidities and mortality in PACU delirium.

Incidence and risk factors of delirium in post-anaesthesia care unit

INTRODUCTION@#Post-anaesthesia care unit (PACU) delirium is a potentially preventable condition that results in a significant long-term effect. In a multicentre prospective cohort study, we investigate the incidence and risk factors of postoperative delirium in elderly patients undergoing major non-cardiac surgery.@*METHODS@#Patients were consented and recruited from 4 major hospitals in Singapore. Research ethics approval was obtained. Patients older than 65 years undergoing non-cardiac surgery >2 hours were recruited. Baseline perioperative data were collected. Preoperative baseline cognition was obtained. Patients were assessed in the post-anaesthesia care unit for delirium 30-60 minutes after arrival using the Nursing Delirium Screening Scale (Nu-DESC).@*RESULTS@#Ninety-eight patients completed the study. Eleven patients (11.2%) had postoperative delirium. Patients who had PACU delirium were older (74.6±3.2 versus 70.6±4.4 years, P=0.005). Univariate analysis showed those who had PACU delirium are more likely to be ASA 3 (63.6% vs 31.0%, P=0.019), had estimated glomerular filtration rate (eGFR) of >60mL/min/1.73m2 (36.4% vs 10.6%, P=0.013), higher HbA1C value (7.8±1.2 vs 6.6±0.9, P=0.011), raised random blood glucose (10.0±5.0mmol/L vs 6.5±2.4mmol/L, P=0.0066), and moderate-severe depression (18.2% vs 1.1%, P=0.033). They are more likely to stay longer in hospital (median 8 days [range 4-18] vs 4 days [range 2-8], P=0.049). Raised random blood glucose is independently associated with increased PACU delirium on multivariate analysis.

Academy of Medicine, Singapore clinical guideline on the use of sedation by non-anaesthesiologists during gastrointestinal endoscopy in the hospital setting

INTRODUCTION@#In Singapore, non-anaesthesiologists generally administer sedation during gastrointestinal endoscopy. The drugs used for sedation in hospital endoscopy centres now include propofol in addition to benzodiazepines and opiates. The requirements for peri-procedural monitoring and discharge protocols have also evolved. There is a need to develop an evidence-based clinical guideline on the safe and effective use of sedation by non-anaesthesiologists during gastrointestinal endoscopy in the hospital setting.@*METHODS@#The Academy of Medicine, Singapore appointed an expert workgroup comprising 18 gastroenterologists, general surgeons and anaesthesiologists to develop guidelines on the use of sedation during gastrointestinal endoscopy. The workgroup formulated clinical questions related to different aspects of endoscopic sedation, conducted a relevant literature search, adopted Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology and developed recommendations by consensus using a modified Delphi process.@*RESULTS@#The workgroup made 16 recommendations encompassing 7 areas: (1) purpose of sedation, benefits and disadvantages of sedation during gastrointestinal endoscopy; (2) pre-procedural assessment, preparation and consent taking for sedation; (3) Efficacy and safety of drugs used in sedation; (4) the role of anaesthesiologist administered sedation during gastrointestinal endoscopy; (5) performance of sedation; (6) post-sedation care and discharge after sedation; and (7) training in sedation for gastrointestinal endoscopy for non-anaesthesiologists.@*CONCLUSION@#These recommendations serve to guide clinical practice during sedation for gastrointestinal endoscopy by non-anaesthesiologists in the hospital setting.

Prevailing practices in airway management: a prospective single-centre observational study of endotracheal intubation

<p><b>INTRODUCTION</b>Airway management during anaesthesia has potential difficulties and risks. We aimed to investigate the utility of routine airway assessment for predicting difficult tracheal intubation, review the prevailing practice of videolaryngoscope use amongst anaesthetists in a teaching hospital and determine the incidence of intraoperative and postoperative airway-related complications.</p><p><b>METHODS</b>A prospective observational study of 1,654 patients undergoing general anaesthesia with endotracheal intubation over a seven-month period was performed. Data regarding airway and anaesthetic management was collected and analysed.</p><p><b>RESULTS</b>Videolaryngoscopes were used as the first-choice equipment in 60.5% of the cohort. The incidence of difficult intubation was 2.1%, of which 45.7% of cases were unanticipated. The sensitivity of airway assessment was 54.3%, with a positive predictive value of 8.1%. When difficult intubation was anticipated, more videolaryngoscopes were used as the first equipment of choice compared to the Macintosh laryngoscope (p < 0.001). In the Macintosh group, more patients required a change of airway equipment (p = 0.015), but the number of intubation attempts was similar (p = 0.293). The incidence of intraoperative (p = 0.920) and postoperative complications (p = 0.380) were similar in both groups.</p><p><b>CONCLUSION</b>Using the current predictors of difficult intubation, half of the difficult airways we encountered were unanticipated. Videolaryngoscopes were preferred when difficulty was anticipated and were also used in routine tracheal intubation.</p>

Melatonin premedication versus placebo in wisdom teeth extraction: a randomised controlled trial

<p><b>INTRODUCTION</b>Pain after wisdom teeth surgery can be moderate in severity and is compounded by preoperative anxiety in young patients. We studied the effect of melatonin premedication on postoperative pain and preoperative anxiety in patients undergoing wisdom teeth extractions.</p><p><b>METHODS</b>This randomised controlled trial recruited 76 patients at Khoo Teck Puat Hospital who were American Society of Anesthesiologists physical status I and II, aged 21 to 65 and scheduled to undergo elective extraction of all four wisdom teeth under general anaesthesia. Patients with a history of long-term use or allergy to melatonin were excluded. The patients received either 6 mg melatonin or a placebo 90 minutes before surgery. Visual analogue scale (VAS) scores at multiple time intervals for postoperative pain and preoperative anxiety, patient satisfaction and first-night sleep quality scores were obtained. Mixed-effects regression models were used for longitudinal analysis of VAS pain, anxiety and satisfaction scores.</p><p><b>RESULTS</b>Maximum VAS scores for pain and anxiety were 18.6 ± 19.1 mm at 60 minutes postoperatively and 26.2 ± 23.4 mm at 90 minutes preoperatively, respectively. After adjusting for gender, female patients who received melatonin had a faster rate of reduction of VAS pain (p = 0.020) and anxiety scores (p = 0.003) over time compared to the placebo group. No such effect was demonstrated in male patients. There was no significant difference in sleep quality or satisfaction scores.</p><p><b>CONCLUSION</b>Melatonin use did not consistently contribute to pain and anxiety amelioration in all patients. Our study demonstrated a positive effect in female patients, suggestive of sexual dimorphism.</p>

High STOP-BANG questionnaire scores predict intraoperative and early postoperative adverse events

<p><b>INTRODUCTION</b>Obstructive sleep apnoea (OSA) is the most common sleep-related breathing disorder associated with multisystemic organ involvement. The STOP-BANG questionnaire is a concise, validated questionnaire that is used to screen for OSA. This study aimed to establish the use of the STOP-BANG questionnaire for perioperative patient risk stratification.</p><p><b>METHODS</b>In this retrospective cohort study, we extracted the demographic, medical and perioperative outcome data of all patients who underwent elective surgery, excluding ophthalmic surgeries, from January to December 2011. Multivariate regression analysis was used to predict independent risk factors for intraoperative and early postoperative adverse events.</p><p><b>RESULTS</b>Of the 5,432 patients analysed, 7.4% had unexpected intraoperative and early postoperative adverse events. We found that the risk of unexpected intraoperative and early postoperative adverse events was greater in patients with STOP-BANG scores ≥ 3 compared to those with a STOP-BANG score of 0 (score 3: odds ratio [OR] 3.6, 95% confidence interval [CI] 2.1-6.3, p < 0.001; score 4: OR 3.4, 95% CI 1.8-6.5, p < 0.001; score 5: OR 6.4, 95% CI 2.7-15.0, p < 0.001; score ≥ 6: OR 5.6, 95% CI 2.1-15.4, p < 0.001). Patients with STOP-BANG scores ≥ 5 had a fivefold increased risk of unexpected intraoperative and early postoperative adverse events, while patients with STOP-BANG scores ≥ 3 had a 'one in four' chance of having an adverse event. Other independent predictors included older age (p < 0.001), American Society of Anesthesiologists class ≥ 2 (p < 0.003) and uncontrolled hypertension (p = 0.028).</p><p><b>CONCLUSION</b>STOP-BANG score may be used as a preoperative risk stratification tool to predict the risk of intraoperative and early postoperative adverse events.</p>

The use of laryngeal mask airway Supreme™ in rescue airway situation in the critical care unit

We herein report a witnessed cardiopulmonary collapse of a patient with difficult mask ventilation and near-impossible laryngoscopy-cum-intubation in the critical care unit. The airway was successfully rescued with a laryngeal mask airway Supreme™, followed by an open, crash tracheostomy by the otolaryngologist.

Comparison of results from novice and trained personnel using the Macintosh laryngoscope, Pentax AWS®, C-MAC™ and Bonfils intubation fibrescope: a manikin study

<p><b>INTRODUCTION</b>Indirect laryngoscopes offer improved laryngeal view and higher success rates of intubation, particularly for difficult airways. We hypothesised that: (a) the time required for intubation, overall success rates and ease of intubation with indirect laryngoscopes would be better than with the Macintosh laryngoscope; and (b) novices may achieve higher success rates and intubate faster using indirect laryngoscopes.</p><p><b>METHODS</b>In a cross-sectional observational study, 13 novices and 13 skilled anaesthetists were recruited. Participants were compared when intubating a manikin simulating normal and difficult airway scenarios using the Macintosh laryngoscope, Pentax Airway Scope® (AWS), C-MAC[TM] and Bonfils intubation fibrescope.</p><p><b>RESULTS</b>There was no significant difference in intubation success rates between the groups. Skilled anaesthetists intubated faster than novices with Pentax AWS in the difficult airway scenario (22 s vs. 33 s, p = 0.047). The mean intubation times for C-MAC and Pentax AWS were shorter than for the Macintosh laryngoscope and Bonfils intubation fibrescope in both difficult (C-MAC: 24 s, Pentax AWS: 28 s, Macintosh: 80 s, Bonfils: 61 s; p < 0.001) and normal (C-MAC: 17 s, Pentax AWS: 19 s, Macintosh: 39 s, Bonfils: 38 s; p = 0.002) airway scenarios.</p><p><b>CONCLUSION</b>We found that intubation success was more than 85% with all indirect laryngoscopes compared to 69% for the Macintosh laryngoscope. Both C-MAC and Pentax AWS achieved faster intubation times compared to the Macintosh laryngoscope and Bonfils intubation fibroscope for both airway scenarios. Skilled anaesthetists were 33% faster than novices when intubating a difficult airway using Pentax AWS.</p>

Percutaneous pedicle screw fixation for thoracolumbar burst fracture: a Singapore experience

<p><b>INTRODUCTION</b>This study aimed to evaluate the clinical and radiological outcomes, and safety and efficacy of percutaneous pedicle screw fixation (PPSF) in the treatment of thoracolumbar burst fractures.</p><p><b>METHODS</b>This was a retrospective review of patients with thoracolumbar burst fractures treated with PPSF in a single hospital from 2010 to 2011. Baseline data included patient demographics, mechanism of injuries, fracture level, neurologic status and the number of percutaneous screws inserted. Kyphotic angle correction, vertebral body height restoration and mid-sagittal canal diameter improvement were used to assess radiological outcome. Screw misplacement, operative complications, functional improvement (ASIA score) and pain score on visual analogue scale were used to assess safety and clinical outcomes.</p><p><b>RESULTS</b>21 patients with 25 thoracolumbar burst fractures were treated with 134 percutaneous screws. There was significant improvement in kyphotic angle correction (mean difference 6.1 degrees, p = 0.006), restoration of anterior and posterior vertebral height (mean difference 19.7%, p < 0.01 and mean difference 6.6%, p = 0.007, respectively) and mid-sagittal canal diameter (mean difference 15.6%, p = 0.007) on discharge. These improvements remained statistically significant at six months post operation for restoration of anterior vertebral body height (mean difference 9.8%, p = 0.05) and mid-sagittal diameter (mean difference 30.0%, p < 0.01).</p><p><b>CONCLUSION</b>In this first local review, we have shown that PPSF is a relatively safe and effective technique for treating selected thoracolumbar burst fractures, and that it yields satisfactory results. However, its long-term outcome and efficacy need to be further evaluated.</p>