BOSTN Bundle Intervention for Perioperative Screening and Management of Patients With Suspected Obstructive Sleep Apnea

Neck Circumference is Associated with General and Central Obesity in Young Indian Adults

Background

Obesity has been a major concern due to its increasing prevalence and associated metabolic complications. Body mass index (BMI) assesses general obesity, but it does not distinguish between muscle and fat accumulations, so using only BMI can lead to an erroneous result. Waist circumference (WC), a marker of central obesity, predicted mortality risk better than BMI. However, WC can be affected by abdominal distension, is time-consuming, and may not be culture-sensitive. Neck circumference (NC) is devoid of these disadvantages and is believed to be an index of upper body fat distribution. This study aimed to assess the association of neck circumference with general and central obesity and to identify the cut-off points for evaluating obesity in young adults using NC.

Material and Methods

Height, weight, waist, and hip circumference were measured to determine BMI and waist-hip ratio. NC was measured at the level of the mid-cervical spine and mid-anterior neck in a standing position with the arms hanging freely. For males with a laryngeal prominence, NC was measured just below the prominence.

Results

In total, 357 (170 male and 187 female) young, healthy Indian adults aged 18-25 participated. Neck circumference (NC) is significantly associated with BMI and WC in both genders. We found the best cut-off for male and female participants to be ≥34 cm and ≥30.5 cm, with a sensitivity of 88.3% and 84.4% for assessing obesity.

Conclusion

NC may be a better alternative to BMI and WC as a marker to assess obesity since it is more practical, simple, inexpensive, time-saving, and less invasive.

REsidual Neuromuscular Block Prediction Score Versus Train-of-Four Ratio and Respiratory Outcomes: A Retrospective Cohort Study

BACKGROUND

Residual neuromuscular blockade is associated with an increased incidence of postoperative respiratory complications. The REsidual neuromuscular block Prediction Score (REPS) identifies patients at high risk for residual neuromuscular blockade after surgery.

METHODS

A total of 101,510 adults undergoing noncardiac surgery under general anesthesia from October 2005 to December 2018 at a tertiary care center in Massachusetts were analyzed for the primary outcome of postoperative respiratory complications (invasive mechanical ventilation requirement within 7 postoperative days or immediate postextubation desaturation [oxygen saturation {Spo2} <90%] within 10 minutes). The primary objective was to assess the association between the REPS and respiratory complications. The secondary objective was to compare REPS and train-of-four (TOF) ratio <0.90 on the strength of their association with respiratory complications.

RESULTS

A high REPS (≥4) was associated with an increase in odds of respiratory complications (adjusted odds ratio [OR], 1.13 [95% confidence interval {CI}, 1.06-1.21]; P < .001). In 6224 cases with available TOF ratio measurements, a low TOF ratio (<0.9) was associated with respiratory complications (adjusted OR, 1.43 [95% CI, 1.11-1.85]; P = .006), whereas a high REPS was not (adjusted OR, 0.96 [95% CI, 0.74-1.23]; P = .73) (P = .018 for comparison between ORs).

CONCLUSIONS

The REPS may be implemented as a screening tool to encourage clinicians to use quantitative neuromuscular monitoring in patients at risk of residual neuromuscular blockade. A positive REPS should be followed by a quantitative assessment of the TOF ratio.

Supraglottic airway device versus tracheal intubation and the risk of emergent postoperative intubation after general anaesthesia in adults: a retrospective cohort study

BACKGROUND

We examined the association between emergent postoperative tracheal intubation and the use of supraglottic airway devices (SGAs) vs tracheal tubes.

METHODS

We included data from adult noncardiac surgical cases under general anaesthesia between 2008 and 2018. We only included cases (n=59 991) in which both airways were deemed to be feasible options. Multivariable logistic regression, instrumental variable analysis, propensity matching, and mediation analysis were used.

RESULTS

Use of a tracheal tube was associated with a higher risk of emergent postoperative intubation (adjusted absolute risk difference [ARD]=0.80%; 95% confidence interval (CI), 0.64-0.97; P<0.001), and a higher risk of post-extubation hypoxaemia (ARD=3.9%; 95% CI, 3.4-4.4; P<0.001). The effect was modified by the use of non-depolarising neuromuscular blocking agents (NMBAs); mediation analyses revealed that 28.9% (95% CI, 14.4-43.4%; P<0.001) of the main effect was attributable to NMBA. Airway management modified the association of NMBA and risk of emergent postoperative intubation (P_interaction=0.02). Patients managed with an SGA had higher odds of NMBA-associated reintubation compared to patients managed with a tracheal tube (adjusted odds ratio [aOR]=3.65, 95% CI, 1.99-6.67 vs aOR=1.68, 95% CI, 1.29-2.18 [P<0.001], respectively).

CONCLUSIONS

In patients undergoing procedures under general anaesthesia that could be managed with either SGA or tracheal tube, use of an SGA was associated with lower risk of emergent postoperative intubation. The effect can partly be explained by use of NMBAs. Use of NMBAs in patients with an SGA appears to increase the risk of emergent postoperative intubation.

A comparison of postoperative respiratory complications associated with the use of desflurane and sevoflurane: a single-centre cohort study

Sevoflurane and desflurane are the most commonly used volatile anaesthetics for maintenance of anaesthesia. In this study, we aimed to evaluate the relationship between choice of volatile anaesthetic and early postoperative respiratory complications, and to address a critical knowledge gap in safety outcomes between these two commonly used agents. We performed a retrospective analysis of adult (non-cardiac surgery) patients who received sevoflurane or desflurane for the maintenance of general anaesthesia at our institution between 2005 and 2018. We evaluated the association between desflurane exposure (when compared with sevoflurane) and the primary outcome of postoperative respiratory complications, defined by early post-extubation desaturation (S_p O₂  < 90%) or re-intubation within 7 days postoperatively. Multivariable regression analyses were performed and adjusted for confounding factors, including patient, anaesthetic and surgical factors. Propensity matched, interaction and sub-group analyses were performed to assess outcomes in high-risk groups: morbidly obese (BMI > 35 kg.m^-2 ); elderly (age > 65 years); and high risk of respiratory complications as well as the primary outcome at 24 h. Desflurane was used for 23,830 patients and sevoflurane for 84,608 patients. Patients exposed to desflurane did not demonstrate a reduced risk of postoperative respiratory complications when compared with sevoflurane (adjusted odds ratio 0.99, 95%CI 0.94-1.04, p = 0.598). These findings were consistent across all sub-groups of high-risk patients and in the propensity score matched cohort. In summary, desflurane use was not associated with reduced postoperative respiratory complications when compared with sevoflurane. In the context of environmental and cost concerns with volatile anaesthetic agents, our study provides important data to support organisational decisions regarding the use of desflurane.

Ventilatory frequency during intraoperative mechanical ventilation and postoperative pulmonary complications: a hospital registry study

BACKGROUND

High ventilatory frequencies increase static lung strain and possibly lung stress by shortening expiratory time, increasing intrathoracic pressure, and causing dynamic hyperinflation. We hypothesised that high intraoperative ventilatory frequencies were associated with postoperative respiratory complications.

METHODS

In this retrospective hospital registry study, we analysed data from adult non-cardiothoracic surgical cases performed under general anaesthesia with mechanical ventilation at a single centre between 2005 and 2017. We assessed the association between intraoperative ventilatory frequency (categorised into four groups) and postoperative respiratory complications, defined as composite of invasive mechanical ventilation within 7 days after surgery or peripheral oxygen desaturation after extubation, using multivariable logistic regression. In a subgroup, we adjusted analyses for arterial blood gas parameters.

RESULTS

A total of 102 632 cases were analysed. Intraoperative ventilatory frequencies ranged from a median (inter-quartile range [IQR]) of 8 (8-9) breaths min^-1 (Group 1) to 15 (14-18) breaths min^-1 (Group 4). High ventilatory frequencies were associated with higher odds of postoperative respiratory complications (adjusted odds ratio=1.26; 95% confidence interval, 1.14-1.38; P<0.001), which was confirmed in a subgroup after adjusting for arterial partial pressure of carbon dioxide and the ratio of arterial oxygen partial pressure to fractional inspired oxygen. We identified considerable variability in the use of high ventilatory frequencies attributable to individual provider preference (ranging from 22% to 88%) and temporal change; however, the association with postoperative respiratory complications remained unaffected.

CONCLUSIONS

High intraoperative ventilatory frequency was associated with increased risk of postoperative respiratory complications, and increased postoperative healthcare utilisation.