Obstructive Sleep Apnea-a Perioperative Risk Factor

Impact of mini-dose dexmedetomidine supplemented analgesia on sleep structure in patients at high risk of obstructive sleep apnea: a pilot trial

Background

Obstructive sleep apnea (OSA) is common in surgical patients and associated with worse perioperative outcomes.

Objectives

To investigate the effect of mini-dose dexmedetomidine supplemented analgesia on postoperative sleep quality pattern in patients at high risk of OSA.

Design

A pilot randomized, double-blind, placebo-controlled trial.

Setting

A tertiary university hospital in Beijing, China.

Patients

One hundred and fifty-two adult patients who had a STOP-Bang score ≥3 and a serum bicarbonate level ≥28 mmol/L and were scheduled for major noncardiac surgery between 29 January 2021 and 20 September 2022.

Intervention

After surgery, patients were provided with high-flow nasal cannula and randomized in a 1:1 ratio to receive self-controlled opioid analgesia supplemented with either mini-dose dexmedetomidine (median 0.02 μg/kg/h) or placebo. We monitored polysomnogram from 9:00 pm to 6:00 am during the first night.

Main outcome measures

Our primary outcome was the percentage of stage 2 non-rapid eye movement (N2) sleep. Secondary and exploratory outcomes included other postoperative sleep structure parameters, sleep-respiratory parameters, and subjective sleep quality (Richards-Campbell Sleep Questionnaire; 0-100 score range, higher score better).

Results

All 152 patients were included in intention-to-treat analysis; 123 patients were included in sleep structure analysis. Mini-dose dexmedetomidine supplemented analgesia increased the percentage of stage N2 sleep (median difference, 10%; 95% CI, 1 to 21%; p = 0.029); it also decreased the percentage of stage N1 sleep (median difference, -10%; 95% CI, -20% to -1%; p = 0.042). Other sleep structure and sleep-respiratory parameters did not differ significantly between the two groups. Subjective sleep quality was slightly improved with dexmedetomidine on the night of surgery, but not statistically significant (median difference, 6; 95% CI, 0 to 13; p = 0.060). Adverse events were similar between groups.

Conclusion

Among patients at high risk of OSA who underwent noncardiac surgery, mini-dose dexmedetomidine supplemented analgesia may improve sleep quality without increasing adverse events.

Clinical trial registration

Clinicaltrials.gov, identifier NCT04608331.

Non-brachycephalic dogs with stertor have higher nasopharyngeal collapsibility compared with dogs without stertor and foramen lacerum level is ideal for evaluating nasopharyngeal collapse on dynamic CT

Stertor, a clinical sign associated with obstructive airway syndrome, is often observed in non-brachycephalic dogs. This prospective, case-control study aimed to compare soft palate dimensions, nasopharyngeal cross-sectional area (CSA), and nasopharyngeal collapsibility at various locations in non-brachycephalic dogs with and without stertor. A total of 50 dogs were recruited and stratified into control (n = 34) and stertor (n = 13) groups. Static and dynamic computed tomography was conducted without tracheal intubation, and the following variables were calculated: normalized soft palate length and thickness, normalized maximum and minimum nasopharyngeal CSAs (rCSAmax and rCSAmin), and nasopharyngeal collapsibility at the level of the cranial end of the soft palate, pterygoid hamulus, foramen lacerum, bony labyrinth, and caudal end of the soft palate. The stertor group demonstrated significantly lower rCSAmax and rCSAmin, as well as higher nasopharyngeal collapsibility compared with the control group, while no significant differences were noted in the soft palate dimension. Evaluating nasopharyngeal collapse at the foramen lacerum level was recommended due to the clear presence of identifiable bony landmarks and lower overlap in the nasopharyngeal collapsibility between dogs with and without stertor. Physical dimensions of the soft palate may not be the primary contributing factor to nasopharyngeal collapse and clinical signs in non-brachycephalic dogs.

Anesthesia for Morbidly Obese Patients

BACKGROUND

The prevalence of morbid obesity (BMI >35 kg/m2) has risen steadily in recent decades. With the corresponding rise in the number of bariatric operations, anesthesiologists deal with this patient group more commonly than before, particularly in specialized centers.

METHODS

This review is based on publications retrieved by a selective search in PubMed, including current guidelines and recommendations issued by specialist societies, as well as expert opinion.

RESULTS

In the anesthesiological care of morbidly obese patients, a preoperative assessment and risk stratification are just as important as the thoughtful selection of the anesthesia technique, the drugs used and their dosage, and perioperative management. A thorough understanding of the pathophysiological changes and comorbidities of morbid obesity and the associated risks is essential. The risk of pulmonary complications such as respiratory failure, hypoxia, and apnea is markedly higher in morbidly obese patients, especially those with obstructive sleep apnea. Short-acting, less lipophilic anesthetic drugs are particularly useful, as is multimodal pain therapy for the avoidance of high opiate doses. The indication for intensified postoperative monitoring depends on the patient's preexisting illnesses, the type of anesthesia, and the type of surgical procedure. Regional anesthetic techniques should be used if possible.

CONCLUSION

The perioperative care of morbidly obese patients presents special challenges. The anesthesiologist must be aware of potential comorbidities, specific risks, and pathophysiological changes in order to provide adequate care to this patient group.

Preoperative risk evaluation and perioperative management of patients with obstructive sleep apnea: a narrative review

Obstructive sleep apnea (OSA) is a common sleep-breathing disorder associated with significant comorbidities and perioperative complications. This narrative review is aimed at comprehensively overviewing preoperative risk evaluation and perioperative management strategies for patients with OSA. OSA is characterized by recurrent episodes of upper airway obstruction during sleep leading to hypoxemia and arousal. Anatomical features, such as upper airway narrowing and obesity, contribute to the development of OSA. OSA can be diagnosed based on polysomnography findings, and positive airway pressure therapy is the mainstay of treatment. However, alternative therapies, such as oral appliances or upper airway surgery, can be considered for patients with intolerance. Patients with OSA face perioperative challenges due to difficult airway management, comorbidities, and effects of sedatives and analgesics. Anatomical changes, reduced upper airway muscle tone, and obesity increase the risks of airway obstruction, and difficulties in intubation and mask ventilation. OSA-related comorbidities, such as cardiovascular and respiratory disorders, further increase perioperative risks. Sedatives and opioids can exacerbate respiratory depression and compromise airway patency. Therefore, careful consideration of alternative pain management options is necessary. Although the association between OSA and postoperative mortality remains controversial, concerns exist regarding adverse outcomes in patients with OSA. Understanding the pathophysiology of OSA, implementing appropriate preoperative evaluations, and tailoring perioperative management strategies are vital to ensure patient safety and optimize surgical outcomes.

[Safety and monitoring of patient-controlled intravenous analgesia : Clinical practice in German hospitals]

BACKGROUND

Patient-controlled intravenous analgesia (PCIA) is a well-established technique in acute pain management and available in most German hospitals. Despite its widespread use, information on current clinical practice is limited. This investigation evaluated clinical practice and monitoring as well as PCIA-associated adverse events and critical incidents in German hospitals.

METHODS

An invitation to participate in this online-survey was sent to 995 heads of anesthesiology departments belonging to the "German Society of Anaesthesiology and Intensive Care Medicine".

RESULTS

Of the departments receiving the link, 244 took part (response rate 25%). PCIA was used in 193 of these hospitals (79%). All the following statements relate to the hospitals in which PCIA was used. Piritramide was the most frequently used opioid. In parallel with PCIA, additional nonopioid analgesics were used in 94% of the hospitals, and in 38%, additional slow-release oral opioids were used. Parenteral opioids were administered by the ward staff in 4% of the hospitals. In 75% of hospitals, there were standardized indications for PCIA therapy, with almost two thirds of respondents stating that PCIA was the technique of second choice if regional procedures were contraindicated or failed. In all, 76% of the hospitals had an acute pain service. Twenty-four percent of the hospitals regularly used PCIA in non-surgical patients. In pediatric patients, PCIA was used in 62 hospitals (32%). Only 31% of the hospitals reported the use of standardized protocols for the specific monitoring of patients' vital signs on general wards, exceeding general care. Of the department, 158 (82%) reported adverse events in connection with the use of PCIA within the six-month period preceding the survey (most frequently due to patients' noncompliance [52%], dislocated intravenous lines [41%], communication errors [16%], administration of additional analgesics [16%] and/ or sedatives [14%], problems with the pump [16%], programming errors [9%], incorrect opioid concentration in the reservoir [8%], non-observance of contraindications [7%], incorrect dosing [6%] and self-dosing by the patient [4%] or by third parties [3%], filling the reservoir with thewrong medication [2%]; and other problems [5%]). Only 35 of the hospitals (18%) reported no problems associated with PCIA therapy. Seventy-five of the 193 respondents (39%) stated that at least one critical incident had occurred in the context of the use of PCIA. This resulted in a total of 335 cases out of an estimate of 50.000 patients treated with PCIA. The respondents classified these as follows: I) 273 incidents requiring a prolonged stay in the recovery room, but without further complications, II) 58 requiring transfer to the intensive care unit, but without further complications, III) three resulting in permanent harm to the patient and IV) one resulting in the death of the patient. A comparison of the monitoring standards for PCIA showed that critical incidents were reported less frequently in hospitals with less intensive monitoring, and more frequently in hospitals with higher monitoring standards.

CONCLUSION

PCIA is a frequently used analgesic technique in German hospitals. There were many differences in how PCIA therapy was applied and monitored on general wards. Adverse events occurred to a significant extent, with a considerable part of them, which might be preventable. Critical incidents were perceived more often when standards for monitoring on general wards were higher. Consented current recommendations regarding treatment and monitoring standards as well as the systematic recording of complications when using PCIA are pending.

Use of CPAP Machines in the Perioperative Setting in Ambulatory Surgical Centers

INTRODUCTION

Obstructive sleep apnea is a common sleep-related breathing disorder that is associated with significant perioperative complications. In 2012 and 2017, Society of Ambulatory Anesthesia and Society of Anesthesia and Sleep Medicine published consensus statements for the selection of patients with OSA scheduled for ambulatory surgery. Despite these recommendations, the need for a CPAP device in the immediate postoperative period at ambulatory surgical centers remains controversial because these ambulatory patients are healthier and have fewer complications. This study aims to investigate the compliance rate with this recommendation among busy ASCs.

METHODS

We created a survey to investigate if ASCs require patients to bring their CPAP devices to the facility. The survey measured compliance rates of ASCs to SAMBA's recommended guidelines of having CPAP machines available.

RESULTS

The survey had a response rate of 60.9% encompassing 408,147 cases among 1946 providers. Of the facilities that responded, only 59.7% of them required their patients to bring their CPAP devices on the day of surgery. Out of the 67 facilities that responded, only 25.37% reported using a CPAP machine postoperatively within the past 2 years, with the highest CPAP usage at one facility being 20 times in that 2-year period.

DISCUSSION

This would mean that 40.3% of ASCs that did respond do not have access to a CPAP device on-site and may possibly lack the proper equipment needed to handle these complications. The frequency and fatality rate associated with postoperative respiratory complications requiring a CPAP device are still inconclusive, making the need for CPAP devices during perioperative management controversial. Studies further in-depth are therefore necessary to assess postoperative complications that require the use of a CPAP device to determine the urgency of ASCs implementing SAMBA's recommendations.

Electroacupuncture: A New Approach for Improved Postoperative Sleep Quality After General Anesthesia

General anesthesia produces a state of drug-induced unconsciousness that is controlled by the extent and duration of administered agents. Whether inhalation or intravenous in formulation, such agents may interfere with normal sleep-wake cycles, impairing postoperative sleep quality and creating complications. Electroacupuncture is a new approach widely applied in clinical practice during recent years. This particular technology helps regulate neurotransmitter concentrations in the brain, lowering norepinephrine and dopamine levels to improve sleep quality. It also alleviates surgical pain that degrades postoperative sleep quality after general anesthesia by downregulating immune activity (SP, NK-1, and COX-1) and upregulating serotonin receptor (5-HT1AR, 5-HT2AR) and endocannabinoid expression levels. However, large-scale, multicenter studies are still needed to determine the optimal duration, frequency, and timing of electroacupuncture for such use.

Prevalence and Prediction of Obstructive Sleep Apnea Prior to Bariatric Surgery-Gender-Specific Performance of Four Sleep Questionnaires

PURPOSE

Bariatric surgery (BS) is a treatment option for morbid obesity leading to substantial and sustained weight loss in adults. As obstructive sleep apnea (OSA) is highly prevalent in obese subjects and may increase the perioperative risk, screening for OSA is recommended prior to BS. In clinical routine, BS is performed more frequently in women. Therefore, we sought to assess the gender-specific performance of four sleep questionnaires (Epworth Sleepiness Scale (ESS), Fatigue Severity Scale (FSS), STOPBang, and NoSAS) to predict moderate to severe OSA in the morbidly obese population.

MATERIAL AND METHODS

We applied all four questionnaires to patients scheduled for BS with polygraphic OSA screening at our institution between 2012 and 2015 and performed gender-specific sensitivity analyses.

RESULTS

We included 251 bariatric patients (76% female, median age 39 years, median BMI 42.0 kg/m²). OSA (AHI > 5/h; AHI > 15/h) was present in 43% (females 35%, males 68%; p < 0.001) and 21% (females 13%, males 45%; p < 0.001). STOPBang and NoSAS performed markedly better than ESS and FSS. With the exception of the ESS, all sleep questionnaires allowed better OSA prediction in women than in men.

CONCLUSION

In obese patients scheduled for BS, a gender-specific difference was observed in the performance of the evaluated OSA screening questionnaires. This needs to be considered when these questionnaires are used. Our results underline the need for better gender-specific OSA screening algorithms in morbidly obese patients.

Postoperative sleep disorders and their potential impacts on surgical outcomes

Postoperative sleep disturbance is a common occurrence with significant adverse effects on patients including delayed recovery, impairment of cognitive function, pain sensitivity and cardiovascular events. The development of postoperative sleep disturbance is multifactorial and involves the surgical inflammatory response, the severity of surgical trauma, pain, anxiety, the use of anesthetics and environmental factors such as nocturnal noise and light levels. Many of these factors can be managed perioperatively to minimize the deleterious impact on sleep. Pharmacological and non-pharmacological treatment strategies for postoperative sleep disturbance include dexmedetomidine, zolpidem, melatonin, enhanced recovery after surgery (ERAS) protocol and controlling of environmental noise and light levels. It is likely that a combination of pharmacological and non-pharmacological therapies will have the greatest impact; however, further research is required before their use can be routinely recommended.

Postoperative complications with neuromuscular blocking drugs and/or reversal agents in obstructive sleep apnea patients: a systematic review

BACKGROUND

Neuromuscular blocking drugs (NMBD) are administered intra-operatively to facilitate intubation and to achieve muscle relaxation for surgical procedures. Incomplete reversal of NMBD can lead to adverse events in the postoperative period. Patients with obstructive sleep apnea (OSA) may be at higher risk of complications related to the use of NMBD. The objectives of this systematic review were to determine whether: 1) OSA patients are at higher risk of postoperative complications from the use of NMBD than non-OSA patients, and 2) the choice of NMBD reversal agent affects the risk of postoperative complications in OSA patients.

METHODS

A literature search of multiple databases was conducted up to April 2017. The inclusion criteria were: (1) adult surgical patients (≥18 years old) with OSA diagnosed by polysomnography, or history, or suspected by screening questionnaire; (2) patients who were given NMBD and/or NMBD reversal agents intraoperatively; (3) reports on postoperative adverse events, particularly respiratory events were available; (4) published studies were in English; and (5) RCTs or observational cohort studies. The quality of evidence was determined by the Oxford Center for Evidence Based Medicine levels of evidence.

RESULTS

Out of 4123 studies, five studies (2 RCTs and 3 observational studies) including 1126 patients were deemed eligible. These studies were heterogeneous precluding a meta-analysis of the results. Two of three studies (1 RCT, 2 observational studies) reported that OSA patients given NMBD may be at higher risk of developing postoperative pulmonary complications (PPCs) like hypoxemia, residual neuromuscular blockade or respiratory failure compared to non-OSA patients. Two studies (1 RCT, 1 observational study) reported that OSA patients who were reversed with sugammadex vs. neostigmine had less PPCs and chest radiographic changes, but the quality of the included studies was Oxford level of evidence: low to moderate.

CONCLUSIONS

OSA patients who receive intraoperative NMBD may be at higher risk for postoperative hypoxemia, respiratory failure and residual neuromuscular blockade compared to non-OSA patients. There is some, albeit very limited evidence that NMBD reversal with sugammadex may be associated with less PPCs than neostigmine in patients with OSA. More high-quality studies are needed.

Validation of a photoplethysmography device for detection of obstructive sleep apnea in the perioperative setting

Obstructive sleep apnea (OSA) is a risk factor for perioperative complications, but many OSA patients present undiagnosed. While polysomnography (PSG) is the "gold standard" for diagnosis, its application is technology-intense, time-consuming, expensive, and requires specialists, often delaying surgery. Thus, miniaturized devices were developed for OSA screening aimed at ruling out major OSA while measuring a lesser number of biological signals. We evaluated the accuracy of a photoplethysmography (PPG)-based device for OSA detection. 48 patients with established or strongly suspected (STOP-Questionnaire) OSA scheduled for surgery underwent in their preoperative nights parallel recordings by PPG and a classic polygraphy (PG) devices (SomnoLab2®). We compared the diagnostic accuracy of the PPG in diagnosing mild [Apnea-/Hypopnea-Index (AHI) 5-14 events/h] and moderate-to-severe OSA (AHI > 15). PPG and PG-derived AHI correlated significantly (r = 0.85, p < 0.0001) and high area under curve (AUC) in receiver operator characteristics (ROC) values were seen for both AHI thresholds (0.93 and 0.95, respectively). For an AHI > 5, sensitivity was 100%, specificity 44%, positive predictive value (PPV) 62%, negative predictive value (NPV) 100%, likelihood ratio (LHR) 1.79, and Cohen κ was 0.43. For an AHI > 15, sensitivity was 92%, specificity 77%, PPV 60%, NPV 96%, LHR 4.04, and Cohen κ was 0.59. In a typical perioperative cohort of confirmed and suspected OSA patients, PPG reliably detected OSA patients while showing some false-positive results. Such devices are helpful for preoperative OSA screening.

Obstructive sleep apnea as an independent predictor of postoperative delirium and pain: protocol for an observational study of a surgical cohort

Introduction: Postoperative delirium and pain are common complications in adults, and are difficult both to prevent and treat. Obstructive sleep apnea (OSA) is prevalent in surgical patients, and has been suggested to be a risk factor for postoperative delirium and pain. OSA also might impact pain perception, and alter pain medication requirements. This protocol describes an observational study, with the primary aim of testing whether OSA is an independent predictor of postoperative complications, focusing on (i) postoperative incident delirium and (ii) acute postoperative pain severity. We secondarily hypothesize that compliance with prescribed treatment for OSA (typically continuous positive airway pressure or CPAP) might decrease the risk of delirium and the severity of pain. Methods and analysis: We will include data from patients who have been enrolled into three prospective studies: ENGAGES, PODCAST, and SATISFY-SOS. All participants underwent general anesthesia for a non-neurosurgical inpatient operation, and had a postoperative hospital stay of at least one day at Barnes Jewish Hospital in St. Louis, Missouri, from February 2013 to May 2018.  Patients included in this study have been assessed for postoperative delirium and pain severity as part of the parent studies. In the current study, determination of delirium diagnosis will be based on the Confusion Assessment Method, and the Visual Analogue Pain Scale will be used for pain severity. Data on OSA diagnosis, OSA risk and compliance with treatment will be obtained from the preoperative assessment record. Other variables that are candidate risk factors for delirium and pain will also be extracted from this record. We will use logistic regression to test whether OSA independently predicts postoperative delirium and linear regression to assess OSAs relationship to acute pain severity. We will conduct secondary analyses with subgroups to explore whether these relationships are modified by compliance with OSA treatment.

Perioperative incidence of airway obstructive and hypoxemic events in patients with confirmed or suspected sleep apnea - a prospective, randomized pilot study comparing propofol/remifentanil and sevoflurane/remifentanil anesthesia

BACKGROUND

Obstructive sleep apnea (OSA) is a risk factor for perioperative complications but data on anesthesia regimen are scarce.

METHODS

In patients with established or strongly suspected OSA, we assessed in a prospective, randomized design the effects on nocturnal apnea-hypopnea-index (AHI) and oxygen saturation (SpO₂) of propofol/remifentanil or sevoflurane/remifentanil based anesthesia. Patients were selected by a history for OSA and / or a positive STOP - questionnaire and received general anesthesia using remifentanil (12 μg/kg/h) combined either with propofol (4-6 mg/kg/h, n = 27) or sevoflurane (approx. 2.2 vol% endtidal, n = 27). AHI and SpO₂ were measured during the nights before and after anesthesia.

RESULTS

There were no differences in AHI between anesthetic regimens nor between the pre- and postoperative nights (propofol: 8.6 h^- 1 (median, CI: 3.6-21.9) vs. 7.9 h^- 1 (1.8-28.8); p = 0.97; sevoflurane: 3.8 h^- 1 (1.8-7.3) vs. 2.9 h^- 1 (1.2-9.5); p = 0.85). Postoperative minimum SpO₂ (propofol: 80.7% ± 4.6, sevoflurane: 81.6 ± 4.6) did not differ from their respective preoperative baselines (propofol: 79.6% ± 6.5; p = 0.26, sevoflurane: 80.8% ± 5.2; p = 0.39). Even in patients with a preanesthetic AHI > 15, nocturnal AHI remained unchanged postoperatively.

CONCLUSION

Thus, in a cohort of patients with suspected or confirmed OSA undergoing surgery of moderate duration and severity neither the volatile agent sevoflurane nor the intravenous anesthetic propofol altered nocturnal AHI or oxygen saturation, when combined with the short acting opioid remifentanil.

TRIAL REGISTRATION

German Clinical Trials Register, DRKS00005824 retrospectively registered on 03/12/2014.

Are the Epworth Sleepiness Scale and Stop-Bang model effective at predicting the severity of obstructive sleep apnoea (OSA); in particular OSA requiring treatment?

Obstructive sleep apnoea (OSA) is a condition characterised by repetitive upper airway collapse during sleep. The condition carries a range of health sequelae that can prove fatal in cases with co-existing risk factors for the condition, such as obesity and hypertension. Utilisation of a high-performance screening tool for OSA is thus important. A retrospective audit using the ESS and Stop-Bang scores, alongside Apnoea-Hypopnea Index values, for patients who underwent polysomnography over 1 year. Multinomial logistic regression was used to compare the predictive abilities of ESS, SBM, and body mass index (BMI) for the patient outcome groups, "None" (No OSA), "Notreat" (OSA not requiring treatment) and "treat" (OSA requiring treatment). The influences of age, gender and BMI on outcome group were also assessed. 126 bariatric and 66 non-bariatric patients were included. Multinomial logistic regression failed to demonstrate predictive ability of ESS. A higher Stop-Bang score significantly increases the risk being in the "treat" group. In addition, male gender, greater age and a higher BMI each individually increase the risk of OSA requiring treatment. Stop-Bang failed to demonstrate predictive significance when age and gender were controlled for. ESS is not an appropriate screening tool for OSA. Stop-Bang, however, remains a useful screening tool, with the ability to detect patient with OSA in need of treatment. Further study may benefit the development and implementation of a concise and more specific screening tool that considers high evidence-based risk factors for OSA, including male gender, greater age and raised BMI.

Monitoring respiration and oxygen saturation in patients during the first night after elective bariatric surgery: A cohort study

Background: Obstructive sleep apnoea and obese hypoventilation is not uncommon in patients with obesity. Residuals effect from surgery/anaesthesia and opioid analgesics may worsen respiration during the first nights after bariatric surgery. The aim of this observational study was to monitor respiration on the first postoperative night following elective bariatric surgery.

Methods: This observational study aimed to determine the incidence and severity of hypo/apnoea in low risk obsess patients undergoing elective bariatric surgery in general anesthaesia. Patients with known or suspected sleep respiratory disturbances was not included. ESS was scored prior to surgery. Oxygen desaturation was analyzed by continuous respiratory monitoring. Mean oxygen saturation (SpO2), nadir SPo2, apnoea/hypopnea index and oxygen desaturation index was assess by standard tools.

Results: 45 patients were monitored with portable polygraphy equipment (Embletta, ResMed) during the first postoperative night at the general ward following elective laparoscopic bariatric surgery. The prop ESS was 0-5 in 22, 6-10 in 14 and 11-16 in 6 of the patients studied (missing data 3). Mean SpO2 was 93%; 10 patients had a mean SpO2 of less than 92% and 4 of less than 90%. The lowest mean SpO2 was 87%. There were 16 patients with a nadir SpO2 of less than 85%, lowest nadir SpO2 being 63%. An Apnoea Hypo/apnoea Index (AHI) > 5 was found in 2 patients only (AHI 10 and 6), and an Oxygen Desaturation index (ODI) > 5 was found in 3 patients (24, 10 and 6, respectively). 3 patients had more prolonged (> 30 seconds) apnoea with nadir SpO2 81%, 83% and 86%. ESS score and type of surgery did not impact on respiration/oxygenation during the observation period.

Conclusions: A low mean SpO2 and episodes of desaturation were not uncommon during the first postoperative night following elective bariatric surgery in patients without history of night time breathing disturbance. AHI and/or ODI of more than 5 were only rarely seen. Night-time respiration monitoring provided seemingly sparse additional information. Further studies are need to assess risk factors and potential impact of the desaturation episodes that occurs during sleep.

Monitoring respiration and oxygen saturation in patients during the first night after elective bariatric surgery: A cohort study

Background: Obstructive sleep apnoea and obese hypoventilation is not uncommon in patients with obesity. Residuals effect from surgery/anaesthesia and opioid analgesics may worsen respiration during the first nights after bariatric surgery. The aim of this observational study was to monitor respiration on the first postoperative night following elective bariatric surgery. Methods: This observational study aimed to determine the incidence and severity of hypo/apnoea in low risk obsess patients undergoing elective bariatric surgery in general anesthaesia. Patients with known or suspected sleep respiratory disturbances was not included. ESS was scored prior to surgery. Oxygen desaturation was analyzed by continuous respiratory monitoring. Mean oxygen saturation (SpO2), nadir SPo2, apnoea/hypopnea index and oxygen desaturation index was assess by standard tools. Results: 45 patients were monitored with portable polygraphy equipment (Embletta, ResMed) during the first postoperative night at the general ward following elective laparoscopic bariatric surgery. The prop ESS was 0-5 in 22, 6-10 in 14 and 11-16 in 6 of the patients studied (missing data 3). Mean SpO2 was 93%; 10 patients had a mean SpO2 of less than 92% and 4 of less than 90%. The lowest mean SpO2 was 87%. There were 16 patients with a nadir SpO2 of less than 85%, lowest nadir SpO2 being 63%. An Apnoea Hypo/apnoea Index (AHI) > 5 was found in 2 patients only (AHI 10 and 6), and an Oxygen Desaturation index (ODI) > 5 was found in 3 patients (24, 10 and 6, respectively). 3 patients had more prolonged (> 30 seconds) apnoea with nadir SpO2 81%, 83% and 86%. ESS score and type of surgery did not impact on respiration/oxygenation during the observation period. Conclusions: A low mean SpO2 and episodes of desaturation were not uncommon during the first postoperative night following elective bariatric surgery in patients without history of night time breathing disturbance. AHI and/or ODI of more than 5 were only rarely seen. Night-time respiration monitoring provided seemingly sparse additional information. Further studies are need to assess risk factors and potential impact of the desaturation episodes that occurs during sleep.

Continuous intraoperative epidural infusions affect recovery room length of stay and analgesic requirements: a single-center observational study

PURPOSE

Continuous intraoperative epidural analgesia may improve post-operative pain control and decrease opioid requirements. We investigate the effect of epidural infusion initiation before or after arrival in the post-anesthesia care unit on recovery room duration and post-operative opioid use.

METHODS

We performed a retrospective chart review of abdominal, thoracic and orthopedic surgeries where an epidural catheter was placed prior to surgery at the University of Washington Medical Center during a 24 month period.

RESULTS

Patients whose epidural infusions were started prior to PACU arrival (Group 2: n = 540) exhibited a shorter PACU length of stay (p = .004) and were less likely to receive intravenous opioids in the recovery room (34 vs. 48%; p < .001) compared to patients whose infusions were started after surgery (Group 1: n = 374). Although the highest patient-reported pain scores were lower in Group 2 (5.3 vs. 6.0; p = .030), no differences in the pain scores prior to PACU discharge were observed.

CONCLUSION

Intraoperative continuous epidural infusions decrease PACU LOS as discharge criteria for patient-reported NRS pain scores are met earlier.