Emerging role of complement in COVID-19 and other respiratory virus diseases.

The complement system, a key component of innate immunity, provides the first line of defense against bacterial infection; however, the COVID-19 pandemic has revealed that it may also engender severe complications in the context of viral respiratory disease. Here, we review the mechanisms of complement activation and regulation and explore their roles in both protecting against infection and exacerbating disease. We discuss emerging evidence related to complement-targeted therapeutics in COVID-19 and compare the role of the complement in other respiratory viral diseases like influenza and respiratory syncytial virus. We review recent mechanistic studies and animal models that can be used for further investigation. Novel knockout studies are proposed to better understand the nuances of the activation of the complement system in respiratory viral diseases.

Retrospective Analysis of Perioperative Dexmedetomidine Use in Retina Surgeries: Impact on Postanesthesia Care.

BACKGROUND AND OBJECTIVE: Dexmedetomidine (Precedex®) has been linked to depressive hemodynamic effects and increased length of stay in the post-anesthesia care unit (PACU) when used in ambulatory phacoemulsification procedures. We aimed to determine the prevalence and impact of dexmedetomidine use during ambulatory vitreoretinal procedures. PATIENTS AND METHODS: This retrospective cohort study involved 9,666 adult vitrectomies. Cases were divided into groups by anesthesia type: general anesthesia (GA) and monitored anesthesia care (MAC). For each group, various factors were compared between those who did and did not receive dexmedetomidine. Chi-squared and t tests were used for comparisons. RESULTS: Changes in mean arterial pressure in the MAC group were -1.69 ± 0.23 mmHg for no dexmedetomidine patients and -6.31 ± 0.39 mmHg for dexmedetomidine patients (P < 0.01). In the GA group, mean arterial pressure was -6.1 ± 0.35 mmHg for no dexmedetomidine patients and -11.18 ± 0.88 mmHg for dexmedetomidine patients (P < 0.01). PACU Phase II time in the MAC group was 36.93 ± 0.37 minutes and 40.67 ± 0.86 minutes for no dexmedetomidine and dexmedetomidine patients, respectively (P < 0.01). In the GA group, PACU Phase II time was 58.63 ± 0.95 minutes and 65.19 ± 2.38 minutes for no dexmedetomidine and dexmedetomidine patients, respectively (P < 0.01). CONCLUSIONS: Dexmedetomidine use in vitrectomies was associated with significant PACU delays. These delays may stem from adverse hemodynamic effects. [Ophthalmic Surg Lasers Imaging Retina 2024;55:86-91.].

Postoperative and postdischarge nausea and vomiting following ambulatory eye, head, and neck surgeries: a retrospective cohort study comparing incidence and associated factors.

BACKGROUND: Ambulatory surgery is often followed by the development of nausea and/or vomiting (N/V). Although risk factors for postoperative nausea and vomiting (PONV) are frequently discussed, the distinction between PONV and postdischarge nausea and vomiting (PDNV) is unclear. This is especially troublesome given the potential consequences of postdischarge nausea and vomiting (PDNV), which include major discomfort and hospital readmission. METHODS: In this retrospective cohort study, data from 10,231 adult patients undergoing ambulatory ophthalmology or otolaryngology procedures with general anesthesia were collected and analyzed. Binary and multinomial logistic regression was used to assess the association between patient and anesthetic characteristics (including age, body mass index (BMI), American Society of Anesthesiologists Physical Status (ASA P/S) classification, current smoker status, and intra- and postoperative opioid usage) and the odds ratios of experiencing only PDNV, only PONV, or both PONV and PDNV, as compared to not experiencing N/V at all. RESULTS: We found that 17.8% of all patients developed N/V (PONV and/or PDNV). Patients who experienced PONV had a 2.79 (95% confidence interval 2.24-3.46) times greater risk of reporting PDNV. Binary logistic regression found that younger age, opioid use, and female sex were associated with an increased likelihood of experiencing any N/V. Increased use of nitrous oxide and a higher ASA P/S class was associated with elevated likelihood of PONV, but not PDNV or PONV plus PDNV. CONCLUSIONS: Patients experiencing N/V in the PACU are observed to develop PDNV disproportionately by a factor of 2.79. The patients have distinct predictors, indicating important opportunities for care improvements beyond current guidelines.

Post-anesthesia care unit desaturation in adult deep extubation patients.

OBJECTIVE: Deep extubation refers to endotracheal extubation performed while a patient is deeply anesthetized and without airway reflexes. After deep extubation, patients are sent to the post-anesthesia care unit (PACU) to recover, an area with notably different management and staffing than the operating room (OR). One of the most frequent and concerning complications to occur in the PACU is hypoxemia. As such, this study seeks to evaluate the incidence of desaturation, defined by SpO2 < 90% for longer than 10 s, in the PACU following deep extubation. Additionally, we hope to assess the consequence of desaturation on perioperative workflow by comparing PACU recovery times. RESULTS: Following deep extubation, 4.3% of patients (13/300) experienced desaturation in the PACU. Every episode was notably minor, with patients reverting to normal saturation levels within a minute. Of the 26 case factors assessed, 24 had no significant association desaturation in the PACU, including the amount of time spent in the PACU. History of asthma was the only statistically significant factor found to be positively associated with desaturation. We find that PACU desaturation episodes following deep extubation are rare. Our findings suggest that deep extubation is a viable and safe option for patients without significant respiratory tract pathology.

Incidence of airway complications associated with deep extubation in adults.

BACKGROUND: Endotracheal extubation is the most crucial step during emergence from general anesthesia and is usually carried out when patients are awake with return of airway reflexes. Alternatively, extubations can also be accomplished while patients are deeply anesthetized, a technique known as "deep extubation", in order to provide a "smooth" emergence from anesthesia. Deep extubation is seldomly performed in adults, even in appropriate circumstances, likely due to concerns for potential respiratory complications and limited research supporting its safety. It is in this context that we designed our prospective study to understand the factors that contribute to the success or failure of deep extubation in adults. METHODS: In this prospective observational study, 300 patients, age ≥ 18, American Society of Anesthesiologists Physical Status (ASA PS) Classification I - III, who underwent head-and-neck and ocular surgeries. Patients' demographic, comorbidity, airway assessment, O2 saturation, end tidal CO2 levels, time to exit OR, time to eye opening, and respiratory complications after deep extubation in the OR were analyzed. RESULTS: Forty (13%) out of 300 patients had at least one complication in the OR, as defined by persistent coughing, desaturation SpO2 < 90% for longer than 10s, laryngospasm, stridor, bronchospasm and reintubation. When comparing the complication group to the no complication group, the patients in the complication group had significantly higher BMI (30 vs 26), lower O2 saturation pre and post extubation, and longer time from end of surgery to out of OR (p < 0.05). CONCLUSIONS: The complication rate during deep extubation in adults was relatively low compared to published reports in the literature and all easily reversible. BMI is possibly an important determinant in the success of deep extubation.