Abstract Background Rates of penicillin allergy mislabeling (PAM) are prevalent and lead to suboptimal antibiotic selection. However, data regarding PAM are lacking for people with HIV (PWH). We aimed to characterize the penicillin allergy labels for PWH at the University of California, San Diego’s (UCSD) HIV primary care clinic, evaluate the impact of penicillin allergy labels on treatment choice for syphilis and gonorrhea, and implement a quality improvement project to address PAM. Methods We conducted a cross-sectional study of PWH with a penicillin allergy label in their medical record who were seen in our clinic between 2018 and 2022. We collected demographic information, type of allergic reaction listed, whether patients tolerated other beta-lactam antibiotics, whether patients were referred for formal Allergy consultation, and, where relevant, what treatment they received for syphilis and/or gonorrhea. Results Among the 4,702 people with HIV receiving care in our clinic between 2018 and 2022, 427 (9.1%) had a penicillin allergy label in the medical record. This cohort reflected the demographics of the general clinic population (Table 1). Even though the majority of allergic reactions (327, 77%) were labeled as IgE-mediated, 282 (66%) patients tolerated another beta-lactam antibiotic (Table 2). Referrals to Allergy Clinic were rare (52, 12%). The majority of patients with syphilis (91/140, 65%) received 2nd line therapy with doxycycline. However, most patients with gonorrhea (65/88, 74%) were treated with a preferred ceftriaxone-based regimen. When relevant, we updated penicillin labels for 209/268 (77.9%) patients to indicate that they had tolerated other beta-lactam antibiotics and created a tiered referral process to prioritize the highest-risk patients for Allergy Clinic referral (Figure 1). Conclusion Penicillin allergy labels were prevalent in our cohort of PWH and often resulted in receiving 2nd line therapy for treatment of syphilis. We updated allergy labels for a substantial number of patients and created a triage system to refer patients to Allergy clinic for further testing based on risk in order to decrease PAM. Disclosures All Authors: No reported disclosures.

Purpose

Patients with obesity and elevated serum bicarbonate suggesting obesity hypoventilation syndrome (OHS) undergoing bariatric surgery may represent a unique subgroup. Information regarding surgical outcomes in this population remains limited. We sought to test the hypothesis that an elevated bicarbonate would be an important predictor of perioperative complications (i.e., length of hospital stay) and postsurgical outcomes (i.e., weight loss at 1 year).

Materials and methods

Consecutive patients undergoing bariatric surgery between January 2015 and December 2018 were included. Patients with a preoperative serum bicarbonate ≥ 27 mEq/L were classified as suspected OHS.

Results

Of 297 patients, the prevalence of suspected OHS based on an elevated bicarbonate was 19.5% (95% CI: 15.3 to 24.6%). Length of hospital stay was similar in the suspected OHS and non-OHS control group (1.50 vs 1.49 days, P = 0.98). The achieved weight loss from peak preoperative weight to 1 year post-surgery was less in the suspected OHS vs the control group (4.2% [95% CI 1.6 to 6.8]; P = 0.002).

Conclusion

Patients with serum bicarbonate ≥ 27 mEq/L as a surrogate marker for OHS experienced weight loss that was significantly less than their normal serum bicarbonate counterparts, but still achieved weight loss deemed clinically important by current guidelines. We observed no significant difference in length of hospital stay at time of surgery.

Purpose

Obstructive sleep apnea (OSA)-related pulmonary hypertension (PH) can often be reversed with treatment of OSA via continuous positive airway pressure. We hypothesized that treatment of OSA would be associated with a greater improvement in exercise capacity (EC) with cardiac rehabilitation (CR), especially in patients with PH as compared with those who are untreated.

Methods

We reviewed medical records of 315 consecutive patients who participated in CR. Pulmonary hypertension status was assessed on the basis of peak tricuspid regurgitant velocity (>2.8 m/sec) on pre-CR echocardiograms. The OSA status (no, untreated, or treated OSA) was determined on the basis of results from sleep studies, continuous positive airway pressure device data, and physician notes. Exercise capacity was assessed by measuring metabolic equivalents (METs) using a treadmill stress test before and after CR.

Results

We included 290 patients who participated in CR with available echocardiographic data: 44 (15%) had PH, and 102 (35%) had known OSA (30 treated and 72 untreated). Patients with OSA versus those with no OSA were more likely to have PH ( P = .06). Patients with PH versus no-PH were associated with significantly lower baseline METs in crude and adjusted analyses ( P ≤. 004). The PH and OSA status in isolation were not associated with changes in METs ( P > .2) with CR. There was a significant interaction between OSA treatment and PH in crude and adjusted analyses ( P ≤.01): treatment vs no treatment of OSA was associated with a clinically and statistically greater improvement in METs in patients who participated in CR with but not without PH.

Conclusion

Baseline PH was associated with decreased baseline EC but did not attenuate CR-related improvements in METs. However, in the subset of OSA patients with PH, OSA therapy was associated with improved EC after CR.