Atrial flutter and fibrillation in patients with pulmonary arterial hypertension or chronic thromboembolic pulmonary hypertension in the ASPIRE registry: Comparison of rate versus rhythm control approaches.

BACKGROUND: The development of atrial flutter and fibrillation (AFL/AF) in patients with pre-capillary pulmonary hypertension has been associated with an increased risk of morbidity and mortality. Rate and rhythm control strategies have not been directly compared. METHODS: Eighty-four patients with pulmonary arterial hypertension (PAH) or chronic thromboembolic pulmonary hypertension (CTEPH) with new-onset AFL/AF were identified in the ASPIRE registry. First, baseline characteristics and rates of sinus rhythm (SR) restoration of 3 arrhythmia management strategies (rate control, medical rhythm control and DC cardioversion, DCCV) in an early (2009-13) and later (2014-19) cohort were compared. Longer-term outcomes in patients who achieved SR versus those who did not were then explored. RESULTS: Sixty (71%) patients had AFL and 24 (29%) AF. Eighteen (22%) patients underwent rate control, 22 (26%) medical rhythm control and 44 (52%) DCCV. SR was restored in 33% treated by rate control, 59% medical rhythm control and 95% DCCV (p < 0.001). Restoration of SR was associated with greater improvement in functional class (FC) and Incremental Shuttle Walk Distance (p both <0.05). It also independently predicted superior survival (3-year survival 62% vs 23% in those remaining in AFL/AF, p < 0.0001). In addition, FC III/IV independently predicted higher mortality (HR 2.86, p = 0.007). Right atrial area independently predicted AFL/AF recurrence (OR 1.08, p = 0.01). DCCV was generally well tolerated with no immediate major complications. CONCLUSIONS: Restoration of SR is associated with superior functional improvement and survival in PAH/CTEPH compared with rate control. DCCV is generally safe and is more effective than medical therapy at achieving SR.

Critical care outcomes in patients with pre-existing pulmonary hypertension: insights from the ASPIRE registry.

Pulmonary hypertension (PH) is a life-shortening condition characterised by episodes of decompensation precipitated by factors such as disease progression, arrhythmias and sepsis. Surgery and pregnancy also place additional strain on the right ventricle. Data on critical care management in patients with pre-existing PH are scarce. We conducted a retrospective observational study of a large cohort of patients admitted to the critical care unit of a national referral centre between 2000-2017 to establish acute mortality, evaluate predictors of in-hospital mortality and establish longer term outcomes in survivors to hospital discharge. 242 critical care admissions involving 206 patients were identified. Hospital survival was 59.3%, 94% and 92% for patients admitted for medical, surgical or obstetric reasons, respectively. Medical patients had more severe physiological and laboratory perturbations than patients admitted following surgical or obstetric interventions. Higher APACHE II (Acute Physiology and Chronic Health Evaluation) score, age and lactate, and lower oxygen saturation measure by pulse oximetry/inspiratory oxygen fraction (S pO2 /F iO2 ) ratio, platelet count and sodium level were identified as independent predictors of hospital mortality. An exploratory risk score, OPALS (oxygen (S pO2 /F iO2 ) ≤185; platelets ≤196×109·L-1; age ≥37.5 years; lactate ≥2.45 mmol·L-1; sodium ≤130.5 mmol·L-1), identified medical patients at increasing risk of hospital mortality. One (11%) out of nine patients who were invasively ventilated for medical decompensation and 50% of patients receiving renal replacement therapy left hospital alive. There was no significant difference in exercise capacity or functional class between follow-up and pre-admission in patients who survived to discharge. These data have clinical utility in guiding critical care management of patients with known PH. The exploratory OPALS score requires validation.

Metformin-associated lactic acidosis: reinforcing learning points.

Metformin-associated lactic acidosis (MALA) carries a high mortality rate. It is seen in patients with type 2 diabetes on metformin or patients who attempt suicide with metformin overdose. We present the case of a man in his early 20s with type 2 diabetes, hypertension and hypothyroidism who presented with agitation, abdominal pain and vomiting after ingesting 50-60 g of metformin; he developed severe lactic acidosis (blood pH 6.93, bicarbonate 7.8 mEq/L, lactate 28.0 mEq/L). He was managed with intravenous 8.4% bicarbonate infusion and continuous venovenous haemodiafiltration. He also developed acute renal failure (ARF) requiring intermittent haemodialysis and continuous haemodiafiltration. MALA is uncommon and causes changes in different vital organs and even death. The primary goals of therapy are restoration of acid-base status and removal of metformin. Early renal replacement therapy for ARF can result in rapid reversal of the acidosis and good recovery, even with levels of lactate normally considered to be incompatible with survival.

Use of intravenous immunoglobulin therapy in the treatment of septic shock, in particular severe invasive group A streptococcal disease.

Group A streptococcus (GAS) is a ß-hemolytic bacterium often found in the throat and skin. The two most severe clinical manifestations of GAS are streptococcal toxic shock syndrome and necrotizing fasciitis. Intravenous immunoglobulin (IVIg) is a gamma globulin made from purified pooled plasma of thousands of donors, consisting mainly of IgG. We report the case of a 40-year-old man admitted after 2 days of vomiting and severe right-sided chest pain. He was hypotensive with a sinus tachycardia, pyrexial, and vasodilated. The only other positive finding was a swollen and erythematous chest wall. Muscle layer biopsies and blood cultures soon grew extensive GAS, and an initial diagnosis of necrotizing fasciitis was made. The clinical syndrome was of severe septic shock secondary to invasive GAS. The patient quickly deteriorated with a worsening metabolic acidosis. Despite maximal intensive care therapy including fluids, vasoactive agents, and also activated protein C, the patient continued to remain profoundly hypotensive. A decision was made to commence IVIg, with the aim of immunomodulation of the inflammatory cascade seen in sepsis. Over the next 24 hours the patient improved, was extubated 3 days later, and subsequently discharged from hospital after 2 weeks. Although the evidence for the use of IVIg in severe invasive GAS disease is limited, we feel that on reviewing the available literature its use in this case was justified. The limited worldwide supply and high costs, together with a limited evidence base, warrant restricting its use to cases in which conventional therapy has failed. The literature for use of intravenous immunoglobulin in invasive GAS infection will be reviewed in this article.

Catheter access for hemodialysis defines higher mortality in late-presenting dialysis patients.

BACKGROUND: This study explores the relationship between mortality and late presentation for dialysis, focusing on the role of catheter access for hemodialysis (HD). METHODS: We analyzed data from a cohort of 286 patients commencing dialysis in 2000-2001. Survival and factors associated with death were analyzed by univariate and multivariate analysis. Dialysis access was considered in three groups: HD-AVF, HD-Catheter, and peritoneal dialysis (PD). Late referral (LR) was defined as first review by a nephrologist less than 90 days before dialysis. RESULTS: One-year mortality was low at 10.1%. HD-Catheter patients were older (p < 0.001), more hypoalbuminemic (p < 0.001), more anemic (p = 0.005), and more likely to be LR (p < 0.001). HD-Catheter patients did not have significantly higher comorbidity (p = 0.128). HD-Catheter was strongly associated with late presentation (75% LR vs. 28% early referral, p < 0.001). Factors associated with death by univariate analysis included age (p < 0.0001), comorbidity (p < 0.0001), HD-Catheter (p < 0.0001), LR (p = 0.0001), hypoalbuminemia (p = 0.0011), and diabetes (p = 0.02). When corrected for these factors, HD-Catheter was associated with death (HR 2.226, 95% CI 1.314-3.772, p = 0.003) but LR was not (p = 0.38). CONCLUSIONS: A predominant feature of LR that predicts mortality is the use of catheter access for HD. This may be modifiable in those LR patients who do not present as uremic emergencies.