Case report of an acute myocardial infarction after high-dose recreational nitrous oxide use: a consequence of hyperhomocysteinaemia?

Background: Nitrous oxide (NO, laughing gas) is increasingly used as a recreational drug and is presumed relatively safe and innocent. It is often being used in combination with other substances, such as cannabis. Case summary: A young adult attended the emergency room because of chest pain after recreational use of very high-dose nitrous oxide in combination with cannabis. Electrocardiography demonstrated ST-elevation in the anterior leads. Coronary angiography showed thrombus in the proximal and thrombotic occlusion of the distal left anterior descending coronary artery for which primary percutaneous coronary intervention was attempted. Thrombus aspiration was unsuccessful and the patient was further treated with a glycoprotein IIb/IIIa in addition to dual platelet therapy. Blood results showed low vitamin B12 and folic acid status with concomitant hyperhomocysteinaemia, a known cause of hypercoagulation. Transthoracic echocardiogram showed a moderately reduced left ventricular ejection fraction (LVEF). Three months later, an improvement in LVEF and no recurrent angina or symptoms of heart failure were noticed. Discussion: We report a case of acute myocardial infarction secondary to very high-dose nitrous oxide abuse in combination with cannabis and possible hypoxia. We propose that severe hyperhomocysteinaemia secondary to nitrous oxide-induced vitamin B12 deficiency together with the vasoconstrictive effects of cannabis might pose a seriously increased risk for intracoronary, among others, thrombus formation. In conclusion, we contest the safety and innocence of recreational nitrous oxide (ab)use, notably in the context of other factors increasing the risk of coagulation

The effect of the timing of invasive management on cardiac function in patients with nste-acs, insights from the optima-2 randomized controlled trial

The timing of coronary angiography in patients with non-ST-elevation acute coronary syndrome (NSTE-ACS) remains a matter of debate. The relationship between the timing of invasive management and left ventricular function (LVF) is largely unknown. The An Immediate or Early Invasive Strategy in Non-ST-Elevation Acute Coronary Syndrome trial (OPTIMA-2) was a randomized controlled prospective open-label multicenter trial that randomized 249 NSTE-ACS patients to either an immediate (<3 h) invasive treatment strategy or an early strategy (12–24 h). Patients were pre-treated with a combination of aspirin, ticagrelor and fondaparinux. The aim of this prespecified sub-analysis was to assess (the recovery of) left ventricular function by analysing echocardiography data obtained <72 h after admission and at 30-day follow-up, for patients with a confirmed diagnosis of acute coronary syndrome. LVF was determined using ejection fraction (EF) and global longitudinal strain (GLS). Inter-observer variability was tested. No difference in the recovery of EF was found between an immediate and early strategy if the follow-up echocardiograms were compared to baseline: 2.5% (standard deviation (SD): 7.9) and 3.3% (SD: 8.5), p = 0.51, nor was there any difference in GLS recovery between the study groups: −0.8% (SD: 2.5) vs. −0.7% (SD 2.8) p = 0.82. If baseline and follow-up echocardiograms were compared, there was a similar but significant improvement in both EF and GLS in both separate study groups. An immediate invasive strategy in NSTE-ACS patients did not result in an improved left ventricular EF or GLS recovery compared with an early strategy

Nitrous oxide abuse leading to extreme homocysteine levels and thrombosis in young adults: a case series

BACKGROUND: Neurologic complications from recreational use of nitrous oxide (N2O), which are attributed to vitamin B12 deficiency, have been well documented. With increasing dosages and frequency of N2O use, an additional association with thromboembolisms is becoming apparent. OBJECTIVES: To assess thrombotic complications of recreational N2O use. METHODS: All medical charts at the largest hospital in Amsterdam were searched for N2O use and subsequent neurologic and/or thrombotic events. For patients with thrombotic events, we extracted data on the risk factors for arterial and venous thrombosis as well as serum vitamin B12 and homocysteine concentrations. RESULTS: Between January 2015 and May 2021, 326 patients who reported recreational use of N2O were identified; of these, 17 (5%) patients presented with severe thrombotic events associated with N2O (71% men; median age, 26 years [range, 18-53 years]), 5 patients presented with arterial thrombosis (3 with acute coronary syndrome, 1 with femoral artery thrombosis, and 1 with middle cerebral artery thrombus), and 12 patients presented with venous thromboembolisms (10 with pulmonary embolisms, 1 with portal vein thrombosis and 1 with cerebral vein thrombosis). Additionally, homocysteine were concentrations severely increased (median, 125 μmol/L [range, 22-253 μmol/L]; reference, <15 μmol/L). Patients reported use of 400 to 6000 g (ie, 50-750 balloons) of N2O in 1 day. Fifty percent of these patients had experienced neurologic symptoms before the thrombotic event. CONCLUSION: We describe an alarming incidence of serious thrombotic events among young adults after excessive recreational use of N2O, accompanied by extremely high homocysteine concentrations. The upward trend in the recreational use of N2O warrants more awareness of its dangers among both users and medical professionals. Furthermore, these findings could reopen the discussion on possible associations between hyperhomocysteinemia and thrombosis mediated through N2O

The HYSTER study: the effect of intracervically administered terlipressin versus placebo on the number of gaseous emboli and fluid intravasation during hysteroscopic surgery: study protocol for a randomized controlled clinical trial

Abstract Background Transcervical resection of myoma or endometrium is a safe, hysteroscopic, minimally invasive procedure. However, intravasation of distension fluid is a common phenomenon during these procedures. In a previous study we observed venous gas emboli in almost every patient. The severity of hysteroscopic-derived embolization has been shown to be correlated to the amount of intravasation. In addition, paradoxical gas embolism, which is potentially dangerous, was observed in several patients. Studies have shown a reduction of intravasation by using intracervically administered vasopressin during hysteroscopy. We think that its analog, terlipressin, should have the same effect. In our previous research we observed more gaseous emboli as intravasation increased. Whether or not the insertion of intracervically administered terlipressin leads to a lower incidence and severity of gas embolism is unknown. We hypothesize that intracervically administered terlipressin leads to a reduction of intravasation with a lower incidence and severity of gas embolism. Terlipressin may be of benefit during hysteroscopic surgery. Methods/design Forty-eight patients (ASA 1 or 2) scheduled for transcervical resection of large, types 1–2 myoma or extensive endometrium resection will be included. In a double-blind fashion patients will be randomized 1:1 according to surgical treatment using either intracervically administered terlipressin or placebo. Transesophageal echocardiography will be used to observe and record embolic events. A pre- and post-procedure venous blood sample will be taken to calculate intravasation based on hemodilution. Our primary endpoint will be how terlipressin influences the severity of embolic events. Secondary endpoints include the effect of terlipressin on the amount of intravasation and on hemodynamic parameters. Discussion If terlipressin does indeed reduce the number of gaseous emboli and intravasation occurring during hysteroscopic surgery, it would be a simple method to minimize potential adverse events. It also allows for prolonged operating time before the threshold of intravasation is reached, thereby reducing the need for a second operation. Trial registration Nederlands Trial Register (Dutch Trial Register), ID: NTR5577. Registered retrospectively on 18 December 2015

Gas embolism during hysteroscopic surgery using bipolar or monopolar diathermia: a randomized controlled trial

OBJECTIVE: The objective of the study was to determine the incidence and amount of gas embolism during hysteroscopic surgery using either monopolar or bipolar diathermia and to investigate the relationship between the severity of gas embolism and the amount of intravasation of distension fluid. STUDY DESIGN: This was a randomized, observer-blinded trial. Fifty patients, scheduled for hysteroscopic surgery, were assigned to either monopolar or bipolar diathermia. Transesophageal echocardiography was used to detect and classify gas embolism (grade 0-IV). Intravasation of distension fluid was measured. RESULTS: Venous gas embolism was observed in all but 1 patient. A higher incidence of more extensive (grade IV) was seen during bipolar diathermia (42% vs 13%; P = .031). Paradoxical embolism was observed in 2 patients. When intravasation exceeded 1000 mL, significantly more grade IV venous gas embolism was seen (P = .049). CONCLUSION: During hysteroscopic surgery, gas embolism was equally observed irrespective of the type of diathermia. However, more extensive embolism was observed when intravasation of distension fluid exceeded 1 L. These results question the acceptance of up to 2500 mL intravasation of distension fluid if bipolar diathermia is use

One-year mortality in NSTEMI patients is unaffected by timing of PCI within the first week of admission: Results of a real-world cohort analysis

Objectives: We aimed to explore the impact of time to percutaneous coronary intervention (PCI) (T2P) on 1-year mortality in non-ST-elevation myocardial infarction (NSTEMI) patients. Background: The current guidelines recommend an early invasive strategy for NSTEMI patients. However, impact of an early invasive strategy on mortality is a matter of debate. For that reason, real world data are of great value to determine the optimal treatment window. Methods: This retrospective single center cohort study was performed in a high-volume PCI center in Amsterdam, The Netherlands. Intermediate- and high-risk NSTEMI patients undergoing PCI were included. The main discriminant was timing of PCI after admission (T2P), stratified according to different time windows (7 days). We analyzed 1-year mortality and the time distribution of overall survival. Results: In total, 848 patients treated between January 1, 2016 and January 1, 2018 were included in the analysis. T2P was 7 days in 236 patients. The mean GRACE-risk score was 127.1 (SD 28.7), 130.0 (33.1), 133.8 (32.1), and 148.7 (34.6) respectively, p = 7 days (OR = 3.20; 95% CI = 1.06–9.68). Conclusions: In an unselected cohort of patients with NSTEMI, treatment by PCI 7 days after admission resulted in worse outcome