Safety of hyperbaric oxygen therapy in patients with heart failure: A retrospective cohort study.

BACKGROUND: Hyperbaric oxygen therapy (HBOT) has several hemodynamic effects including increases in afterload (due to vasoconstriction) and decreases in cardiac output. This, along with rare reports of pulmonary edema during emergency treatment, has led providers to consider HBOT relatively contraindicated in patients with reduced left ventricular ejection fraction (LVEF). However, there is limited evidence regarding the safety of elective HBOT in patients with heart failure (HF), and no existing reports of complications among patients with HF and preserved LVEF. We aimed to retrospectively review patients with preexisting diagnoses of HF who underwent elective HBOT, to analyze HBOT-related acute HF complications. METHODS: Research Ethics Board approvals were received to retrospectively review patient charts. Patients with a history of HF with either preserved ejection fraction (HFpEF), mid-range ejection fraction (HFmEF), or reduced ejection fraction (HFrEF) who underwent elective HBOT at two Hyperbaric Centers (Toronto General Hospital, Rouge Valley Hyperbaric Medical Centre) between June 2018 and December 2020 were reviewed. RESULTS: Twenty-three patients with a history of HF underwent HBOT, completing an average of 39 (range 6-62) consecutive sessions at 2.0 atmospheres absolute (ATA) (n = 11) or at 2.4 ATA (n = 12); only two patients received fewer than 10 sessions. Thirteen patients had HFpEF (mean LVEF 55 ± 7%), and seven patients had HFrEF (mean LVEF 35 ± 8%) as well as concomitantly decreased right ventricle function (n = 5), moderate/severe tricuspid regurgitation (n = 3), or pulmonary hypertension (n = 5). The remaining three patients had HFmEF (mean LVEF 44 ± 4%). All but one patient was receiving fluid balance therapy either with loop diuretics or dialysis. Twenty-one patients completed HBOT without complications. We observed symptoms consistent with HBOT-related HF exacerbation in two patients. One patient with HFrEF (LVEF 24%) developed dyspnea attributed to pulmonary edema after the fourth treatment, and later admitted to voluntarily holding his diuretics before the session. He was managed with increased oral diuretics as an outpatient, and ultimately completed a course of 33 HBOT sessions uneventfully. Another patient with HFpEF (LVEF 64%) developed dyspnea and desaturation after six sessions, requiring hospital admission. Acute coronary ischemia and pulmonary embolism were ruled out, and an elevated BNP and normal LVEF on echocardiogram confirmed a diagnosis of pulmonary edema in the context of HFpEF. Symptoms subsided after diuretic treatment and the patient was discharged home in stable condition, but elected not to resume HBOT. CONCLUSIONS: Patients with HF, including HFpEF, may develop HF symptoms during HBOT and warrant ongoing surveillance. However, these patients can receive HBOT safely after optimization of HF therapy and fluid restriction.

The unknown known: non-cardiogenic pulmonary edema in amlodipine poisoning, a cohort study.

Context: Amlodipine is the most common calcium channel blocker (CCB) on the Swedish market, and poison center (PC) consultations for amlodipine overdoses are increasing. The clinical picture is dominated by vasodilation with relative preservation of cardiac function. CCBs selectively dilate vessels on the afferent side of the capillary network which, in states of preserved or increased blood flow may lead to edema formation, including non-cardiogenic pulmonary edema (NCPE). This complication has been considered rare in CCB poisoning. In this cohort study of nineteen amlodipine poisonings with high amlodipine blood levels, the incidence and clinical significance of NCPE in severe amlodipine poisoning are explored.Methods: During 2017-2018 the Swedish PC prospectively encouraged the gathering of blood samples in amlodipine poisonings with symptoms requiring treatment with inotropes or vasopressors. Samples were sent by mail to the Forensic Toxicology Division at the Swedish National Board of Forensic Medicine for screening and quantification of relevant toxicants. Patients with blood amlodipine levels >0.25 µg/mL were included in a cohort whose case details were gathered from medical records and PC-case notes with a special focus on signs of NCPE.Results: Nineteen patients met the blood amlodipine inclusion criteria. Four (21%) died and one patient was treated with VA-ECMO. Nine patients developed NCPE defined as a need for positive pressure ventilation (PPV) while having an echocardiographically normal left ventricular function.Conclusion: In this prospective cohort study of consecutive and analytically confirmed significant amlodipine poisonings NCPE was a common finding occurring in 47% of the whole cohort and in 64% of patients who did not go on to develop complete hemodynamic collapse.

HSP-70-Mediated Hyperbaric Oxygen Reduces Brain and Pulmonary Edema and Cognitive Deficits in Rats in a Simulated High-Altitude Exposure.

High-mountain sickness is characterized by brain and pulmonary edema and cognitive deficits. The definition can be fulfilled by a rat model of high-altitude exposure (HAE) used in the present study. This study aimed to investigate the protective effect of hyperbaric oxygen therapy (HBO2T) and to determine the underlying mechanisms. Rats were subjected to an HAE (9.7% O2 at 0.47 absolute atmosphere of 6,000 m for 3 days). Immediately after termination of HAE, rats were treated with HBO2T (100% O2 at 2.0 absolute atmosphere for 1 hour per day for 5 consecutive days) or non-HBO2T (21% O2 at 1.0 absolute atmosphere for 1 hour per day for 5 consecutive days). As compared to non-HAE+non-HBO2T controls, the HAE+non-HBO2T rats exhibited brain edema and resulted in cognitive deficits, reduced food and water consumption, body weight loss, increased cerebral inflammation and oxidative stress, and pulmonary edema. HBO2T increased expression of both hippocampus and lung heat shock protein (HSP-70) and also reversed the HAE-induced brain and pulmonary edema, cognitive deficits, reduced food and water consumption, body weight loss, and brain inflammation and oxidative stress. Decreasing the overexpression of HSP-70 in both hippocampus and lung tissues with HSP-70 antibodies significantly attenuated the beneficial effects exerted by HBO2T in HAE rats. Our data provide in vivo evidence that HBO2T works on a remodeling of brain/lung to exert a protective effect against simulated high-mountain sickness via enhancing HSP-70 expression in HAE rats.

A diver with immersion pulmonary oedema and prolonged respiratory symptoms.

Immersion pulmonary oedema (IPE) is particularly associated with an excessive reaction to exercise and/or cold stress. IPE usually resolves without recompression therapy within a day or two. Herein we report a diver diagnosed with IPE, in whom symptoms persisted for five days. A 58-year-old man presented with sudden onset of dyspnoea, cough and haemoptysis after surfacing. He was an experienced diving instructor with a history of moderate mitral valve regurgitation. While IPE was diagnosed and oxygen administered, respiratory symptoms deteriorated, and serum C-reactive protein elevated. No evidence of infection was seen. Three hyperbaric oxygen treatments were given on the basis of suspected decompression sickness, and symptoms subsequently resolved. The recently diagnosed mitral valve regurgitation and inflammatory response were considered to have contributed to the prolongation of symptoms.

Fatal Pulmonary Edema in a Child After Jellyfish Stings in Korea.

Jellyfish have been increasing at a global scale in recent years. These blooms not only have deleterious effects on marine ecosystems, they also increase the risk of jellyfish stings and accompanying envenomation. Here, we report a fatal case of pulmonary edema caused by jellyfish envenomation in a child in Korea. The patient died 4 h after envenomation despite cardiopulmonary resuscitation. Nemopilema nomurai was the suspected species of jellyfish encountered by the patient, although we are unable to confirm this. With this case report, we aim to inform on the serious issue of toxicity associated with jellyfish species that bloom mainly along Korean, east Chinese, and Japanese shores and to discuss appropriate first aid methods in case of jellyfish stings.

Severe beta blocker and calcium channel blocker overdose: Role of high dose insulin.

A 54-year-old female presented after taking an overdose of an unknown amount of hydrochlorothiazide, doxazocin, atenolol and amlodipine. She was initially refractory to treatment with conventional therapy (intravenous fluids, activated charcoal, glucagon 5 mg followed with glucagon drip, calcium gluconate 10%, and atropine). Furthermore, insulin at 4 U/kg was not effective in improving her hemodynamics. Shortly after high dose insulin was achieved with 10 U/kg, there was dramatic improvement in hemodynamics resulting in three of five vasopressors being weaned off in 8 h. She was subsequently off all vasopressors after six additional hours. The role of high dose insulin has been documented in prior cases, however it is generally recommended after other conventional therapies have failed. However, there are other reports that suggest it as initial therapy. Our patient failed conventional therapies and responded well only with maximum dose of insulin. Physicians should consider high dose insulin early in severe beta blocker or calcium channel blocker overdose for improvement in hemodynamics. This leads to early discontinuation of vasopressors. It is important that emergency physicians be aware of the beneficial effects of high dose insulin when initiated early as opposed to waiting for conventional therapy to fail; as these patients often present first to the emergency department. Early initiation in the emergency department can be beneficial in these patients.

Cardiovascular Abnormalities in Carbon Monoxide Poisoning.

Acute carbon monoxide (CO) poisoning is the most common cause of poisoning and poisoning-related death in the United States. It manifests as broad spectrum of symptoms ranging from mild headache, nausea, and fatigue to dizziness, syncope, coma, seizures resulting in cardiovascular collapse, respiratory failure, and death. Cardiovascular complications of CO poisoning has been well reported and include myocardial stunning, left ventricular dysfunction, pulmonary edema, and arrhythmias. Acute myocardial ischemia has also been reported from increased thrombogenicity due to CO poisoning. Myocardial toxicity from CO exposure is associated with increased short-term and long-term mortality. Carboxyhemoglobin (COHb) levels do not correlate well with the clinical severity of CO poisoning. Supplemental oxygen remains the cornerstone of therapy for CO poisoning. Hyperbaric oxygen therapy increases CO elimination and has been used with wide variability in patients with evidence of neurological and myocardial injury from CO poisoning, but its benefit in limiting or reversing cardiac injury is unknown. We present a comprehensive review of literature on cardiovascular manifestations of CO poisoning and propose a diagnostic algorithm for managing patients with CO poisoning.

[Treatment by bloodletting in the past and present].

INTRODUCTION: Therapeutic bloodletting has been practiced at least 3000 years as one of the most frequent methods of treatment in general, whose value was not questioned until the 19th century, when it was gradually abandoned in Western medicine, while it is still practiced in Arabic and traditional Chinese medicine. CONTENT: In modern medicine bloodletting is practiced for very few indications. Its concept was modeled on the process of menstrual bleeding, for which it was believed to"purge women of bad humours. "Thus, bloodletting was based more on the belief that it helps in the reestablishment of proper balance of body "humours" than on the opinion that it serves to remove excessive amount of blood as well as to remove toxic "pneumas" that accumulate in human body. It was indicated for almost all known diseases, even in the presence of severe anemia. Bloodletting was carried out by scarification with cupping, by phlebotomies (venesections), rarely by arteriotomies, using specific instruments called lancets, as well as leeches. In different periods of history bloodletting was practiced by priests, doctors, barbers, and even by amateurs. In most cases, between one half of liter and two liters of blood used to be removed. Bloodletting was harmful to vast majority of patients and in some of them it is believed that it was either fatal or that it strongly contributed to such outcome. In the 20th century in the "Western"medicine bloodletting was still practiced in the treatment of hypertension and in severe cardiac insufficiency and pulmonary edema, but these indications were later abandoned. CONCLUSION: Bloodletting is still indicated for a few indications such as polycythemia, haemochromatosis, and porphyria cutanea tarda, while leeches are still used in plastic surgery, replantation and other reconstructive surgery, and very rarely for other specific indications.

Wilderness Medical Society practice guidelines for the prevention and treatment of acute altitude illness: 2014 update.

To provide guidance to clinicians about best practices, the Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for prevention and treatment of acute mountain sickness, high altitude cerebral edema, and high altitude pulmonary edema. These guidelines present the main prophylactic and therapeutic modalities for each disorder and provide recommendations about their role in disease management. Recommendations are graded based on the quality of supporting evidence and balance between the benefits and risks/burdens according to criteria put forth by the American College of Chest Physicians. The guidelines also provide suggested approaches to prevention and management of each disorder that incorporate these recommendations. This is an updated version of the original WMS Consensus Guidelines for the Prevention and Treatment of Acute Altitude Illness published in Wilderness & Environmental Medicine 2010;21(2):146-155.

[Late pneumomediastinum revealed by acute pulmonary edema in hemodialysis]. / Pneumomédiastin tardif révélé par un œdème aigu du poumon en hémodialyse.

Central venous catheterization occupies an important place in the treatment of end stage renal disease pending the creation of an arteriovenous fistula. However, this procedure is not devoid of complications. We report a case of late pneumomediastinum revealed by an acute pulmonary edema in a young patient on hemodialysis, and we discuss its characteristics.

Wilderness Medical Society consensus guidelines for the prevention and treatment of acute altitude illness.

To provide guidance to clinicians about best practices, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the prevention and treatment of acute mountain sickness (AMS), high altitude cerebral edema (HACE), and high altitude pulmonary edema (HAPE). These guidelines present the main prophylactic and therapeutic modalities for each disorder and provide recommendations for their roles in disease management. Recommendations are graded based on the quality of supporting evidence and balance between the benefits and risks/burdens according to criteria put forth by the American College of Chest Physicians. The guidelines also provide suggested approaches to the prevention and management of each disorder that incorporate these recommendations.

Prevention and treatment of high-altitude pulmonary edema.

We distinguish two forms of high altitude illness, a cerebral form called acute mountain sickness and a pulmonary form called high-altitude pulmonary edema (HAPE). Individual susceptibility is the most important determinant for the occurrence of HAPE. The hallmark of HAPE is an excessively elevated pulmonary artery pressure (mean pressure 36-51 mm Hg), caused by an inhomogeneous hypoxic pulmonary vasoconstriction which leads to an elevated pulmonary capillary pressure and protein content as well as red blood cell-rich edema fluid. Furthermore, decreased fluid clearance from the alveoli may contribute to this noncardiogenic pulmonary edema. Immediate descent or supplemental oxygen and nifedipine or sildenafil are recommended until descent is possible. Susceptible individuals can prevent HAPE by slow ascent, average gain of altitude not exceeding 300 m/d above an altitude of 2500 m. If progressive high altitude acclimatization would not be possible, prophylaxis with nifedipine or tadalafil for long sojourns at high altitude or dexamethasone for a short stay of less then 5 days should be recommended.

[Acute pulmonary edema in adult caused by tonsillar hypertrophy following removal of laryngeal mask airway].

Negative pressure pulmonary edema (NPPE) has been described after acute airway obstruction. In the following case, we observed a rare occurrence of pulmonary edema caused by chronic tonsillar hypertrophy in a woman following removal of laryngeal mask airway (LMA). A 38-year-old woman with breast cancer underwent mastectomy under general anesthesia using the LMA. With the patient fully awake, the LMA was removed. Abruptly 7 minutes afterward, she showed signs of intense dyspnea, generalized rhonchus and progressive desaturation, and obstructive tonsillar hypertrophy was noticed. Acute lung edema was suspected and treatment started with oxygen therapy, bronchodilators, intravenous corticoids and loop diuretics. She was then intubated to secure airway and provide adequate ventilation with PEEP. Fortunately, the symptoms progressively remitted satisfactorily, and she was subsequently extubated 18 hours later with no complications. NPPE is an infrequent medical emergency and its early diagnosis and recognition are likely to lead to successful management of this potentially serious complication.

Negative pressure pulmonary edema complicating an electrophysiological study.

We report on a case of acute non-cardiogenic negative-pressure pulmonary edema developed during an ablation procedure of an accessory pathway in a patient with no structural heart disease. That potentially serious complication has not been previously reported during an interventional cardiology procedure.

Hypertensive crises.

The key points of this article are: (1) A hypertensive crisis is present when markedly elevated blood pressure is accompanied by progressive or impending acute target organ damage. (2) Most instances of very elevated blood pressure encountered in the office setting will not be crises and will not require acute reduction of blood pressure. (3) Hypertensive crises are largely preventable and often result from inadequate management of hypertension or poor adherence to therapy. (4) Effective triage of patients into categories of severe hypertension, hypertensive urgency, and hypertensive emergency through an expeditious history, examination, and testing should guide therapy. (5) Hypertensive urgency is managed with oral medications and usually on an outpatient basis; a hypertensive emergency warrants intensive care unit admission and parenteral therapy. (6) Ensuring adequate follow-up after treatment of very elevated blood pressure is a critical step that is often mishandled.

Recompression treatment for decompression illness: 5-year report (2003-2007) from National Centre for Hyperbaric Medicine in Poland.

A serious diving accident can occur in recreational diving even in countries where diving is not very popular due to the fact that diving conditions there are not as great as in some tropical diving locations. The estimated number of injured divers who need recompression treatment in European hyperbaric facilities varies between 10 and 100 per year depending on the number of divers in the population, number of dives performed annually, and number of hyperbaric centres in the country. In 5 years of retrospective observation in Poland (2003-2007) there were 51 cases of injured recreational divers recorded. They either dived locally or after returning home by air from a tropical diving resort. All of them were treated with recompression treatment in the National Centre for Hyperbaric Medicine in Gdynia which has capability to treat any patient with decompression illness using all currently available recompression schedules with any breathing mixtures including oxygen, nitrox, heliox or trimix. The time interval between surfacing and first occurrence of symptoms was significantly lower in the group of patients with neurological decompression sickness or arterial gas embolism (median 0.2 hours) than in the group of patients with other types of decompression sickness (median 2.0 hours). In both groups, there were different types of recompression tables used for initial treatment and different number of additional sessions of hyperbaric oxygenation (HBO) prescribed, but the final outcome was similar. Complete resolution of symptoms after initial recompression treatment was observed in 24 cases, and this number was increased to 37 cases after additional HBO sessions (from 1 to 20). In the final outcome, some residual symptoms were observed in 12 cases. In 2 cases initial diagnosis of decompression sickness type I was rejected after initial recompression treatment and careful re-evaluation of diving profiles, risk factors and reported symptoms.

Treatment of high altitude pulmonary edema at 4240 m in Nepal.

High altitude pulmonary edema (HAPE) is the leading cause of death from altitude illness and rapid descent is often considered a life-saving foundation of therapy. Nevertheless, in the remote settings where HAPE often occurs, immediate descent sometimes places the victim and rescuers at risk. We treated 11 patients (7 Nepalese, 4 foreigners) for HAPE at the Himalayan Rescue Association clinic in Pheriche, Nepal (4240 m), from March 3 to May 14, 2006. Ten were admitted and primarily treated there. Seven of these (6 Nepalese, 1 foreigner) had serious to severe HAPE (Hultgren grades 3 or 4). Bed rest, oxygen, nifedipine, and acetazolamide were used for all patients. Sildenafil and salmeterol were used in most, but not all patients. The duration of stay was 31 +/- 16 h (range 12 to 48 h). Oxygen saturation was improved at discharge (84% +/- 1.7%) compared with admission (59% +/- 11%), as was ultrasound comet-tail score (11 +/- 4 at discharge vs. 33 +/- 8.6 at admission), a measure of pulmonary edema for which admission and discharge values were obtained in 7 patients. We conclude it is possible to treat even serious HAPE at 4240 m and discuss the significance of the predominance of Nepali patients seen in this series.