Anesthesia in drug addiction

The growing social problem of drug abuse has increased the likelihood that anesthesiologists will find acute or chronic drug users among patients requiring anesthesia for elective or emergency surgery. We must therefore be aware of the effects drugs have on the organism and their possible pharmacokinetic and pharmacodynamic interactions with anesthetic agents in order to prevent complications during surgery and postoperative recovery. Such knowledge is required for the management of abstinence syndrome or overdose, which pose the greatest potential dangers for the hospitalized drug addict.     

药物成瘾的表观遗传机制

背景 奖赏脑区基因表达异常是药物成瘾的关键基因机制,但决定药物成瘾的表观遗传学机制并不清楚.目的 研究慢性外源性药物暴露转变为药物成瘾的表观遗传发病机理.内容 综述有关DNA甲基化与组蛋白表观遗传调节药物依赖或成瘾的证据. 趋向 这些表观遗传变异介导药物滥用与依赖的新颖见解,将为改善药物成瘾的治疗提供新途径.     

Renal complications of drug addiction

The kidney is one of the target organs involved as a consequence of the systemic complications seen in drug abusers. This may manifest itself in one of the following forms: acute hepatitis with modest proteinuria (less than 2 Gm. per day); bacterial endocarditis with hematuria, azotemia, and a focal or diffuse glomerulonephritis; the nephrotic syndrome with focal mesangial sclerosis and diffuse interstitial nephritis often pursuing a fulminant course terminating in uremia; acute renal failure secondary to rhabdomyolysis and myoglobinuria; polyarteritis nodosa with renal involvement; and obstructive uropathy secondary to fungus ball in the urinary tract.     

Pyogenic splenic abscess in intravenous drug addiction

Among the surgical complications of intravenous drug addiction, pyogenic splenic abscess is considered to be a rare entity. A review of the literature reveals only 24 cases of splenic abscess secondary to this particular etiology. The authors report five patients with intravenous drug addiction who underwent splenectomy for pyogenic splenic abscess within 1 year. Fever and abdominal pain were the only constant physical signs. Three patients had associated infective endocarditis, and the other two patients sustained blunt trauma to the left side of the trunk weeks earlier. Computed tomography (CT) and ultrasound were diagnostic in all five patients preoperatively, and they were complementary when combined. Four of the five patients had Staphylococcus aureus septicemia at the time of splenectomy. Three patients recovered from their operations, and the other two, both with endocarditis, died postoperatively from causes unrelated to splenic abscess and splenectomy. A high index of suspicion is warranted in this susceptible group of patients with vague abdominal signs and persistent sepsis to rule out splenic suppuration. The noninvasive imaging methods, CT scan and ultrasound, facilitate early diagnosis in these patients.     

Pulmonary and cardiovascular implications of drug addiction

One hundred thirteen patients were seen with pulmonary or cardiovascular complications secondary to intravenous drug abuse. More than 60% of these patients had such pulmonary problems as pulmonary edema, recurrent septic pulmonary emboli, asymptomatic hilar adenopathy, or pneumonia. Twelve patients were treated for bacterial endocarditis; 6 subsequently required valve replacement. Vascular complications included complete venous occlusion of the hand, transient arterial insufficiency, and mycotic aneurysm secondary to intraarterial injections of narcotics.     

Penile ecthyma gangrenosum. Complication of drug addiction

We present a case of ecthyma gangrenosum involving the penis in an IV drug abuser probably resulting from direct arterial septic embolization from a femoral injection site. An increased awareness of this condition is essential because misdiagnosis has been reported in up to 100 percent of cases. Prompt diagnosis is essential to begin appropriate therapy.     

Infected venous pseudoaneurysm. A complication of drug addiction

There has been an increase in the incidence of major vascular complications of intravenous drug addiction. We studied five patients who had infected venous pseudoaneurysms of the femoral vein. Patients may have cryptic sepsis or an infected hematoma from venous rupture. The vein containing pus may drain through a venipuncture site. Treatment is complete excision of the involved vein with packing of the wound. Complications due to septic embolization or metastatic infection from septicemia are common. Venous reconstruction is unwarranted.     

The biology of addiction

In this narrative review, the neurobiological mechanisms underlying substance abuse and addiction are discussed with a particular emphasis on the mechanisms that promote ongoing use and relapse. Addiction is estimated to affect 10-15% or more of the adult population, including physicians. Genetic predisposition, psychological and environmental risk factors, the timing of exposure to the substance, the type of substance used, and the frequency of use influence the individual’s susceptibility to addiction. Abused substances act on the brain’s reward system, a neural circuit that produces pleasurable feelings in response to stimuli that promote survival, thereby modifying future behavior to seek out similar stimuli. Endogenous activators include food, sex, and social interaction. Drugs of abuse hijack the reward circuit, producing intense activation. Repetitive exposure to substances leads to persistent, altered genetic expression and accumulation of ΔFos-B and corticotropin-releasing factor. High levels of these substances suppress the reward circuit and activate the endogenous stress response, resulting in a generalized state of discord. These changes are enduring and can trigger substance use relapse even after long periods of abstinence.