Leads cardiac monitoring

Truppmann and Ellenby routinely used cardiac monitoring when doing phenol peels, and detected many arrhythmias. In 1979, they published the results of a study on 48 patients treated with phenol peels. Saponified and non-saponified Baker or Litton formulas were studied. They report that 23% of patients treated with phenol showed arrhythmia, on average 17.5 minutes after the phenol was first applied. These arrhythmias were often premature ventricular (Figure 28.3) or supraventricular contractions, bigeminy, or supraventricular (Figure 28.2) or ventricular tachycardias (Figure 28.7). Tachycardia, which in extreme cases can sometimes reach 220—230 beats per minute, can turn into ventricular fibrillation and lead to cardiac arrest. 

This table lists the best leads for monitoring challenging cardiac arrhythmias. 

Q waves greater than 2 mm in depth can sometimes be seen. They are usually found in lead III, and without chest pain. If the patient is attached to a cardiac monitor and asked to take a deep breath the Q waves will normally diminish in depth indicating that they are a normal variant associated with a slight shift of the heart in the chest. 

Phenol peels are categorized as deep peels. Similar to TCA, phenol works through protein denaturation and coagulation. However, phenol differs from TCA in that it penetrates quickly to the level of the reticular dermis. Phenol is partially detoxified by the liver and excreted through the kidneys. Percutaneous absorption of phenol can lead to rapid elevation of serum phenol levels, resulting in systemic toxicity and cardiac arrhythmias. Therefore, all patients should be cleared from a cardiac, hepatic, and renal standpoint preoperatively. In addition, intraoperative cardiac monitoring is imperative. 

The table below lists the best leads for monitoring challenging cardiac arrhythmias and special situations such as acute coronary syndromes. 

Six helpful appendices are included Quick guide to cardiac arrhythmias summarizes the details of 20 arrhythmias Cardiac drug overview covers commonly used cardiac drugs Best monitoring leads shows the most beneficial leads to monitor for the most challenging arrhythmias Depolarization-repolarization cycle explains the five phases of this cardiac cycle Action potential curves reviews the cellular changes that occur during the depolarization-repolarization cycle and Cardiac conduction system reviews how electrical impulses affect heart function. 

For acute symptomatic hypocalcemia, 200 to 300 mg of elemental calcium is administered IV and repeated until symptoms are fully controlled. This is achieved by infusing 1 g of calcium chloride or 2 to 3 grams of calcium at a rate no faster than 30 to 60 mg of elemental calcium per minute. More rapid administration is associated with hypotension, bradycardia, or cardiac asystole. Total calcium concentration is commonly monitored in critically ill patients. Under normal circumstances, about half of calcium is loosely bound to serum proteins while the other half is free. Total calcium concentration measures bound and free calcium. Ionized calcium measures free calcium only. Under usual circumstances, a normal calcium level implies a normal free ionized calcium level. Ionized calcium should be obtained in patients with comorbid conditions that would lead to inconsistency between total calcium and free serum calcium (abnormal albumin, protein, or immunoglobulin concentrations). For chronic asymptomatic hypocalcemia, oral calcium supplements are given at doses of 2 to 4 g/day of elemental calcium. Many patients with calcium deficiency have concurrent vitamin D deficiency that must also be corrected in order to restore calcium homeostasis.2,37,38... 

Cardiac patients need to be monitored closely when receiving these drugs because of their bradycardiac effects (which can lead to ectopic arrhythmias), and hypotensive effects resulting from prolonged vasodilation. In addition, the drugs stiffen the chest wall musculature, an effect reversed by naloxone. 

Carbamazepine overdose first leads to neuromuscular disturbances, such as nystagmus, myoclonus, and hyperreflexia, with later progression to seizures and coma. Cardiac conduction changes are possible. Nausea, vomiting, and urinary retention also may occur. Treatment should include induction of vomiting, gastric lavage, and supportive care. After a serious overdose, blood pressure and respiratory and kidney function should be monitored for several days. 

As noted earlier, lithium is contraindicated in patients with unstable congestive heart failure or the sick sinus node syndrome ( 307, 328). In older patients or those with prior cardiac histories, a pretreatment ECG should be obtained. Except for the potential adverse interactions with diuretics, the concomitant use of other cardiac drugs is generally safe. Because verapamil may lower serum levels of lithium, however, more careful monitoring may be required to assure continued therapeutic effects (329). Some data also indicate that verapamil may predispose to lithium neurotoxicity. Conversely, increased lithium levels leading to toxicity has occurred with methyidopa and enalapril. When antihypertensive therapy is necessary, b-blockers are a reasonable choice when lithium is coadministered. 

A common reason for diuretic use is for reduction of peripheral or pulmonary edema that has accumulated as a result of cardiac, renal, or vascular diseases that reduce blood delivery to the kidney. This reduction is sensed as insufficient effective arterial blood volume and leads to salt and water retention and edema formation. Judicious use of diuretics can mobilize this interstitial edema without significant reductions in plasma volume. However, excessive diuretic therapy may lead to further compromise of the effective arterial blood volume with reduction in perfusion of vital organs. Therefore, the use of diuretics to mobilize edema requires careful monitoring of the patient s hemodynamic status and an understanding of the pathophysiology of the underlying illness. 

Topical minoxidil (Rogaine) is effective in reversing the progressive miniaturization of terminal scalp hairs associated with androgenic alopecia. Vertex balding is more responsive to therapy than frontal balding. The mechanism of action of minoxidil on hair follicles is unknown. Chronic dosing studies have demonstrated that the effect of minoxidil is not permanent, and cessation of treatment will lead to hair loss in 4-6 months. Percutaneous absorption of minoxidil in normal scalp is minimal, but possible systemic effects on blood pressure (see Chapter 11) should be monitored in patients with cardiac disease. 

With proper pharmacotherapy and optimization of overall clinical status, most patients will be able to overcome the problem of orthopnea for the duration of interventional procedure. Diuretic therapy preintervention may be useful. In the very ill patient with hemodynamic compromise, and where intervention may lead to an improvement in cardiac function, supportive measure, such as intra-aortic balloon counterpulsation, pressure monitoring, or ventilation may be necessary during the acute phase of the illness. 

IMATINIB ANALGESICS-OPIOIDS May cause t plasma concentrations, with a risk of toxic effects of codeine, dextromethorphan, hydroxycodone, methadone, morphine, oxycodone, pethidine and tramadol Inhibition of CYP2D6-mediated metabolism of these opioids Monitor for clinical efficacy and toxicity. Warn patients to report t drowsiness, malaise or anorexia. Measure amylase and lipase levels if toxicity is suspected. Tramadol causes less respiratory depression than other opiates, but need to monitor BP and blood counts, and advise patients to report wheezing, loss of appetite and fainting attacks. Need to consider 1 dose. Methadone may cause Q-T prolongation the CHM has recommended that patients with heart and liver disease who are on methadone should be carefully monitored for heart conduction abnormalities such as Q-T prolongation on ECG as they may lead to sudden death. Also need to monitor patients on more than 100 mg methadone daily and thus an t in plasma concentrations necessitates close monitoring of cardiac and respiratory function... 

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