CANCER: THE PRACTICAL GUIDE TO ENJOYING SUNSHINEThe advice that we have given here about avoiding malignant melanoma has to be set firmly within a reasonable perspective. Melanoma is a risk that can be eliminated by simple changes in lifestyle for ourselves and our children. Our advice should not be interpreted as meaning that the outdoor life, recreation, sport and summer holidays are necessarily harmful. Simple measures to avoid sunburn will mean that all of these can be enjoyed to the full without incurring risk. There are good reasons for wishing for this, and not only because of the great pleasure enjoyed by millions in outdoor recreations and pastimes – it is recognized that fit and happy people are less likely to get all sorts of diseases, not least cancer. We will discuss briefly the topic of exercise and work patterns in relation to cancer. It is sufficient to say here that retaining an outdoor lifestyle and having a good time is quite compatible with a low risk of melanoma.*77\194\4*

PEDIATRIC ONCOLOGY: THERAPEUTIC MEASURESA. Device-related septicemiaInfection remains a significant cause of morbidity for patients with long-term venous access devices. The incidence of device-related infections reportedly ranges from 2% to >60%. Externally tunneled silastic catheters have a much higher rate of infection than totally implanted ports. The most common organism involved in a device-related bacteremia is Staphylococcus epidermidis. External catheters are also at higher risk for infections caused by gram-negative enteric organisms.Device-related infections may be treated by administering an antibiotic through the infected device or removing the device and administering an antibiotic through a peripheral site. Consider removing the device if it is no longer required, if the patient is septic with signs of clinical instability, or if there is persistent device-related bacteremia unresponsive to appropriate antibiotic therapy in 24-48 hours.a. Neutropenic patienti. For suspected device-related septicemia, broad-spectrum gram-positive and gram-negative antibiotic coverage is indicated until the source of the infection is identified. The patient should be givenvancomycin (40 mg/kg/day in patients with normalrenal function), tobramycin (6-7.5 mg/kg/dayin patients with normal renal function), andceftazidime (100-150 mg/kg/day).ii. It is essential to treat through the lumen(s) of thedevice rather than through a peripheral intra-venous line.iii. Consider thrombolytic therapy with urokinase(5000 U/mL). The medication comes prepared in1 mL vials. For most pediatric internal catheters, mL will be an adequate amount. For most ports,vials (2 mL) should be injected. The entire volume may be injected into the device at one time and allowed to dwell undisturbed for 30-60 minutes. It should then be aspirated rather than flushed through, to avoid an additional bacteremia. The device should then be properly flushed. iv. If cultures are positive, continue specific antibioticcoverage for 7-14 days after cultures are negative. Obtain surveillance cultures at intervals during the course of therapy, v. If cultures remain positive after 48 hours of appropriate therapy or if clinical signs of deterioration develop and no other source of infection is clearly present, remove the device, b. Non-neutropenic patienti. For suspected device-related septicemia in the non-neutropenic patient, use vancomycin (40 mg/kg/dayfor patients with normal renal function) due to thehigh incidence of coagulase-negative staphylococcal infections. Monitor serum concentrations. Inaddition, an aminoglycoside (6-7.5 mg/kg/day forpatients with normal renal function) or anadvanced-generation cephalosporin such as ceftazidime (100-150 mg/kg/day) may be added untilculture results are known. Some clinicians woulduse the cephalosporin alone until cultures indicatethe need for vancomycin.ii. Consider administering urokinase (5000 U/mL) asdescribed above.iii. If cultures are positive, continue specific antibioticcoverage for 7-14 days after cultures are negative.Obtain surveillance cultures at intervals during thecourse of therapy.iv. If cultures remain positive after 48 hours of appropriate therapy or if clinical signs of deteriorationdevelop and no other source of infection is clearlypresent, remove the device.Despite the high salvage rate (>75%) of infected devices and the importance of preserving access when limited sites are available, avoid prolonged efforts at salvaging the device in the ill, immune-compromised child.A number of clinical studies have demonstrated a relationship between thrombus formation and device infection. Thrombolytic therapy, most often with urokinase, has been reported as a successful adjuvant in the therapy of infected catheters.If fungal sepsis is present, a device can be infrequently salvaged (<10%). However, if access is limited, treatment may be initiated through an existing device. If subsequent cultures remain positive or if the patient shows clinical signs of deterioration, remove the device. 6. If a device is removed because of sepsis, the insertion of a new device should await the completion of antibiotic therapy if possible. Additionally, in the neutropenic patient, neutrophil counts should be allowed to normalize as well. If peripheral access is impossible during this time period, a temporary central venous catheter or PICC line can be used. If necessary, a new device may be inserted during the course of antibiotic treatment if the patient has no signs of sepsis, surveillance blood cultures are negative, and the neutrophil count is acceptable.
B. Local device-related infections1. Infection of the catheter exit-site and/or tunnela. Exit site infections may be very difficult to control andoften lead to the removal of the catheter if the cathetercuff is infected. However, local wound care of the exitsite may prove beneficial in the treatment of an earlysite infection. Avoid transparent, occlusive plasticdressings, since these have been found to increase therisk of catheter colonization. Topical antibiotics(polymyxin, Neosporin, bacitracin, etc.) are also effective in minimizing catheter colonization, whereas povidone-iodine ointment is ineffective.b. Use systemic antibiotic therapy for the neutropenicpatient and the patient who does not respond rapidlyto local therapy. Obtain blood cultures and exit site cultures. Start therapy with dicloxacillin 25 mg/kg/day bymouth (PO) or nafcillin 150 mg/kg/day intravenous(IV). If there is progression in the exit site infectionafter 48 hours or if a tunnel infection develops, changeto broad-spectrum antibiotics and remove thecatheter.c. Tunnel infections of either an external catheter or animplanted port usually require the removal of thedevice, since systemic antibiotic therapy with broad-spectrum gram-positive coverage is seldom effective incontrolling the infection.2. Infection of the reservoir or pocketAn infection of the reservoir or pocket of an implanted port is difficult to clear without removal of the entire device. When this is suspected, do not access the device. Initiate systemic antibiotic therapy with broad-spectrum gram-positive coverage through a peripheral site if salvage of the device is to be attempted.C. Device-related occlusion1. Fibrinolytic therapyMost cases of total or partial occlusion of the device can be successfully treated with urokinase. In the case of a total occlusion, obtain a radiograph to rule out the possibility of mechanical complication such as catheter dislodgement or migration.a. Urokinase is available in premeasured 1 mL vials at aconcentration of 5000 U/mL. Draw up enough urokinase into a syringe to fill the device. For most pediatricBroviac catheters, 1 mL will be an adequate amount,while most ports have a fill volume closer to 2 mL. Forthe larger devices, do not dilute the medication; morethan one vial of the medication may be required.b. Inject the urokinase into the device and lock in place.If resistance during the injection becomes too high, initially inject one-third to one-half of the volume and lockin place. Inject the remaining volume 30 minutes later.c. Wait 60 minutes and then aspirate. If unable to with-draw, repeat with a second administration of urokinase.d. After successful treatment of the occlusion, immediately flush the device with saline and then heparinizedsaline as per institutional protocol to prevent rethrombosis.e. For persistent occlusive problems minimally responsive to bolus therapy, a continuous infusion of urokinase at 200 U/kg/h for 24 hours can be attempted. Thisapproach does not require intensive monitoring of thepatient or assessment of coagulation parameters.2. Precipitate occlusionThe device that has been occluded by precipitation from total parenteral nutrition (TPN) or medication incompatibility may be treated by attempting to solubilize the precipitate by altering its pH through the administration of HC1 or NaHC03. Such a condition is to be suspected when precipitate is visible in the clear intravenous tubing line connected to the device.a. For TPN-associated occlusions, which usually involveCaP04 precipitation, do the following.i. Mix 1 mL of sterile 0.1 N HC1 with 9 mL standardheparin lock (Hep-Lock) saline (10 U/mL) for a finalconcentration of 0.01 N HC1.ii. Inject 0.5 mL of the solution into the device and lockin place.iii. Wait 30 minutes and then aspirate. If unable to with-draw, repeat the administration of 0.5 mL of thesolution every 5 minutes until 30 minutes haveelapsed or device patency is restored.iv. After successful treatment of the occlusion, immediately flush the device with saline and thenheparinized saline as per institutional protocol toprevent rethrombosis.b. For medication incompatibilities resulting in an occluding precipitation, a similar protocol may be attemptedusing sodium bicarbonate at a concentration of1 mEq/mL.Mechanical problems1. Reservoir extravasation from implanted portsExtravasation of injected fluids may occur as a result of inappropriate needle placement for port access before the infusion, needle dislodgement during the infusion, or malfunction of the device. Causes of device malfunction include the separation of the catheter from the reservoir, a fracture or break in the reservoir structure, and a fracture or break in the tunneled catheter portion of the port.a. When inappropriate needle placement or dislodgement is suspected do the following.i. Attempt to reaccess the reservoir properly.ii. Flush the device with heparinized saline to preventocclusion if the device is not to be used.iii. Use local therapy with warm compresses to helpeliminate the surrounding swelling.iv. See Chapter 14 for treatment recommendations if adrug extravasation has occurred.b. If proper needle position has been confirmed and anextravasation due to a structural problem with theport is suspected, a contrast injection study of thedevice will help pinpoint the defect. Therapy usuallyrequires complete removal of the port, although salvage of the site can be attempted if there is no associated infection.2. Extravasation within a tunnel of an external cathetera. A contrast injection study of the device will help pin-point the defect.b. Therapy usually requires complete removal of thecatheter, although salvage of the site can be attemptedif there is no associated infection by insertion of aguidewire before its removal.Dislodgement or malposition of the catheter Dislodgement or malposition of the intravascular catheter portion of the device generally requires replacement of the device. Occasionally, manipulating the guidewire under sterile conditions may be successful.Fracture of the devicea. External catheteri. Cracks or breaks of the external catheter can berepaired with kits available for the specific size andbrand of the catheter. Carefully follow the instructions accompanying the kit.ii. Use sterile technique, including mask, gloves, andsurgical preparation, to avoid contamination.iii. Temporary repair of an external catheter can beaccomplished by the insertion of an appropriate-sized plastic IV catheter into the lumen of thecatheter at the break point under sterile technique.iv. The catheter should then be flushed withheparinized saline solution to prevent occlusion.Permanent repair should be accomplished as soonas a kit is available.b. Internal catheteri. Fracture of the tunneled or intravascular portion ofthe catheter of either an external catheter or animplanted port may lead to intravascular embolization of that portion of the catheter.ii. The most common site of the catheter for this tooccur is the point where the catheter passesbetween the clavicle and the first rib.iii. The embolized portion of the catheter usually travels to the right ventricle or to the pulmonary arteryoutflow tract.iv. Retrieval of the embolized catheter can usually be accomplished in the cardiac catheterization laboratory.*77\168\2*

The only way we can tell the exact type of cancer is by looking at a specimen under the microscope. There is more about this in the next chapter.

Wherever cancer growths are in the body, they are still named according to where the primary growth was—that is, where the cancer started. If a cancer starting in the breast spreads to the bones or liver, it is still called breast cancer, not bone or liver cancer. This is because it still looks like breast cancer under the microscope and it still acts like breast cancer. The secondary growths in the bones or liver will react to the treatments to which breast cancer reacts. A primary cancer of the bone (one starting there) would behave differently and respond to quite different sorts of treatment.

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