When planning the care for a client during the first 24 hours postpartum, the nurse expects to monitor the client's pulse and blood pressure frequently based on the understanding that the client is at risk for which condition?

Injecting the medication into the vastus lateralis. This is because the vastus lateralis is a large muscle in the thigh that is suitable for intramuscular injections in newborns³. The vitamin K injection helps prevent vitamin K deficiency bleeding, which is a rare but serious condition that can cause bleeding in the brain or other organs¹. The American Academy of Pediatrics recommends that all newborns receive a single intramuscular dose of 0.5 to 1 mg of vitamin K within one hour of birth².

Choice A is wrong because a 21 gauge needle is too large for a newborn's muscle. A 25 or 27 gauge needle is more appropriate.

Choice B is wrong because injecting at a 45-degree angle may not reach the muscle tissue. A 90-degree angle is more appropriate.

Choice C is wrong because injecting 1cc of medication is too much for a newborn's muscle. The recommended dose of vitamin K is 0.5 to 1 mg, which is equivalent to 0.05 to 0.1 mL.

Anticoagulants for 6 weeks. This is because the client’s symptoms suggest that she has deep vein thrombosis (DVT), which is a blood clot in a deep vein of the leg. DVT is a serious condition that can lead to pulmonary embolism, which is a blockage of a blood vessel in the lungs. The treatment for DVT involves anticoagulants, which are drugs that prevent blood clots from growing or forming new ones. The duration of anticoagulant therapy depends on the risk factors and severity of DVT, but it is usually at least 6 weeks.

Choice A is wrong because gentle massage of the affected leg can dislodge the clot and cause a pulmonary embolism.

Choice C is wrong because passive leg exercises can increase blood flow and worsen pain and swelling.

Choice D is wrong because the application of ice to the affected leg can reduce inflammation but does not treat the underlying clot.