A male client with a massive pulmonary embolus is tachycardic, hypotensive, and has audible bilateral pulmonary crackles. His arterial blood gas (ABG) results are: pH 7.0: PaCO, 66 mm Fig; HCO3- 24 mEq/L (24 mmol/L); PaO, 60 mm Hg. Based on these findings, this client is at greatest risk for which pathophysiological condition?

Reference Ranges:

pH [7.35 to 7.45] PaCO, [35 to 45 mm Hg]

HCO3- [21 to 28 mEq/L (21 to 28 mmol/L)]

PaO, [80 to 100 mm Hg]

A) Sensory neuropathy:

Sensory neuropathy, while common in diabetes mellitus, primarily affects sensation in the extremities and can lead to reduced pain perception and protective sensation. While sensory neuropathy can contribute to the development of foot ulcers by reducing the ability to detect trauma or pressure, it is not the primary factor influencing the ability of the ulcer to heal.

B) Hyperlipidemia:

Hyperlipidemia, characterized by elevated levels of lipids (cholesterol and triglycerides) in the blood, is a common comorbidity in diabetes mellitus. It can contribute to the development of atherosclerosis and macrovascular complications such as coronary artery disease and peripheral arterial disease. While macrovascular disease can impair wound healing by reducing blood flow to the affected area, it is not the primary contributing factor to the ability of the ulcer to heal.

C) Ketoacidosis:

Ketoacidosis, a serious complication of uncontrolled diabetes mellitus, results from the accumulation of ketones in the blood, leading to metabolic acidosis. While ketoacidosis can have systemic effects and impair overall health, it is not directly related to the ability of a foot ulcer to heal.

D) Microvascular changes:

Correct. Microvascular changes, such as thickening of the capillary basement membrane and endothelial dysfunction, are hallmark features of diabetes mellitus. These changes lead to impaired microcirculation, reduced oxygen delivery, and compromised nutrient supply to tissues, including the skin and soft tissues of the foot. Poor microvascular perfusion contributes to delayed wound healing and an increased risk of infection in individuals with diabetes mellitus. Addressing microvascular changes is essential for promoting wound healing in diabetic foot ulcers, making it the primary contributing factor to the ability of the ulcer to heal.

The atrioventricular (AV) node is an essential component of the cardiac conduction system responsible for transmitting electrical impulses from the atria to the ventricles. The inherent rate of the AV node refers to its intrinsic ability to generate electrical impulses in the absence of external influences.

Here's a breakdown of each option:

A) 40 to 60:

Correct. The inherent rate of the AV node is typically 40 to 60 beats per minute (bpm). This rate is slower than that of the sinoatrial (SA) node, which has an inherent rate of 60 to 100 bpm. The AV node acts as a backup pacemaker, ensuring that the ventricles receive electrical impulses even if the SA node fails to function properly.

B) 20 to 40:

This range is not consistent with the typical inherent rate of the AV node. A rate of 20 to 40 bpm would be unusually slow and could indicate significant conduction system abnormalities rather than the normal functioning of the AV node.

C) 60 to 80:

This range is more characteristic of the inherent rate of the SA node rather than the AV node. The SA node is the primary pacemaker of the heart, and its inherent rate is typically 60 to 100 bpm.

D) 80 to 100:

Similar to option C, this range is more consistent with the inherent rate of the SA node rather than the AV node. The SA node typically has a faster intrinsic rate compared to the AV node.