Pressure Sore Flashcards
A 34-year-old T12 paraplegic man presents with a Stage IV sacral pressure sore. The ulcer has been persistent and chronic, with exposed structures down to bone. Serial bedside debridements have maintained a clean and healthy-appearing wound. On admission, the patient has an increased erythrocyte sedimentation rate (ESR). Prior to definitive coverage, which of the following is the most appropriate next step in management?
A) Bone biopsy and culture
B) CT scan with IV contrast
C) Gadolinium-enhanced MRI
D) Tagged white blood cell scan
E) Triple phase bone scan
The correct response is Option A.
The preoperative management of pressure sores is vital to successful surgical outcomes and healing. When a patient presents, one of the first assessments must be whether that patient has evidence of osteomyelitis. For patients presenting with chronic exposed wounds at Stage III or Stage IV, the risk of pelvic osteomyelitis is very high. This will require intravenous antibiotic treatment and bony debridement prior to coverage. To establish this diagnosis, especially in a patient with an increased ESR, a bone biopsy is needed. This will help guide initiation and maintenance of treatment.
While a positive bone scan may indicate the presence of osteomyelitis, this test carries a high rate of false positives in patients with open wounds. Thus, the next line of workup for osteomyelitis would be a bone biopsy, with the tissue being sent for cultures and sensitivities. This should be done in such a way that some of the deeper pelvic bone is sampled, and not just the superficially exposed bone. This will allow for both diagnosis and a guide for directed antibiotic therapy.
In cases where bone biopsy is not available, a gadolinium-enhanced MRI or tagged white blood cell scan can be used to assess for the characteristic inflammation associated with osteomyelitis, and make a diagnosis indicating the need for antibiotic treatment. A CT scan with IV contrast is a last-line test used for this purpose, as it is less sensitive at showing localized inflammation, and is more helpful in assessing depth of invasion and defining exposed structures.
Thus, in this case, given the chronic nature of this open wound, and the fact that it is ready for closure based on clinical examination, a bone biopsy would be most helpful as the first step in ensuring there is no osteomyelitis prior to closure.
2018
An 84-year-old man comes to the office accompanied by his son-in-law for evaluation of an ulcer of the ischium. Physical examination of the patient shows not only a Stage IV ulcer of the right ischium, but also multiple bruises of the extremities including circumferential upper extremity ecchymoses. The son-in-law claims the patient sustained a fall, but the patient is silent and avoids eye contact when questioned. Because of the unusual physical findings and questionable history, elder abuse is suspected. Which of the following is the most appropriate response in this situation?
A) Proceed with excision and flap reconstruction of the ulcer since there is no definite proof of elder abuse
B) Pull the son-in-law aside and ask him in private about the suspected elder abuse
C) Referral to a wound care center
D) Report the suspected elder abuse to adult protective services
E) Report the suspicion of elder abuse only with the patient’s permission
The correct response is Option D.
Although elder abuse may be relatively rare in consultation, plastic surgeons must be aware that it is treated similarly to child abuse. The healthcare provider has a responsibility to report the suspected offense even if the patient denies the abuse if the physician has any reason to suspect that the elder abuse may be occurring. Elderly patients may be just as vulnerable as children to abuse and are often overlooked because of the fact that they frequently are competent adults. Similar to children, geriatric patients may be reluctant to report the abuse for fear of repercussions such as withholding of care. Breaching patient confidentiality rights is acceptable if the interests of the vulnerable patient are best served by reporting the incident in good faith and can be made without fear of liability to the provider. In these cases, delays in reporting may result in additional harm to the elderly person.
2018
A 45-year-old paraplegic man with a history of type 1 diabetes mellitus comes to the physician because of a stage 3 trochanteric pressure sore. The wound has been adequately debrided, and myocutaneous flap reconstruction is planned. Albumin concentration is 3.8 mg/dL, and hemoglobin A1c concentration is 6.3%. Diet includes protein intake of 2.5 g/kg daily. Which of the following factors is most likely to be associated with failure of the reconstruction?
A) Albumin concentration
B) Hemoglobin A1c
C) Patient age
D) Pressure sore location
E) Protein intake
The correct response is Option B.
Preoperative optimization is essential in patients undergoing pressure sore reconstruction. This includes adequate nutrition (albumin greater than 3.5 g/dL, 1.5 to 3.0 g/kg/day of protein intake, 25 to 35 cal/kg of nonprotein calories daily), eradication of infection, treatment of spasms/contractures, smoking cessation, urinary/stool diversion in select circumstances, and an appropriate postoperative plan of care including pressure off-loading. A multivariate analysis of risk factors for failure of pressure sore flap reconstruction included hemoglobin A1c greater than 6%, younger age, albumin concentration less than 3.5 g/dL, and ischial location. In this patient, the primary risk factor for failure of reconstruction would be a high hemoglobin A1c.
2017
A 22-year-old man who is a wheelchair-bound paraplegic is evaluated because of a recurrent pressure sore. The patient has had previous surgeries to repair a left trochanteric pressure sore and a large midline sacral pressure sore. A photograph is shown. The most appropriate treatment is debridement followed by coverage with which of the following?
A) Adjacent skin advancement
B) Gluteal fasciocutaneous flap
C) Posterior thigh musculocutaneous flap
D) Split-thickness skin graft
E) Tensor fascia lata flap
The correct response is Option C.
In this patient, a posterior thigh flap consisting of the biceps femoris, semitendinosus, and semimembranosus muscles and overlying skin is the most appropriate treatment option. Advantages of this flap include a reliable vascular supply (first perforating branch of profunda femoris artery), a generous amount of skin, fat, and muscle to obliterate the dead space after ulcer excision, and the ability to re-advance the flap in the event of ulcer recurrence. Additionally, a posterior thigh flap preserves other donor sites such as the medial thigh, lateral thigh, and gluteal muscles for secondary problems or the inevitable pressure sore in another location. The chief disadvantage of the posterior thigh flap is its upward mobility, as maximal movement is 10 to 12 cm. For extensive ischial defects, a second flap or another flap option may be necessary. Generally, this flap is limited to non-ambulatory patients due to the harvest of multiple knee flexors. Transfer of the biceps femoris alone has been described for small defects in ambulatory patients. The posterior thigh flap is a Mathes/Nahai Type II muscle, with a primary dominant pedicle (first perforating branch of the profunda femoris artery) with smaller segmental distal pedicles. These segmental secondary pedicles can typically be divided with little effect on flap survival. It is recommended that the origin and insertion of the muscles be divided to maximize flap mobility and minimize tension at the inset site. These flaps can be designed as a V-Y configuration or designed in a rotational configuration as shown in the perioperative photograph.
The temptation to perform a primary closure should be resisted, as pressure sores by definition indicate a soft tissue deficiency. Simply pulling tissues together over a bony prominence will very likely fail because of wound tension and dehiscence. In this patient, this was already attempted previously with a predictable outcome. Skin grafts have very limited success in this location because of a lack of bulk and resistance to pressure and shearing forces. The gluteal fasciocutaneous flap is based on the inferior gluteal artery and is a good option in the ambulatory patient with an ischial pressure sore. In this case, however, the pedicle is not available owing to the previous gluteal V-Y flap used to repair the sacral pressure sore. In cases when a gluteal fasciocutaneous flap has been utilized previously, the posterior thigh musculature may still be used in the face of a recurrent ischial pressure sore; however, a skin graft would be required.
The tensor fascia lata (TFL) flap is the first-line choice for trochanteric pressure sores and has already been used in this patient. The TFL has been described for ischial pressure sores, but only after more reliable flaps have been exhausted. Because the distal 6 to 8 cm of the TFL are unreliable, flap delay or pre-transfer expansion are recommended prior to transfer for an ischial reconstruction.
2017
A 40-year-old man with T3 paraplegia undergoes operative debridement of a stage III ischial decubitus ulcer. In the recovery room, the nurse reports that the patient is saying he has severe headache and nausea. Temperature is 37.0°C (99.0°F), blood pressure is 180/90 mmHg, and heart rate is 50 bpm. He is flushed and diaphoretic. Which of the following is the most appropriate initial management of this patient’s condition?
A) Administer dantrolene 2.5 mg/kg intravenously
B) Administer nitroglycerin lingual spray
C) Insert a Foley catheter
D) Perform carotid massage
E) Place patient in Trendelenburg position
The correct response is Option C.
This patient has autonomic dysreflexia (AD). During an episode of AD, the patient sustains an uncontrolled sympathetic response to a stimulus (precipitant). It usually occurs in patients whose level of paralysis is above T6. AD occurs in 50 to 70% of patients with lesions above T6. Fatal complications may ensue in affected patients.
Common symptoms of AD include headache, hypertension, bradycardia, and flushing, blotching, or sweating above the level of the lesion.
The most common precipitants of AD are urologic (principally bladder distention), gastrointestinal (rectal distention), and musculoskeletal (fractures, dislocations, and heterotopic calcification). Other less common precipitants include skin ulcerations and infections as well as pregnancy and labor.
Primary treatments of AD include removing any stimulus. Remove tight clothing and be sure that a full bladder or rectum is not serving as a precipitant. Sublingual nifedipine may be used secondarily as an oral hypotensive agent. Nitrates are not part of the initial management of AD. A fluid bolus would have no role in the treatment of AD or hypertensive crisis. Dantrolene is used in the management of malignant hyperthermia, not AD. Administration of dextrose in 50% water intravenously is used to manage symptomatic hypoglycemia.
Carotid massage causes vago stimulation and is contraindicated in this patient.
Trendelenburg is usually used for hypotension, not hypertension.
2017
A 46-year-old man is evaluated for a large grade IV left ischial pressure ulcer. Medical history includes a 6-month history of traumatic T12 paraplegia. Excision of the pressure ulcer and reconstruction with a left inferior gluteal thigh flap are planned. During induction of anesthesia, the patient has the onset of cardiac arrhythmia with peaked T waves and tachycardia. Pulse oximetry is 100% with normal end-tidal CO2. Temperature is 37.0°C (98.6°F). It is discovered that the patient was given succinylcholine for rapid-sequence intubation by the anesthesia resident. Which of the following is the most appropriate initial management of the patient’s condition?
A) Intravenous adenosine
B) Intravenous amiodarone
C) Intravenous calcium chloride
D) Intravenous dantrolene
E) Synchronized cardioversion
The correct response is Option C.
Perioperative complications arising from intravenous paralytics and inhalational anesthetics may have devastating outcomes, including death. Rapid and accurate diagnosis is essential for efficient treatment and maximizing successful outcomes. The paraplegic patient presented in this clinical scenario has developed acute hyperkalemia from the use of succinylcholine. Hyperkalemia after succinylcholine administration may result in paraplegics or any patients with upper or lower motor neuron injury, severe burns, crush injuries, or conditions causing rhabdomyolysis. This phenomenon results from the upregulation of nicotinic acetylcholine receptors in denervated or traumatized muscle.
Initial treatment of acute hyperkalemia causing cardiac compromise involves antagonizing the effects of potassium on cardiac conduction and shifting potassium from the extracellular space back into intracellular fluid. Calcium directly antagonizes the hyperkalemia-induced depolarization of resting membrane potential by increasing the threshold potential to stabilize the membrane. Sodium bicarbonate and glucose combined with insulin will promote cellular uptake of potassium. Acidosis enhances the release of potassium from the cell and can be reversed with sodium bicarbonate. In addition, alkalization of plasma decreases levels of ionized calcium permitting the more liberal use of calcium in the treatment of acute hyperkalemia.
Intravenous dantrolene is appropriate for the initial management of malignant hyperthermia (MH). MH may also arise from the use of succinylcholine or inhalational anesthetics. It is caused by a hereditary abnormality that interferes with calcium regulation within skeletal muscle. Once triggered, an uncontrolled hypermetabolism in the muscle occurs secondary to the buildup of calcium in the skeletal muscle. The earliest sign of malignant hyperthermia is a rapid and unexplained increase in end-tidal CO2 that progresses to the presence of fever. This patient is afebrile and has a normal end-tidal CO2. However, if the patient presentation did indeed suggest MH, intravenous calcium chloride would be contraindicated secondary to the already increased levels of calcium present.
Synchronous cardioversion and intravenous adenosine and amiodarone are modalities to consider in the ACLS algorithm for treatment of unstable and stable tachycardia of unknown etiology. They are not first-line medications in the treatment of the hyperkalemia that is causing this patient’s symptoms.
2017
An otherwise healthy 55-year-old man with paraplegia is evaluated because of a recurrent ischial pressure ulcer. History includes previous coverage of the ulcer with a posterior thigh rotation-advancement flap. After appropriate optimization of both patient and wound, which of the following is the most appropriate surgical intervention for reclosure of the wound?
A) Gracilis musculocutaneous flap
B) Inferior gluteal flap
C) Re-rotation of posterior thigh flap
D) Tensor fascia lata flap
E) V-Y hamstring flap
The correct response is Option C.
The most appropriate surgical treatment option would be to re-rotate the posterior thigh flap.
One of the main principles in surgical flap closure of pressure ulcers (PUs) is to utilize large rotation flaps so that they may be re-rotated in the case of recurrences. Although it is debatable whether to re-flap a patient who has a PU recurrence, some clinical situations require a redo flap closure. In those circumstances, instead of using a new flap or donor site, re-elevation of the original flap and re-advancing it is usually the first-line flap option. The posterior thigh flap is a fasciocutaneous flap based on the descending branch of the inferior gluteal artery (if elevated as a purely V-Y flap, or if raised as a superiorly based “tongue” flap). However, if elevated as a rotation-advancement flap, it also has blood flow from medial or lateral thigh skin perforators depending on where the flap incisions are made on the posterior thigh.
In all forms of the flap, the entire posterior thigh skin and fascia is elevated off the hamstring muscles (semitendinosus, semimembranosus, biceps femoris), thus severing all the musculocutaneous perforators from those muscles to the overlying skin and fascia. Therefore, the V-Y hamstring flap (a musculocutaneous flap) is not available after a posterior thigh flap has been raised. Though the inferior gluteal artery flap, gracilis, and possibly the tensor fascia lata flaps may be used, they are not the most appropriate surgical option when a re-rotation thigh flap is still available.
2016
A 45-year-old man is hospitalized in the intensive care unit for 3 weeks after sustaining blunt force trauma to the head during an assault and develops a pressure ulcer over the right ischium. Six weeks later, the wound has not healed despite multiple bedside debridements and daily wound care. The patient is ambulatory. Physical examination shows an 8 × 4 × 4-cm stage III pressure ulcer at the right inferior gluteal fold with an indurated bursa. After nutritional optimization, which of the following surgical techniques is most appropriate for closure after excising the bursa?
A) Gracilis musculocutaneous rotation flap
B) Negative pressure wound therapy then primary closure
C) Posterior thigh fasciocutaneous rotation flap
D) Superiorly based gluteal musculocutaneous rotation flap
E) Tensor fasciae latae island rotation flap
The correct response is Option C.
The best reconstructive option for an ambulatory patient with a chronic ischial pressure sore is to spare muscle and use a fasciocutaneous flap. Fasciocutaneous flaps offer an axial blood supply with durable coverage and minimal potential for a functional deformity. The flaps closely reconstruct the normal anatomical arrangement over bony prominences. Disadvantages include limited bulk to fill large defects.
Musculocutaneous flaps offer excellent blood supply and bulky tissue and can be re-rotated like fasciocutaneous flaps. However, in an ambulatory patient, they may cause functional impairment.
The tensor fasciae latae flap is occasionally used to close the ischial ulcer. Unfortunately, the distal aspect of the flap that is used to reach the ischial region is usually too thin to offer adequate padding to be effective. Therefore, this is not the most appropriate option.
Primary closure is associated with an increased rate of wound recurrence. A large dead space is usually present due to the absence of tissue, and the induration of adjacent areas makes them difficult to mobilize for a tension-free closure.
2016
A 66-year-old man with paraplegia is evaluated because of a 6-month history of Grade IV pressure ulcer. Medical history includes multiple debridements with appropriate off-loading and good wound care. The patient shows no clinical improvement. Chronic osteomyelitis is suspected. Which of the following is the most appropriate next step in diagnosis?
A) Bone biopsy
B) CT scan
C) Dual energy x-ray absorptiometry (DEXA) scan
D) MRI
E) Triphasic technetium scan
The correct response is Option A.
The accurate diagnosis of chronic osteomyelitis in long-standing wounds can be extremely difficult. The gold standard to diagnose chronic osteomyelitis is bone biopsy. Bone biopsy can provide histopathologic as well as microbiologic data that are sensitive and specific for chronic osteomyelitis.
Triphasic technetium-99 bone scan or scintigraphy is a nuclear study that serves as a functional test to assess bone metabolism. MRI uses a magnetic field and radio waves to reconstruct anatomical structures of interest. CT scan can reveal small areas of osteolysis, small foci of gas, or foreign bodies. Triphasic bone scan, MRI, and CT scan have all been used to evaluate for osteomyelitis clinically. However, these studies lack specificity and can be misleading in the presence of a chronic soft-tissue injury or previous bony injury from prior debridements.
A dual energy x-ray absorptiometry (DEXA) scan is a low-exposure x-ray study measuring bone density in order to assess for osteoporosis. It has no role in evaluating osteomyelitis.
2016
A 50-year-old man with paraplegia and diabetes mellitus is evaluated because of an ischial stage 4 pressure ulcer. Optimizing the patient’s nutrition and diabetic control is attempted, and aggressive resection of the ulcer and underlying bone with a locoregional flap closure is planned. Which of the following characteristics places this patient at increased risk for late recurrence of the ulcer?
A) Age greater than 45 years
B) Defect size greater than 20 cm2
C) Hemoglobin A1c of less than 6%
D) Location of ulcer
E) Osteomyelitis confirmed by bone biopsy
The correct response is Option D.
The risk factor in this patient associated with the greatest risk of late recurrence is ischial ulcer location.
The treatment of pressure ulcers remains a difficult problem for medical practitioners and plastic surgeons. In a recent study, risk factors were identified as predictors of flap failure after resection and reconstruction with a flap. Factors associated with dehiscence include age less than 45 years, history of previous same-site surgery failure, albumin concentration of less than 3.5 mg/dL, and poor diabetic control (hemoglobin A1c of more than 6%). Factors associated with recurrence include ischial wound location, previous same-site surgery failure, and poor diabetic control. Osteomyelitis confirmed by bone biopsy and size of defect were not associated with dehiscence or recurrence. Patients with multiple risk factors showed a dramatic trend toward dehiscence and flap failure.
Other studies corroborate the finding that ischial ulcer location is difficult for achieving coverage. This is most likely secondary to the high pressure over the ischial tuberosities in the seated position. Pressure maps have shown that, when seated, the pressure exceeds 80 to 100 mmHg compared with supine sacral pressures of 60 mmHg.
2015
A 47-year-old man with complete T12 paraplegia presents with a 5 × 5 × 4-cm stage IV sacral pressure ulcer. Physical examination shows the wound is clean with granulation tissue. Coverage with a local tissue flap is planned. In designing the flap, careful consideration must be made regarding which of the following?
A) Avoiding incisions near the anus to minimize bacterial contamination
B) Confining scar to a cosmetically acceptable location
C) Designing incisions allowing for future re-advancement
D) Localizing individual perforators
E) Preserving sensory innervation
The correct response is Option C.
A systematic review of the literature was performed by Sameem et al., to determine the relative efficacy of musculocutaneous versus fasciocutaneous versus perforator flaps in the treatment of pressure ulcers. In their analysis, they concluded that all flaps had a significant recurrence and complication rate; however, there was no difference between the types of flaps used. Their paper did not specifically address the issue of how patients’ conditions were subsequently managed when they did develop a recurrence. This is important, because a key surgical strategy is to consider the need for subsequent surgical procedures; in fact, perhaps more critical than the composition of the flap and the nature of its blood supply is the design of the flap and where the incisions are planned. A fundamental principle in surgical management of pressure ulcers is being able to provide healthy vascularized tissue into the wound bed and to completely obliterate dead space. Furthermore, the flap should be designed such that if a recurrence develops, the patient continues to have surgical options available, such as re-advancement or re-rotation of the prior flap(s).
Preservation of sensory innervation is important for patients who still have sensation in this area. However, in patients who are completely paraplegic, there is a lack of adequate sensory innervation and a lack of the ability to ambulate, which is what ultimately leads to the development of pressure ulcers.
Confining the scar to a cosmetically acceptable location is not a major priority in managing pressure ulcers. The cosmetic appearance of scars in this area is relatively unimportant in light of the presence of an open wound.
Localizing individual perforators is not necessary when large rotation or advancement flaps are designed. In those situations, a broad blood supply is maintained, and multiple perforators are typically kept intact and do not require individual localization or dissection. However, it is important when a single perforator flap is being designed. Perforator flaps when used as pedicle flaps may be more prone to venous congestion and slightly higher complication rates due to the delicate dissection and isolation of the sole blood supply, which in turn is more prone to mechanical twisting and kinking. Perforator flaps ideally preserve the muscular function of the donor site, which may not be important in a patient who is paraplegic.
2014
A 21-year-old ambulatory man with spina bifida at the level of S2 is scheduled to undergo closure of a stage IV ischial decubitus ulcer. Rotational flap closure is planned. Which of the following flaps is most appropriate considering wound closure and ambulation?
A) Gluteal thigh
B) Gluteus muscle
C) Hamstring
D) Reverse latissimus dorsi
E) Vastus lateralis
The correct response is Option A.
This patient, who has S2 paraplegia, has complete muscle function in the upper extremities, thoracic musculature, hips, and knees. Thus, detachment and relocation of hamstring muscles, the primary flexors of the knee, would greatly decrease this patient’s ability to ambulate. Although the vastus lateralis is a significant knee extender, and the use of this muscle would weaken the function of the quadriceps, other quadriceps muscles (vastus intermedius, vastus medialis, and rectus femoris) can sufficiently compensate for its loss.
Reverse latissimus dorsi can be useful for lower back and sacral coverage, but it does not have sufficient reach to cover the ischium. Tensor fascia lata assists in femoral flexion and abduction, but it is a minor muscle and has little functional impact. Gluteal thigh flaps are based on the descending gluteal artery and are typically raised as fasciocutaneous flaps. Thus, it would have little effect on ambulation or lower extremity motion.
2014
A 55-year-old man with an ulcer of the left ischium (stage 4) undergoes debridement, ostectomy, and transfer of a gluteal myocutaneous flap for closure of the wound. Which of the following risk factors is associated with the highest rate of recurrence?
A) Incontinence
B) Obesity
C) Paraplegia
D) Patient age
E) Vitamin deficiency
The correct response is Option C.
In a study out of Johns Hopkins, pressure ulcer patients who underwent reconstruction had a recurrence rate of 82% if they were paraplegic compared with 0% in non-paraplegic patients. Other risk factors for recurrence after repair include factors that predispose patients to prolonged pressure ischemia and/or reduced capacity for tissue repair. These include age greater than 70 years, immobility, poor nutrition, low BMI, anemia, diabetes, end-stage renal disease, cerebrovascular disease, hip fracture within 3 months, and prior pressure ulcer surgery. Although malnutrition is associated with pressure ulcers, micronutrient deficiencies such as vitamin C or zinc are not associated with formation or recurrence. A subsequent Cochrane Database Study showed that nutritional and vitamin supplementation is not associated with improved healing. There is no evidence to show that incontinence is associated with pressure ulcer formation or recurrence.
2019
A 48-year-old man with a 5-month history of traumatic paraplegia presents with a large grade IV right ischial pressure ulcer. The patient undergoes operative excision of the pressure ulcer and coverage with an inferior gluteal rotation flap. On induction of anesthesia, the patient has onset of cardiac arrhythmia with peaked T-waves, ventricular tachycardia, and hypotension. Pulse oximetry is 100% with normal end-tidal CO2. Temperature is 37.0ºC (98.6ºF). It is discovered that the patient was given succinylcholine for rapid sequence intubation. Which of the following laboratory abnormalities is most likely associated with this patient’s condition?
A) Hyperkalemia
B) Hypernatremia
C) Hypocalcemia
D) Hypoglycemia
E) Hypomagnesemia
The correct response is Option A.
Perioperative complications arising from intravenous paralytics and inhalational anesthetics may have devastating outcomes including death. Rapid and accurate diagnosis is essential for efficient treatment and maximizing successful outcomes. The paraplegic patient presented in this clinical vignette has developed acute hyperkalemia from the use of succinylcholine. Hyperkalemia after succinylcholine administration may result in paraplegics or any patients with upper or lower motor neuron injury, severe burns, crush injuries, or conditions causing rhabdomyolysis. This phenomenon results from the upregulation of nicotinic acetylcholine receptors in denervated or traumatized muscle.
Initial treatment of acute hyperkalemia causing cardiac compromise involves antagonizing the effects of potassium on cardiac conduction and shifting potassium from the extracellular space back into intracellular fluid. Calcium directly antagonizes the hyperkalemia-induced depolarization of resting membrane potential by increasing the threshold potential to stabilize the membrane. Sodium bicarbonate and glucose combined with insulin will promote cellular uptake of potassium. Acidosis enhances the release of potassium from the cell and can be reversed with sodium bicarbonate. In addition, alkalization of plasma decreases levels of ionized calcium permitting the more liberal use of calcium in the treatment of acute hyperkalemia.
While hypomagnesemia, hypoglycemia, hypernatremia, and hypocalcemia can all result in electrocardiography changes including tachycardia, prolonged QT interval, shortened PR interval, and ST depression, these electrolyte abnormalities are not the most likely to be associated with the clinical scenario.
2020
A 65-year-old man with a spinal cord injury and a chronic ischial pressure sore undergoes preoperative optimization with pressure offloading and nutritional supplementation. Medical history includes type 2 diabetes mellitus and chronic ischialosteomyelitis. The patient undergoes thorough debridement of the ulcer and myocutaneous flap reconstruction with appropriate intravenous antibiotic therapy. Four months after surgery, he presents to the clinic with a new wound in the same region as the previous reconstruction. Which of the following factors most likely led to the recurrence of the ischial pressure wound?
A) Hemoglobin A1c greater than 6%
B) Osteomyelitis
C) Patient age
D) Prealbumin less than 20 mg/dL
The correct response is Option A.
The presence of poor glycemic control, as indicated by a Hemoglobin A1c greater than 6%, is a predictor of recurrence of pressure ulcers. Age less than 45 years old at the time of surgery is a predictor of recurrence. Older age at the time of surgery appears to be protective against recurrence. The presence of osteomyelitis at the time of surgery does not appear to contribute to disease recurrence. A low prealbumin (less than 20 mg/dL) does not appear to contribute to recurrence when evaluated on multivariate models. Poor glycemic control contributes to disease recurrence as well as early return to the operating room for wound dehiscence.
2021
