Stabilization of cats with urethral closure before transfer
Article in the original by: Elizabeth Thomovsky, DVM, MS, Dacvecc, Purdue University
Introduction
Urethral closure is common in male cats and can be idiopathic or can be caused by urine tubes, urolithiasis, strictures or neoplasia.¹, ² The recommended treatment usually consists in a urethral catheterization.¹ Before giving sedation or anesthesia, it is necessary to facilitate the placement of a urine catheter.
Azotemia, electrolytic disorders (e.g. hypercalaemia), acidemia and cardiac events (e.g. arrhythmias) are among the most common comorbidities in cats with urethral closure. In a study with 168 cats, 57 % azotemia, 46 % hyperkalaemia, 73 % acidemia and 33.5 % arrhythmias had; Arrhythmias were mostly bradycardia (88.5 %) and ventricular extrasystoles (11.4 %; see step 4) .³ The lack of P waves in normal QRS complexes (i.e. atrial standstill) is also often in blocked cats with hyperkalemia .⁴ Cats can also be presented with hypovolemia and hypotension or a significant clinical dehydration (53 % of cats in one study).
The aim of stabilization is to identify and treat the expected comorbidities in order to optimally prepare the patient for secure sedation or anesthesia before placing a urine catheter. Before sedation or anesthesia, the cats should be normovolemic, have normal blood pressure, have a normal sinus rhythm in the EKG and, if potassium> 7 meq/l (7 mmol/l) is, treatment of hyperkalaemia. Blocked cats are only completely stable when a urinary catheter has been laid. A cancellation of the closure should usually be sought before the transfer to further care and hospitalization.
If a patient is critically ill, it can be particularly difficult to talk about money - financial aspects can be crucial for patient care. Prepare these conversations in such a way that you run successfully:
- Make a safe, private place for the owner (not in the waiting area) and sit down together.
- Recognize the financial burden of the owner (if applicable) and offer a partnership -based solution finding.
- Ask for permission before submitting suggestions.
- Order small amounts of information and give the owner time to record them and formulate questions.
- Explain the reason and use of the diagnostic measures and treatments that you intend.
Step-by-step: stabilization of cats with urethral closure before transfer
What you need
- IV catheter
- Crystalloid liquid (usually a buffered isotonic crystalloid) ²
- Monitoring units
- ECG
- Blood pressure monitor (ultrasound -based Doppler or oscillometric device)
- Blood gas analysis devices or other device that can measure electrolyte and ideally either the blood-pH or total carbon dioxide to estimate the metabolic acidosis
- Pharmacological interventions
- Calcium
- 50 % dextrose
- Regular insulin (for short)
- Bicarbonate
- Opioid pain medication (e.g. buprenorphine, methadone) ± sedativum (e.g. acepromazine, midazolam, dexmedetomidine, ketamine)
- Urinary catheter
- Equipment for a decompressive cystocentesis
- Hypodermic needle (22 gauge, 1 or 1.5 inches)
- Stopcock
- IV extension set
- 12- or 20 ml syringe
- Container for the urine collection
- Heat sources : warm air device, circulating hot water ceiling and/or blankets
Step 1: Assess the patient
Carry out a physical examination to determine whether the cat is in a shock state and identify cardiac abnormalities (e.g. heart noises, arrhythmias) before starting fluid therapy.
Authors' note
The scanning of the pulse quality, blood pressure measurement as well as the assessment of heart rate and rhythm, the mucous membrane, the rectal temperature and the general condition help to diagnose a shock. Most blocked cats are not in shock. The author does not routinely measure the blood pressure, except for patients who are apathetic, lying on the side and Bradykard (heart rate <160 bpm).
Step 2: Place IV catheters, give the patient warm & analgesics
Place an IV catheter to facilitate medication (e.g. analgesia, anesthesia), fluid therapy and blood samples. Warm hypothermic cats with a warm air device, a circulating hot water blanket and/or normal blankets. If indicated, if it is indicated, no NSAIDs, since cats with urethral closure are often dehydrated (and/or hypovolemic) and acotemic.
Authors' note
Methadone (0.1–0.2 mg/kg IV) or buprenorphine (0.01–0.03 mg/kg IV) are often administered for pain relief. With buprenorphine, the activity can take 20-30 minutes or longer.
Step 3: Remove blood sample
Ideally, you carry out a complete serum chemical profile and a blood count (CBC). If these analyzes are not practical due to time or blood volume restrictions, measure the hematocrit/overall protective value and carry out a limited panel that includes bun, creatinine and electrolytes (especially potassium, but also sodium and chloride). Measure the pH value directly or estimate it using the total carbon dioxide or bicarbonate, if available.
Authors' note
According to the author, blood sampling is easiest at the time of catheter placement via an unpaid IV catheter, but blood can be removed from any container.
A potassium value of> 7 MEQ/L (7 mmol/l) usually requires treatment (see step 5), especially in patients with bradycardia or other arrhythmias or in the case of serious illness. , since the praise proportion of azotaemia is improved by fluid therapy and the postal effects are corrected by urine catheterization.
Step 4: carry out the EKG
Perform an EKG to determine whether there is an arrhythmia.
If an arrhythmia that is due to hyperkalaemia (i.e. Bradycardia [Figure 1], Atrial Still [Figures 2 and 3]) or a ventricular arrhythmia is present and potassium> 7 MeQ/l (7 mmol/l) is of hyperkalaemia (see step 5). Check the EKG again after the treatment to assess whether the arrhythmia has been remedied.
In rarer cases in which ventricular arrhythmia (intermittent ventricular extrasystoles or persistent ventricular blows) occurs with a potassium value of <7 MeQ/l (7 mmol/l) or after the treatment of hyperkalaemia, place fluids (typically 10–20 ml /kg bolus) to improve the oxygen supply of the tissue and to compensate for hypotension (if available) - in addition to oxygen intake by flow. If the arrhythmia and a heart rate of> 180 to 200 bpm (i.e. ventricular tachycardia) remain after fluid and oxygen therapy, give a bolus lidocaine (0.2–0.5 mg/kg IV).
Figure 1
Sinusbradycardia (heart rate: 126 BPM) with P waves and deep negative T-waves
Figure 2
Atrial stand still with a ventricular extrasystole (arrow), negatively deflected T waves and missing P waves
Figure 3
Atrial stand still with a ventricular extrasystole (arrow), positively deflected T waves that are as high as the QRS complexes, and missing P waves
Authors' note
Ideally, the EKG should be carried out before the administration of sedativa or anesthetics; However, sedation or anesthesia may be necessary in the case of rebellious patients to obtain an EKG.
The author does not always carry out the ECG in cats that appear clinically awake and attentive and in which there is a heart rate> 180 BPM at the presentation.
The author always gives a fluid bolus (5–10 ml/kg IV over 15–30 minutes) to improve the liquid status in front of and during sedation/anesthesia and to compensate for mild dehydration.
Step 5: Treatment of hyperkalaemia
If there is hyperkalaemia, administer IV fluids (see step 6) and select a cardioprotective medication that lowers the potassium level in the blood or improves the function of the heart muscle cells (see Table 1).
Table 1: Medicines for the treatment of hyperkalaemia
| drug | dose | Mechanism of action | Advantages and/or disadvantages |
|---|---|---|---|
| 10 % calcium gluconate | 0.5–1 ml/kg (4.6–9.3 mg/kg elementary calcium) IV over 10–30 minutes under EKG monitoring | Increases the threshold potential of the heart muscle cells; temporarily restores the normal depolarization of the cardiac muscle cells | Look quickly; Duration of action approx. 30 minutes; Can induce bradycardia or asystolia if the administration is too fast |
| 50 % dextrose and regular (short) insulin | 1 Unit of regular insulin/Kat IV, followed by 2–5 g dextrose per unit insulin IV | Insulin stimulates the sodium-potassium-atpase so that potassium is moved into the cells | Duration of action of several hours; Delayed effect in reducing hyperkalaemia; Blood sugar should be monitored to recognize hypoglycemia; Hypoglycemic effects can last up to 6 hours after insulating - some cats need additional dextrose as bolus or cri during this period |
| 8.4 % sodium bicarbonate | (0.3 × body weight [kg] × base deficit [meq/l]); a quarter to a third of the calculated dose IV | Increases the blood pH; leads to an intracellular exchange of hydrogen ions for potassium ions | Can lead to reflex -like respiratory acidosis and aggravation of any ionized hypocalcaemia that may exist; Bicarbonate is usually not necessary to correct acidemia in cats with urethral closure, as these are normalized again after urine catheterization |
Authors' note
The author prefers calcium gluconate, since the combination of dextrose and regular insulin can induce acute or delayed (hourly -specific) hypoglycaemia and the duration of the effect of calcium gluconat is usually sufficient to remove the closure of the cat (i.e. the definitive treatment of hyperkalaemia).
Step 6: Add fluid therapy
Give buffered isotonic crystalloids to increase the glomerular filtration rate and to promote the excretion of potassium, bun and creatinine over the kidneys (see Table 2).
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Table 2: proposed fluid therapy for frequent scenarios in blocked cats
| Clinical situation | Proposed therapy |
|---|---|
| Hypovolemia (pale mucous membranes, weak pulse, apathy, hypotension) | Give of a liquid bolus (a quarter of the blood volume, ie approx. 15 ml/kg IV over 10–15 minutes), followed by a new assessment of heart rate, mucosal color, condition and blood pressure. Hypovolemia should be treated before the transfer. |
| Azotemia/hyperkalaemia (potassium> 7 meq/l [7 mmol/l], especially for associated arrhythmias) ± dehydation | A small fluid bolus (5–10 ml/kg IV over 15–30 minutes) can be considered at the time the closure is canceled to optimize the patient for anesthesia or sedation and to correct subclinical dehydration. Then: gift of conservation fluids (40–60 ml/kg/day Cri) ± replacement of the dehydration deficit over 12–24 hours (valued % dehydration × weight [kg] = liter liquid) ± medication for the treatment of hyperkalaemia. |
| Normocalemia, <7-10 % dehydration, stable patient | No liquid therapy is required before the closure is canceled. After urinary catheterization, the dehydration deficits (valued % dehydration × weight [kg] = liter of liquid) takes place over 12–24 hours and the administration of maintenance fluids (40–60 ml/kg/day Cri). |
Authors' note
A heart noise or a gallop rhythm can indicate an underlying heart disease. In these cases, lower maintenance rates (40 ml/kg/day CRI) should be used and dehydration deficits in stable patients should be replaced over ≥24 hours. In the case of bolus administer liquids to hypovolemic cats with suspected heart disease, smaller amounts of bolus (5–10 ml/kg) or a longer administration (20–30 minutes) should be considered.
If you recommend a transfer, include the owner in the decision and take into account whether the owner is willing to be treated in another facility and whether additional treatments are financially portable.
Step 7: Prepare the patient for the transfer
Try to place a urinary catheter. If this does not succeed, you determine whether the patient can be transferred without catheterization and whether a decompressive cystocentesis is necessary.
Authors' note
Urban catheterization before transfer (preferred):
Ideally, cats should be blocked by placing a urine catheter before they are transferred to 24-hour hospitalization and monitoring-especially cats that are hyper-calemical when presenting. The patients should be transported with the urinary catheter and a collecting bag.
[You can find more information on urethral decoration in cats in this guide .]
Transfer without urinary catheterization:
If the transferring clinic is ≤2 hours away and the cat is neither hypotensive, nor Bradykard or hyperkalemic, the patient can be transferred even without catheterization if catheterization was unsuccessful - so that possible complications of a decompressive cystocentesis (e.g. . If no pain medication was administered as part of the IV or urinary catheterization attempt, an opioid pain reliever (see step 2) can be given.
Decompressive cystocentesis before transfer:
If the transferring clinic is> 2 hours away or the cat was hypotensive, Bradykard and/or hyperkalemic, a decompressive cystocentesis should be carried out to maintain the stability of the patient during transport (see "Step-- For-step: decompressive cystocentesis ”). The owners should be informed about the risk of bladder injury and/or a uro abdomen in decompressive cystocentesis. A uro abdomen is usually determined by the transferring clinic before urinary catheterization or after manipulation of an injured bladder during catheterization.
Step-by-step: Decompressive cystocentesis
Step 1
, if necessary, administer a sedation to prevent the patient's movements and minimize the risk of bladder injury.
Step 2
Insert a 22-gauge needle (1 or 1.5-inch) in the middle of the bladder at an angle of 30 to 90 degrees to the body-either by palpation (blind) or under ultrasonic guidance. If necessary, stabilize the bladder with one hand as you insert the needle.
Step 3
Connect the needle to an extension set, Stopcock and Spray.
Step 4
empty as much urine as possible from the bladder.
Authors' note
A 1.5-inch needle helps to ensure that the needle remains in the bladder while it contracts when emptying. Repeated puncture of the bladder should be avoided in order to reduce the risk of damage to the bladder wall - and thus a Uroabdomen.
In order to make transfers in the emergency room (ER) less stressful for both teams, please note the following information from ER clinic:
- Call yourself in the emergency room. It is easier to discuss the condition of a patient directly with the clinician.
- Prepare the owner for cost estimates, forecast and expected waiting times and document the conversation.
- Communicate with the Er-Kliniker about discussions with the owner and expectations.
- Share the documents electronically and also hand over a printed copy to the owner.
- Enter exact times for vital parameters, doses and treatments.
FAQ to stabilize cats with urethral closure
Why is the stabilization of cats with urethral closure so important?
The stabilization of cats with urethral closure is crucial to save the life of the cat and minimize complications. A urethral closure means that the cat can no longer urinate, which leads to severe metabolic slices within a few hours or days.
Without quick stabilization, it can come to:
✔ Hyperkalemia (increased potassium values) that causes fatal cardiac arrhythmias.
✔ Azotemia (increase in urea and creatinine in the blood), which can result in severe kidney damage.
✔ Metabolic acidosis , a acidification of the blood, affects vital body functions.
✔ Shocking states come from dehydration and circulatory problems.
The aim of stabilizing cats with urethral closure is to put the cat into a state in which it can be safely sedated or anesthetized in order to solve the blockade through a urine catheter. This requires targeted treatment of the complications mentioned above by fluid therapy, electrolyte compensation, pain management and, if necessary, the immediate treatment of cardiac arrhythmias . The actual urethral closure can only be remedied after successful stabilization.
Which measures are part of the stabilization of cats with urethral tubes?
The stabilization of cats with urethral closure takes place in several important steps:
1. General examination and initial assessment
review of the general condition (heart rate, pulse quality, mucous membranes, temperature, mentation).
Blood tests (electrolytes, kidney values, pH value).
ECG for the identification of hyperkalaemia-related arrhythmias.
Measurement of blood pressure, especially with low pulse quality or awareness.
2. Placement of an IV catheter and liquid therapy
Hypovolemia? → liquid bolus of 10–20 ml/kg crystalloids over 10–15 minutes.
Dehydration? → Replacement of the fluid deficit over 12–24 hours.
Hyperkalemia? → Liquid therapy to promote potassium excretion via the kidneys.
3. Pain management and sedation
opioids (e.g. methadone or buprenorphine) for pain relief.
Sedativa (e.g. dexmedetomidine, ketamine, midazolam) in very anxious or aggressive cats.
No NSAIDS! - Since many cats with urethral closure are dehydrated and NSAID's kidney damage can be worse.
4. Treatment of hyperkalaemia
calcium gluconat (0.5–1 ml/kg IV over 10–30 minutes) → protects the heart.
Insulin + dextrose → promotes potassium absorption into the cells.
Bicarbonate → only required for severe acidosis.
5. Preparation for catheterization or transfer,
if possible, immediate blanket with a urine catheter .
If not possible, decompressive cystocentesis to relieve urine.
Decision on a transfer if the blockade cannot be solved in practice.
Each of these measures contributes to preparing the cat safely for the next treatment level.
When should a cat with urethral closure be transferred?
A transfer should be considered if:
✔ The blockade cannot be solved successfully.
Some cats have such strong urethral cramps or deposits that an blanket in initial care practice does not succeed.
✔ The potassium value above 8 MeQ/l is or the cat shows heavy cardiac arrhythmias.
In these cases there is a high risk of sudden cardiac arrest.
✔ The cat is persistent hypoton or shows signs of shock.
Cats with severe circulatory insufficiency need intensive care monitoring.
✔ The owner does not have the means or the will to continue the treatment in practice.
If longer hospitalization or further diagnostics (e.g. surgical measures) is necessary.
If a transfer is made, cats should ideally be stabilized with a urinary catheter to improve the forecast. If this is not possible, decompressive cystocentesis be carried out before transportation to enable temporary pressure relief.
What are the risks of stabilizing cats with urethral closure?
While stabilizing cats with urethral closure, there are some potential risks:
🚨 Cardiac arrest by hyperkalaemia
If hyperkalaemia is recognized too late or not treated, sudden fatal arrhythmias may occur.
🚨 Hypoglycemia through insulin therapy
in the treatment of hyperkalaemia with insulin must be checked by blood sugar.
🚨 Fluid overload
cats with heart disease could decompensate by excessive fluid therapy.
🚨 Bladder rupture due to improper cystocentesis
The puncture that is too deep or repeated several times can lead to a Uroabdomen.
It is therefore crucial to individually tailor all therapeutic measures to the cat and continuously monitor.
How can a new urethral closure be prevented after stabilization?
Another urethral closure is a common complication and can occur within hours or days after the blanket. The following measures are therefore essential:
✔ Continuous IV fluid therapy after catheterization to promote urine production.
✔ Pain management and spasmolytics (e.g. Prazosin or dantrolen) to relax the urethral muscles.
✔ Diet change to special feed (e.g. struvita -proceeding or purinre food) to prevent new deposits.
✔ Increasing water absorption by wet food and drinking well .
✔ Regular control of urine to inflammation or crystals .
✔ Long -term urinary catheterization only if absolutely necessary - because it can increase the risk of infection .
Despite careful measures, repeated closures can occur in some cats. In severe cases, surgical perinealurethrostomy (expansion of the urethra) be considered to prevent further blockages.
Summary: Stabilization of cats with urethral closure
The stabilization of cats with urethral closure is a crucial step before a possible transfer to a clinic. A urethral closure often occurs in male cats and can be caused urinary stones The stabilization of cats with urethral closure includes early identification and treatment of accompanying problems such as azotemia, hyperkalaemia, acidemia and cardiovascular disorders.
A central aspect of stabilization of cats with urethral closure is the assessment of the general condition of the cat, including blood pressure, heart rate and EKG. In many cases, liquid therapy is required to correct hypovolemia and improve the glomerular filtration rate. The stabilization of cats with urethral closure also includes the administration of analgesics to relieve pain, with opioid being preferred.
The stabilization of cats with urethral closure also requires targeted treatment of hyperkalaemia when potassium values are above 7 MeQ/l. Calcium gluconate, insulin dextrose infusions or sodium bicarbonate are used here. While stabilizing cats with urethral closure , it is important to carry out ECG monitoring in order to recognize and treat possible arrhythmias.
The stabilization of cats with urethral closure also includes the attempt to place a urea catheter. If this does not succeed, decompressive cystocentesis may be required. The decision to transfer should be well weighed down while stabilizing cats with urethral closure , especially if transport to another clinic is required.
An important part of the stabilization of cats with urethral closure is communication with the animal owners about possible costs and treatment options. The stabilization of cats with urethral closure not only includes medical measures, but also close cooperation with the owners in order to make a well -founded decision on further treatment.
In summary, it can be said that stabilization of cats with urethral closure is a systematic process that includes identification, treatment and monitoring of accompanying problems. Successful stabilization of cats with urethral closure increases the chances of a complications -free blanket and significantly improves the prognosis.
Therefore, the stabilization of cats with urethral closure be carried out according to a structured protocol to ensure the best possible patient care. The stabilization of cats with urethral closure is an interdisciplinary task that integrates veterinarians, veterinary assistants and pet owners alike. A clearly defined procedure for stabilizing cats with urethral tubes can be crucial for survival and the long -term health of the patient.
In emergency situations, stabilization of cats with urethral tubes the first and most important step to minimize complications. A well -thought -out management of stabilizing cats with urethral closure reduces risks such as kidney failure or cardiovascular events. Each measure within the stabilization of cats with urethral tube closure should be tailored to the specific needs of the patient.
The correct use of fluid therapy, analgesia and electrolyte management is essential for stabilizing cats with urethral tubes . A standardized procedure for stabilizing cats with urethral closure not only improves the forecast, but also the efficiency of treatment in veterinary practice.
Ultimately, the stabilization of cats with urethral closure an essential part of emergency care and should always be carried out with the greatest care. Successful stabilization of cats with urethral closure means to create the best basis for further therapy and the long -term recovery of the cat.
Sources
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- Cosford Kl, Koo St. In-Hospital Medical Management of Feline urethral obstruction: a review of recent clinical research. Can Vet j . 2020; 61 (6): 595-604.
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- Jones JM, Burkitt-Creedon JM, Epstein SE. Treatment strategies for hyperkalemia secondary to urethral obstruction in 50 times Cats: 2002-2017. J Feline Med Surg . 2022; 24 (12): E580-E587. DOI: 10.1177/1098612x221127234
- Robakiewicz P, Halfacree Z. Urinary Tract Trauma in Cats: Stabilization, Diagnosis and Management. J Feline Med Surg . 2023; 25 (3): 1098612x231159073. DOI: 10.1177/1098612x231159073
- Thomovsky ej. Managing the Common Comorbidities of Feline Urethral Obstrue. DVM360. Published July 1, 2011. Accessed August 8, 2024. Https://www.dvm360.com/view/managing-comon-comorbidities-feline-urethral-obstrue