Patient Monitoring During Dialysis

Contents:

General Observations 

Particular Observations:

Laboratory tests:

·      Patient monitoring is a series of repeated or continuous observation of the patient’s appearance and physiologic state before, during and after dialysis procedure. These observations are charted and made part of the patient’s permanent record. The objectives are to provide as comfortable and safe procedure as possible for the patient and to detect as early as possible  any complication during dialysis.

 General Observations 

Weight:

The weight of the patient is a good index of how well , or how poorly , the patient is controlling his fluid balance between dialyses. The pre and postdialysis weight provide the best indication of the amount of  ultrafiltration needed during the procedure. The patient should be weighted immediately before and after each dialysis, wearing the same articles of clothing and using the same scale. the patient should weigh himself or herself daily. One should strive to keep the interdialysis weight gain below  1.0 kg/day

The dry weight is the target postdialysis weight that ideally would results in removal the excess body fluid.. The dry weight for each patient must be determined on trial-and-error basis. If the dry weight is set too high the patient will have clinical evidence of fluid overload. On the other hand if it set too low the patient may suffer from malaise ,dizziness ,weakness , cramps , and frequent hypotension episodes.

Pulse Rate:

At the start of dialysis, pulse , temperature, BP observations serve as baseline A rapid pulse may indicate low hematocrit or fluid overload. An increase in pulse rate during dialysis my be associated with  decreasing blood volume from ultrafiltration and may occur before blood pressure drop. Arrhythmia may indicate some complications e.g. ,cardiac instability, electrolyte disturbance ......etc.,it should be brought to the physician’s attention.

Temperature:

High temperature suggests infection or complicating illness. The patient should be questioned as to other symptoms The vascular access should be inspected carefully for evidence of infection, swabs and cultures should be collected ,and evaluation by the physician is mandatory. Temperature during dialysis may be the result of warm dialysis fluid , a pyrogen reaction or  showering of the bacteria from the infected access.

Blood Pressure: 

·      Blood pressure is the pressure exerted by the blood against the walls of the arterial blood vessels during systole and diastole of the heart. It results from the pumping force of the heart and the resistance of the vessels.

Usually BP is measured indirectly with a cuff-type sphygmomanometer. Occasionally both arms are used to complete the blood circuit, in such instance, the cuff can be wrapped  around  the midthigh area and the stethoscope applied at the bend of the knee. The BP obtained by this method, however, will be 20-40 mm Hg higher than arm pressure.                                                                                                                        

·      For patients on dialysis, normal BP is largely individual matter. That is, we are interested in changes that may occur than in absolute values. The patient’s BP should be monitored every 30 minutes for an acute dialysis and every 30-60 minutes for chronic dialysis. A systolic value greater than  200 or diastolic greater than 110 should be brought  to   physician’s     attention. Predialysis hypertension is usually  volume  related. Lowering dialysate sodium concentration (not below 135-140 mEq/L) and restriction of salt fluid intake is of great help to control predialysis hypertension. Most of the patient are instructed not to take antihypertensive medication prior to dialysis .In severely hypertensive patient , patients being dialyzed in the afternoon and those patient if hypotension during dialysis is not a problem., they can take their antihypertensive medication safely.

Causes ,prevention ,and management  of interdialytic hypotension were discussed previously.

Food and Oral Fluid intake:

·      There are several reasons for watching food and oral fluid intake during dialysis. The amount of fluid removed by ultrafiltration  is estimated by the net change in the weight from the predialysis to the postdialysis state. The quantity of food or fluid ingested should be taken into consideration in making this calculation. A pint of fluid is equals to half kilogram. Although it is permissible for most patients to eat during dialysis ,if desired ,it is best to limit this to a small meal or snack.

·      Digestion may contribute to development of hypotension and vomiting. This is distressing and increases the risk of aspiration as well as interfering with a smooth dialysis.

·      Ice chips can be used as water substitute, it is effective  in alleviating the sensation of thirst than water. The disadvantage of ice is that is water, and people tend to disregard this fact. A 200 ml of ice chips is equivalent to 150 ml of water.

·     It is not recommended that to oral fluids be given in large amount as a control  for excess ultafiltration. Such fluids may reach the intracellular compartment during dialysis and then be difficult to remove. Also, oral fluid is always hypotonic, contributing to hyponatremia.  

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Particular Observations:

General condition  and response of the patient during the procedure .Nausea ,Vomiting ,Apprehension, Shortness of breath, Chest pain, Sweating, Pallor, Restlessness or agitation , Irritability, Itching, Flushing , Childish or Hysterical behavior, Sleepiness ,and complaints of pain are some of many points to be noted.

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Laboratory tests

The plasma urea nitrogen and s creatinine are monitored monthly. The midweek, predialysis level is commonly followed. The plasma urea level is largely determined by the amount of protein ingested, while the plasma creatinine level depends on the muscle mass. Factors other than protein can affect plasma urea .If the plasma urea is higher than expected many factors should be excluded e.g. Increased dietary intake, Hypercatbbolic state , GIT bleeding , V.Access Recirculation, Dehydration. On the other hand if it is lower than expected; Decreased dietary protein intake, Increased dialysis treatment, and Liver diseases should be excluded. For patients with high predialysis  S.Potassium diet control and resin exchange is necessary.

·      Monitoring S Calcium, S Phosphate and Alk Phophatase are helpful tests to prevent and treat renal bone disease These values are usually checked monthly predialysis. The target  plasma calcium should be at the upper level of normal and plasma phosphate should be at the lower level of normal.

LFTs are usually checked monthly ,and may unmask silent liver disease ,especially Hepatitis or Hemosidrosis. The aim of monitoring Hemogram ,S Iron ,Tranfserrin ,Ferritin is to detect and treat Hematological Abnormalities in dialysis patient

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