Question

Patient Profile

R.B. is a 55-year-old woman who presented to the emergency department (ED) via ambulance for acute shortness of breath. Her daughter called an ambulance after finding her mother with an increased respiratory rate and shortness of breath. Upon arrival to the ED, R.B.’s respirations were 40 and shallow with wheezing in the lower lobes and rhonchi in the upper lobes bilaterally. She had positive jugular vein distention and a heart rate of 128. After treatment with albuterol nebulizer via mask, her vital signs were temperature 96.8°F, pulse 98, respirations 28, blood pressure 148/84, and O₂ saturation 94% with 15 LPM via mask. Arterial blood gasses showed her pH 7.19, pCO₂ 90, PO₂ 92%, HCO₃ 38. R.B. was intubated for hypercapnia. After an echocardiogram showed an ejection fraction less than 50%, she had an emergency left heart catheterization done with two stent placements into the left anterior descending artery. A pulmonary artery catheter was placed, and the initial hemodynamic readings show elevated left ventricular preload. R.B. is now being transferred to the intensive care unit (ICU).

Subjective Data

• Lives with her single daughter, who cares for D.B. full time
• Daughter is not present at bedside
• Smokes 1 pack of cigarettes per day
• No longer active outside of the home because of her chronic illness
• Does not drink alcohol

Objective Data

Physical Examination

• Orally intubated #8 endotracheal (ET) tube taped at 26 cm to lip
• Ventilator settings: FIO₂ 60%, tidal volume 700, assist control (A/C), rate 16, PEEP of 5
• Height 5'5", weight 117 kg
• Alert and oriented to person, place, and time
• Fine crackles and wheezes bilateral lower lobes
• 2+ pitting edema bilateral lower extremities

Diagnostic Studies

• Chest x-ray postintubation: ET tube 4 cm from carina. Infiltrates in both bases; left base is worse than right
• 12-lead ECG: ST elevation
• Troponin: 41.94
• Lung V/Q scan negative for pulmonary embolism
• Urinalysis: dark yellow and cloudy, protein 28 mg/dL, positive for casts, positive for red blood cells and white blood cells, positive for glucose and ketones

Question 5

You obtain a set of hemodynamic monitoring values. Interpret these results.

Heart rate	110	Blood pressure	142/58
Cardiac output (CO)	4.06 L/min	Pulmonary artery	52/32 mm Hg
Central venous pressure (CVP)	10 mm Hg	Systemic vascular resistance (SVR)	1499 dynes/sec/cm-5
Pulmonary artery wedge pressure (PAWP)	16 mm Hg	Pulmonary vascular resistance (SVR)	549 dynes/sec/cm-5
Cardiac index (CI)	2.25 L/min/m2	Mixed venous oxygen saturation	SvO2 62%

Question 6

Describe each of R.B.’s ventilator settings and the rationale for the selection of each.

Question 7

How does PEEP lower CO?

Question 8

R.B. is started on intravenous dobutamine and sodium nitroprusside. How will these medications affect her hemodynamic status?

Answer 1

Ques5: cardiac output is the amount of blood ejected from th left ventricle and right ventricle ina minute it ranges from 4-8l/mt. Here it is normal as 4.06l/mt. Heart rate is the speed of the heartbeat measured by the number of contractions (beats) of the heart per minute (bpm). It ranges from 60-100 beats/mt. In some conditions like myocardial infarction, heartfailure, pulmonary edema it may increase, here it is 110b/mt that is tachycardia. Cardiac index (CI) is a haemodynamic parameter that relates the cardiac output (CO) from left ventricle in one minute to body surface area (BSA),[1] thus relating heart performance to the size of the individual. The normal range of cardiac index at rest is 2.6–4.2 L/min/m2.If the CI falls acutely below 2.2 L/min/m2, the patient may be in cardiogenic shock.here it is 2.25l/mt/m2.Central venous pressure (CVP) is the blood pressure in the venae cavae, near the right atrium of the heart. CVP reflects the amount of blood returning to the heart and the ability of the heart to pump the blood back into the arterial system.it ranges from 2-6mmhg. Increase in cvp indicates decrease cardiac performance, here cvp is 10mmhg. Pulmonary artery wedge pressure is the measurement in the left atrium, it ranges from 6-12mmhg. It increases in leftheart failure. Here it is 16mmhg.

Question 6:fio2 is the fractional inspired oxygen, it is set according to the oxygen level in blood. It should not exceed more in hypercapnia. So it is set as 60%.tidal volume ranges are depends upon the cardiac output, in case of hypercapnia Raising the rate or the tidal volume, as well as increasing T low, will increase ventilation and decrease CO2.normal setting is 500ml, here it is 700ml, for co2 excretion. Normally it will set as 8-12 beats/mt. In case of this patient it is 16bt/mt, because for easy was out of co2 from blood. So rate se as 16bt/mt. Peep is the positive end expiratory pressure normal peep is 3-5cmh2o. The reasoning for increasing levels of PEEP in critically ill patients is to provide acceptable oxygenation and to reduce the FiO2 to nontoxic levels (FiO2< 0.5). Here for maintaining normal expiratory pressure. Peep set as 5.

Question 7:Theoretical effects of PEEP on venous return (VR) and cardiac output (CO). PEEP causes an increase in intrathoracic pressure (ITP) and a right shift in the cardiac function curve. If there were no change in the VR curve, then CO and VR would decrease. increases workload of right side of the heart which in turn affects left side and it cause decrease in co.

Question 8:In patients with severe heart failure additional therapeutic support with intravenous inotropic or vasodilator drugs is frequently used in the attempt to obtain hemodynamic control. The nature and extent to which diastolic filling, atrial function, and mitral regurgitation are modified by these drugs have not been fully explored. In patients with advanced congestive heart failure both nitroprusside and dobutamine improve cardiac output, with different adaptations of left ventricular performance and left atrial function. Nitroprusside seems to restore both atrial and ventricular pump function better.Nitroprusside increased cardiacoutput, reduced left ventricular filling pressure , and improved left atrial pump volume without variations in left atrial reservoir and conduit volume. The restoration of preload reserve and improvement of the atrial contribution to left ventricular diastolic filling. Dobutamine also increase cardiac output.