Ocular Neuropathic Pain: An Overview Focusing on Ocular Surface Pains.

OBJECTIVE: This paper reviews ocular pain with the main focus on ocular surface discomfort and dry eye pain. Anatomy, physiology, epidemiology, assessment, and treatment are discussed in this paper. METHODS: A PubMed search was conducted for studies published from 2000 to 2019 on the anatomy, pathophysiology, epidemiology, assessment, and treatment of ocular pain. Reviews, meta-analyses, and randomized clinical trials were included. Inclusion criteria focused on ocular surface discomfort, dry eye pain and neuropathic pain. RESULTS: A total of 112 articles were found through searches, 45 of which were selected and studied in this review. DISCUSSION: Pain in general can be acute or chronic. Acute pain is usually a physiologic response to a serious damage to the tissues and alleviates with pain relief treatments. Chronic pain is defined as the persistence of pain for more than three months. From another point of view, pain has been classified into either nociceptive or neuropathic. Nociceptive pain is a physiologic response to a noxious stimulus. Both central and peripheral nervous systems can be involved in the development of a neuropathic pain, which is characterized by positive or negative sensory signs, a pain perceived disproportionate to a noxious stimulus, and/or not responsive to analgesics. Chronic pain usually has a neuropathic component. Ocular surface pain is a well-known complaint after any corneal surgery. This is mainly due to abnormal regeneration of damaged corneal nerve endings and abnormal connections with adjacent nerve endings which produce spontaneous activity. Tear hyperosmolarity and the resultant ocular surface inflammation can also trigger voluntary activity of corneal nerve endings. Referral pain to the first and second division of the trigeminal nerve has been reported. Interference with vision and even sleep, which is out of proportion to the examination are among patients' complaints. All of these elements proposed the new concept of ocular neuropathic pain syndrome. The first step in conventional evaluation of ocular discomfort is search for tear insufficiency. Pathologies of lid and blinking as well as conjunctival irregularities should be addressed. Anti-inflammatory agents and, in resistant cases, systemic neuromodulators are shown to be helpful. Education on behavioral changes and reassurance are essential steps. Considering the neuropathic origin for the ocular pain, treatment modalities used for such pain in other parts of the body can be considered for this syndrome.

Predicting Factors of Pain Duration in Patients with Chronic Pain: A Large Population-based Study.

BACKGROUND: Chronic pain is the third main problem of global health and the most common cause of long-term disabilities. The duration that patients suffer from chronic pain is directly proportional to the extent of the suffering and to the amount of health care resources allocated to this problem. There is no research that has studied the risk factors associated with the long pain duration in chronic pain patients. METHODS: We investigated the potential risk factors associated with long pain duration in a population with diverse pain conditions in a cross-sectional study. We used a questionnaire that included a number of potential risk factors including sex, age, marital status, household condition, number of children, employment, education, body mass index (BMI), pain intensity, and the level of anxiety/depression. The data were analyzed by univariable and multivariable linear regression models. RESULTS: We recruited 780 patients. The analyses showed that age and abnormal BMI had a positive correlation with pain duration. CONCLUSIONS: The risk factors that might be associated with longer pain duration include older age and abnormal BMI.

Prevalence and Risk Factors of Hypoxemia after Coronary Artery Bypass Grafting: The Time to Change Our Conceptions.

Background: Acute hypoxemia is the main characteristic of acute respiratory distress syndrome (ARDS), which is one of the most critical complications of coronary artery bypass grafting (CABG). Given the dearth of data on acute hypoxemia, we sought to determine its prevalence and risk factors among post-CABG patients. Methods: This cross-sectional study was conducted on on-pump CABG patients in Tehran Heart Center in 2 consecutive months in 2012. The effects of arterial blood gas variables, age, gender, the duration of the pump and cross-clamping, the ejection fraction, the creatinine level, and the body mass index on the prevalence of hypoxemia at the cutoff points of ARDS and acute lung injury were assessed. Results: Out of a total of 232 patients who remained in the study, 174 (75.0%) cases were male. The mean age was 60.60±9.42 years, and the mean body mass index was 27.15±3.93 kg/m2. None of the patients expired during the current admission. The ratio of partial pressure arterial oxygen to the fraction of inspired oxygen (PaO2/FiO2) 1 hour after admission to the intensive care unit (ICU), before extubation, and at 4 hours after extubation was less than 300 mmHg in 66.6%, 72.2%, and 86.6% of the patients and less than 200 mmHg in 20.8% 17.7%, and 30.2% of the patients, respectively. Among the different variables, only a heavier weight was associated with a PaO2/FiO2 ratio of less than 300 mmHg at 1 hour after ICU admission and at 4 hours after extubation (P=0.001). A rise in the cross-clamp time showed a significant association with the risk of a PaO2/FiO2 ratio of less than 200 mmHg at 4 hours after extubation (P=0.014). Conclusion: This study shows that hypoxemia following CABG is very common in the first 48 postoperative hours, although it is a benign and transient event. The high prevalence may affect the accuracy of the ARDS criteria and their positive or negative predictive value.

Effect of Hypoxemia in the Determination of Short-Term Prognosis of Coronary Artery Bypass Graft Patients: A Prospective Study.

BACKGROUND: Respiratory failure and hypoxemia are the known complications of anesthesia and surgery. As a major surgery mainly at advanced ages, the coronary artery bypass graft (CABG) surgery could lead to hypoxemia in the early post-operative phase. Currently, the fraction of partial pressure of arterial oxygen to the fraction of inspired oxygen (PiO2/FiO2) is used to determine the severity of the respiratory assault. OBJECTIVES: This study aimed to find the effect of hypoxemia measured by PaO2/FiO2 at the first hour following CABG in the determination of short-term prognosis of CABG. METHODS: Being approved by a local ethics committee, this observational cross-sectional study was conducted in 212 patients undergoing CABG on the cardiopulmonary pump, with no concurrent surgery or other cardiac pathologies. Factors like age, sex, weight, height, the duration of pump and cross-clamp, as well as other medical conditions including chronic obstructive pulmonary disease (COPD), diabetes mellitus (DM), opioid use, ejection fraction (EF), and creatinine clearance (CrCl) before the surgery were brought into consideration as possible confounders. The ratio of PiO2/FiO2 in the first hour after the surgery was measured, and its effect on intubation time and intensive care unit (ICU) length of stay was evaluated as the primary outcomes. The t-test and chi-squared were used to compare quantitative and qualitative variables, respectively. The repeated measures ANOVA test was used to compare the means. RESULTS: There was no significant relationship between hypoxemia measured as the ratio of PaO2/FiO2 and the duration of ICU length of stay (P value = 0.220) and the total intubation time (P value = 0.661). Among the qualitative variables, just opium addiction in patients with PaO2/FiO2 > 300 was associated with significantly longer intubation time (P value = 0.016). Furthermore, in the quantitative variables, longer intubation time was associated with higher cross-clamp time (P value = 0.035) in hypoxemia in the range of ARDS patients. CONCLUSIONS: Hypoxemia after the CABG surgery is common and does not affect the short-term prognosis of CABG patients.

Superior Hypogastric Plexus Block in the Lateral Position: A Case Report.

INTRODUCTION: Patients with severe visceral abdominal or pelvic pain are sometimes candidates for celiac or superior hypogastric block. These blocks are performed in the prone position that is usually very painful for these patients. We introduce another position for these blocks that can be better tolerated. CASE PRESENTATION: We performed the superior hypogastric plexus block in the lateral position in a patient who was suffering from severe abdominal and pelvic pain. The procedure was done under the guide of C-Arm fluoroscopy. After the procedure, the pain score reduced to 2 out of 10 on the 11-point Numeric Rating Scale and the patient was discharged without any complication. CONCLUSIONS: Superior hypogastric plexus block in the lateral position was safe and effective for a patient with severe abdominal and pelvic pain.

Risk Factors for Acute Kidney Injury in Coronary Artery Bypass Graft Surgery Patients Based on the Acute Kidney Injury Network Criteria.

Background: Acute kidney injury (AKI) after coronary artery bypass graft surgery (CABG) is a common complication. The present study sought to determine AKI risk factors based on the Acute Kidney Injury Network (AKIN) classification. Methods: In a cross-sectional study, performed from March 2010 to April 2012 at Tehran Heart Center, affiliated with Tehran University of Medical Sciences, 29 independent risk factors for AKI based on the AKIN criteria were examined in isolated post-CABG patients. The patients' demographic data and risk factors were extracted from the Electronic Database of Tehran Heart Center. According to restricted inclusion and exclusion criteria as well as a creatinine rise to AKI Stage 1, the patients were divided into 2 groups of AKI-negative and AKI-positive and the risk factors were compared between these groups. Results: Out of 3473 included patients at a mean age of 60.78 (±9.46) years, the majority (2474 [71.23%]) were male. Totally, 958 (27.7%) patients had AKI, according to a creatinine rise to AKI Stage 1. Logistic regression analysis demonstrated that higher age (OR=1.021; P<0.001), higher body mass index (OR=1.035; P<0.001), lower preoperative creatinine level (OR=0.417; P<0.001), longer cardiopulmonary bypass time (OR=1.004; P=0.007), blood transfusion in the ICU (OR=1.408; P=0.001), and lack of intraoperative blood transfusion (OR=0.823; P=0.044) were the independent risk factors for AKI after CABG. Conclusion: Based on the findings of the current study, older age, higher body mass index, lower preoperative creatinine level, more blood transfusion in the intensive care unit (ICU), lack of intraoperative blood transfusion, and high cardiopulmonary bypass time may serve as risk factors for the development of AKI in CABG patients.

Normal Reference Interval of WBC Count After On - Pump Coronary Artery Bypass Graft; When Values Could Be Misleading.

BACKGROUND: Applying the cardiopulmonary pump produces inflammatory responses and induces leukocytosis. White Blood Cell (WBC) count has a diagnostic value for detecting different infections. In this study, we want to redefine the normal value reference intervals of WBC count in Coronary Artery Bypass Graft (CABG) patients, to prevent misdiagnose leukocytosis as a sign of infection. METHODS: In an observational study, 140 patients who underwent on - pump CABG were enrolled to find out normal values of the reference interval. WBC counts were evaluated for all of them one day before the operation, first 30 minutes of ICU entrance, after 24 hours, and 48 hours after operation. Normal values of reference intervals were calculated for each measurement by two different statistical methods. RESULTS: There were 102 men and 38 women with age average of 61 years. There was no significant difference between genders' WBC counts before operation (P = 0.151), ICU entrance (P = 0.391), 24 hours after surgery (P = 0.698), and 48 hours after surgery (P = 0.523). The mean values of WBC after surgery were higher than the normal range of reference interval and had an increasing trend in the first 48 hours after surgery. The WBC values were significantly different between pre and post operation (before operation and ICU admission (P = 0.001), ICU admission and 24 hours later (P = 0.001), 24 hours after surgery, and 48 hours after surgery (P = 0.001)). All post - operative reference values were significantly higher than the range for the general population. CONCLUSIONS: There is a significant increase in WBC count after on - pump CABG. The normal range of WBC should be revised and adjusted to prevent misinterpretation as a sign of infection.

Long-Lasting Orthostatic Hypotension and Constipation After Celiac Plexus Block; A Case Report.

This case report presents a 55 years old man, presented with abdominal pain and diagnosed with a metastatic pancreatic tumor, who developed long lasting orthostatic hypotension and constipation following a celiac plexus block.

Effect of Intravenous Acetaminophen on Postoperative Pain in Vitrectomy: A Randomized, Double-Blind, Clinical Trial.

BACKGROUND: Nowadays, pain, nausea, and vomiting are regarded as important complications of anesthesia and surgery. The current study aimed at assessing the effect of preemptive intravenous acetaminophen on control of pain, nausea, vomiting, shivering, and drowsiness following the general anesthesia for retina and/or vitrectomy surgeries. METHODS: In a randomized, double-blind, clinical trial, 83 candidates for retina or vitrectomy eye surgery under general anesthesia were distributed into 3 groups: A) 41 patients in the control group who received 100 mL of normal saline just before the surgery and 100 mL of normal saline 20 minutes before the end of surgery; B) 21 patients in the preemptive group who received acetaminophen 15 mg/kg in 100 mL normal saline just before the surgery and 100 mL normal saline 20 minutes before the end of surgery; C) 21 patients in the preventive group who received 100 mL normal saline just before the surgery and acetaminophen 15 mg/kg in 100 mL normal saline 20 minutes before the end of surgery. Pain, nausea, vomiting, and shivering were assessed at the recovery and 2, 4, and 24 hours after the operation. Anesthesia emergence situation was assessed after arrival in the recovery room by the Richmond agitation-sedation scale (RASS) questionnaire. Blood pressure and heart rate were recorded before anesthesia induction, just after intubation, before extubation, and on discharge from the recovery room. RESULTS: Total intraoperative fentanyl, duration of operation, and duration of anesthesia were not different among the studied groups. Vital signs were not statistically different among the groups at before anesthesia induction, just after intubation, before extubation, and on discharge from the recovery room. Thirty-three patients in the control group (87.8%), 11 in preemptive (52.4%), and 14 in preventive groups (66.7%) needed acetaminophen in the first 24 hours after the surgery (P value = 0.008). Pain scores measured by visual rating scale (VRS) was lower in the preemptive and preventive groups, compared with those of the control group, in the recovery (P value = 0.006), 2 hours after the surgery (P value = 0.008), and 4 hours after the surgery (P value = 0.012), but not in 24 hours after the operation (P value = 0.1). CONCLUSIONS: Intravenous acetaminophen administered as preemptive or preventive medication was effective and safe to control acute postoperative pain and analgesic request after the vitrectomy eye surgery.

The Efficacy of Systemic Lidocaine in the Management of Chronic Pain: A Literature Review.

CONTEXT: Despite recent advances in the understanding of the chronic pain concept, its diagnosis and management remains a daily challenge for clinicians and patients. Based on the published literature, this review discusses and tries to organize the current knowledge and the up-to-date clinical experience about the efficacy and safety of the use of intravenous lidocaine in treatment and prevention of chronic pain. EVIDENCE ACQUISITION: To prepare this narrative review, we performed an in depth literature review using the PubMed searching engine. We extracted all relevant articles published in English, up to April 2016. RESULTS: Lidocaine, administered as transdermal patch or intravenous lidocaine, is a safe and effective modality in the treatment of post-herpetic neuralgia (PHN), complex regional pain syndrome, as well and for prevention of chronic pain. It may be effective in the management of neuropathic pain syndromes, chronic pain, post-operative pain, and refractory cancer pain. CONCLUSIONS: Intravenous lidocaine and lidocaine patch are effective and safe for the treatment of several chronic or neuropathic pain syndromes. The use of lidocaine during surgery could prevent the development of some chronic post-surgical pain syndromes.

Comparison of Arterial Oxygenation Following Head-Down and Head-Up Laparoscopic Surgery.

BACKGROUND: Regarding the role of gas entry in abdomen and cardiorespiratory effects, the ability of anesthesiologists would be challenged in laparoscopic surgeries. Considering few studies in this area and the relevance of the subject, this study was performed to compare the arterial oxygen alterations before operation in comparison with after surgery between laparoscopic cholecystectomy and ovarian cystectomy. METHODS: In this prospective cohort, 70 consecutive women aged from 20 to 60 years who were candidate for laparoscopic cholecystectomy (n = 35) and ovarian cystectomy (n = 35) with reverse (20 degrees) and direct (30 degrees) Trendelenburg positions, respectively, with ASA class I or II were enrolled. After intubation and before operation, for the first time, the arterial blood gas from radial artery in supine position was obtained for laboratory assessment. Then, the second blood sample was collected from radial artery in supine position and sent to the lab to be assessed with the same device after 30 minutes from surgery termination. The measured variables from arterial blood gas were arterial partial pressure of oxygen (PaO2) and Oxygen saturation (SpO2) alterations. RESULTS: Total PaO2 was higher in the first measurement. The higher values of PaO2 in cholecystectomy (upward) than in ovarian cystectomy (downward) were not significant in univariate (P = 0.060) and multivariate analysis (P = 0.654). Furthermore, higher values of SpO2 in cholecystectomy (upward) than in ovarian cystectomy (downward) were not significant in univariate (P = 0.412) and multivariate analysis (P = 0.984). CONCLUSIONS: In general, based on the results of this study, the values of PaO2 in cholecystectomy (upward) were not significantly higher than the values in cystectomy (downward) in laparoscopic surgeries when measured 30 minutes after surgery.

Postthoracotomy Ipsilateral Shoulder Pain: A Literature Review on Characteristics and Treatment.

Context. Postthoracotomy Ipsilateral Shoulder Pain (IPS) is a common and sometimes intractable pain syndrome. IPS is different from chest wall pain in type, origin, and treatments. Various treatments are suggested or applied for it but none of them is regarded as popular accepted effective one. Objectives. To review data and collect all present experiences about postthoracotomy IPS and its management and suggest future research directions. Methods. Search in PubMed database and additional search for specific topics and review them to retrieve relevant articles as data source in a narrative review article. Results. Even in the presence of effective epidural analgesia, ISP is a common cause of severe postthoracotomy pain. The phrenic nerve has an important role in the physiopathology of postthoracotomy ISP. Different treatments have been applied or suggested. Controlling the afferent nociceptive signals conveyed by the phrenic nerve at various levels-from peripheral branches on the diaphragm to its entrance in the cervical spine-could be of therapeutic value. Despite potential concerns about safety, intrapleural or phrenic nerve blocks are tolerated well, at least in a selected group of patient. Conclusion. Further researches could be directed on selective sensory block and motor function preservation of the phrenic nerve. However, the safety and efficacy of temporary loss of phrenic nerve function and intrapleural local anesthetics should be assessed.

Effects of Intrathecal Opioids Use in Cesarean Section on Breastfeeding and Newborns' Weight Gaining.

Objective: To assess the association between intrapartum intrathecal opioid use and breastfeeding and weight gain following cesarean section. Materials and methods: The prospective double-blinded study was conducted on term pregnant women, undergoing elective cesarean section under spinal anesthesia. They divided into two groups. In the first group, intrathecal Morphine was used to achieve analgesia during or after the operation. The remainder divided into two subgroups, those who did not receive any opioid or those received systemic opioids. Following labor breastfeeding accessed in a follow-up, two month latter. Results: There was no difference between the demographic variables of the mothers and newborns APGAR score and weight at the time of birth. Breastfeeding rate was similar in intrathecal group in compare with other patents (P value = 0.518). While, the infants' weight at the end of second month was lower in spinal opioid group (P value = 0.036). Conclusion: The present study was the first to suggest that spinal (intrathecal) opioids do not have any impact on breastfeeding. However the relationship between spinal anesthesia on weight gaining needs more investigation.

Preoperative Gabapentin to Prevent Postoperative Shoulder Pain After Laparoscopic Ovarian Cystectomy: A Randomized Clinical Trial.

BACKGROUND: Patients undergoing gynecology laparoscopy frequently experience shoulder pain as a common postoperative complication. Considering diaphragm stimulation in its pathophysiology, there are some advice to prevent or control this special form of referral pain. OBJECTIVES: The current study aimed to assess the prophylactic effect of preoperative administration of oral gabapentin to prevent Post Laparoscopic Shoulder Pain (PLSP) after laparoscopic ovarian cystectomy. PATIENTS AND METHODS: In a randomized, double blind, placebo controlled trial 40 female patients who were candidates to have elective laparoscopic ovarian cystectomy, received uniformed capsules containing gabapentin 600 mg or placebo 30 minutes before anesthesia induction. All patients had the American Society of Anesthesiologists (ASA) Physical Status of I-II and none had pervious abdominal surgery. Thereafter, the presence of side effects and PLSP and its severity was assessed by Visual Analog Scale (VAS) in the beginning of surgery and 2, 6, 12 hours after the surgery. RESULTS: Comparing the gabapentin (n = 20) and placebo (n = 20) groups, basic characteristics including age (P = 0.446), Body Mass Index (BMI) (P = 0.876), pregnancy history (P = 0.660), and surgery time (P = 0.232) were statistically similar. PLSP occurrence was less frequent in the gabapentin group (45%) compared with the placebo group (75%) (P = 0.053), while In gabapentin group the VAS scores were lower in 2(P = 0.004), 6 (P = 0.132), and 12 (P = 0.036) hours, post operatively. CONCLUSIONS: Prophylactic gabapentin administration could be considered as an effective and safe intervention to reduce occurrence and severity of PLSP after gynecologic laparoscopic cystectomy.

Permcath catheter embolization: a case report.

INTRODUCTION: Nowadays, many types of intravascular devices and catheters are used in order to diagnose and treat diseases. Complications related to these instruments are the costs that doctors and patients have to pay to benefit from their advantages. Catheter embolization is one of these side effects. Patients with devices in their cardiopulmonary system are at risk for severe complications such as arrhythmias, pulmonary embolism, myocardial injuries, hemoptysis, thrombosis and perforation. CASE PRESENTATION: A 50-years-old woman, with a history of breast cancer, had a PermCath emplacement in right subclavian vein for a course of chemotherapy. The treatment for cancer seemed to be successful and the PermCath had remained in its position without complication, for a couple of years however, the catheter was founded broken and embolized to the right ventricle and the main left pulmonary artery, diagnosed by a chest X-ray study incidentally. CONCLUSIONS: It is better to remove the unused devices safely to prevent and decrease their possible complications.

The effect of intra-articular meperidine and bupivacaine 0.5% on postoperative pain of arthroscopic knee surgery; a randomized double blind clinical trial.

BACKGROUND: Arthroscopic knee surgeries have a painful postoperative course, which often necessitates acute pain management. Among different analgesia techniques, Intra-articular injection is the technique of choice for many pain specialists, based on its confined effect to the surgical site (knee), lack of systemic effects and promotion of safe early ambulation. OBJECTIVES: The aim of this study was to compare analgesic effects of intra-articular meperidine, bupivacaine 0.5% or their combination after knee arthroscopic surgery. PATIENTS AND METHODS: Sixty ASA class I-II patients' candidates for arthroscopy knee surgery enrolled in a randomized double blind study to receive either 20 mL of bupivacaine 0.5%; 100 mg meperidine (diluted in normal saline) or bupivacaine 0.5% along with 100 mg meperidine. A written informed consent was obtained from all patients. Postoperative analgesia duration, VAS at 2, 6, 12 and 24 hours, the first analgesic request time, total fentanyl consumption in first 24 hours, patients' satisfaction and adverse effects were recorded. RESULTS: The bupivacaine-meperidine group had better duration of postoperative analgesia (P = 0.001), latter first analgesic request (P ≤ 0.001), lower total fentanyl consumption in first 24 hours after the operation (P = 0.001), less mean VAS at 2 hours (P = 0.001) and more patients' overall satisfaction (P = 0.01) compared with each medication alone. VAS at 6, 12 and 24 postoperative hours were not different between the groups of study. No adverse effects were observed. CONCLUSIONS: Although postoperative intra-articular meperidine is a better alternative for bupivacaine, their combination could improve their analgesic effects compared with each other alone.

Incidence and complications of acute kidney injury following coronary artery bypass graft: a retrospective cohort study.

INTRODUCTION: Acute kidney injury (AKI) is a common complication of coronary artery bypass graft with several serious complications. This study aimed to find the incidence of AKI after coronary artery bypass graft and its complications based on the Acute Kidney Injury Network (AKIN) criteria. MATERIALS AND METHODS: This study was done on 3470 patients who had undergone isolated coronary artery bypass graft. Acute kidney injury's incidence was based on the AKIN criteria (only based on serum creatinine irrespective of urine output). Patients' demographic data, in-hospital complications, and out-hospital mortality were collected from hospital databases and compared between the patients with and without AKI. RESULTS: Based on serum creatinine, the incidence of AKI was 27.7% (958 patients) on the 1st postoperative day. Nine patients (0.3%) needed hemodialysis during their hospital stay, and 31 patients (0.7%) developed persistent kidney failure until the discharge day. The number of patients undergoing hemodialysis was not significantly difference but persistent kidney failure was significantly more frequent in patients with AKI (P < .001). Those with AKI also experienced longer length of stay (P = .04) and longer length of stay in intensive care unit (P < .001), and their mortality rate was higher in hospital (P < .001) and during the 3-year follow-up period (P < .001). CONCLUSIONS: Although AKI is associated with great patients' morbidity and in-hospital and long-term mortality, most of AKI episodes after coronary artery bypass graft are mild with no need for hemodialysis, and they mostly improve spontaneously.

Acute Respiratory Distress Syndrome diagnosis after coronary artery bypass: comparison between diagnostic criteria and clinical picture.

Acute Respiratory Distress Syndrome (ARDS) is a potential complication of cardiac surgery, given that patients undergoing CABG frequently have hypoxemia and pulmonary dysfunction during initial hours after surgery. Thus, ARDS criteria in these patients are more likely to be positive while these criteria may not match the patient`s clinical picture. We aimed to investigate frequency of rapid onset hypoxemia in Pressure of Arterial Oxygen to Fractional Inspired Oxygen Concentration (PaO2/FiO2) less than 200 and diffuse pulmonary infiltrates as two diagnostic criteria forwards and compared these criteria with the clinical picture of the patients after Coronary Artery Bypass Graft (CABG) in this study. The study was prospective case series which carried out in about six months. All patients admitted to intensive care unit of Tehran Heart Center, who had undergone CABG on cardiopulmonary pump (CPB) recruited in the study. After considering inclusion criteria, age, sex, duration of intubation, arterial blood gas and chest radiography, on 24 hours and 48 hours after admission to the ICU were recorded. Then, patients with rapid onset of hypoxemia (PaO2/FiO2≤200mmHg) and diffuse pulmonary infiltrates and without sign or symptoms of obvious heart failure (probable positive ARDS cases) criteria were recorded and comparison between these probable positive cases with clinician`s clinical diagnosis (blinded to the study) was performed. In this study, a total of 300 patients after on-pump coronary artery bypass surgery were included. Postoperatively, 2 (0.66 %) in the 24 hours and 4 (1.33%) patients in 48 hours after surgery were positive for the two ARDS criteria according to the checklists, but; nobody had saved persistently ARDS criteria persistently during 48 hours after surgery. At the same time, clinician did not report any case of ARDS among 300 patients. In this study patients with ARDS criteria had no significant differences in age (P.value=0.937) and sex (P.value=0.533). Duration of intubation in patients with ARDS (14.26 ± 4.25 hours) in the first 48 hours was higher but not statistically different from the group without ARDS (11.60 ± 5.45 hours) (P.value=0.236). ARDS diagnosis based on rapid onset of hypoxemia (PaO2/FiO2≤200 mmHg) and diffuse pulmonary infiltrates and without signs or symptoms of obvious heart failure criteria in patients undergoing CABG could lead to overdiagnosis or misdiagnosis in less than 24 hours follow up. We recommend following patients for more than 24 hours and revise the current ARDS criteria for CABG patients.

Hospital-acquired pneumonia in patients undergoing coronary artery bypass graft; comparison of the center for disease control clinical criteria with physicians' judgment.

BACKGROUND: Following coronary artery bypass graft (CABG), patients are at high risk (3.2%-8.3%) for developing hospital-acquired pneumonia (HAP) with mortality rate of 24% to 50%. Some of routine features in patients undergoing CABG are similar to clinical criteria of Center of Disease Control (CDC) for diagnosis of pneumonia. This may lead to over-diagnosis of pneumonia in these patients. OBJECTIVES: This study aimed to assess the frequency of CDC criteria for diagnosis of pneumonia in patients undergoing CABG. PATIENTS AND METHODS: This study was performed on CABG candidates admitted to post cardiac surgery Intensive Care Unit (ICU) in a six-month period. Patient's records, Chest-X-Ray, and Laboratory tests were assessed for PNU1-CDC criteria for HAP diagnosis. At the same time, a physician who was unaware of the study protocol assessed the clinical diagnosis. Then the results were compared with CDC criteria-based diagnosis. RESULTS: Of total 300 patients, 9 (3%) met CDC criteria for diagnosis of pneumonia while none of the cases were diagnosed as HAP according to the physicians' clinical diagnosis. All nine patients were discharged with proper general condition and no need of antibiotic therapy. This study showed that loss of consciousness, tachypnea, dyspnea, PaO2 < 60 mm Hg, PaO2/FiO2 < 240, and local infiltration in 24 hours of operation were misleading features of CDC criteria, which were not considered in physicians' clinical judgment to establish the diagnosis. CONCLUSIONS: Our findings suggest that in Post-CABG patients, physicians could judge the occurrence of HAP more accurately in comparison to making the diagnosis based on CDC criteria alone. Expert physician may intentionally do not take some of these criteria into account according the patients' course of disease. Therefore, it is suggested that the value of these criteria in special group of patients like those undergoing CABG should be re-evaluated.