Poor oxygenation in the lungs of patients with hyperosmolar hyperglycemic non-ketotic diabetic coma after cardiac surgery

The ratio of PaO2 to FiO2 was often low (300 or less) in four patients with complications of hyperosmolar hyperglycemic non-ketotic diabetic coma (HHNKDC) following open heart surgery. Four of our patients had poor oxygenation and subsequent spontaneous recovery from in the immediate post-operative period, although HHNKDC occurred only in one during this period. In the 3 others, poor oxygenation without accompanying HHNKDC lasted for 1-6 days and HHNKDC developed about 2 weeks after open heart surgery at time when poor oxygenation reoccurred. If a working diagnosis of congestive heart failure was made only on the basis of the most common probability, and the fluid supply was restricted, HHNKDC would readily occur or be aggravated by the dehydration iatrogenically produced. It is thus concluded that HHNKDC should be included in diagnoses for pulmonary dysfunction.     

Metabolic profile of patients after elective open heart surgery

To evaluate the surgical stress of open heart surgery with moderate hypothermic cardiopulmonary bypass (CPB), oxygen consumption (V¨_{O 2}), carbon dioxide production (V¨_{CO 2}), resting energy expenditure (REE), respiratory quotient (RQ), 24 hour-urinary urea nitrogen excretion (UUN), and glucose, fat and protein utilization were determined in 20 patients before and after open heart surgery. Proteins (albumin, prealbumin and transferin) and body weight were measured preoperatively and on 6th postoperative day (POD). Preoperative predicted EE as determined by the Harris-Benedict equation was correlated with measured REE. No significant alteration in V¨_{O 2}, V¨_{CO 2}, REE, 24 hour UUN and protein utilization was observed on the first 6 PODs. RQ decreased significantly on the 1st, 3rd and 4th POD. This was attributed to greater fat utilization due to reduced calorie intake during the early postoperative period. Transport proteins reduced slightly but insignificantly. There was a significant reduction in body weight at the end of the study period due probably to loss of body water. We conclude that patients in the early postoperative period after uneventful open heart surgery are neither hypermetabolic nor hypercatabolic when compared with their stable state before operation.(Lee TL, Boey WK, Woo MLH, et al.: Metabolic profile of patients after elective open heart surgery. J Anesth 7: 131–138, 1993)     

Assessment of pulmonary function in patients before and after laparoscopic and open esophagogastric surgery

Background Laparoscopy is a technique used in various surgical procedures. Few studies in the literature compare stress between laparoscopic and open surgery used for esophagogastric surgical procedures. Pulmonary function is known to be significantly affected in open surgeries, increasing postoperative morbidity and mortality. The current study aimed to assess pulmonary function in patients before and after open and laparoscopic esophagogastric surgery.Methods For this study, 75 patients were divided into two groups: 50 patients undergoing laparoscopy and 25 patients undergoing open surgery. The following parameters were determined by spirometry before and after surgery: forced expiratory volume in the first second (FEV₁), forced vital capacity (FVC), and forced expiratory flow in the midexpiratory phase (FEF_25–75%).Results A decrease in FEV_1, FVC, and FEF_(25–75%) was observed in the two groups on postoperative days 2, 3, and 4, as compared with the preoperative period. Likewise, FEV₁ and FVC showed a significant reduction on postoperative days 2, 3, and 4 in the patients who underwent to open surgery, but only on the day 2 in those who underwent to laparoscopic surgery. A significant decrease in FEF_(25–75%) was observed only on postoperative day 2 in the group that underwent open surgery. Significant differences in FEV₁ between the groups were observed on postoperative days 2, 3, and 4. No significant difference in FVC was noted between the groups, and a difference in FEF_(25–75%) was observed only on postoperative day 4.Conclusions Postoperative pulmonary dysfunction was more important for the patients undergoing open surgery than for those undergoing laparoscopic surgery.     

Jugular bulb desaturation during coronary artery surgery: a comparison of off-pump and on-pump procedures

Background. Conventional coronary artery bypass surgery hasbeen associated with cerebral injury attributed to cardiopulmonarybypass (CPB) and surgical manipulation of the ascending aorta.Off-pump coronary artery surgery avoids these factors and couldprevent cerebral injury. However, moving the heart from itsnatural position affects the circulation and could compromisecerebral oxygenation and perfusion. We set out to compare episodesof poor global cerebral oxygenation, defined as a jugular bulbsaturation less than 50%, between patients randomized to off-pumpor (conventional) on-pump coronary artery surgery. Methods. One hundred and eighty-seven patients were assignedrandomly to off-pump or on-pump coronary artery surgery. Oxygensaturation in the jugular bulb (     

Beyond feasibility: a comparison of newborns undergoing thoracoscopic and open repair of congenital diaphragmatic hernias

Background

Although both laparoscopic and thoracoscopic repair of congenital diaphragmatic hernia (CDH) have been described in the literature, neither appropriate selection criteria nor improved outcomes for minimally invasive repair over open repair have been clearly delineated.

Methods

We reviewed our experience with neonatal CDH repair between 2004 and 2007 to determine clinical parameters that are associated with successful thoracoscopic CDH repair. We compared these patients to a similarly matched cohort of patients who had undergone an open neonatal CDH repair between 1999 and 2003.

Results

From 2004 to 2007, 20 (61%) of 33 patients underwent successful neonatal thoracoscopic CDH repair. Characteristics common to all patients who underwent successful thoracoscopic repair included absence of congenital heart defects, no need for extracorporeal membrane oxygenation, ventilatory peak inspiratory pressure of less than 26 cmH₂O, and oxygenation index less than 5 on the day of planned surgery. From 1999 to 2003, 40 patients underwent an open neonatal CDH repair, of which 18 (45%) patients would have matched our selection criteria for thoracoscopic repair. These 2 cohorts were similar in age, estimated gestational age, weight, APGAR scores, and oxygenation index at the time of surgery. The thoracoscopic cohort had statistically and clinically significant quicker return to full enteral feeds, had shorter duration on the ventilator postoperatively, and required less narcotic/sedation postoperatively. Less severe complications occurred in the thoracoscopic cohort. Adjusted total hospital charges were less for the thoracoscopic repair.

Conclusions

Successful thoracoscopic CDH repair can be expected in newborns, which has limited respiratory compromise. Thoracoscopic CDH repair is associated with lower morbidity and quicker recovery than traditional open repair and without increased risk of recurrence or complications.     

ETIOLOGY,PROGNOSIS, AND OUTCOME OF POST-OPERATIVE ACUTE RENAL FAILURE

A Multivariate analysis was done in all patients who developed post operative ARF, during the period 1990–1995 to determine the etiological spectrum and to identify various variables affecting the outcome. Of 140 patients (110 operated at SGPGI and 30 operated outside) 116 underwent elective surgery. The different types of surgery leading to ARF were urosurgery (3.5%), open heart surgery (32.9%), gastrosurgery (16.4%), pancreatic surgery (9.3%), obstetrical surgery (3.6%) and others (2.8%). The incidence of ARF in SGPGI patients was highest in pancreatic surgery group (8.2%) followed by open heart surgery (3%). The different etiological factors responsible for ARF were perioperative hypotension (67.1%), sepsis (63.6%) and exposure to nephrotoxic drugs (29.3%). Sixty-four patients (45.7%) required dialysis. The overall mortality was 45% The mortality was highest in patients who underwent open heart surgery (89.1%) followed by pancreatic surgery (84.6%). The factors associated with high mortality, other than the type of surgery, were preoperative hypotension (p <0.05), oliguria (p <0.01), need for dialysis (p <0.05) and multiorgan failure (p <0.001). AM following emergency surgery had poor outcome, though not statistically significant. Perioperative sepsis (p <0.05) and preoperative use of aminoglycoside (p <0.05) were significantly higher in patients operated outside SGPGI. This was associated with higher incidence of ARF. Thus we conclude that presence of multiorgan failure, oligoanuria, preoperative hypotension and need far dialysis are poor prognostic markers in ARF following surgery.     

Venovenous extracorporeal membrane oxygenation for cyanotic congenital heart disease

Background

Severe, refractory hypoxemia complicating uncorrected cyanotic congenital heart disease is a potentially lethal condition, even when urgent surgical intervention is undertaken. When a viral pneumonia initiates hypoxemia, the likelihood of a satisfactory outcome is further reduced. We examined our policy of venovenous extracorporeal membrane oxygenation support through the hypoxic event and performing delayed surgery, if required, to separate from extracorporeal membrane oxygenation.

Methods

A single institution, retrospective review of an Institutional Review Board approved database was undertaken. Over a 6-year period, 18 instances were identified for 17 patients who became acutely hypoxemic from either inadequate pulmonary blood flow (8 instances) or a viral pneumonia (10 instances) complicating their cyanotic heart disease. Demographics, duration of venovenous extracorporeal membrane oxygenation and outcomes are reported.

Results

The length of venovenous extracorporeal membrane oxygenation ranged from 13.5 to 362.5 hours (mean 130 ± 121 hours). During 10 supports, operations were performed to facilitate weaning from support. In 7 patients, extracorporeal support was weaned during this surgery. Follow-up was obtained in all patients over a period ranging from 4 months to 7 years (mean 39.0 ± 23.0 months). There were two late deaths due to sepsis 1.4 and 2.5 months after extracorporeal support.

Conclusions

Venovenous extracorporeal membrane oxygenation allows time for the recovery of acute hypoxic insult and resolution of some viral pneumonia processes. Palliative surgical procedures may be safely undertaken during extracorporeal support. Viral pneumonia is a risk for prolonged support. Venovenous extracorporeal membrane oxygenation is useful in these high-risk patients.     

Lung function after open versus laparoscopic cholecystectomy

Postoperative lung function and gas exchange were studied in 36 patients after cholecystectomy. Twenty-four of the patients underwent laparoscopic cholecystectomy while the remaining twelve were operated with open technique. Before surgery all patients had normal ventilatory volumes (forced vital capacity, FVC and forced expired volume in 1 s, FEV₁) and normal gas exchange. Two hours postoperativley FVC was reduced to 64±16% (P<0.05) of the preoperative level in the laparoscopic group and to 45±23% (P<0.05) after open cholecystecomy. On the first postoperative day FVC was virtually normal in the laparoscopic patients (77±17% of preoperative level, NS), whereas the open surgery patients still had a decreased FVC (56±13% of preoperative, P<0.05). FEV₁ in the postoperative period followed the same course as FVC. Gas exchange was significantly impaired in the early postoperative period in all patients but no difference between the two groups was found. Two hours postoperatively Pao₂ was reduced to 85% (P<0.05) of preoperative value and Paco₂ had increased by 0.5 kPa (p<0.05). The alveolo-arterial oxygen tension difference (PA-ao₂) had increased by approximately 45% to a mean of 3.7 kPa (P<0.05). On the first postoperative day gas exchange was still significantly impaired in the open surgery patients. Atelectasis detected by computed X-ray tomography of the lungs were found in both groups. However, the amount of atelectasis tended to be smaller in the laparoscopic group than in the open surgery patients. In summary, cholecystectomy irrespective of whether it was performed by open or laparoscopic technique was followed by deterioration in ventilatory function and gas exchange. However, the magnitude of this impairment was less pronounced in laparoscopic cholecystectomy patients than in the open surgery patients which may suggest that this minimal invasive procedure is favourable with respect to postoperative lung function.     

Relationship between changes in thyroid hormone level and severity of the postoperative course in neonates undergoing open-heart surgery

Background: Our aim was to determine whether the changes in thyroid function after open‐heart surgery in neonates depend on the postoperative course. Methods: Twenty neonates undergoing open‐heart surgery for congenital heart disease were prospectively studied in the cardiac intensive care unit of a university‐affiliated children's hospital. The patients were divided into two groups by level of inotropic support (high or mild). Results: The groups were similar in age, bypass time and ultrafiltration volume. In both groups, there was a significant reduction in levels of thyroid‐stimulating hormone and FT₄ at 24 h postoperatively. However, in the high inotropic support group, FT₄ was lower for a longer time. This group also had a significantly higher score on The Pediatric Risk of Mortality (PRISM; P < 0.042) and a longer duration of ventilation (P < 0.014). Conclusions: Neonates after open‐heart surgery undergo changes in thyroid function characteristic of euthyroid sick syndrome. The degree of hypothyroxinemia may be related to the severity of illness and the postoperative course.     

Elective Decompression of the Left Ventricle in Pediatric Patients May Reduce the Duration of Venoarterial Extracorporeal Membrane Oxygenation

We aimed to determine the effect of elective left heart decompression at the time of initiation of central venoarterial extracorporeal membrane oxygenation (VA ECMO) on VA ECMO duration and clinical outcomes in children in a single tertiary ECMO referral center with a large pediatric population from a national referral center for pediatric cardiac surgery. We studied 51 episodes of VA ECMO in a historical cohort of 49 pediatric patients treated between the years 1990 and 2013 in the Paediatric Intensive Care Unit (PICU) of the Royal Children's Hospital, Melbourne. The cases had a variety of diagnoses including congenital cardiac abnormalities, sepsis, myocarditis, and cardiomyopathy. Left heart decompression as an elective treatment or an emergency intervention for left heart distension was effectively achieved by a number of methods, including left atrial venting, blade atrial septostomy, and left ventricular cannulation. Elective left heart decompression was associated with a reduction in time on ECMO (128 h) when compared with emergency decompression (236 h) (P = 0.013). Subgroup analysis showed that ECMO duration was greatest in noncardiac patients (elective 138 h, emergency 295 h; P = 0.02) and in patients who died despite both emergency decompression and ECMO (elective 133 h, emergency 354 h; P = 0.002). As the emergency cases had a lower pH, a higher PaCO₂, and a lower oxygenation index and were treated with a higher mean airway pressure, positive end‐expiratory pressure, and respiratory rate prior to receiving VA ECMO, we undertook multivariate linear regression modeling to show that only PaCO₂ and the timing of left heart decompression were associated with ECMO duration. However, elective left heart decompression was not associated with a reduction in length of PICU stay, duration of mechanical ventilation, or duration of oxygen therapy. Elective left heart decompression was not associated with improved ECMO survival or survival to PICU discharge. Elective left heart decompression may reduce ECMO duration and has therefore the potential to reduce ECMO‐related complications. A prospective, randomized controlled trial is indicated to study this intervention further.     

Predictive value of preoperative serum cholinesterase concentration in patients with liver dysfunction undergoing cardiac surgery

OBJECTIVE: There are an increasing number of patients with severe liver dysfunction subjected to open heart surgery. This retrospective study was designed to assess operative results and clarify the degree of liver injury in patients with liver dysfunction undergoing open heart surgery. In addition, determinants influencing their prognosis were assessed. METHODS: In a 9-year period from 1988 to 1996, we operated on 31 patients with posthepatitis liver dysfunction and 16 with chronic passive congestion of the liver. This group was 2.3% and 1.6% of the 1368 patients undergoing cardiac surgery in the same period. We compared several perioperative factors between survivors and nonsurvivors to determine risk factors affecting mortality. RESULTS: In the group with posthepatitis liver dysfunction, the postoperative course of 5 patients among 31 (16.1%) was poor. Serum cholinesterase concentration was lower only in the nonsurvivor group (nonsurvivor vs survivor: 1979+/-949 vs 3515+/-1424 IU/I, p < 0.05). All patients with cholinesterase < 2000 IU/L died. The duration of CPB (212+/-53 vs 150+/-54 minutes, p < 0.03) and ACC time (151+/-38 vs 96+/-40 minutes, p < 0.02) was longer in the nonsurvivor group. In the group with chronic passive congestion, the postoperative course of 5 of 16 (31.3%) patients with valvular disease was poor. Serum cholinesterase concentration was lower only in the nonsurvivor group (nonsurvivor vs survivors: 2006+/-435 vs 3483+/-1442 IU/L, p < 0.02), and all patients with cholinesterase < 2000 IU/L died. Postoperative bleeding was greater in the nonsurvivor group (3327+/-2106 vs 1428+/-643 mL, p < 0.05). Multivariate logistic regression analysis including the described pre- and intraoperative factors identified only serum cholinesterase concentration (F = 9.18) as significant. CONCLUSIONS: A low value of preoperative serum cholinesterase (< 2,000 IU/L) is thought to be the predictor of prognosis after open heart surgery in patients with severe posthepatitis and congestive liver dysfunction. Operative factors (cardiopulmonary time in posthepatitis liver dysfunction and postoperative bleeding in the congestive liver dysfunction) also influenced the prognosis.     

Effects of pulsatile and nonpulsatile perfusion on cerebral regional oxygen saturation and endothelin-1 in tetralogy of fallot infants

Although benefits of pulsatile flow during cardiopulmonary bypass (CPB) in pediatric heart surgery remain controversial and nonpulsatile CPB is still widely used in clinical cardiac surgery, pulsatile CPB must be reconsidered due to its physiologic features. In this study, we aimed to evaluate the effects of pulsatile perfusion (PP) and nonpulsatile perfusion (NP) on cerebral regional oxygen saturation (rSO₂) and endothelin‐1 (ET‐1) in pediatric tetralogy of Fallot (TOF) patients undergoing open heart surgery with CPB. Forty pediatric patients were randomly divided into the PP group (n = 20) and the NP group (n = 20). Pulsatile patients used a modified roller pump during the cross‐clamp period in CPB, while NP patients used a roller pump with continuous flat flow perfusion. The subjects were monitored for rSO₂ from the beginning of the operation until 6 h after returning to the intensive care unit (ICU). We also monitored the hemodynamic status and ET‐1 concentration and plasma free hemoglobin (PFH) in blood samples of all patients over time. Effective PP was monitored in PP patients, and pulse pressure was significantly higher in the PP group than in the NP group (P < 0.01). rSO₂ of the PP group was higher than that of the NP group (P < 0.01) during the cross‐clamp period, and this advantage of PP would be maintained until 2 h after patients returned to the ICU (P < 0.05). ET‐1 level in blood samples was lower at clamping off and CPB weaning and early ICU period in the PP group than in the NP group (P < 0.01), and ET‐1 concentration remained at a normal level after patients were transferred to the ICU 24 h in all patients. PFH levels in the PP group at pre‐clamp off and CPB weaned off were higher than those of the NP group (P < 0.05) in these cyanotic patients. PP can increase rSO₂ and improve microcirculation during cross‐clamping period in TOF pediatric patients, while PP resulted in more severe hemolysis in these cyanotic patients than NP.     

Exploring the limits of prolonged apnoea with high-flow nasal oxygen: an observational study

High-flow nasal oxygen is increasingly used for oxygenation during apnoea. Extending apnoea duration using this technique has mainly been investigated during minor laryngeal surgery, but it is unclear how long it can be administered for before it should be discontinued due to acidosis. We aimed to describe the dynamics of arterial blood gases during apnoeic oxygenation with high-flow nasal oxygen with jaw thrust only, to explore the limits of this technique. We included adult orthopaedic patients scheduled for general anaesthesia. After pre-oxygenation, anaesthesia with neuromuscular blockade was induced and high-flow nasal oxygen (70 l.min⁻¹) was continued with jaw thrust as the only means of airway management, with monitoring of vital signs and arterial blood gas sampling every 5 minutes. Apnoeic oxygenation with high-flow nasal oxygen was discontinued when arterial carbon dioxide tension (PaCO₂) exceeded 12 kPa or pH fell to 7.15. This technique was used in 35 patients and median (IQR [range]) apnoea time was 25 (20–30 [20–45]) min and was discontinued in all patients when pH fell to 7.15. The mean (SD) PaCO₂ increase was 0.25 (0.06) kPa.min⁻¹ but it varied substantially (range 0.13–0.35 kPa.min⁻¹). Mean (SD) arterial oxygen tension was 48.6 (11.8) kPa when high-flow nasal oxygen was stopped. Patients with apnoea time > 25 minutes were significantly older (p = 0.025). We conclude that apnoeic oxygenation with high-flow nasal oxygen resulted in a significant respiratory acidosis that varies substantially on the individual level, but oxygenation was maintained.     

Tissue Oxygenation in Obese and Non-obese Patients During Laparoscopy

Background: Wound infection risk is inversely related to subcutaneous tissue oxygenation, which is reduced in obese patients and may be reduced even more during laparoscopic procedures. Methods: We evaluated subcutaneous tissue oxygenation (PsqO₂) in 20 patients with a body mass index (BMI) ≥40 kg/m² (obese group) and 15 patients with BMI <30 kg/m² (non-obese group) undergoing laparoscopic surgery with standardized anaesthesia technique and fluid administration. Arterial oxygen tension was maintained near 150 mmHg. PsqO₂ was measured from a surrogate wound on the upper arm. Results: A mean FIO₂ of 51% (13%) was required in obese patients to reach an arterial oxygen tension of 150 mmHg; however, a mean FIO₂ of only 40% (7%) was required to reach the same oxygen tension in non-obese patients (P=0.007). PsqO₂ was significantly less in obese patients: 41 (10) vs 57 (15) mmHg (P<0.001). Conclusion: Obese patients having laparoscopic surgery require a significantly greater FIO₂ to reach an arterial oxygen tension of about 150 mmHg than non-obese patients; they also have significantly lower subcutaneous oxygen tensions. Both factors probably contribute to an increased infection risk in obese patients.     

Etiology, prognosis, and outcome of post-operative acute renal failure

A Multivariate analysis was done in all patients who developed post operative ARF, during the period 1990-1995 to determine the etiological spectrum and to identify various variables affecting the outcome. Of 140 patients (110 operated at SGPGI and 30 operated outside) 116 underwent elective surgery. The different types of surgery leading to ARF were urosurgery (3.5%), open heart surgery (32.9%), gastrosurgery (16.4%), pancreatic surgery (9.3%), obstetrical surgery (3.6%) and others (2.8%). The incidence of ARF in SGPGI patients was highest in pancreatic surgery group (8.2%) followed by open heart surgery (3%). The different etiological factors responsible for ARF were perioperative hypotension (67.1%), sepsis (63.6%) and exposure to nephrotoxic drugs (29.3%). Sixty-four patients (45.7%) required dialysis. The overall mortality was 45%. The mortality was highest in patients who underwent open heart surgery (89.1%) followed by pancreatic surgery (84.6%). The factors associated with high mortality, other than the type of surgery, were preoperative hypotension (p < 0.05), oliguria (p < 0.01), need for dialysis (p < 0.05) and multiorgan failure (p < 0.001). AM following emergency surgery had poor outcome, though not statistically significant. Perioperative sepsis (p < 0.05) and preoperative use of aminoglycoside (p < 0.05) were significantly higher in patients operated outside SGPGI. This was associated with higher incidence of ARF. Thus we conclude that presence of multiorgan failure, oligoanuria, preoperative hypotension and need far dialysis are poor prognostic markers in ARF following surgery.     

Enalaprilat in the treatment of hypertension and heart failure in critical care

Abstract: Neurosurgical patients are particularly vulnerable to uncontrolled hypertension. If the patient has an unclipped cerebral arterial aneurysm, sudden increases in arterial pressure, as may be induced by laryngoscopy and tracheal intubation, may lead to rupture or rebleeding. During the immediate postoperative period after cerebrovascular surgery and intracranial neurosurgery, blood pressure elevation may lead to postoperative hemorrhage and cerebral edema. Left ventricular (LV) dysfunction is common in acute myocardial infarction (AMI). After open heart surgery, LV dysfunction may follow a perioperative AMI or mobilization of peripheral edema. Preceding ischemic cardiomyopathy and a stunned or hibernating myocardium may predispose to postoperative heart failure. In severe forms of heart failure, conventional therapy with inotropes, nitrates and diuretics may prove inadequate, and there is a need to further reduce raised preload and afterload. The present series of studies was carried out in order to assess the effects of pharmacological inhibition of angiotensin converting enzyme (ACE) on the hemodynamics, systemic oxygenation and hormonal regulation of the blood circulation in patients subjected to anesthesia due to neurosurgery or intensive care due to neurosurgery or heart failure complicating AMI or open heart surgery. Oral enalapril premedication or intravenous (i.v.) enalaprilat was either compared to inert placebo or used in five before-after designed studies with a total of 40 neurosurgical patients and 26 heart failure patients. Oral enalapril premedication (0.1 mg/kg) was effective in preventing a blood pressure increase in response to tracheal intubation in patients subjected to cerebrovascular surgery. At a dose of 0.015 mg/kg, i.v. enalaprilat effectively controlled the postoperative hypertension of patients subjected to intracranial surgery. In patients with heart failure complicating AMI or open heart surgery, the addition of i.v. enalaprilat to conventional therapy (median doses 0.3 mg, 0.9 mg, and 2.0 mg in the three studies) relieved left ventricular filling pressure while maintaining cardiac function and systemic oxygenation. Further, enalaprilat had potentially beneficial hormonal effects in patients with severe heart failure, e.g. by lowering plasma levels of endothelin. Thus, ACE inhibition may expand our armamentarium of drugs to treat hypertension and heart failure in the intensive care unit and to prevent hypertension associated with tracheal intubation.     

异丙酚对低温体外循环期间脑氧合的影响

目的：观察异丙酚对低温ＣＰＢ期间脑氧合的影响。方法：心内直视手术病人２０例,随机分为对照组为异丙酚组,通过测定颈内静脉血氧饱和度（ＳｊＯ２）、动－颈内静脉血氧含量差、脑氧摄取率（ＣＥＯ２）和动－颈内静脉血乳酸含量差,分析ＣＰＢ期间脑氧合状况。结果：异丙酚组ＳｊＯ２在ＣＰＢ降温期较前升高、Ｄａ－ｖＯ２减少,复温时与降温期比较无显著变化。与对照组相比,降温和低温期差异显著。两组病人Ｄａ－ｖＬ在ＣＰＢ期     

Extracorporeal membrane oxygenation is superior to right ventricular assist device for acute right ventricular failure after heart transplantation

Background

Acute right ventricular failure after heart transplantation is a life-threatening condition, and sometimes the use of mechanical circulatory support is inevitable. The aim of this retrospective study was to investigate the effectiveness of two different mechanical circulatory support systems for this indication.

Methods

From 1984 to 2003, 28 heart transplant recipients exhibited right ventricular failure resistant to drug therapy. Right ventricular assist device (n = 15) or extracorporeal membrane oxygenation (n = 13) was implanted to support the failing heart.

Results

Overall in-hospital survival was 43%. In the right ventricular assist device group, only 2 patients (13%) could be weaned from mechanical circulatory support compared with 10 patients (77%) in the extracorporeal membrane oxygenation group (p = 0.001). Retransplantation was necessary in 6 patients in the right ventricular assist device group and in 1 patient in the extracorporeal membrane oxygenation group (p = 0.049). There was no difference in patient survival between groups, but graft survival was significantly better in the extracorporeal membrane oxygenation group (p = 0.005).

Conclusions

In view of these results, extracorporeal membrane oxygenation seems to be the better option as mechanical circulatory support for right ventricular failure in heart transplantation.     

Potential Pitfalls in Apnea Testing

Summary  To determine the influence of baseline paCO₂ on the results of apnea testing in the diagnosis of brain death, we performed an open prospective study on 36 patients fulfilling all other criteria for the diagnosis of brain death according to the criteria proposed by the Advisory Board of the German Federal Chamber of Physicians.  For testing of apnea, patients underwent hypoventilation with 100% oxygen supply until a baseline paCO₂ of 40 torr (5.3 kPa, n=24, group 1) or 60 torr (8.0 kPa, n=12, group 2) was reached. Then, patients were disconnected from the ventilator and apneic oxygenation with insufflation of 6 l O₂/min into the tracheal cannula was performed for five minutes. Arterial blood gas samples were obtained every minute during the testing period. In parallel, patients were observed for signs of spontaneous breathing. All patients remained apneic during the five minute test period. No relevant hypoxia (paO₂<80 torr [10.6 kPa]) was observed in either group. In group 1, a mean baseline paCO₂ of 45 torr (6.0 kPa) was registered, mean end-paCO₂ was 75 torr (10.0 kPa). In group 2, paCO₂ values were 66 torr (8.8 kPa) and 90 torr (12 kPa), respectively. Baseline pH in group 1 (7.32) decreased to 7.18 at the end of testing and from 7.23 to 7.13 in group 2. Patients in group 2 were in possible danger of developing a CO₂-induced narcosis mimicking apnea. Secondary organ damage due to severe respiratory acidosis could not be excluded in the patients of group 2.  As no complications were observed in group 1 and apnea was evident in all these patients, we consider a baseline paCO₂ of 40 torr (5.3 kPa) sufficient to establish apnea after five minutes of apneic oxygenation if an increase of baseline paCO₂ of at least 20 mmHg is documented by arterial blood gas sampling. A higher baseline paCO₂ may endanger patients without yielding more specific testing results.     

Factors influencing survival in newborns with congenital diaphragmatic hernia: the relative role of timing of surgery

Purpose

Controversy persists regarding the factors influencing survival in patients with congenital diaphragmatic hernia (CDH), in particular, the role of timing of surgery. The authors therefore sought to determine such factors and to assess the relative role of timing of surgery on outcome.

Methods

All CDH newborns 1991 through 2002 (n = 111) were divided into those undergoing repair before (“early” n = 35), or after (“late” n = 76) 48 hours. A multivariate analysis was performed to determine the relative impact of various factors on survival rate.

Results

Overall survival rate was 64%. There was no effect on survival of heart rate, temperature, systolic blood pressure, age, extracorporeal membrane oxygenation use, mesh use, infections, or intracranial hemorrhage, and there was no difference between early (68%) or late (62%) repair (P = .2). Initial pco₂ greater than 50, po₂ less than 40, cardiac defects, or renal failure significantly decreased survival rate.

Conclusions

Significant factors influencing survival rate in patients with CDH include cardiac defects, renal failure, and the initial blood gases and not the timing of surgery. CDH repair should be based on the optimization of clinical parameters as opposed to a specific time period to improve outcome.